JP7573009B2 - SPIRO COMPOUNDS AND THEIR USE AS MELANOCORTIN 4 RECEPTOR ANTAGONISTS - Patent application - Google Patents

Description

The present invention relates to novel pharmaceutical compounds, pharmaceutical compositions containing the compounds, and the use of the compounds as melanocortin receptor 4 (MC4R) antagonists.

Melanocortins are peptides derived from proopiomelanocortin (POMC) that bind to and activate G protein-coupled receptors (GPCRs) of the melanocortin receptor family. Melanocortins regulate a diverse number of physiological processes, including sexual function and behavior, food intake and metabolism. To date, five melanocortin receptors (MCRs), MC1R, MC2R, MC3R, MC4R and MC5R, have been identified in mammals, which are expressed in various tissues. MC1R is specifically expressed in melanocytes and melanoma cells, MC2R is the ACTH receptor and is expressed in adrenal tissue, MC3R is primarily expressed in the brain and limbic system, MC4R is widely expressed in the brain and spinal cord, and MC5R is expressed in the brain and many peripheral tissues, including skin, adipose tissue, skeletal muscle and lymphatic tissue. See, for example, U.S. Pat. No. 8,138,188 and Saleh et al., Front. Pharmacol. , 2018, 9:560.

MC4R is a G protein-coupled seven-transmembrane receptor that is expressed primarily in the hypothalamus, hippocampus, and thalamus (Gantz et al., 1993 J. Biol. Chem. 268:15174-15179). This receptor is involved in the central regulation of body weight, and MC4R is activated by α-melanocyte-stimulating hormone (MSH), which is derived from proopiomelanocortin and inactivated by agouti gene-related protein (AGRP). α-MSH induces weight loss, whereas ectopic expression of agouti protein leads to obesity in agouti mice (Fan et al., 1993 Nature 385:165-168; Lu et al., 1994 Nature 371:799-802). Additional evidence for a role for MC4R in weight regulation comes from both knockout models in mice (Huszar et al., 1997 Cell 88:131-141) and haploinsufficient mutations in humans (Vaissé et al., 1998 Nat. Genet. 20:113-114; Yeo et al., 1998 Nat. Genet. 20:111-112; Hinney et al., 1999 J. Clin. Endocrinol. Metab. 84:1483-1486). In MC4R knockout mice, increased body weight was discernible by 5 weeks of age. By 15 weeks of age, homozygous mutant females weighed on average twice as much as their wild-type littermates, whereas homozygous mutant males were approximately 50% heavier than wild-type controls. Mice heterozygous for the MC4R knockout showed weight gain intermediate to that seen in wild-type and homozygous mutant littermates, thus demonstrating a gene dosage effect of MC4R ablation on weight regulation. Food intake in homozygous mutants was increased by approximately 50% compared to that in wild-type siblings (Huszar et al., 1997 Cell 88:131-141) [from Am. J. Hum. Genet., 65:1501-1507, 1999]. MC4R activation has been shown to induce penile erection in rodents, and MC4R inactivation has been shown to cause obesity (reviewed in Hadley, 1999, Ann. NY Acad. Sci., 885:1-21; Wikberg et al., 2000, Pharmacol. Res., 42(5), 393-420; and Saleh et al., Front. Pharmacol., 2018, 9:560).

In recent years, several small molecule MC4R antagonists have been reported in the literature and patent applications [e.g., WO2010052256; WO2010081666; U.S. Pat. No. 8,044,068; Chaki et al., Current Topics in Medicinal Chemistry, 2007, 7, 1145-1151; Foster et al., Current Topics in Medicinal Chemistry, 2007, 7, 1131-1136; Pontillo et al., Bioorganic & Medicinal Chemistry Letters, 2007, 7, 1131-1136]. 15 (2005) 2541-46; Vos et al., Bioorganic & Medicinal Chemistry Letters 16 (2006) 2302-2305; Tao, Endocrine Reviews, 2010, 31(4):506-543; and Saleh et al., Front. Pharmacol., 2018, 9:560. These MC4R antagonists are useful in treating an MC4R-associated condition, disease or disorder, such as cachexia (e.g., cachexia associated with a chronic disease, including, for example, cachexia associated with cancer, cachexia associated with acquired immune deficiency syndrome (AIDS), cachexia associated with heart failure, including, for example, cachexia associated with congestive heart failure (CHF), cachexia associated with chronic kidney disease (CKD); cachexia associated with the treatment of a chronic disease, including, for example, cachexia associated with the treatment of cancer or cachexia associated with the treatment of heart failure (e.g., CHF)); anorexia or anorexia nervosa (e.g., anorexia in the elderly, The compounds are useful for treating and/or preventing anorexia associated with chemotherapy and/or radiation therapy; nausea; vomiting; weight loss (e.g., involuntary weight loss); growth retardation; sarcopenia; muscle wasting; muscle weakness; frailty; osteoporosis; bone disorders (e.g., bone loss); pain; neuropathic pain; anxiety (e.g., post-traumatic stress disorder or PTSD); depression; hypertension; malnutrition; obesity (e.g., sarcopenia resulting from chronic obesity); sexual dysfunction; and inflammatory disorders (e.g., anorexia or cachexia or sarcopenia or inflammatory disorders associated with muscle wasting).

There remains a continuing need for alternative MC4R antagonists, for example, to develop new and/or improved pharmaceuticals (e.g., more effective, more selective, less toxic, and/or having improved biopharmaceutical properties, e.g., physical stability; solubility; oral bioavailability; suitable metabolic stability; clearance; half-life) for treating or preventing MC4R-associated conditions, diseases, or disorders, such as those described herein. The present invention is directed to these and other important objectives.

In one embodiment (embodiment A1), the present invention provides a compound of formula I:

または薬学的に許容できるその塩［式中、
Ｒ^１は、Ｈ、ハロゲン、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_３～６シクロアルキル、４から７員のヘテロシクロアルキル、フェニルまたはＲ^１ａであり、ここで、Ｃ_３～６シクロアルキルおよび４から７員のヘテロシクロアルキルのそれぞれは、１、２、３または４個の独立に選択されるＣ_１～４アルキルで置換されていてもよく、フェニルは、１、２、３または４個の独立に選択されるＲ^Ｂで置換されていてもよく、ここで、各Ｒ^Ｂは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシ、Ｃ_１～４ハロアルコキシ、Ｃ_３～４シクロアルキルまたはＲ^Ｂ１であるか、または、２個の隣接するＲ^Ｂは、それらが結合したフェニルの２個の環形成原子と一緒になって、縮合した５または６員のヘテロアリールを形成し、そのそれぞれは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２または３個の置換基で置換されていてもよく、
Ｒ^１ａは、１、２、３または４個の独立に選択されるＲ^Ａで置換されていてもよい５または６員のヘテロアリールであり、ここで、各Ｒ^Ａは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシ、Ｃ_１～４ハロアルコキシ、Ｃ_３～４シクロアルキル、－Ｎ（Ｃ_１～４アルキル）_２、Ｒ^Ａ１または（Ｃ_３～４シクロアルキル）－Ｃ_１～４アルキル－であり、ここで、Ｃ_１～４アルキル、Ｃ_３～４シクロアルキルおよび（Ｃ_３～４シクロアルキル）－Ｃ_１～４アルキル－のそれぞれは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２、３、４または５個の置換基で置換されていてもよいか、または、２個の隣接するＲ^Ａは、それらが結合した５または６員のヘテロアリールの２個の環形成原子と一緒になって、縮合ベンゼン環または縮合した５もしくは６員のヘテロアリールまたは縮合した５もしくは６員のヘテロシクロアルキルまたは縮合した５もしくは６員のシクロアルキルを形成し、そのそれぞれは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２または３個の置換基で置換されていてもよく、
Ｒ^Ａ１は、５もしくは６員のヘテロアリールまたは５もしくは６員のヘテロシクロアルキルであり、そのそれぞれは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２または３個の置換基で置換されていてもよく、
Ｒ^Ｂ１は、５または６員のヘテロアリールであり、そのそれぞれは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２または３個の置換基で置換されていてもよく、
Ｘ^１は、Ｃ（Ｒ^Ｘ）_２であり、ここで、各Ｒ^Ｘは、独立に、ＨまたはＣ_１～４アルキルであり、
Ｒ^２およびＲ^３のそれぞれは、独立に、Ｈ、ハロゲン、Ｃ_１～４アルキル、Ｃ_１～４ヒドロキシアルキル、Ｃ_１～４ハロアルキル、（Ｃ_１～４アルコキシ）－Ｃ_１～４アルキル－、Ｃ_３～４シクロアルキルまたは（Ｃ_３～４シクロアルキル）－Ｃ_１～４アルキルであり、ここで、Ｃ_３～４シクロアルキルおよび（Ｃ_３～４シクロアルキル）－Ｃ_１～４アルキル－のそれぞれは、ハロゲン、－ＯＨ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２、３、４または５個の置換基で置換されていてもよいか、
または、Ｒ^２およびＲ^３は、それらが結合した炭素原子と一緒になって、ハロゲン、－ＯＨ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２、３、４または５個の置換基で置換されていてもよい、Ｃ_３～６シクロアルキルを形成し、
Ｙ^１、Ｙ^２、Ｙ^３、Ｙ^４およびＹ^５のそれぞれは、独立に、ＣＲ^４またはＮであり、ただし、Ｙ^１、Ｙ^２、Ｙ^３、Ｙ^４およびＹ^５のうちの３個以下がＮであり、
各Ｒ^４は、独立に、Ｈ、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシ、Ｃ_１～４ハロアルコキシ、－Ｎ（Ｃ_１～２アルキル）_２、Ｃ_３～４シクロアルキルまたは（Ｃ_３～４シクロアルキル）－Ｃ_１～４アルキル－であり、ここで、Ｃ_１～４アルキル、Ｃ_３～４シクロアルキルおよび（Ｃ_３～４シクロアルキル）－Ｃ_１～４アルキル－のそれぞれは、ハロゲン、－ＯＨ、－ＣＮ、Ｃ_１～４アルキル、Ｃ_１～４ハロアルキル、Ｃ_１～４アルコキシおよびＣ_１～４ハロアルコキシからそれぞれ独立に選択される１、２、３、４または５個の置換基で置換されていてもよい］
を提供する。

or a pharma- ceutically acceptable salt thereof,
R ¹ is H, halogen, C _1-4 alkyl, C _1-4 haloalkyl, C _3-6 cycloalkyl, 4- to 7-membered heterocycloalkyl, phenyl or R ^1a , where each of the C _3-6 cycloalkyl and the 4- to 7-membered heterocycloalkyl is optionally substituted with _1, 2, 3 or 4 independently selected C 1-4 alkyl, and the phenyl is optionally substituted with 1, 2, 3 or 4 independently selected R ^B , where each R ^B is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy, C _3-4 cycloalkyl or R ^B1 ; or two adjacent R ^B together with two ring-forming atoms of the phenyl to which they are attached form a fused 5- or 6-membered heteroaryl, each of which is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C optionally substituted with 1, 2 or 3 substituents each independently selected from _1-4 alkoxy and C _1-4 haloalkoxy;
R ^1a is a 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _{1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, C 1-4 haloalkoxy, C 3-4 cycloalkyl, -N(C 1-4 alkyl) 2 , R A1 or (C 3-4 cycloalkyl)-C 1-4 alkyl-, where each of C 1-4 alkyl , C 3-4 cycloalkyl and} ⁽ _{C 3-4 cycloalkyl )-C 1-4 alkyl- is optionally substituted with 1, 2 , 3 ,} 4 or 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy, or two adjacent R ^A together with the two ring-forming atoms of the 5- or 6-membered heteroaryl to which they are attached form a fused benzene ring, or a fused 5- or 6-membered heteroaryl, or a fused 5- or 6-membered heterocycloalkyl, or a fused 5- or 6-membered cycloalkyl, each of which is optionally substituted by 1, ₂ or 3 substituents each independently selected from halogen, -OH, -CN, _C1-4 alkyl, _C1-4 haloalkyl, _C1-4 alkoxy and C1-4 haloalkoxy;
R ^A1 is a 5- or 6-membered heteroaryl or a 5- or 6-membered heterocycloalkyl, each of which is optionally substituted with 1, 2, or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy;
R ^B1 is a 5- or 6-membered heteroaryl, each of which is optionally substituted with 1, _{2, or 3 substituents each independently selected from halogen, -OH, -CN, C 1-4} alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy;
X ¹ is C(R ^X ) ₂ , where each R ^X is independently H or C _1-4 alkyl;
each of R ² and R ³ is independently H, halogen, C _1-4 alkyl, C _1-4 hydroxyalkyl, C _1-4 haloalkyl, (C _1-4 alkoxy)-C _1-4 alkyl-, _{C 3-4} cycloalkyl or (C _3-4 cycloalkyl)-C 1-4 alkyl, wherein each of C _3-4 cycloalkyl and (C _3-4 cycloalkyl)-C _1-4 alkyl- is optionally substituted with 1, 2, 3, 4 or ₅ substituents each independently selected from halogen, —OH, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy;
or R ² and R ³ together with the carbon atom to which they are attached form a C _3-6 cycloalkyl, optionally substituted with 1, 2, 3, 4 or 5 substituents each independently selected from halogen, —OH, C _1-4 alkyl, C 1-4 haloalkyl, _{C 1-4 alkoxy} and C _1-4 haloalkoxy;
each of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is independently CR ⁴ or N, with the proviso that no more than three of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ are N;
each R ⁴ is independently H, halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy, -N(C _1-2 alkyl) ₂ , C 3-4 cycloalkyl or (C _3-4 cycloalkyl)-C _1-4 alkyl-, wherein each of C _1-4 alkyl, C _3-4 cycloalkyl and (C _3-4 cycloalkyl)-C _1-4 alkyl- is optionally substituted with 1, 2, _{3, 4} or 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy;
to deliver.

The present invention also provides a pharmaceutical composition having a therapeutically effective amount of a compound of formula I or a pharma- ceutically acceptable salt of said compound and a pharma- ceutically acceptable carrier.

The present invention also provides a method for treating an MC4R-associated condition, disease or disorder in a mammal (e.g., a human) in need of such treatment, comprising administering to the mammal (e.g., a human) a compound of formula I or a pharma- ceutically acceptable salt of the compound.

The present invention also provides a compound of formula I, or a pharma- ceutically acceptable salt of said compound, for use in treating an MC4R-associated condition, disease or disorder.

MC4R-associated conditions, diseases or disorders include cachexia (e.g., cachexia associated with a chronic disease, including, for example, cachexia associated with cancer, cachexia associated with acquired immune deficiency syndrome (AIDS), cachexia associated with heart failure, including, for example, cachexia associated with congestive heart failure (CHF), cachexia associated with chronic kidney disease (CKD); cachexia associated with the treatment of a chronic disease, including, for example, cachexia associated with the treatment of cancer or cachexia associated with the treatment of heart failure (e.g., CHF)); anorexia or anorexia nervosa (e.g., anorexia in the elderly, cachexia associated with chemotherapy and/or radiation therapy, anorexia associated with chronic obesity); nausea; vomiting; weight loss (e.g., involuntary weight loss); failure to thrive; sarcopenia; muscle wasting; muscle weakness (e.g., muscle weakness associated with chronic obstructive pulmonary disease (COPD)); frailty; osteoporosis; bone disorders (e.g., bone loss); pain; neuropathic pain; anxiety (e.g., post-traumatic stress disorder or PTSD); depression; hypertension; malnutrition; obesity (e.g., sarcopenia resulting from chronic obesity); sexual dysfunction; and inflammatory disorders (e.g., anorexia or cachexia or sarcopenia or inflammatory disorders associated with muscle wasting).

The present invention relates to a method for treating a condition, disease or disorder in a mammal (e.g., a human) in need of such treatment, comprising the step of administering to the mammal (e.g., a human) a compound of formula I or a pharma- ceutically acceptable salt of the compound, wherein the condition, disease or disorder is cachexia [e.g., cachexia associated with a chronic disease, e.g., cachexia associated with cancer, cachexia associated with acquired immune deficiency syndrome (AIDS), cachexia associated with heart failure, e.g., cachexia associated with congestive heart failure (CHF), cachexia associated with chronic kidney disease (CKD); cachexia associated with the treatment of a chronic disease, e.g., cachexia associated with cancer treatment or heart failure (e.g., cachexia associated with chronic kidney disease (CKD)); Also provided are methods for treating anorexia, including cachexia associated with the treatment of chronic HF; anorexia or anorexia nervosa (e.g., anorexia in the elderly, anorexia associated with chemotherapy and/or radiation therapy); nausea; vomiting; weight loss (e.g., involuntary weight loss); failure to thrive; sarcopenia; muscle wasting; muscle weakness; frailty; osteoporosis; bone disorders (e.g., bone loss); pain; neuropathic pain; anxiety (e.g., post-traumatic stress disorder or PTSD); depression; hypertension; malnutrition; obesity (e.g., sarcopenia resulting from chronic obesity); sexual dysfunction; and inflammatory disorders (e.g., anorexia or cachexia or inflammatory disorders associated with sarcopenia or muscle wasting).

The present invention also provides a method for antagonizing the melanocortin-4 receptor (MC4R), comprising contacting the MC4R with a compound of formula I or a pharma- ceutically acceptable salt of said compound.

It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

FIG. 1 shows an illustrative single crystal structure of compound Example 14. FIG. 1 shows an illustrative single crystal structure of compound Example 15. FIG. 1 shows representative observed powder X-ray diffraction patterns of crystalline forms of P23. FIG. 1 shows a representative observed powder X-ray diffraction pattern of a crystalline form of C69. FIG. 1 shows representative observed powder X-ray diffraction patterns of crystalline forms of P28. FIG. 1 shows a representative observed powder X-ray diffraction pattern of the crystalline form of Example 14.

The present invention may be more readily understood by reference to the following detailed description of exemplary embodiments of the invention and the examples included therein.

It is to be understood that the present invention is not limited to specific synthetic methods for preparation, which may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings:

As used herein, "a" or "an" can mean one or more. When used in the claims, when used in conjunction with the word "comprising," the word "a" or "an" can mean one or more than one. As used herein, "another" can mean at least a second or more.

The term "about" refers to a relative term indicating an approximation of plus or minus 10% of the nominal value to which it refers, and in one embodiment, plus or minus 5%, and in another embodiment, plus or minus 2%. Within the scope of this disclosure, this level of approximation is appropriate unless the value is specifically stated to require a narrower range.

"Compound", as used herein, includes conformational isomers (e.g., cis and trans isomers) and all optical isomers (e.g., enantiomers and diastereomers), racemic, diastereomeric and other mixtures of such isomers, as well as any pharma- ceutically acceptable derivatives or variations, including solvates, hydrates, isomorphs, polymorphs, tautomers, esters, salt forms and prodrugs. The expression "prodrug" refers to a compound that is a drug precursor that releases a drug in vivo after administration via some chemical or physiological process (e.g., a prodrug is brought to physiological pH or converted to the desired drug form via enzymatic action).

The term "alkyl" refers to an acyclic saturated aliphatic hydrocarbon group, which may be straight/linear or branched. Examples of such groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, butyl, sec-butyl, isobutyl, and tert-butyl. The carbon atoms comprising alkyl and various other hydrocarbon-containing moieties are designated by prefixes that specify the lower and upper number of carbon atoms in the moiety, i.e., the prefix C _i-j designates a portion from integer "i" to integer "j" carbon atoms, inclusive. Thus, for example, C _1-4 alkyl refers to an alkyl of 1 to 4 carbon atoms, inclusive. Representative examples of C _1-4 alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl. As another example, C _1-4 alkyl refers to an alkyl of 1 to 2 carbon atoms, inclusive (i.e., methyl or ethyl). Where so specified, an alkyl group may be optionally substituted with one or more (eg, 1 to 5) suitable substituents.

At various places in the present specification, substituents of compounds of the invention are disclosed in groups or in ranges. It is specifically intended that the present invention includes all individual subcombinations of each of the members of such groups and ranges. For example, the term "C _1-4 alkyl" is specifically intended to include C ₁ alkyl (methyl), C ₂ alkyl (ethyl), C ₃ alkyl, and C ₄ alkyl. As another example, the term "4- to 7-membered heterocycloalkyl" is specifically intended to include any 4-, 5-, 6-, or 7-membered heterocycloalkyl group.

As used herein, the term "n-membered," where n is an integer, typically describes the number of ring-forming atoms in a moiety where the number of ring-forming atoms is n. For example, pyridinyl is an example of a 6-membered heteroaryl ring and pyrazolyl is an example of a 5-membered heteroaryl group.

As used herein, the term "alkoxy" or "alkyloxy" refers to an --O-alkyl group. For example, the term "C _1-4 alkoxy" or "C _1-4 alkyloxy" refers to an --O-(C _1-4 alkyl) group; as another example, the term "C _1-2 alkoxy" or "C _1-2 alkyloxy" refers to an --O-(C _1-2 alkyl) group. Examples of alkoxy include methoxy, ethoxy, propoxy (e.g., n-propoxy and isopropoxy), tert-butoxy, and the like. When so specified, an alkoxy or alkyloxy group may be optionally substituted by one or more (e.g., 1 to 5) suitable substituents.

The term "halo" or "halogen" as used herein means -F, -Cl, -Br or -I.

As used herein, the term "haloalkyl" refers to an alkyl group having one or more halogen substituents (up to perhaloalkyl, i.e., all hydrogen atoms on the alkyl group are replaced by halogen atoms). For example, the term "C _1-4 haloalkyl" refers to a C 1-4 alkyl group having one or more halogen substituents (up to perhaloalkyl, i.e., all hydrogen atoms on the alkyl group are replaced by halogen atoms); the term "C _1-2 haloalkyl" refers to a C _1-2 alkyl group (i.e., methyl or ethyl) having one _{or more} halogen substituents (up to perhaloalkyl, i.e., all hydrogen atoms on the alkyl group are replaced by halogen atoms). Examples of haloalkyl groups include -CF ₃ , -CHF ₂ , -CH ₂ F, -CH ₂ CF ₃ , -C ₂ F ₅ , -CH ₂ Cl, and the like.

"Fluoroalkyl" means alkyl, as defined herein, substituted with one or more fluoro (-F) substituents (up to perfluoroalkyl, i.e., all hydrogen atoms on the alkyl group are replaced by fluorine atoms). The term " _C1-2 fluoroalkyl" refers to a C1-2 alkyl group (i.e., methyl or ethyl) having one or more fluorine substituents (up to perfluoroalkyl, i.e., all hydrogen atoms on the alkyl group are replaced by fluorine atoms); the term " _C1 fluoroalkyl" refers to a methyl having one, _two or three fluorine substituents. Examples of _C1 fluoroalkyl include fluoromethyl, difluoromethyl and trifluoromethyl; some examples of _C2 fluoroalkyl include 1-fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 1,2-difluoroethyl, 2,2,2-trifluoroethyl, 1,1,2-trifluoroethyl, and the like.

As used herein, the term "haloalkoxy" refers to an -O-haloalkyl group. For example, the term " _C1-4 haloalkoxy" refers to the group -O-( _C1-4 haloalkyl); the term " _C1-2 haloalkoxy" refers to the group -O-( _C1-2 haloalkyl). As yet another example, the term " _C1 haloalkoxy" refers to a methoxy group having 1, 2 or 3 halogen substituents. Examples of haloalkoxy are _-OCF3 or _-OCHF2 .

As used herein, the term "fluoroalkoxy" refers to an -O-fluoroalkyl group. For example, the term "C _1-2 fluoroalkoxy" refers to an -O-(C _1-2 fluoroalkyl) group; the term "C ₁ fluoroalkoxy" refers to an -O-(C ₁ fluoroalkyl) group. Examples of C ₁ fluoroalkoxy include -O-CH ₂ F, -O-CHF ₂ , and -O-CF _3. Some examples of C ₂ fluoroalkoxy include -O-CH ₂ CHF ₂ , -O-CH ₂ -CHF ₂ , -O-CH ₂ CF ₃ , -O-CF ₂ CH ₃ , and -O-CF ₂ CF ₃ .

As used herein, the term "hydroxylalkyl" or "hydroxyalkyl" refers to an alkyl group having one or more (e.g., 1, 2 or 3) OH substituents. The term "C _1-4 hydroxylalkyl" or "C _1-4 hydroxyalkyl" refers to a C _1-4 alkyl group having one or more (e.g., 1, 2 or 3) OH substituents; the term "C _{1-2 hydroxylalkyl" or "C 1-2 hydroxyalkyl} " refers to a C _1-2 alkyl group having one or more (e.g., 1, 2 or 3) OH substituents. Examples of hydroxylalkyl are -CH ₂ OH or -CH ₂ CH ₂ OH.

As used herein, the term "cycloalkyl" refers to a saturated or unsaturated, non-aromatic, monocyclic or polycyclic (including bicyclic) hydrocarbon ring (e.g., a monocyclic, e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or bicyclic rings containing spiro, fused or bridged systems (e.g., bicyclo[1.1.1]pentanyl, bicyclo[2.2.1]heptanyl, bicyclo[3.2.1]octanyl, or bicyclo[5.2.0]nonanyl, decahydronaphthalenyl, etc.). Cycloalkyl groups have 3 to 15 (e.g., 3 to 14, 3 to 10, 3 to 6, 3 to 4, or 4 to 6) carbon atoms. In some embodiments, cycloalkyls may contain one, two, or more non-cumulative non-aromatic double or triple bonds and/or one to three oxo groups. In some embodiments, a bicycloalkyl group has from 6 to 14 carbon atoms. The term "C _3-4 cycloalkyl," as used herein, means a saturated cyclic hydrocarbon group containing from 3 to 4 carbons. Examples of C _3-4 cycloalkyl include cyclopropyl and cyclobutyl. Also included in the definition of cycloalkyl are moieties having one or more aromatic rings (including aryl and heteroaryl) fused to a cycloalkyl ring, e.g., a benzo or pyridinyl derivative of cyclopentane (a 5-membered cycloalkyl), cyclopentene, cyclohexane (a 6-membered cycloalkyl), etc., e.g., 6,7-dihydro-5H-cyclopenta[b]pyridinyl, 5,6,7,8-tetrahydroquinolinyl, or 1 5,6,7,8-tetrahydroisoquinolinyl, each of which contains a 5- or 6-membered cycloalkyl moiety (i.e., a pyridinyl ring) fused to a heteroaryl ring. Where so specified, a cycloalkyl or C _3-4 cycoalkyl group may be optionally substituted by one or more (eg, 1 to 5) suitable substituents.

The term " _C3-4 cycloalkyl- _C1-4 alkyl-" as used herein means a _C3-4 cycloalkyl, as defined herein, appended to the parent molecular moiety through a _C3-4 alkyl group, as defined herein. Some examples of _C3-4 cycloalkyl- _C1-4 alkyl- include cyclopropylmethyl, 2-cyclopropylethyl, 2-cyclopropylpropyl, 3-cyclopropylpropyl, cyclobutylmethyl, 2-cyclobutylethyl, 2-cyclobutylpropyl and 3-cyclobutylpropyl.

As used herein, the term "heterocycloalkyl" refers to a monocyclic or polycyclic [including two or more rings fused together, including spiro, fused or bridged systems, e.g., bicyclic ring systems], saturated or unsaturated, non-aromatic 4- to 15-membered ring system (such as a 4- to 14-membered ring system, a 4- to 12-membered ring system, a 5- to 10-membered ring system, a 4- to 7-membered ring system, a 4- to 6-membered ring system, or a 5- to 6-membered ring system) containing 1 to 14 ring-forming carbon atoms and 1 to 10 ring-forming heteroatoms, each independently selected from O, S, and N (and optionally including P or B, if present). Heterocycloalkyl groups may also contain one or more oxo (i.e., =O) or thiono (i.e., =S) groups. For example, the term "4- to 7-membered heterocycloalkyl" refers to a monocyclic or polycyclic, saturated or unsaturated, non-aromatic 4- to 7-membered ring system containing one or more ring-forming heteroatoms independently selected from O, S, and N. As another example, the term "5- or 6-membered heterocycloalkyl" refers to a monocyclic or polycyclic, saturated or unsaturated, non-aromatic 5- or 6-membered ring system containing one or more ring-forming heteroatoms independently selected from O, S, and N. Heterocycloalkyl groups, when so specified, may be substituted by one or more (e.g., 1 to 5) suitable substituents.

Some examples of 4- to 7-membered heterocycloalkyl include azetidinyl, oxetanyl, tetrahydrofuranyl, imidazolidinyl, pyrrolidinyl, piperidinyl, piperazinyl, oxazolidinyl, thiazolidinyl, pyrazolidinyl, thiomorpholinyl, tetrahydrothiazinyl, tetrahydrothiadiazinyl, morpholinyl, tetrahydrodiazinyl, and tetrahydropyranyl (also known as oxanyl). Some further examples of 4 to 7-heterocycloalkyl are tetrahydrofuran-2-yl, tetrahydrofuran-3-yl, tetrahydropyranyl (e.g., tetrahydro-2H-pyran-4-yl), imidazolidin-1-yl, imidazolidin-2-yl, imidazolidin-4-yl, pyrrolidin-1-yl, pyrrolidin-2-yl, pyrrolidin-3-yl, piperidin-1-yl, piperidin-2-yl, piperidin-3-yl, piperidin-4-yl, piperazin-1-yl, piperazin-2-yl. , 1,3-oxazolidin-3-yl, 1,4-oxazepan-2-yl, isothiazolidinyl, 1,3-thiazolidin-3-yl, 1,2-pyrazolidin-2-yl, 1,2-tetrahydrothiazin-2-yl, 1,3-thiazinane-3-yl, 1,2-tetrahydrodiazin-2-yl, 1,3-tetrahydrodiazin-1-yl, 1,4-oxazin-4-yl, oxazolidinonyl, 2-oxo-piperidinyl (e.g., 2-oxo-piperidin-1-yl), 2-oxoazepan-3-yl, and the like.

As used herein, the term "heteroaryl" refers to a monocyclic or fused-ring polycyclic aromatic heterocyclic group having one or more heteroatom ring members (ring-forming atoms) independently selected from O, S, and N in at least one ring. Heteroaryl groups have 5 to 14 ring-forming atoms, including 1 to 13 carbon atoms and 1 to 8 heteroatoms selected from O, S, and N. In some embodiments, heteroaryl groups have 5 to 10 ring-forming atoms, including 1 to 4 heteroatoms. Heteroaryl groups can also contain 1 to 3 oxo or thiono (i.e., =S) groups. In some embodiments, heteroaryl groups have 5 to 8 ring-forming atoms, including 1, 2, or 3 heteroatoms. For example, the term "5-membered heteroaryl" refers to a monocyclic heteroaryl group as defined above having 5 ring-forming atoms in the monocyclic heteroaryl ring; the term "6-membered heteroaryl" refers to a monocyclic heteroaryl group as defined above having 6 ring-forming atoms in the monocyclic heteroaryl ring; the term "5- or 6-membered heteroaryl" refers to a monocyclic heteroaryl group as defined above having 5 or 6 ring-forming atoms in the monocyclic heteroaryl ring. When so specified, the heteroaryl group may be substituted by one or more (e.g., 1 to 5) suitable substituents. Examples of monocyclic heteroaryls include those having 5 ring-forming atoms with 1 to 3 heteroatoms or those having 6 ring-forming atoms with 1, 2 or 3 nitrogen heteroatoms. Examples of fused bicyclic heteroaryls include two fused 5- and/or 6-membered monocyclic rings with 1 to 4 heteroatoms.

Some examples of heteroaryl groups are pyridinyl (e.g., pyridin-2-yl, pyridin-3-yl, pyridin-4-yl), pyrazinyl, pyrimidinyl (e.g., pyrimidin-2-yl, pyrimidin-4-yl, or pyrimidin-5-yl), pyridazinyl (e.g., pyridazin-3-yl, or pyridazin-4-yl), thienyl, furyl, imidazolyl (e.g., 1H-imidazol-4-yl), pyrrolyl, oxazolyl (e.g., 1,3-oxazolyl, 1,2-oxazolyl), thiazolyl (e.g., 1,2-thiazolyl, 1,3-thiazolyl), Pyrazolyl (e.g. pyrazol-1-yl, pyrazol-3-yl, pyrazol-4-yl), tetrazolyl (e.g. 2H-tetrazol-5-yl), triazolyl (e.g. 1,2,3-triazolyl, 1,2,4-triazolyl), oxadiazolyl (e.g. 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl or 1,3,4-oxadiazolyl), thiadiazolyl (e.g. 1,3,4-thiadiazolyl or 1,2,4-thiadiazolyl), quinolyl, isoquinolyl, benzothienyl, benzofuryl, indolyl, benzothiazolyl 1,2-benzoxazolyl, 1H-imidazo[4,5-c]pyridinyl, imidazo[1,2-a]pyridinyl, 1H-pyrrolo[3,2-c]pyridinyl, imidazo[1,2-a]pyrazinyl, imidazo[2,1-c][1,2,4]triazinyl, imidazo[1,5-a]pyrazinyl, imidazo[1,2-a]pyrimidinyl, 1H-indazolyl, 9H-purinyl, imidazo[1,2-a]pyrimidinyl, [1,2,4]triazolo[1,5-a]pyridinyl, [1,2,4]triazolo[1,5-a]pyrimidinyl, [1,2,4]triazolo[4,3- b]pyridazinyl, isoxazolo[5,4-c]pyridazinyl, isoxazolo[3,4-c]pyridazinyl, pyrazolo[1,5-a]pyrimidinyl, 6,7-dihydro-5H-pyrrolo[1,2-b][1,2,4]triazolyl, pyridone, pyrimidone, pyrazinone, pyrimidinone, 1H-imidazol-2(3H)-one, 1H-pyrrole-2,5-dione, 3-oxo-2H-pyridazinyl, 1H-2-oxo-pyrimidinyl, 1H-2-oxo-pyridinyl, 2,4(1H,3H)-dioxo-pyrimidinyl, 1H-2-oxo-pyrazinyl, etc.

As used herein, the compounds of formula I as described herein include optional substitutions and variables. It is understood that the normal valence of each of the designated (optionally substituted) atoms or moieties is not exceeded, and that any of the optional substitutions will result in stable compounds. It is also understood that combinations of optional substituents and/or variables are permissible only if such combinations result in stable compounds.

As used herein, unless otherwise specified, the point of attachment of a substituent can be from any suitable position of the substituent. For example, piperidinyl can be piperidin-1-yl (attached through the N atom of piperidinyl), piperidin-2-yl (attached through the C atom at the 2-position of piperidinyl), piperidin-3-yl (attached through the C atom at the 3-position of piperidinyl) or piperidin-4-yl (attached through the C atom at the 4-position of piperidinyl). As another example, pyridinyl (or pyridyl) can be 2-pyridinyl (or pyridin-2-yl), 3-pyridinyl (or pyridin-3-yl) or 4-pyridinyl (or pyridin-4-yl).

As used herein, the point of attachment of a substituent may be designated to indicate the position at which the substituent is attached to another moiety. For example, "(C _3-4 cycloalkyl)-C _1-4 alkyl-" means the point of attachment occurs at the "C _1-4 alkyl" portion of "(C _3-4 cycloalkyl)-C _1-4 alkyl-".

When a substituted or optionally substituted moiety is described without indicating the atom through which such moiety is attached to the substituent, the substituent may be attached via any suitable atom on such moiety. For example, in a substituted "(C _3-4 cycloalkyl)-C _1-4 alkyl-", the substituent on the cycloalkylalkyl [i.e., (C _3-4 cycloalkyl)-C _1-4 alkyl-] is attached to any carbon atom on the alkyl or cycloalkyl portion of the cycloalkylalkyl. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.

As used herein, the term "adjacent" when describing the relative positions of two substituent groups in a ring structure refers to two substituent groups that are each bonded to two ring-forming atoms of the same ring, where the two ring-forming atoms are directly connected via a chemical bond. For example, in the structure below:

のそれぞれにおいて、
２個のＲ^７０基のいずれかが、Ｒ^６０の隣接基である。

In each of the above,
Either of the two R ⁷⁰ groups is an adjacent group to R ⁶⁰ .

"Mammal" refers to warm-blooded vertebrate animals characterized by the production of milk by the females for the nourishment of their young, such as guinea pigs, mice, rats, gerbils, cats, rabbits, dogs, cows, goats, sheep, horses, monkeys, chimpanzees, and humans.

The term "pharmaceutical acceptable" means a substance (e.g., a compound of the invention) and any salt thereof, or a composition containing a substance or salt of the invention, that is suitable for administration to a patient.

As used herein, the expressions "reaction inert solvent" and "inert solvent" refer to a solvent or mixture thereof that does not interact with the starting materials, reagents, intermediates, or products in a manner that adversely affects the yield of the desired product.

As used herein, the term "selectivity" or "selective" refers to a compound whose effect in a first assay is greater than the effect of the same compound in a second assay. For example, for an "intestine-selective" compound, the first assay is for the compound's half-life in the small intestine and the second assay is for the compound's half-life in the liver.

"Therapeutically effective amount" means an amount of a compound of the present invention that (i) treats or prevents a particular disease, condition, or disorder; (ii) attenuates, improves, or eliminates one or more symptoms of a particular disease, condition, or disorder; or (iii) prevents or delays the onset of one or more symptoms of a particular disease, condition, or disorder described herein.

The terms "treating," "treat," or "treatment" as used herein encompass both prophylactic, i.e., protective, and palliative treatment, including reversing, alleviating, relieving, or slowing the progression of any tissue damage associated with a disease (or disorder or condition) or one or more symptoms of a disease (or disorder or condition).

As used herein, the term "contacting" refers to bringing the indicated moieties into contact with each other in an in vitro or in vivo system. For example, "contacting" MC4R with a compound of the invention includes administering a compound of the invention to a mammal, such as a human, that has MC4R, and, for example, introducing a compound of the invention into a sample containing a cell or purified preparation that contains MC4R.

Embodiment A2 is a compound of formula I or a pharma- ceutically acceptable salt thereof, which is a compound of formula Ia:

または薬学的に許容できるその塩であり、式中、可変基Ｒ^１、Ｒ^２、Ｒ^３、Ｘ^１、Ｙ^１、Ｙ^２、Ｙ^３、Ｙ^４およびＹ^５が、実施形態Ａ１におけるものと同じに定義される、実施形態Ａ１のさらなる実施形態である。

or a pharma- ceutically acceptable salt thereof, in which the variables ^R1 , ^R2 , ^R3 , ^X1 , ^Y1 , ^Y2 , ^Y3 , ^Y4 and ^Y5 are defined as in embodiment A1.

Embodiment A3 is a compound, or a pharma- ceutically acceptable salt thereof, of formula II:

または薬学的に許容できるその塩であり、式中、可変基Ｒ^１、Ｒ^２、Ｒ^３、Ｘ^１、Ｙ^１、Ｙ^２、Ｙ^３、Ｙ^４およびＹ^５が、実施形態Ａ１におけるものと同じに定義される、実施形態Ａ１またはＡ２のさらなる実施形態である。

or a pharma- ceutically acceptable salt thereof, wherein the variables ^R1 , ^R2 , ^R3 , ^X1 , ^Y1 , ^Y2 , ^Y3 , ^Y4 and ^Y5 are defined the same as in embodiment A1.

Embodiment A4 is a compound, or a pharma- ceutically acceptable salt thereof, of formula III:

または薬学的に許容できるその塩であり、式中、可変基Ｒ^１、Ｒ^２、Ｒ^３、Ｙ^１、Ｙ^２、Ｙ^３、Ｙ^４およびＹ^５が、実施形態Ａ１におけるものと同じに定義される、実施形態Ａ１からＡ３のいずれか１つのさらなる実施形態である。

or a pharma- ceutically acceptable salt thereof, wherein the variables ^R1 , ^R2 , ^R3 , ^Y1 , ^Y2 , ^Y3 , ^Y4 and ^Y5 are defined the same as in embodiment A1.

In embodiment A5,
R ¹ is H, halogen, C _1-4 alkyl, C _1-4 haloalkyl, C _3-6 cycloalkyl, 4- to 7-membered heterocycloalkyl optionally substituted with 1 _to 4 C 1-4 alkyl, or R ^1a ;
R ^1a is a 5- or 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _{1-4 alkoxy, C 1-4} haloalkoxy, C 3-4 cycloalkyl or (C _3-4 cycloalkyl)-C _1-4 alkyl-, where each of the C _1-4 alkyl, C _3-4 cycloalkyl and (C _3-4 cycloalkyl)-C _1-4 alkyl- is optionally substituted with 1, 2, ₃ , 4 _or 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy; or two adjacent R ^A together with the two ring atoms of the 5- or 6-membered heteroaryl to which they are attached form a fused benzene ring or a fused 5- or 6-membered heteroaryl, each of which is optionally substituted with 1, 2, or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy;
A further embodiment of any one of embodiments A1 to A4.

Embodiment A6 is a further embodiment of any one of Embodiments A1 through A4, wherein R ¹ is H, halogen, or 4- to 7-membered heterocycloalkyl.

Embodiment A7 is a further embodiment of any one of Embodiments A1 through A4, wherein R ¹ is H or halogen.

Embodiment A8 is a further embodiment of any one of Embodiments A1 through A4, wherein R ¹ is H.

Embodiment A9 is a further embodiment of any one of Embodiments A1 through A4, wherein R ¹ is halogen (eg, Cl).

Embodiment A10 is a further embodiment of any one of Embodiments A1 to A4, wherein R ¹ is a 4- _to 7-membered heterocycloalkyl optionally substituted with 1 to 4 C 1-4 alkyl (e.g., tetrahydrofuranyl, tetrahydropyranyl, pyrrolidinyl, piperidinyl, piperazinyl or morpholino).

Embodiment A11 is a further embodiment of any one of Embodiments A1 to A4, wherein R ¹ is R ^1a .

In embodiment A12,
R ¹ is R ^1a ;
R ^1a is a 5-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C 1-4 alkoxy, C _1-4 haloalkoxy, C _3-4 cycloalkyl or (C _3-4 cycloalkyl)-C _1-4 alkyl-, where each of the _{C 1-4} alkyl, C _3-4 cycloalkyl and (C _3-4 cycloalkyl)-C _1-4 alkyl- is optionally substituted with 1, 2, _3, 4 or 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy; or two adjacent R ^A together with the two ring atoms of the 5-membered heteroaryl to which they are attached form a fused 5- or 6-membered heteroaryl, each of which is optionally substituted with 1, _{2, or 3 substituents each independently selected from halogen, -OH, -CN, C 1-4} alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy;
A further embodiment of any one of embodiments A1 to A4.

Embodiment A13 is a further embodiment of Embodiment A11 or A12 wherein R ^1a is 5-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _{1-4 alkoxy, C 1-4} haloalkoxy, C _3-4 cycloalkyl or (C _3-4 cycloalkyl)-C _1-4 alkyl-, where each of C _1-4 alkyl, C _3-4 cycloalkyl and (C _3-4 cycloalkyl)-C _{1-4 alkyl- is optionally substituted with 1} , 2, ₃ , 4 or 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy.

Embodiment A14 is a further embodiment of Embodiment A11 or A12 wherein R ^1a is 5-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _{1-4 alkoxy, C 1-4 haloalkoxy, or C 3-4 cycloalkyl .}

Embodiment A15 is a further embodiment of any one of Embodiments A12 through A14, wherein each of the ring-forming atoms of the 5-membered heteroaryl of R ^1a is a carbon or nitrogen atom.

Embodiment A16 is a further embodiment of Embodiment A11 in which R ^1a is pyrazolyl, 1,2,4-triazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2-thiazolyl, 1,3,4-thiadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-oxadiazolyl, 1,2,4-oxadiazolyl, 1,3-thiazolyl, imidazoly, pyrazolo[1,5-a]pyrimidinyl or [1,2,4]triazolo[1,5-a]pyridinyl-, each of which is optionally substituted with 1, 2 or 3 substituents each independently selected from halogen, _{-OH, -CN} , C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C 1-4 haloalkoxy, and _{C 3-4} cycloalkyl.

Embodiment A17 is an embodiment in which R ^1a is 1H-pyrazol-4-yl, 1H-1,2,4-triazol-3-yl, 2H-1,2,3-triazol-4-yl, 2H-tetrazol-5-yl, 1,2-thiazol-5-yl, 1,3,4-thiadiazol-2-yl, 1,2,4-thiadiazol-5-yl, 1,3,4-oxadiazol-2-yl, 1,2,4-oxadiazol-3-yl, 1,3-thiazol-2-yl, 1,3-thiazol-4-yl, 1H-imidazol-4-yl, pyrazolo[1,5-a]pyrimidin-3-yl or [1,2,4]triazolo[1,5-a]pyridin-2-yl, each of which is selected from halogen, —OH, —CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C This is a further embodiment of Embodiment A11, optionally substituted with 1, 2 or 3 substituents each independently selected from _1-4 haloalkoxy, and C _3-4 cycloalkyl.

In embodiment A18,
R ¹ is R ^1a ;
R ^1a is a 5-membered heteroaryl substituted with 2, 3, or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C 1-4 alkoxy, C _1-4 haloalkoxy, C _3-4 cycloalkyl, or (C _3-4 cycloalkyl)-C _{1-4 alkyl-, where each of the C 1-4 alkyl, C 3-4 cycloalkyl, and (C 3-4 cycloalkyl)-C 1-4 alkyl- is optionally substituted with 1, 2 , 3 , 4} , or 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy, or two adjacent R ^A together with the two ring atoms of the 5-membered heteroaryl to which they are attached form a fused 5- or 6-membered heteroaryl or a fused 5- or 6-membered heterocycloalkyl, each of which is optionally substituted with 1, 2, or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy;
A further embodiment of any one of embodiments A1 to A4.

Embodiment A19 is an embodiment in which two R ^A are adjacent and together with the two ring atoms of the 5-membered heteroaryl to which they are attached form a fused 5- or 6-membered heteroaryl optionally substituted with 1, ₂ or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C 1-4 alkoxy and C _1-4 haloalkoxy, where each remaining R ^A , if present, is independently halogen, -OH, -CN, C _1-4 alkyl, C 1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy, C _{3-4 cycloalkyl or (C 3-4 cycloalkyl)-C 1-4 alkyl-, where each of C 1-4 alkyl, C 3-4 cycloalkyl and (} C _3-4 cycloalkyl)-C 1-4 alkyl- is halogen, -OH, -CN, C _1-4 alkyl, C 1-4 alkoxy, C 1-4 haloalkoxy, C _{3-4 cycloalkyl or (C 3-4 cycloalkyl} )-C _1-4 alkyl-. This is a further embodiment of Embodiment A18, optionally substituted with _{1, 2, 3, 4 or 5 substituents each independently selected from 1-4} haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy.

Embodiment A20 is an embodiment in which two R ^A are adjacent and together with the two ring atoms of the 5-membered heteroaryl to which they are attached form a fused 5- or 6-membered heterocycloalkyl optionally substituted with 1, ₂ or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C 1-4 alkoxy and C _1-4 haloalkoxy, where each remaining R ^A , if present, is independently halogen, -OH, -CN, C _1-4 alkyl, C 1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy, C 3-4 cycloalkyl or (C _3-4 cycloalkyl)-C _1-4 alkyl-, where each of C _1-4 alkyl, C _3-4 cycloalkyl and (C _3-4 cycloalkyl)-C _{1-4 alkyl- is halogen, -OH, -CN, C 1-4} alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, C _{1-4 haloalkoxy, C 3-4 cycloalkyl or (C 3-4 cycloalkyl} )-C _1-4 alkyl-. This is a further embodiment of Embodiment A18, optionally substituted with _{1, 2, 3, 4 or 5 substituents each independently selected from 1-4} haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy.

In embodiment A21,
R ¹ is R ^1a ;
R ^1a is a 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C 1-4 alkoxy, C _1-4 haloalkoxy, C _3-4 cycloalkyl or (C _3-4 cycloalkyl)-C _1-4 alkyl-, where each of the _{C 1-4} alkyl, C _3-4 cycloalkyl and (C _3-4 cycloalkyl)-C _1-4 alkyl- is optionally substituted with 1, 2, _3, 4 or 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy; or two adjacent R ^A together with the two ring atoms of the 6-membered heteroaryl to which they are attached form a fused benzene ring or a fused 5- or 6-membered heteroaryl, each of which is optionally substituted with 1, 2, or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, and C _1-4 haloalkoxy;
A further embodiment of any one of embodiments A1 to A4.

Embodiment A22 is a further embodiment of Embodiment A21 in which R ^1a is 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _{1-4 haloalkyl, C 1-4} alkoxy, C _1-4 haloalkoxy, C _3-4 cycloalkyl or (C _3-4 cycloalkyl)-C _{1-4 alkyl-, where each of C 1-4 alkyl, C 3-4 cycloalkyl and (C 3-4 cycloalkyl)-C 1-4 alkyl- is optionally substituted with 1, 2, 3, 4 or} 5 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy and C _1-4 haloalkoxy.

Embodiment A23 is a further embodiment of Embodiment A21 wherein R ^1a is 6-membered heteroaryl optionally substituted with 1, 2, 3 or 4 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _{1-4 alkoxy, C 1-4 haloalkoxy, or C 3-4 cycloalkyl .}

[0033] Embodiment A24 is a further embodiment of any one of Embodiments A21 to A23, wherein each of the ring-forming atoms of the 6-membered heteroaryl of R ^1a is a carbon or nitrogen atom. In a further embodiment, one, two or three of the ring-forming atoms of the 6-membered heteroaryl of R ^1a are nitrogen atoms (and the remainder of the ring-forming atoms are carbon atoms).

Embodiment A25 is a further embodiment of any one of Embodiments A21 through A23 wherein R ^1a is pyridinyl, pyridazinyl, pyrazinyl or pyrimidinyl, each of which is optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl.

Embodiment A26 is a further embodiment of any one of Embodiments A21 through A23 wherein R ^1a is pyridin-2-yl, pyridin-3-yl, pyridazin-3-yl, pyridazin-4-yl, pyrazin-2-yl, pyrimidin-2-yl, pyrimidin-4-yl, or pyrimidin-5-yl, each of which is optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy, or C _3-4 cycloalkyl.

Embodiment A27 is a further embodiment of any one of Embodiments A21 through A23 wherein R ^1a is pyrimidinyl optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, --OH, --CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy, or C _3-4 cycloalkyl.

Embodiment A28 is a further embodiment of any one of Embodiments A21 through A23 wherein R ^1a is pyrimidin-2-yl optionally substituted with 1 or 2 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _{1-4 alkoxy, C 1-4 haloalkoxy, or C 3-4 cycloalkyl .}

Embodiment A29 is a further embodiment of any one of Embodiments A21 to A23, wherein R ^1a is pyrimidin-2-yl.

Embodiment A30 is a further embodiment of any one of Embodiments A1 through A4 wherein R ¹ is phenyl, where the phenyl is substituted with three or four independently selected R ^B , where two adjacent R ^B , together with the two ring-forming atoms of the phenyl to which they are attached, form a fused 5- or 6-membered heteroaryl, each of which is optionally substituted with 1, ₂ or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C 1-4 alkoxy and C _1-4 haloalkoxy, and where each remaining R ^B is independently halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl.

Embodiment A31 is a further embodiment of Embodiment A30 in which R ¹ is _1,2 -benzoxazolyl (e.g., 2 _- benzoxazol-6-yl) or 1,3-benzothiazolyl (e.g., 1,3 _{-benzothiazol-5-yl), each optionally substituted with 1, 2} , or 3 substituents each independently selected from halogen, —OH, —CN, C _1-4 alkyl, C 1-4 haloalkyl, C 1-4 alkoxy, and C 1-4 haloalkoxy.

Embodiment A32 is a further embodiment of any one of Embodiments A1 through A4 wherein R ¹ is phenyl, where the phenyl is substituted with R ^B1 and optionally substituted with 1, 2 or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy, and C _3-4 cycloalkyl.

Embodiment A33 is a further embodiment of Embodiment A32 in which R ^B1 is 1,3,4-oxadiazolyl (e.g., 1,3,4-oxadiazol-2-yl), 1,2,4-oxadiazolyl (e.g., 1,2,4-oxadiazol-3-yl), or 1,3-oxazolyl (e.g., _1,3 -oxazol-5-yl), each of which is optionally substituted with 1 _{, 2} , or 3 substituents each independently selected from halogen, —OH, —CN, C _1-4 alkyl, C 1-4 haloalkyl, C _{1-4 alkoxy, C 1-4 haloalkoxy, and C 3-4} cycloalkyl.

Embodiment A34 is a further embodiment of any one of Embodiments A1 through A3, and A5 through A33, wherein ^X1 is _CH2 .

Embodiment A35 is a further embodiment of any one of Embodiments A1 through A3, and A5 through A33, wherein X ¹ is CH(CH ₃ ).

Embodiment A36 is a further embodiment of any one of Embodiments A1 through A35, wherein each of R ² and R ³ is independently H, F, or C _1-4 alkyl.

Embodiment A37 is a further embodiment of any one of Embodiments A1 through A35, wherein each of R ² and R ³ is independently H, F, or C _1-2 alkyl.

Embodiment A38 is a further embodiment of any one of Embodiments A1 through A35, wherein each of R ² and R ³ is independently H or C _1-4 alkyl.

Embodiment A39 is a further embodiment of any one of Embodiments A1 through A35, wherein each of R ² and R ³ is independently H or C _1-2 alkyl.

Embodiment A40 is a further embodiment of any one of Embodiments A1 through A35, wherein each of ^R2 and ^R3 is independently H or methyl.

Embodiment A41 is a further embodiment of any one of Embodiments A1 through A35, wherein R ² is C _1-4 alkyl and R ³ is H.

Embodiment A42 is a further embodiment of any one of Embodiments A1 through A35, wherein R ² is C _1-2 alkyl and R ³ is H.

Embodiment A43 is a further embodiment of any one of Embodiments A1 through A35, wherein R ² is methyl and R ³ is H.

Embodiment A44 is a further embodiment of any one of Embodiments A1 to A43, wherein each of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is independently ^CR4 .

Embodiment A45 is a further embodiment of any one of Embodiments A1 to A43, wherein one of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is N, and each of the remainder is independently ^CR4 .

Embodiment A46 is a further embodiment of any one of Embodiments A1 to A43, wherein ^Y3 is N and each of ^Y1 , ^Y2 , ^Y4 , and ^Y5 is independently ^CR4 .

Embodiment A47 is a further embodiment of any one of Embodiments A1 to A43, wherein two of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ are N, and each of the remaining Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is independently ^CR4 .

Embodiment A48 is a further embodiment of any one of Embodiments A1 to A43, wherein ^Y1 is N, ^Y3 is N, and each of ^Y2 , ^Y4 , and ^Y5 is independently ^CR4 .

Embodiment A49 is a further embodiment of any one of Embodiments A1 through A48, wherein each R ⁴ is independently H, halogen, C _1-2 alkyl, C _1-2 haloalkyl, —N(C _1-4 alkyl) ₂ , C _1-2 alkoxy, or C _1-2 haloalkoxy.

Embodiment A50 is a further embodiment of any one of Embodiments A1 through A48, wherein each R ⁴ is independently H, F, Cl, —CH ₃ , C ₁ fluoroalkyl, —OCH ₃ , or C ₁ fluoroalkoxy.

Embodiment A51 is a further embodiment of any one of Embodiments A1 through A48, wherein each R ⁴ is independently H, halogen, or C _1-2 alkoxy.

Embodiment A52 is a further embodiment of any one of Embodiments A1 through A48, wherein each R ⁴ is independently H, F, Cl, or —OCH ₃ .

Embodiment A53 is a further embodiment of any one of Embodiments A1 through A48, wherein each R ⁴ is independently H, F or —OCH ₃ .

Embodiment A54 is
R ¹ is R ^1a ;
R ^1a is pyrazolyl, 1,2,4-triazolyl, 1,2,3-triazolyl, tetrazolyl, 1,2-thiazolyl, 1,3,4-thiadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-oxadiazolyl, 1,2,4-oxadiazolyl, 1,3-thiazolyl, imidazolyl, pyrazolo[1,5-a]pyrimidinyl or [1,2,4]triazolo[1,5-a]pyridinyl-, each of which is optionally substituted by 1, 2 or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _{1-4 haloalkoxy and C 3-4} cycloalkyl _;
^X1 is _CH2 or CH( _CH3 );
R ² is C _1-2 alkyl and R ³ is H;
one of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is N, and the remaining ones of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ are each independently ^CR4 ;
each R ⁴ is independently H, F, Cl, -CH ₃ , C ₁ fluoroalkyl, -OCH ₃ or C ₁ fluoroalkoxy;
A further embodiment of any one of embodiments A1 to A3.

Embodiment A55 is
R ¹ is R ^1a ;
R ^1a is 1,2,4-triazolyl, 1,2,3-triazolyl, or tetrazolyl (e.g., 2H-tetrazol-5-yl), each of which is optionally substituted by 1, ₂ , or 3 substituents each independently selected from halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C 1-4 haloalkoxy, and C _3-4 cycloalkyl;
^X1 is _CH2 ;
R ² is C _1-2 alkyl and R ³ is H;
^Y3 is N, and each of ^Y1 , ^Y2 , ^Y4 and ^Y5 is independently ^CR4 ;
each R ⁴ is independently H, F, Cl, -CH ₃ , C ₁ fluoroalkyl, -OCH ₃ or C ₁ fluoroalkoxy;
A further embodiment of any one of embodiments A1 to A3.

Embodiment A56 is
R ¹ is R ^1a ;
R ^1a is tetrazolyl (e.g., 2H-tetrazol-5-yl) optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl (e.g., R ^1a is 2H-tetrazol-5-yl substituted with C _1-4 alkyl such as methyl);
^X1 is _CH2 ;
^R2 is methyl and ^R3 is H;
^Y3 is N, and each of ^Y1 , ^Y2 , ^Y4 and ^Y5 is independently ^CR4 ;
Each ^R4 is independently H, F, Cl or _-OCH3 ;
A further embodiment of any one of embodiments A1 to A3.

Embodiment A57 is
R ¹ is R ^1a ;
R ^1a is pyrazolyl (e.g., 1H-pyrazol-4-yl) optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl (e.g., R ^1a is 1H-pyrazol-4-yl substituted with C _1-4 alkyl such as methyl);
^X1 is _CH2 ;
^R2 is methyl and ^R3 is H;
^Y3 is N, and each of ^Y1 , ^Y2 , ^Y4 and ^Y5 is independently ^CR4 ;
each R ⁴ is independently H, F, Cl, or —OCH ₃ (e.g., each R ⁴ is independently H, F, or —OCH ₃ );
A further embodiment of any one of embodiments A1 to A3.

Embodiment A58 is
R ¹ is R ^1a ;
R ^1a is pyridinyl, pyridazinyl, pyrazinyl or pyrimidinyl, each of which is optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, _{C 1-4} haloalkyl, C 1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl;
^X1 is _CH2 or CH( _CH3 );
R ² is C _1-2 alkyl and R ³ is H;
one of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is N, and the remaining ones of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ are each independently ^CR4 ;
Each ^R4 is independently H, F, Cl, _-CHF2 or _-OCH3 ;
A further embodiment of any one of embodiments A1 to A3.

Embodiment A59 is
R ¹ is R ^1a ;
R ^1a is pyridinyl, pyridazinyl, pyrazinyl or pyrimidinyl, each of which is optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, _{C 1-4} haloalkyl, C 1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl;
^X1 is _CH2 ;
R ² is C _1-2 alkyl and R ³ is H;
^Y3 is N, and each of ^Y1 , ^Y2 , ^Y4 and ^Y5 is independently ^CR4 ;
Each ^R4 is independently H, F or _-OCH3 ;
A further embodiment of any one of embodiments A1 to A3.

Embodiment A60 is
R ¹ is R ^1a ;
R ^1a is pyrimidinyl (e.g., pyrimidin-2-yl) optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl (e.g., R ^1a is unsubstituted pyrimidin-2-yl);
^X1 is _CH2 ;
^R2 is methyl and ^R3 is H;
^Y3 is N, and each of ^Y1 , ^Y2 , ^Y4 and ^Y5 is independently ^CR4 ;
each R ⁴ is independently H, F, Cl, or —OCH ₃ (e.g., each R ⁴ is independently H, F, or —OCH ₃ );
A further embodiment of any one of embodiments A1 to A3.

Embodiment A61 is
R ¹ is R ^1a ;
R ^1a is [1,2,4]triazolo[1,5-a]pyridin-2-yl optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, C _1-4 haloalkyl, C _1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl (e.g., R ^1a is unsubstituted [1,2,4]triazolo[1,5-a]pyridin-2-yl);
^X1 is _CH2 ;
^R2 is methyl and ^R3 is H;
^Y3 is N, and each of ^Y1 , ^Y2 , ^Y4 and ^Y5 is independently ^CR4 ;
each R ⁴ is independently H, F, Cl, or —OCH ₃ (e.g., each R ⁴ is independently H, F, or —OCH ₃ );
A further embodiment of any one of embodiments A1 to A3.

Embodiment A62 is
R ¹ is R ^1a ;
R ^1a is pyridinyl, pyridazinyl, pyrazinyl or pyrimidinyl, each of which is optionally substituted with 1, 2 or 3 independently selected R ^A , where each R ^A is halogen, -OH, -CN, C _1-4 alkyl, _{C 1-4} haloalkyl, C 1-4 alkoxy, C _1-4 haloalkoxy or C _3-4 cycloalkyl;
^X1 is _CH2 or CH( _CH3 );
R ² is C _1-2 alkyl and R ³ is H;
Each of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is independently ^CR4 ;
each ^R4 is independently H, F, Cl, _-CH3 , _-CF3 , _-CHF2 or _-OCH3 ;
A further embodiment of any one of embodiments A1 to A3.

Embodiment A63 is
^R1 is H;
^X1 is _CH2 or CH( _CH3 );
each of R ² and R ³ is independently H or C _1-2 alkyl (e.g., each of R ² and R ³ is H);
Each of Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ is independently ^CR4 ;
each R ⁴ is independently H, F, Cl, -CH ₃ , -CF ₃ , -CHF ₂ or -OCH ₃ (e.g., each R ⁴ is independently H or F, e.g., one of R ⁴ is F and each remaining R ⁴ is H);
A further embodiment of any one of embodiments A1 to A3.

Embodiment A64 (a further embodiment of embodiment A1) provides a compound or a pharma- ceutically acceptable salt thereof (or a parent compound thereof, e.g., if the exemplary compound is a salt) selected from Examples 1 to 201 in the Examples section described herein.

Embodiment A65 (a further embodiment of embodiment A1) is
2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-[6-(difluoromethoxy)pyridin-3-yl]-1-[7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
1-[7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one;
1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one;
2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
The present invention provides a compound selected from 2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl]propan-1-one; and 2-(5-fluoro-2-methoxypyridin- ⁴ - _yl )-1-{7-methyl-6-[(4,6-2H2)pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl}propan-1-one, or a pharma- ceutically acceptable salt thereof.

Embodiment A66 (a further embodiment of embodiment 1) is
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one;
1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl]propan-1-one; and (2R)-2-(5-fluoro-2-methoxypyridin-4- _yl )-1-{(2S)-7-methyl-6-[( ^4,6-2H2 )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl}propan-1-one, or a pharma- ceutically acceptable salt thereof.

Embodiment A67 (a further embodiment of embodiment A1) is
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one, DIAST-1;
2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one, DIAST-1;
2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one, DIAST-2;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-1;
1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-1;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1; and (2R)-2-(5-fluoro-2-methoxypyridin-4- _yl )-1-{(2S)-7-methyl-6-[( ^4,6-2H2 )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl}propan-1-one, or a pharma- ceutically acceptable salt thereof.

Embodiment A68 (a further embodiment of embodiment A1) provides a compound that is (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, or a pharma- ceutically acceptable salt thereof.

Embodiment A69 (a further embodiment of embodiment A1) provides a compound that is (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one.

Embodiment A70 (a further embodiment of embodiment A69) provides a crystalline form of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one. In a further embodiment of embodiment A70, the crystalline form exhibits a powder X-ray diffraction pattern including at least one characteristic peak selected from those at 8.7±0.2°, 11.1±0.2°, and 13.3±0.2° in terms of 2θ.

In a further embodiment of embodiment A70, the crystalline form is Form I described herein in Example 14. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least one characteristic peak at 8.7±0.2° in 2θ-view. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least one characteristic peak at 11.1±0.2° in 2θ-view. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least one characteristic peak at 13.3±0.2° in 2θ-view. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks selected from those at 8.7±0.2°, 11.1±0.2° and 13.3±0.2° in 2θ-view. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising two characteristic peaks selected from those at 8.7±0.2° and 11.1±0.2° in 2θ-view. In some embodiments, Form I exhibits an X-ray powder diffraction pattern comprising at least three characteristic peaks selected from those at 8.7±0.2°, 11.1±0.2°, and 13.3±0.2° in terms of 2θ.

In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks selected from those at 8.7±0.2°, 11.1±0.2°, and 26.0±0.2° in 2θ terms. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks selected from those at 8.7±0.2° and 26.0±0.2° in 2θ terms. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks selected from those at 11.1±0.2° and 26.0±0.2° in 2θ terms. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least three characteristic peaks selected from those at 8.7±0.2°, 11.1±0.2°, and 26.0±0.2° in 2θ terms.

In some embodiments, Form I exhibits an X-ray powder diffraction pattern in 2θ view that includes at least two characteristic peaks, such as those listed in Table X1. In some embodiments, Form I exhibits an X-ray powder diffraction pattern in 2θ view that includes at least three characteristic peaks, such as those listed in Table X1. In some embodiments, Form I exhibits an X-ray powder diffraction pattern in 2θ view that includes at least four (e.g., 4, 5, 6, 7, 8, 9, or 10) characteristic peaks, such as those listed in Table X1.

In some embodiments, Form I exhibits a powder X-ray diffraction pattern substantially as shown in FIG. 1.

Each embodiment, example, or pharma- ceutically acceptable salt thereof may be claimed individually or grouped together in any combination with any number of any and all of the embodiments described herein.

The spirocyclic compounds of formula I of the present invention (which further include compounds of formula Ia, II or III) may be used in any of the pharmaceutical compositions, uses and methods of the invention described herein.

The compounds of formula I of the present invention, or pharma- ceutically acceptable salts thereof, are MC4R antagonists. Thus, the present invention further provides a method for antagonizing MC4R (either in vitro or in vivo), comprising contacting (including incubating) MC4R with a compound of formula I described herein, or a pharma- ceutically acceptable salt thereof (such as one selected from embodiments A1-A70 or examples 1-201 herein).

The amount of a compound of formula I or a pharma- ceutically acceptable salt thereof used in any one of the methods (or uses) of the invention is effective to antagonize MC4R.

Another embodiment of the invention includes the use of a compound of formula I or a pharma- ceutically acceptable salt of said compound (such as selected from embodiments A1-A70 or examples 1-201 herein) as a medicament, particularly where the medicament is for use in the treatment of an MC4R-associated condition, disease or disorder, comprising administering a therapeutically effective amount to a mammal, such as a human, in need of such treatment.

Another embodiment of the invention includes the use of a compound of formula I or a pharma- ceutically acceptable salt of said compound (such as selected from embodiments A1-A70 or examples 1-201 herein) in the manufacture of a medicament for treating an MC4R-associated condition, disease or disorder, comprising administering a therapeutically effective amount to a mammal, such as a human, in need of such treatment.

Another embodiment of the invention is directed to the use of a compound as a medicament comprising administering to a mammal, such as a human, in need of such treatment a therapeutically effective amount of or a pharma- ceutically acceptable salt of the compound, in particular for the treatment of cachexia (e.g., cachexia associated with a chronic disease, including, for example, cachexia associated with cancer, cachexia associated with acquired immune deficiency syndrome (AIDS), cachexia associated with heart failure, including, for example, cachexia associated with congestive heart failure (CHF), cachexia associated with chronic kidney disease (CKD); cachexia associated with the treatment of a chronic disease, including, for example, cachexia associated with cancer treatment or cachexia associated with heart failure (e.g. CHF) treatment); anorexia or anorexia nervosa (e.g., anorexia in the elderly, cachexia associated with chemotherapy and/or radiation therapy); The present invention includes the use of a compound of formula I or a pharmacologic acceptable salt thereof (such as those selected from embodiments A1-A70 or examples 1-201 herein) for use in the treatment of a condition, disease or disorder selected from: anorexia resulting from chronic obesity; nausea; vomiting; weight loss (e.g., involuntary weight loss); failure to thrive; sarcopenia; muscle wasting; muscle weakness; frailty; osteoporosis; bone disorders (e.g., bone loss); pain; neuropathic pain; anxiety (e.g., post-traumatic stress disorder or PTSD); depression; hypertension; malnutrition; obesity (e.g., sarcopenia resulting from chronic obesity); sexual dysfunction; and inflammatory disorders (e.g., anorexia or cachexia or sarcopenia or inflammatory disorders associated with muscle wasting).

Another embodiment of the invention comprises administering to a mammal, such as a human, in need of such treatment a therapeutically effective amount of a compound of formula I or a pharma- ceutically acceptable salt of said compound, for use in treating cachexia (e.g., cachexia associated with a chronic disease, including, for example, cachexia associated with cancer, cachexia associated with acquired immune deficiency syndrome (AIDS), cachexia associated with heart failure, such as cachexia associated with congestive heart failure (CHF), cachexia associated with chronic kidney disease (CKD); cachexia associated with the treatment of a chronic disease, including, for example, cachexia associated with cancer treatment or cachexia associated with heart failure (e.g. CHF) treatment); anorexia or anorexia nervosa (e.g., anorexia in the elderly, cachexia associated with chemotherapy and/or radiation therapy, anorexia); nausea; vomiting; weight loss (e.g., involuntary weight loss); growth retardation; sarcopenia; muscle wasting; muscle weakness; frailty; osteoporosis; bone disorders (e.g., bone loss); pain; neuropathic pain; anxiety (e.g., post-traumatic stress disorder or PTSD); depression; hypertension; malnutrition; obesity (e.g., sarcopenia resulting from chronic obesity); sexual dysfunction; and inflammatory disorders (e.g., anorexia or cachexia or sarcopenia or inflammatory disorders associated with muscle wasting). The present invention includes the use of a compound of formula I or a pharma- ceutical acceptable salt of the compound (such as those selected from embodiments A1-A70 or examples 1-201 herein) for the manufacture of a medicament in treating a condition, disease, or disorder selected from the group consisting of:

The compounds of the present invention may contain asymmetric or chiral centers and therefore may exist in various stereoisomeric forms. Unless otherwise specified, all stereoisomeric forms of the compounds of the present invention, as well as mixtures thereof, including racemic mixtures, are intended to form part of the present invention. In addition, the present invention encompasses all geometric and positional isomers. For example, if a compound of the present invention incorporates a double bond or a fused ring, both the cis and trans forms, as well as mixtures, are encompassed within the scope of the present invention.

The chiral compounds of the invention (and their chiral precursors) can be obtained in enantiomerically enriched form on the resin using chromatography, typically high pressure liquid chromatography (HPLC) or supercritical fluid chromatography (SFC), with an asymmetric stationary phase and a mobile phase consisting of a hydrocarbon, typically heptane or hexane, containing 0-50% isopropanol, typically 2-20%, and 0-5% alkylamine, typically diethylamine (DEA) or 0.1% isopropylamine. The eluent is concentrated to obtain the enriched mixture. When using SFC, the mobile phase may consist of a supercritical fluid, typically carbon dioxide, containing 2-50% of an alcohol such as methanol, ethanol or isopropanol.

Diastereoisomeric mixtures can be separated into their individual diastereoisomers on the basis of their physicochemical differences by methods well known to those skilled in the art, such as chromatography and/or fractional crystallization. Enantiomers can be separated by converting the enantiomeric mixture into a diastereoisomeric mixture by reaction with a suitable optically active compound (e.g., a chiral auxiliary such as a chiral alcohol or Mosher's acid chloride), separating the diastereoisomers, and converting (e.g., hydrolyzing) the individual diastereoisomers into the corresponding pure enantiomers. Enantiomers can also be separated by use of chiral HPLC columns. Alternatively, specific stereoisomers can be synthesized by using optically active starting materials, by asymmetric synthesis using optically active reagents, substrates, catalysts, or solvents, or by asymmetric transformation to convert one stereoisomer into another.

In some embodiments, the compounds of the present invention may have asymmetric carbon atoms. The carbon-carbon bonds of the compounds of formula I are represented herein by solid lines (

）、波線（

), wavy line (

）、実線楔（

), solid wedge (

）、または点線楔（

), or dotted wedge (

）を使用して描写され得る。不斉炭素原子との結合を描写するための実線の使用は、その炭素原子におけるすべての考えられる立体異性体（例えば、具体的な鏡像異性体、ラセミ混合物等）が含まれることを指し示すようになっている。不斉炭素原子との結合を描写するための実線楔または点線楔のいずれかの使用は、示されている立体異性体のみが含まれるようになっていることを指し示すようになっている。不斉炭素原子との結合を描写するための波線の使用は、（別段の定めがない限り）立体化学が不明であることを指し示すようになっている。本発明の化合物は、１個よりも多い不斉炭素原子を含有し得ることが可能である。それらの化合物において、不斉炭素原子との結合を描写するための実線の使用は、すべての考えられる立体異性体が含まれるようになっていることを指し示すようになっている。例えば、別段の記載がない限り、本発明の化合物は、鏡像異性体およびジアステレオマーとしてまたはそれらのラセミ体および混合物として存在し得ることが意図されている。本発明の化合物中の１個または複数の不斉炭素原子との結合を描写するための実線の使用および同じ化合物中の他の不斉炭素原子との結合を描写するための実線楔または点線楔の使用は、ジアステレオマーの混合物が存在することを指し示すようになっている。

). The use of a solid line to depict bonds to asymmetric carbon atoms is meant to indicate that all possible stereoisomers at that carbon atom (e.g., specific enantiomers, racemic mixtures, etc.) are included. The use of either a solid or dotted wedge to depict bonds to asymmetric carbon atoms is meant to indicate that only the stereoisomer shown is included. The use of a wavy line to depict bonds to asymmetric carbon atoms is meant to indicate that the stereochemistry is unknown (unless otherwise specified). It is possible that the compounds of the present invention may contain more than one asymmetric carbon atom. In those compounds, the use of a solid line to depict bonds to asymmetric carbon atoms is meant to indicate that all possible stereoisomers are included. For example, unless otherwise stated, it is intended that the compounds of the present invention may exist as enantiomers and diastereomers or as racemates and mixtures thereof. The use of solid lines to depict bonds to one or more asymmetric carbon atoms in the compounds of the invention and the use of solid or dotted wedges to depict bonds to other asymmetric carbon atoms in the same compound is meant to indicate that mixtures of diastereomers are present.

When a compound of the invention has two or more asymmetric centers and the absolute or relative stereochemistry is indicated in the name, the symbols R and S each refer to each asymmetric center in ascending numerical order (1, 2, 3, etc.) according to the conventional IUPAC numbering scheme for each molecule. When a compound of the invention has one or more asymmetric centers and the stereochemistry is not indicated in the name or structural formula, it is understood that the name or structure is intended to encompass all forms of the compound, including the racemate.

The compounds of the invention may contain olefin-like double bonds. When such bonds are present, the compounds of the invention exist as cis and trans configurations, as well as mixtures thereof. The term "cis" refers to the orientation of the two substituents relative to each other and to the plane of the ring (either both "up" or both "down"). Similarly, the term "trans" refers to the orientation of the two substituents relative to each other and to the plane of the ring (the substituents are on opposite sides of the ring).

The intermediates and compounds of the present invention may also exist in different tautomeric forms, and all such forms are encompassed within the scope of the present invention. The term "tautomer" or "tautomeric form" refers to structural isomers of different energies that are interconvertible via a low energy barrier. For example, proton tautomers (also known as prototropic tautomers) include interconversions via migration of a proton, such as keto-enol and imine-enamine isomerizations.

Valence tautomers involve interconversions via rearrangement of some of the bonding electrons.

All stereoisomers, geometric isomers, and tautomeric forms of the compounds of formula I, including compounds exhibiting more than one type of isomerism and mixtures thereof, are included within the scope of the claimed compounds of the present invention. Also included are acid addition or base salts in which the counterion is optically active, e.g., D-lactate or L-lysine, or racemic, e.g., DL-tartrate or DL-arginine.

The present invention includes all pharma- ceutically acceptable isotopically labeled compounds of formula I in which one or more atoms are replaced by an atom having the same atomic number but an atomic mass or mass number different from the atomic mass or mass number normally found in nature.

Examples of isotopes suitable for inclusion in the compounds of the invention include isotopes of hydrogen, such as ^2H and ^3H ; carbon, such as ^11C , ^13C and ^14C ; chlorine, such as ^36Cl ; fluorine, such as ^18F ; iodine, such as ^123I , ^124I and ^125I ; nitrogen, such as ^13N and ^15N ; oxygen, such as ^15O , ^17O and ^18O ; phosphorus, such as ^32P ; and sulfur, such as ^35S .

Certain isotopically labeled compounds of Formula I, for example those incorporating a radioactive isotope, are useful in drug and/or substrate tissue distribution studies. The radioactive isotopes tritium, i.e., ^3H , and carbon-14, i.e., ^14C , are particularly useful for this purpose in view of their ease of incorporation and ready means of detection.

Substitution with heavier isotopes such as deuterium, i.e., ^2H , may afford certain therapeutic advantages resulting from greater metabolic stability, such as increased in vivo half-life or reduced dosage requirements, and therefore may be preferable in some circumstances.

Substitution with positron emitting isotopes, such as ¹¹ C, ¹⁸ F, ¹⁵ O and ¹³ N, can be useful in Positron Emission Topography (PET) studies for examining substrate receptor occupancy.

Isotopically labeled compounds of formula I can generally be prepared by conventional techniques known to those skilled in the art or by processes similar to those described in the accompanying examples and preparations, substituting an appropriate isotopically labeled reagent for the previously used non-labeled reagent.

The compounds of the invention can be isolated and used as such or, where possible, in the form of their pharma- ceutically acceptable salts. The term "salts" refers to inorganic and organic salts of the compounds of the invention. These salts can be prepared in situ during the final isolation and purification of the compounds or by separately treating the compounds with a suitable organic or inorganic acid or base and isolating the salt so formed.

Salts encompassed within the term "pharmaceutically acceptable salts" generally refer to compounds of the invention prepared by reacting the free base with a suitable organic or inorganic acid to provide a salt of the compound of the invention that is suitable for administration to a patient. Suitable acid addition salts are formed from acids that form non-toxic salts. Examples are acetate, adipate, aspartate, benzoate, besylate, bicarbonate/carbonate, hydrogensulfate/sulfate, borate, camsylate, citrate, cyclamate, edisylate, esylate, formate, fumarate, gluceptate, gluconate, glucuronate, hexafluorophosphate, hybenzate, hydrochloride/chloride, hydrobromide/bromide, hydroiodide/iodide, isethionate, lactate. , malate, maleate, malonate, mesylate, methylsulfate, naphthylate, 2-napsylate, nicotinate, nitrate, orotate, oxalate, palmitate, pamoate, phosphate/hydrogenphosphate/dihydrogenphosphate, pyroglutamate, saccharate, stearate, succinate, tannate, tartrate, tosylate, trifluoroacetate and xinofoate salts. See, e.g., Berge et al., J. Pharm. Sci. 66, 1-19 (1977); see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley-VCH, 2002).

The compounds of formula I and pharma- ceutically acceptable salts thereof may exist in unsolvated and solvated forms. The term "solvate" is used herein to describe a molecular complex comprising a compound of formula I, or a pharma- ceutically acceptable salt thereof, and one or more pharma- ceutical acceptable solvent molecules, e.g., ethanol. The term "hydrate" is used when the solvent is water.

The currently accepted classification system for organic hydrates defines isolated site, channel or metal ion coordinated hydrates. See Polymorphism in Pharmaceutical Solids, by K. R. Morris (ed. H. G. Brittain, Marcel Dekker, 1995). Isolated site hydrates are those in which the water molecules are isolated from direct contact with each other by intervening organic molecules. In channel hydrates, the water molecules lie in lattice channels where they are adjacent to other water molecules. In metal ion coordinated hydrates, the water molecules are bound to the metal ion.

When the solvent or water is tightly bound, the complex may have a well-defined stoichiometry that is independent of humidity. However, when the solvent or water is weakly bound, such as in channel solvates and hygroscopic compounds, the water/solvent content may depend on humidity and drying conditions. In such cases, non-stoichiometry becomes the norm.

Also included within the scope of the present invention are multicomponent complexes (other than salts and solvates) in which the drug and at least one other component are present in stoichiometric or nonstoichiometric amounts. Complexes of this type include clathrates (drug-host inclusion complexes) and cocrystals. The latter are typically defined as crystalline complexes of neutral molecular components bound together through noncovalent interactions, but may also be complexes of neutral molecules and salts. Cocrystals may be prepared by melt crystallization, by recrystallization from a solvent, or by physically grinding the components together. See O. Almarsson and M. J. Zaworotko, Chem. Commun., 17, 1889-1896 (2004). For a general review of multicomponent complexes, see Haleblian, J. Pharm. Sci., 64(8), 1269-1288 (1975).

The compounds of the present invention include compounds of formula I as defined hereinbefore or pharma- ceutically acceptable salts thereof, polymorphs thereof as defined hereinafter, and isomers (including optical, geometric and tautomers), as well as isotopically labeled compounds of formula I or pharma- ceutically acceptable salts thereof.

The compounds of the invention can be administered as prodrugs. Thus, certain derivatives of compounds of formula I or pharma- ceutically acceptable salts thereof, which may themselves have little or no pharmacological activity, can be converted, e.g., by hydrolytic cleavage, upon administration into or onto the body, to compounds of formula I or pharma-ceutically acceptable salts thereof having the desired activity. Such derivatives are referred to as "prodrugs." [Further information on the use of prodrugs can be found in "Pro-drugs as Novel Delivery Systems, Vol. 14, ACS Symposium Series (T. Higuchi and W. Stella) and "Bioreversible Carriers in Drug Design", Pergamon Press, 1987 (E.B. Roche, ed., American Pharmaceutical Association).]

For example, prodrugs can be prepared by replacing suitable functional groups present in the compounds of formula I or their pharma- ceutically acceptable salts with certain moieties known to those skilled in the art as "promoieties," e.g., as described in "Design of Prodrugs" by H. Bundgaard (Elsevier, 1985).

Some examples of such prodrugs are:
(i) when the compound of formula I or a pharma- ceutically acceptable salt thereof contains an alcohol functional group (-OH), this includes ethers thereof, e.g., replacement of the hydrogen with ( _C1 - _C6 )alkanoyloxymethyl; or phosphate esters (-O- _{PO3H2 )} or sulfate esters (-O- _SO3H ) or pharma- ceutically acceptable salts thereof; and (ii) amides or carbamates of the amino functional group present in formula (I) or (II) in which the hydrogen of the amino NH group is replaced with ( _C1 - _C10 )alkanoyl or ( _C1 - _C10 )alkoxycarbonyl, respectively.

Also included within the scope of the invention are active metabolites of the compounds of formula I (including prodrugs) or their pharma- ceutically acceptable salts, i.e., compounds formed in vivo upon administration of the drug, often by oxidation or dealkylation. Some examples of metabolites according to the invention are:
(i) When a compound of formula I or a pharma- ceutically acceptable salt thereof contains a methyl group, the hydroxymethyl derivative thereof ( _-CH3 → _-CH2OH ).
and (ii) when a compound of formula I or a pharma- ceutically acceptable salt thereof contains an alkoxy group, its hydroxy derivative (-OR→-OH).
Includes.

Certain compounds of the present invention may exist in multiple crystalline forms (generally referred to as "polymorphs"). Polymorphs may be prepared under various conditions, such as crystallization using different solvents or different solvent mixtures for recrystallization; crystallization at different temperatures; and/or various cooling modes ranging from very fast to very slow cooling during crystallization. Polymorphs may be obtained by heating or melting the compounds of the present invention, followed by slow or fast cooling. The presence of polymorphs may be determined by solid probe NMR spectroscopy, IR spectroscopy, differential scanning calorimetry, powder X-ray diffraction or other such techniques.

In general, the compounds of the invention can be made by processes that include processes similar to those known in the chemical arts, particularly in light of the description contained herein. Certain processes for the manufacture of the compounds of the invention are provided as further features of the invention and are illustrated by the reaction schemes below. Other processes may be described in the experimental section. Specific synthetic schemes for the preparation of compounds of formula I or pharma-ceutically acceptable salts thereof are outlined below. It should be noted that tetrazoles are generally high energy functional groups and care should be taken in the synthesis and handling of tetrazole-containing molecules.

The compounds of the present invention can be synthesized by synthetic routes that include processes similar to those well known in the chemical arts, particularly in light of the description contained herein. The starting materials are generally available from commercial sources such as MilliporeSigma (Milwaukee, WI) or are readily prepared using methods well known to those of skill in the art [e.g., Louis F. Fieser and Mary Fieser, Reagents for Organic Synthesis, vols. 1-19, Wiley, New York (eds. 1967-1999), or Beilstein's Handbuch der Organischen Chemie, 4th ed., Springer-Verlag, Berlin (also available through the Beilstein online database), including supplements. Many of the compounds used herein are related to or derived from compounds of great scientific interest and practical demand, and therefore many such compounds are commercially available or reported in the literature, or are easily prepared from other commercially available materials by methods reported in the literature.

In preparing compounds of formula I or their salts, it should be noted that some of the preparation methods described herein may require protection of remote functional groups (e.g., primary amines, secondary amines, carboxyls in the formula I precursor). The need for such protection will vary depending on the nature of the remote functional group and the conditions of the preparation method. The need for such protection is readily determined by one of ordinary skill in the art. The use of such protection/deprotection methods is also within the skill of one of ordinary skill in the art. For a general overview of protecting groups and their use, see T. W. Greene, Protective Groups in Organic Synthesis, 5th Edition, John Wiley & Sons, New York, 2014. For example, certain compounds contain primary amine or carboxylic acid functional groups that, if left unprotected, may interfere with reactions at other sites on the molecule. Thus, such functional groups may be protected by appropriate protecting groups that can be removed in a subsequent step. Suitable protecting groups for amine and carboxylic acid protection include protecting groups commonly used in peptide synthesis (such as N-tert-butoxycarbonyl (Boc), benzyloxycarbonyl (Cbz) and 9-fluorenylmethoxycarbonyl (Fmoc) for amines and lower alkyl or benzyl esters for carboxylic acids), which are generally not chemically reactive under the reaction conditions described and can typically be removed without chemically altering other functional groups in the compound of Formula I.

Reactions can be monitored according to any suitable method known in the art, for example, product formation can be monitored by spectroscopic means such as nuclear magnetic resonance spectroscopy (e.g., ¹ H or ¹³ C), infrared spectroscopy, spectrocolorimetry (e.g., UV-Vis), mass spectrometry, or by chromatographic methods such as high performance liquid chromatography (HPLC) or thin layer chromatography (TLC).

The compounds of formula I, their salts and intermediates may be prepared according to the following reaction schemes and accompanying discussion. The reaction schemes described below are intended to provide an overview of the methodology employed in the preparation of the compounds of the invention. Some of the compounds of the invention will contain a single chiral center with stereochemical designation (R or S) while others will contain two separate chiral centers with stereochemical designation (R or S). It will be apparent to those skilled in the art that most of the synthetic transformations can be carried out in a similar manner whether the materials are enantiomerically enriched or racemic. Furthermore, resolution to the desired optically active materials can occur at any desired point in the sequence using well-known methods such as those described herein and in the chemical literature.

Unless otherwise indicated, R ¹ , R ² , R ³ , X ¹ , Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and structural formula I (including Ia, II) in the reaction schemes and discussion that follow are as defined herein or are consistent with those described herein. Generally, the compounds of the present invention can be made by processes that include processes similar to those known in the chemical arts, particularly in light of the description contained herein. Certain processes for the preparation of the compounds of the present invention and intermediates thereof are provided as further features of the present invention and are illustrated by the reaction schemes below. Other processes are described in the experimental section. The schemes and examples provided herein (including the corresponding descriptions) are for illustrative purposes only and are not intended to limit the scope of the present invention.

In the reaction schemes that follow, the variables ^Xc , ^X2 , X3, ^X4 , ^X5 , ^X6 , ^X7 , ^X8 , ^X9 , ^R5 , ^R6 , ^R7 , ^R8 , ^R9 , ^R10 , ^R11 , ^R12 , ^R13 , ^R14 , ^LG1 , ^LG2 , ^LG3 , ^LG4 , ^PG1 , ^PG2 , ^PG3 , ^PG4 , ^PG5 , ^PG6 , ^{PG7 ,} and ^PG8 are as described herein or in accordance with formula I as described in the claims unless otherwise noted. For each of the variables, the meaning remains the same as originally described unless otherwise indicated later.

Scheme 1 refers to the synthesis of compounds of formula I, Ia and II. Acids of formula 1-1 can be reacted with amines of formula 1-2 (or salts thereof) using standard amidation conditions with coupling reagents such as 1,1'-carbonyldiimidazole, 2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphinane 2,4,6-trioxide (T3P), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU) and others to give compounds of formula I. Alternatively, acids of formula 1-1 can be reacted in a similar manner with amines of formula 1-3 to form compounds of formula Ia. Acids of formula 1-1 can be purchased or can be obtained from Org. Process Res. Dev. 1997, 1, 72 or as described herein. Amines of formula 1-2 can be synthesized as described herein. Compounds of formula I that contain mixtures of enantiomers or diastereomers can be separated using supercritical fluid chromatography or reverse phase chromatography using chiral columns if it is necessary to separate them into the individual diastereomers or enantiomers as desired to produce compounds of formula Ia or II.

Scheme 2 describes an alternative synthesis of compounds of formula II when a single enantiomer of an acid of formula 2-1 (a subtype of the acid of formula 1-1) is used. Some acids of formula 2-1 can be racemized or epimerized under some common amidation conditions as described in Scheme 1. Alternatively, a high enantiomeric excess can be maintained throughout the reaction by using lower temperatures, using a solvent to aid in dissolving the reactants, using additives such as imidazolium or pyridinium salts or other methods as described in Org. Process Res. Dev. 2016, 20, 140; Org. Lett. 2012, 14, 1970; or Org. Process Res. Dev. 2009, 13, 106, or using the free base of the amine of formula 1-3. Alternatively, if typical conditions are used, or if epimerization or racemization occurs, the mixture of diastereomers formed can be separated using supercritical fluid or reverse phase chromatography with a chiral column, or as diastereomeric salts with a suitable chiral acid under typical resolution conditions to form compounds of formula II.

Scheme 3 describes a method for the selective synthesis of acids of formula 2-1 as single enantiomers. Acids of formula 3-1 can be purchased or synthesized using methods from the literature or described herein and reacted with well-known chiral auxiliaries (X ^{c )} such as Evans type (optically pure oxazolidinone), Meyers type (derived from pseudoephedrine) or others described in the literature to form intermediates of formula 3-2. Treatment of compounds of formula 3-2 with strong bases such as lithium diisopropylamide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, and alkyl halides (when R ² and/or R ³ are alkyl groups) or other electrophiles such as N-fluorobenzenesulfonimide (when R ² and/or R ³ are fluorine) can form compounds of formula 3-3 in high diastereomeric excess. Conditions for hydrolysis of the ^Xc group in compounds of formula 3-3 will depend on the particular properties, but often can be used to form compounds of formula 2-1 using reagents such as neat or aqueous potassium hydroxide, sodium hydroxide, lithium hydroxide, and the like (inorganic bases), with or without hydrogen peroxide, and protic solvents such as methanol, ethanol, and others, or aprotic solvents such as tetrahydrofuran, among others.

Scheme 4 describes a method that can be used to synthesize acids of formula 4-9 (a subtype of compounds of formula 1-1), 4-7 (a subtype of compounds of formula 2-1), or 4-8 (a subtype of compounds of formula 2-1). Aryl or heteroaryl compounds of formula 4-1, where ^X2 is a leaving group such as a halide (e.g., F, Cl, Br or I) or -OTf, can be reacted with diprotected malonates of formula 4-2, where ^PG1 can be methyl, ethyl, tert-butyl, benzyl, p-methoxybenzyl, etc. and ^PG2 can be an orthogonally removed protecting group selected from the same selection or can be the same protecting group, using S _N Ar conditions or using palladium catalysts such as palladium(II) acetate or tris(dibenzylideneacetone)dipalladium(0) [Pd ₂ (dba) ₃ ], etc. with a range of available phosphine ligands or copper catalysts such as copper(I) iodide or acidic ligands such as 2-picolinic acid, as described in Org. Lett. 2007, 9, 3469 to give intermediates of formula 4-3. Compounds of formula 4-3 can be treated with a suitable base, such as sodium hydride, lithium diisopropylamide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, potassium carbonate, cesium carbonate, and the like, followed by alkylation with alkylating agents, such as methyl iodide, ethyl iodide, and others, fluorinating agents, such as N-fluorobenzenesulfonimide, or other electrophiles, to give compounds of formula 4-4. Alternatively, compounds of formula 4-1 can be reacted with compounds of formula 4-6 to form compounds of formula 4-4 directly (under similar conditions to the conversion of compounds of formula 4-1 to compounds of formula 4-3). Removal of the protecting group of a compound of formula 4-4 can be carried out using standard methods (basic or acidic hydrolysis); or when PG ¹ or PG ² is benzyl, by using a palladium catalyst with hydrogen or a reducing source such as a formate, trialkylsilane, etc. to form an intermediate of formula 4-5. Alternatively, a compound of formula 4-4 can directly form an acid of formula 4-9 under similar conditions (to those in making a compound of formula 4-5) or conditions that may require elevated temperatures. The diacid of formula 4-5 can be monodecarboxylated using a base, acid, copper(I) oxide, heating, or other suitable conditions to provide the racemic acid of formula 4-9. The acid of formula 4-9, which contains a mixture of enantiomers, can be separated using supercritical fluid or reverse phase chromatography using a chiral column, or can be separated using methods such as those described in Org. Process Res. Dev. The diacids of formula 4-5 can be separated and isolated as diastereomeric salts with a suitable chiral acid under classical resolution conditions, such as those described in Adv. Synth. Catal., 2009, 351, 2333 (see also J. Org. Chem. 2003, 68, 7234), or one enantiomer can be selectively converted to an ester and separated to form an acid of formula 4-7 or 4-8 in high enantiomeric excess using a biocatalyst as described in Adv. Synth. Catal., 2009, 351, 2333 (see also J. Org. Chem. 2003, 68, 7234). The diacids of formula 4-5 can also be mono-decarboxylated using a biocatalyst, such as an arylmalonate decarboxylase (AMDase) enzyme, to provide a single enantiomer of a compound of formula 4-7 or 4-8 in high enantiomeric excess. For example, (a) the diacids of formula 4-5 can be mono-decarboxylated using a biocatalyst, such as an arylmalonate decarboxylase (AMDase) enzyme, to provide a single enantiomer of a compound of formula 4-7 or 4-8 in high enantiomeric excess. 1990, 112, 4077; (b) () Eur J. Biochem. 1992, 210, 475; (c) Appl. Environ. Microbiol. 2007, 73, 5676; (d) Appl. Microbiol. Biotechnol. 2016, 100, 8621.

Scheme 5 refers to the synthesis of acids of formula 5-6 (subtype of compounds of formula 1-1), 5-7 (subtype of compounds of formula 2-1), and 5-8 (subtype of compounds of formula 2-1), where R ^2c can be, for example, H, alkyl, C _3-4 cycloalkyl, etc. (see definition of R ² or R ³ ). Aryl or heteroaryl halides of formula 5-1, where X ³ is I, Br, or in some cases Cl, can be purchased or synthesized using methods well known to those skilled in the synthetic art. Aryl or heteroaryl halides of formula 5-1 can be reacted with an appropriate reagent such as n-butyl lithium, isopropyl magnesium chloride or a similar metal-containing base or magnesium metal to effect metal halogen exchange and quenched with a dicarbonyl compound of formula 5-3 to provide compounds of formula 5-4. Alternatively, arenes or heteroarenes of formula 5-2 can be directly deprotonated with similar strong bases or reagents such as lithium diisopropylamide, lithium 2,2,6,6-tetramethylpiperidide, bis(2,2,6,6-tetramethylpiperidinyl)zinc or other variations thereof and reacted with dicarbonyl compounds of formula 5-3 to form compounds of formula 5-4. Compounds of formula 5-4 can be treated with strong acids such as hydrochloric acid, sulfuric acid, boron trifluoride diethyl etherate or other Bronsted or Lewis acids to form compounds of formula 5-5. Compounds of formula 5-5 can be treated with a reducing agent such as a silane in the presence of an acid, or with hydrogen and a metal catalyst such as palladium to form compounds of formula 5-6. Alternatively, compounds of formula 5-4 can be treated with a similar acid in the presence of a reducing agent such as a silane, or with hydrogen and a metal catalyst such as palladium to form acids of formula 5-6. Alternatively, compounds of formula 5-5 can be treated with hydrogen and metals such as ruthenium or rhodium, etc., and chiral ligands, or many other methods such as those described in Org. Chem. Front. 2014, 1, 155, to selectively form acids of formula 5-7 or 5-8 in high enantiomeric excess. Alternatively, compounds of formula 5-5 can be converted with a biocatalyst such as ENE reductase (such as those described in ACS Catal. 2018, 8, 3532) or other methods to selectively form compounds of formula 5-7 or 5-8 in high enantiomeric excess. Alternatively, compounds of formula 5-6, which contain a mixture of enantiomers, can be separated using supercritical fluid or reverse phase chromatography with a chiral column, or separated and isolated under typical resolution conditions as diastereomeric salts with the appropriate chiral acid to form compounds of general formula 5-7 or 5-8.

Scheme 6 describes certain other methods for the synthesis of acids of formula 1-1 and 2-1. Compounds of formula 6-1 can be deprotonated with a strong base and acylated with carbon dioxide or carbonyl compounds of formula 6-2, where LG ¹ is a leaving group such as chloride or alkoxide and PG ¹ is a protecting group such as those described above, to form compounds of formula 6-3. In a manner similar to that described above for the conversion of compounds of formula 3-2 to compounds of formula 3-3, compounds of formula 6-3 can be deprotonated with a strong base and treated with an alkylating agent to form compounds of formula 6-4. Compounds of formula 6-4 can be treated under hydrolysis conditions, or with a metal catalyst such as palladium on carbon and hydrogen if PG ¹ is a benzyl group, or with an acid if PG 1 can be eliminated or eliminated as a stable cation to form compounds of formula 1-1, in a manner similar to that described above for the conversion of compounds of formula ^3-3 to compounds of formula 2-1, to form compounds of formula 1-1. Alternatively, the steps can be rearranged so that compounds of formula 6-3 are hydrolyzed to compounds of formula 6-5, which are then alkylated using similarly described conditions to form compounds of formula 1-1. Alternatively, compounds of formula 6-4 can be treated with biocatalytic conditions, such as an esterase enzyme, to form acids of formula 2-1 in high enantiomeric excess. Alternatively, compounds of formula 6-6 can be treated with a strong acid, such as hydrochloric acid or sulfuric acid, in the presence of an alcohol, such as methanol or ethanol, to form compounds of formula 6-3. Alternatively, compounds of formula 6-6 can be alkylated to form compounds of formula 6-7 using similar methods described for the conversion of compounds of formula 6-3 to compounds of formula 6-4. Alternatively, compounds of formula 6-7 can be directly hydrolyzed to acids of formula 1-1 using either a strong acid such as hydrochloric acid or sulfuric acid or a strong base such as sodium hydroxide, potassium hydroxide or lithium hydroxide in the presence of water. Alternatively, compounds of formula 6-8 (where ^LG2 is a leaving group such as Cl, Br, I, OMs, OTs, etc.) can be treated with a cyanide source such as sodium cyanide, trimethylsilyl cyanide, etc. to form compounds of formula 6-6. Compounds of formula 6-8 can be purchased or synthesized by a variety of methods as described in the literature, or by reacting compounds of formula 6-1 with halogenated electrophiles such as N-bromosuccinimide, bromine, etc., and radical initiating activators such as 2,2′-azobisisobutyronitrile, light, or other reagents, when LG ² is, for example, Br or Cl. Compounds of formula 6-12 (a subtype of compounds of formula 6-8 where R ² is H) can be converted to all of the analogous intermediates and compounds derived from 6-8 using similar methods. Compounds of formula 6-14 can be treated with base and alkylating agents as described for the conversion of 6-3 to 6-4 to form compounds of formula 1-1. Compounds of formula 6-11 can be purchased or synthesized using methods described in the literature. Compounds of formula 6-9 can also be oxidized using oxidizing reagents such as potassium permanganate to form compounds of formula 6-11. Compounds of formula 6-11 can be homologated to form compounds of formula 6-10 using any number of methods reported in the literature such as the Arndt-Eistert reaction (using an activating reagent such as thionyl chloride, ethyl chloroformate, etc.; followed by a diazomethane reagent; a silver salt such as silver benzoate, silver oxide, etc.; and a nucleophile such as water or an alcohol) or other methods described in the literature such as those described in J. Org. Chem. 2001, 66, 5606. Acids of formula 1-1 containing a mixture of enantiomers can be separated using supercritical fluid or reverse phase chromatography using chiral columns or as diastereomeric salts with the appropriate chiral acid under classical resolution conditions such as those described in Org. Process Res. Dev. 2011, 15, 53, or the undesired enantiomer can be isolated using methods such as those described in Adv. Synth. Catal. , 2009, 351, 2333 (see also J. Org. Chem. 2003, 68, 7234), which can be converted to the ester and separated to form the acid of formula 2-1 in high enantiomeric excess.

Scheme 7 describes the synthesis of compounds of formula 7-3, 7-4, 7-7, 7-8, 7-9 and 7-10 (where Q ¹ can be any fragment of a compound in formula I, Ia, II or described in Schemes 3-6), which can be used as any of the intermediates already described above, where appropriate, and these substituents can be placed at many points during the synthesis described in Schemes 3-6. Compounds of formula 7-1 (where PG ¹ has been described) can be deprotected using dealkylation conditions such as trimethylsilyl iodide, sodium methanethiolate, etc., strong acids such as hydrobromic acid, boron tribromide, or when PG ¹ is a benzyl group, palladium or related metals and hydrogen gas can be used to form compounds of formula 7-2. Compounds of formula 7-2 can be reacted with a difluoromethyl source such as a difluorohaloacetate or (bromodifluoromethyl)trimethylsilane to form compounds of formula 7-3. Compounds of formula 7-2 can also be reacted with a trifluoromethyl source such as a difluorohaloacetate with the addition of an electrophilic fluorine source such as Selectfluor™, a trifluoromethyl halide, or via an intermediate xanthate which can be treated with XtalFluor® and an electrophilic fluorine source such as N-fluorobenzenesulfonimide or 1,3,5-trichloro-1,3,5-triazinane-2,4,6-trione (TCCA) (as described in J. Org. Chem. 2019, 84, 15776), etc. to form compounds of formula 7-4. Compounds of formula 7-5 (where LG ³ can be Cl, Br, I, OTf, etc.) can be treated with a nucleophilic vinyl source such as vinyl boronate, vinyl stannane, etc. using palladium catalyzed cross coupling conditions described in the literature to form compounds of formula 7-6. Compounds of formula 7-6 can be oxidatively cleaved to aldehydes to form compounds of formula 7-7 using reagents such as ozone along with triphenylphosphine or dimethylsulfide, osmium tetroxide (or ruthenium trichloride) and sodium periodate, among others. Compounds of formula 7-7 can be reacted with nucleophilic difluoromethylation sources such as Deoxo-Fluor® or XtalFluor® and related reagents to form compounds of formula 7-8. Compounds of formula 7-5 can be treated with alcohols using palladium and a variety of ligands under S _N Ar or cross-coupling conditions to form compounds of formula 7-9, where R ⁸ is, for example, C _1-4 alkyl (such as methyl) or C _1-4 haloalkyl (such as C ₁ fluoroalkyl). Compounds of formula 7-5 can also be reacted with amines under similar conditions to form compounds of formula 7-10, where each of R ⁶ and R ⁷ is independently C _1-4 alkyl (such as methyl), or R ⁶ and R ⁷ together with the carbon atom to which they are attached form cyclopropyl.

Scheme 8 describes the synthesis of compounds of formula 1-2 and 1-3. Compounds of formula 8-1 (PG ⁴ can be benzyl, p-methoxybenzyl, tert-butoxycarbonyl, benzyloxycarbonyl, acetyl, benzoyl or other common nitrogen protecting groups and PG ⁵ can be the same as PG ⁴ or any similar protecting group that can be orthogonally removed) can be halogenated with electrophilic halogenating agents such as dibromohydantoin, N-bromosuccinimide, N-chlorosuccinimide, bromine, iodine, etc. to form compounds of formula 8-3 (where X ⁴ can be Cl, Br or I). Compounds of formula 8-3 are reacted with a diboron source [such as tetrahydroxydiboron, bis(neopentylglycolato)diboron (5,5,5',5'-tetramethyl-2,2'-bi-1,3,2-dioxaborinane) or bis(pinacolato)diboron (4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi-1,3,2-dioxaborolane)], a ditin source such as bis(tributyltin) and others, a strong metal-containing base such as isopropylmagnesium chloride, followed by a zinc source such as zinc dichloride and others to form compounds of formula 8-2 (where M ¹ can be a boronic acid, boronate, organotin, organozinc, or other metal capable of reacting under C-C cross coupling conditions), which can be isolated if stable or inserted into another reaction if desired. Compounds of formula 8-2 can be reacted with compounds of formula 8-9 (wherein ^X5 is Cl, Br, I, OTf, etc.) under C-C cross-coupling conditions such as Suzuki (M ¹ =boron), Stille (M ¹ =tin), Negishi (M ¹ =zinc halide), Kumada (M ¹ =magnesium halide) type reactions, etc. to form compounds of formula 8-4. Alternatively, compounds of formula 8-3 and 8-10 can be reacted with nucleophiles and electrophiles inverted in a cross-coupling reaction in a manner similar to 8-2 and 8-9 to form compounds of formula 8-4. Alternatively, in some cases, compounds of formula 8-1 can be reacted with compounds of formula 8-9 under CH activation/direct arylation conditions to form compounds of formula 8-4 directly. The PG ⁴ and PG ⁵ groups of compounds of formula 8-4 can be removed using appropriate deprotection conditions such as acid or hydrogenolysis, etc. to form compounds of formula 1-2. Note - When compounds of formula 8-1, 8-2, 8-3, 8-4 or 1-2 contain a mixture of stereochemistry or are racemic, they can be separated into single enantiomers using supercritical fluid or reverse phase chromatography with chiral columns, or separated as diastereomeric salts with appropriate chiral acids under classical resolution conditions to form compounds of formula 8-5, 8-7, 8-6, 8-8 or 1-3 in high enantiomeric excess, respectively. Alternatively, compounds of formula 8-5, 8-7, 8-6 and 8-8 can be reacted under the same conditions as their analogous intermediates from this scheme, without modification of the conditions, resulting in the formation of compounds of formula 1-3.

Scheme 9 refers to the synthesis of compounds of formula 9-13. Compounds of formula 9-1 (wherein X ⁷ is more reactive than X ⁶ , e.g., X ⁷ =Br, X ⁶ =Cl, or X ⁷ =I, X ⁶ =Br or Cl, or similar combinations) can be reacted with compounds of formula 9-2 under Sonogashira conditions using copper and palladium catalysts to form compounds of formula 9-3. Compounds of formula 9-3 can be treated with a variety of palladium, platinum, or rhodium catalysts (on carbon or alumina or free) and hydrogen, trialkylsilanes, formic acid to form compounds of formula 9-8. Compounds of formula 9-8 can be treated under standard C-N cross-coupling conditions, either with S _N Ar type conditions or with palladium or copper bearing appropriate ligands to form compounds of formula 9-4. Compounds of formula 9-8 can be directly converted to compounds of formula 9-6 under similar conditions using certain PG ⁵ groups such as carbamates and stronger bases such as sodium or potassium tert-butoxide. Alternatively, compounds of formula 9-9 (where R ¹¹ can be an arene such as phenyl or an alkyl group such as ethyl or butyl or an alcohol such as ethanol, etc., and (X ⁸ ) ^- can be OMs ^- , OTs ^- , OTf ^- , Cl ^- , Br ^- , I ^-, etc.) and compounds of formula 9-10 can be reacted together under Wittig (such as those described in Tetrahedron Lett. 2007, 48, 3359) or similar conditions using a base such as potassium carbonate, sodium tert-butoxide, n-butyllithium or a similar base to form compounds of formula 9-11. Compounds of formula 9-11 can be converted to compounds of formula 9-8 using conditions similar to those described for compounds of formula 9-3 to compounds of formula 9-8. Alternatively, compounds of formula 9-10 can be converted to compounds of formula 9-12 using an appropriate methylene Wittig salt in a manner similar to the conversion of 9-10 to 9-11. Alternatively, compounds of formula 9-11 can be reacted under photoredox isomerization conditions with a catalyst such as iridium or others with an appropriate ligand using blue LED light to form compounds of formula 9-7. Alternatively, compounds of formula 9-5 can be formed by conversion under the same photoredox conditions where compounds of formula 9-11 are reacted with a second catalyst, usually palladium, added after isomerization to achieve cyclization. Alternatively, compounds of formula 9-3 can be treated with a poisoned catalyst such as Lindlar's catalyst (such as the method in J. Org. Chem. 2001, 66, 3634) or palladium on barium sulfate with a hydrogen source, or as described in Tetrahedron Lett. 2008, 49, 2839, to form compounds of formula 9-7. Alternatively, compounds of formula 9-7 can be treated with hydrogenation conditions similar to those described for the conversion of compounds of formula 9-11 to 9-8 to form compounds of formula 9-8. Alternatively, compounds of formula 9-10 and 9-2 can be interconverted by using alkyne-forming conditions such as Corey-Fuchs et al. to form compounds of formula 9-2, or treated under oxidative cleavage conditions to form compounds of formula 9-10. Alternatively, a compound of formula 9-7 can be reacted under similar conditions as described for the conversion of a compound of formula 9-8 to a compound of formula 9-6 to form a compound of formula 9-5. A compound of formula 9-5 can be reacted under similar conditions as the conversion of a compound of formula 9-11 to a compound of formula 9-8 to form a compound of formula 9-4, 9-13 or 9-6 depending on the choice of protecting group used. Alternatively, a compound of formula 9-5 can be reacted under standard conditions for removing PG ⁵ to form a compound of formula 9-14. The compound of formula 9-14 can then be reacted under similar conditions as the conversion of a compound of formula 9-5 to a compound of formula 9-6 to form a compound of formula 9-6 or 9-13 depending on the choice of protecting group. Alternatively, a compound of formula 9-12 can be converted to a compound of formula 9-11 by using Heck-type cross-coupling conditions with a compound of formula 9-1. Alternatively, compounds of formula 9-12 and 9-1 can be converted to compounds of formula 9-15 by ^using S _N Ar or C—N cross-coupling type conditions (where X ⁶ is more reactive than X ⁷ , e.g., X ⁷ =Cl, X 6 =Cl or Br, or X ⁷ =Br, X ⁶ =Br or I, or similar combinations). Compounds of formula 9-15 can be reacted under conditions similar to those described for the conversion of compounds of formula 9-12 to compounds of formula 9-11 to form compounds of formula 9-5.

Scheme 10 describes the synthesis of compounds of formulas 10-11, subtypes of compounds of formulas 9-13, where the stereochemistry is defined. All transformations shown can be carried out as described for the analogous compounds and intermediates described in Scheme 9, without the need for modification or the use of different conditions.

Scheme 11 describes the synthesis of compounds of formula 11-6 and 11-7, which are subtypes of compounds of formula 9-2 and 10-1, respectively, where PG ⁷ is a protecting group such as benzyl, p-methoxybenzyl, etc. that leaves the adjacent nitrogen nucleophilic, or perhaps no protecting group. Compounds of formula 11-1 can be purchased or synthesized according to methods described in the literature and can be reacted with compounds of formula 11-2 (where PG ⁶ is trimethylsilyl or other suitable alkyne protecting group) deprotonated by the action of a base such as potassium tert-butoxide, lithium diisopropylamide, sodium hydride, n-butyllithium, zinc or magnesium metal to provide compounds of formula 11-3. Compounds of formula 11-3 can then be deprotected to the terminal alkyne with reagents such as tetrabutylammonium fluoride, potassium carbonate, potassium hydroxide, etc. to provide compounds of formula 11-4. The hydroxyl of a compound of formula 11-4 can be activated to a leaving group OR ⁹ (where R ⁹ is acetyl, benzoyl, tert-butoxycarbonyl, dialkylphosphate [P(O)(OAlk) ₂ ], etc.) using acetyl chloride, benzoyl chloride, other acyl halides, other suitably activated acids, or other activating groups such as haloformates, dialkyl halophosphates, etc., and bases such as triethylamine, N,N-diisopropylethylamine, pyridine, 4-(dimethylamino)pyridine, etc. to form an activated compound of formula 11-5. Compounds of formula 11-5 can be reacted with p-methoxybenzyl, benzyl, etc. protected amines in reactions catalyzed by copper(I) chloride, copper(I) bromide (such as in J. Org. Chem. 2013, 78, 5647), ruthenium catalysts (such as in New J. Chem. 2011, 35, 2427), etc. to form compounds of formula 11-6. When compounds of formula 11-6 contain a mixture of stereochemistry or are racemic, they can be separated into single enantiomers using supercritical fluid or reverse phase chromatography with chiral columns, or separated under classical resolution conditions as diastereomeric salts with appropriate chiral acids to form compounds of formula 11-7 in high enantiomeric excess.

Scheme 12 describes the synthesis of compounds of formula 9-1 and 9-9, where R ¹¹ can be an alkyl group, an aryl group, an alkoxy group or combinations thereof, or as oxide versions thereof. Compounds of formula 12-1, which can be purchased or synthesized from 12-6 or other methods described in the literature, can be treated with reducing agents such as aluminum-based hydrides (lithium aluminum hydride, sodium bis(2-methoxyethoxy)aluminum dihydride, diisobutylaluminum hydride, etc.) or borohydride-based (lithium borohydride, sodium borohydride, etc.) to form compounds of formula 12-3. Alternatively, compounds of formula 12-2, which can be purchased or formed from compounds of formula 12-1 using standard hydrolysis conditions or other methods described in the literature, can be converted to form compounds of formula 12-3 using the same reagents, but also using borane or borane-derived reagents. The OH of compounds of formula 12-3 can be activated to a leaving group (LG 4 , which can be OMs, OTs, OTf, Cl, Br, I, etc.) by using an appropriate reagent, for example, methanesulfonyl chloride, p-toluenesulfonyl chloride, triflic anhydride, phosphorus oxychloride or thionyl chloride, phosphorus oxybromide or tribromide, iodine with triphenylphosphine or imidazole, acids such as hydrobromic acid or hydrochloric acid, or by using methanesulfonyl chloride followed by a combination of methods such as sodium iodide, sodium chloride, sodium bromide, potassium iodide ^, potassium chloride, potassium bromide, etc. Alternatively, compounds of formula 12-5 can be halogenated under radical halogenation conditions such as those described for the conversion of compounds of 6-1 to 6-8 to form compounds of formula 12-4. Compounds of formula 12-4 can be reacted with compounds of formula 12-9 (e.g., triphenylphosphine, triethylphosphine, triethyl phosphite, or other phosphorus nucleophiles) to produce compounds of formula 9-9. Compounds of formula 12-6 can be nitrated under standard nitration conditions, such as fuming nitric acid, to produce compounds of formula 12-7. The nitro group of compounds of formula 12-7 can be reduced to an amine using a variety of conditions, such as palladium on carbon with hydrogen, zinc or iron with acetic acid or hydrochloric acid, tin(II) chloride, etc. to produce compounds of formula 12-8. Compounds of formula 12-8 can be treated with sodium or isoamyl nitrite with hydrobromic acid, potassium bromide, potassium iodide, or other standard Sandmeyer-type conditions to produce compounds of formula 9-1. Compounds of formula 9-1 can be treated under carbonylation conditions such as palladium with 1,1′-bis(diphenylphosphino)ferrocene, an appropriate ligand such as a carbon monoxide source and an alcohol such as ethanol or methanol, or under metal-halogen exchange conditions and quenched with an acyl source such as diethyl carbonate, carbon dioxide, ethyl chloroformate, etc. to produce compounds of formula 12-1.

Scheme 13 describes a method for synthesizing compounds of formula 9-10. Compounds of formula 13-1, where PG ⁸ can be any C-linked alkyl or aryl and can be purchased or synthesized using methods described in the literature, can be treated with conditions to eliminate the hydroxyl group, such as those using methanesulfonyl chloride or p-toluenesulfonyl chloride as described in Org. Lett. 2016, 18, 1812, or other standard conditions, to provide compounds of formula 13-2. Compounds of formula 13-2 can be reacted in a 3+2 cycloaddition with commercially available compounds of formula 13-3 to form compounds of formula 13-4. Compounds of formula 13-4 can be directly reduced to compounds of formula 9-10 using conditions such as diisobutylaluminum hydride or other reducing agents that avoid overreduction. Alternatively, compounds of formula 13-4 can be reduced to compounds of formula 13-5 using conditions similar to those described for the conversion of compounds of formula 12-1 to 12-3. Compounds of formula 13-5 can then be oxidized using a number of well-known reagents such as Collins chrome reagent, Dess-Martin periodinane reagent, Paric-Deering reagent, other activated DMSO-based Swern-type reagents, and many others, to provide compounds of formula 9-10. Alternatively, compounds of formula 13-8 can be treated with lithium diisopropylamide, lithium bis(trimethylsilyl)amide, n-butyllithium, or many other similar strong bases, and a suitable acylating reagent such as ethyl chloroformate, ethyl cyanoformate, or diethyl carbonate to form compounds of formula 13-9, where PG ⁹ can be the same as PG ⁸ , or can be a different alkyl or aryl group that can be orthogonally removed under selective conditions. Compounds of formula 13-9 can be selectively hydrolyzed to form compounds of formula 13-10 using one equivalent of base such as sodium hydroxide or lithium hydroxide, among many others, or by using a selective PG ⁹ such as benzyl, which can be removed via treatment with palladium on carbon and hydrogen. Compounds of formula 13-10 can be converted to compounds of formula 13-4 using reactions such as the Curtius rearrangement (such as that described in Org. Biomol. Chem. 2018, 16, 2006) or other similar reactions that rearrange an acid or related acyl group to a dehomologated or protected amine, such as the Hofmann rearrangement, Rossen rearrangement, or Schmidt reaction.

Scheme 14 describes methods for synthesizing compounds of formula 10-8 (a subtype of 9-10 with defined stereochemistry) and related intermediates. Racemic versions or mixtures of compounds of formula 13-4 can be separated into single enantiomers using supercritical fluid or reverse phase chromatography with chiral columns, or, if PG ⁴ or PG ⁵ is a protecting group that does not eliminate the basicity of the nitrogen to which it is attached, can also be separated using chiral acids under classical resolution conditions to give compounds of formula 14-4. Alternatively, compounds of formula 13-9 can be exposed to a variety of biocatalytic conditions, such as the esterase ECS03 (AB503574) from Enzymatics, or as described in Tetrahedron: Asymmetry 1998, 9, 2663, to form compounds of general formula 14-1 (a subtype of compounds of formula 13-10). Using the conditions described, compounds of general formula 14-1 and 14-4 can be converted to their analogous compounds as described in Scheme 13 without the need for any modifications or changes to the reaction conditions.

Scheme 15 describes the synthesis of 15-4, a subtype of compound of formula 8-4 where X ¹ is CH—CH _3. Compounds of formula 11-1 can be reacted with ammonia and allylboron reagents as described in Chem. Commun. 2005, 44, 5551 to form compounds of formula 15-1. Compounds of formula 15-1 can be reacted in a manner similar to that described for the conversion of compounds of formula 9-12 to 9-15 to provide compounds of formula 15-2. Compounds of formula 15-2 can be reacted in a manner similar to that described for the conversion of compounds of formula 9-15 to 9-5 to provide compounds of formula 15-3 with a concomitant rearrangement of the internal olefin as shown. Compounds of formula 15-3 can be converted to compounds of formula 15-4 using a similar methodology described for the conversion of compounds of formula 9-5 to 9-4. Alternatively, compounds of formula 15-2 can be reacted under ozonolysis conditions in the presence of sodium borohydride or other oxidative cleavage conditions to provide compounds of formula 15-7. Compounds of formula 15-7 can be reacted under conditions that eliminate the hydroxyl group to an olefin, such as those using methanesulfonyl chloride or p-toluenesulfonyl chloride followed by a strong base, or by using Grieco elimination conditions with aryl selenocyanates in the presence of trialkylphosphines to provide compounds of formula 15-8, which are a subtype of compounds of formula 9-15 where PG ⁵ is H.

Scheme 16 describes the synthesis of compounds of formula 16-3 (where Y ⁷ is N or CH), 16-7, 16-11 and 16-14, all of which are subtypes of 8-9 that may not be commercially available. Compounds of formula 16-1 can be reacted with an electrophilic halogen source in a manner similar to the conversion of compounds of formula 8-1 to 8-3 to form compounds of formula 16-2. Compounds of formula 16-2 can be reacted under conditions similar to the conversion of compounds of formula 7-2 to 7-3 (when R ¹² is H) or compounds of formula 7-2 to 7-4 (when R ¹² is F) to provide compounds of formula 16-3. Compounds of formula 16-4, where X ⁹ can be the same halogen as X ⁵ , or can be more reactive such that X ⁹ is Br when X ⁵ is Cl, or I when X ⁵ is ^Br or Cl, can be reacted under Chang-Lam type conditions with cyclopropylboronic acid (when R ¹³ is cyclopropyl) and a copper source such as copper(II) acetate or others and a suitable ligand such as 2,2′-bipyridine, and any number of bases such as carbonates or amines, and a co-oxidant such as oxygen, which can be added or derived from the air, to produce compounds of formula 16-5. Compounds of formula 16-5 (which can be purchased or made as described herein or in the literature, such as when R ¹³ is methyl) can be reacted under metal-halogen exchange conditions such as isopropylmagnesium chloride, n-butyllithium, magnesium, etc., and quenched with a carbonyl source such as N,N-dimethylformamide, morpholine-4-carbaldehyde, etc., to produce compounds of formula 16-6. Compounds of formula 16-6 can be reacted under conditions similar to the conversion of compounds of formula 7-7 to 7-8 to produce compounds of formula 16-7. Compounds of formula 16-4 can be reacted with 4-halo-1-butenes in the presence of a base such as potassium carbonate, sodium bicarbonate, sodium hydride, lithium diisopropylamide, etc., to produce compounds of formula 16-8. Compounds of formula 16-8 can be reacted under Heck-like conditions as described for the conversion of compounds of formula 9-15 to 9-5 to produce compounds of formula 16-9. Compounds of formula 16-9 can be reacted through several steps in a similar manner as described for the sequence converting compounds of formula 7-6 to 7-7 to 7-8 to form compounds of formula 16-10 and 16-11. Compounds of formula 16-12 (wherein X ¹⁰ can be Cl, Br, or I, OTf, etc.) can be reacted with palladium on carbon or other common catalysts and deuterium gas (or other deuterium sources such as deuterated formates under transfer hydrogenation conditions) to form compounds of formula 16-13. Compounds of formula 16-13 can be reacted under similar Sandmeyer-type conditions as described for the conversion of compounds of formula 12-8 to 9-1 to produce compounds of formula 16-14. Alternatively, compounds of formula 16-15 can be reacted under similar Sandmeyer-type conditions as described for the conversion of compounds of formula 12-8 to 9-1.

Scheme 17 describes a method for the synthesis of compounds of formula 17-5, which are a subtype of compounds of formula 8-4, where R ¹ is a tetrazole substituted with R ¹⁴ , which is an optionally substituted alkyl or aryl group. Compounds of formula 17-1 can be reacted via transformations similar to those described for the synthesis of compounds of formula 7-5 to 7-6 and 7-7 to form compounds of formula 17-2 and 17-3. Alternatively, compounds of formula 17-1 can be directly converted to compounds of formula 17-3 in a manner similar to the conversion of compounds of formula 16-5 to compounds of formula 16-6. Compounds of formula 17-3 can be reacted with substituted hydrazines under standard condensation conditions using acid or base catalysis to form compounds of formula 17-4. Compounds of formula 17-4 can be reacted with a diazo compound such as diethyl or di-tert-butyl azodicarboxylate in the presence of a hypervalent iodine source such as [bis(trifluoroacetoxy)iodo]benzene, etc. to produce compounds of formula 17-5.

Detailed descriptions of the individual reaction steps are provided in the Examples section below. Those of skill in the art will recognize that other synthetic routes can be used to synthesize the compounds. Although specific starting materials and reagents are discussed below, other starting materials and reagents can be readily substituted to provide a variety of derivatives and/or reaction conditions. In addition, many of the compounds prepared by the methods described below can be further modified in light of this disclosure using conventional chemistry well known to those of skill in the art.

Combination The compound of the present invention can be administered alone or in combination with one or more additional therapeutic agents. By "administered in combination" or "combination therapy" is meant that the compound of the present invention and one or more additional therapeutic agents are administered simultaneously to the mammal being treated. When administered in combination, each component may be administered simultaneously or sequentially in any order at different times. Thus, each component may be administered separately but sufficiently close in time to provide the desired therapeutic effect. The phrases "concurrent administration", "co-administration", "simultaneous administration" and "administered at the same time" mean that the compounds are administered in combination. Thus, the methods of prevention and treatment described herein include the use of combinations.

The combination is administered to a mammal in a therapeutically effective amount. By "therapeutically effective amount" is meant an amount of a compound of the present invention that, when administered to a mammal alone or in combination with an additional therapeutic agent, is effective to treat the desired disease/disorder/condition (e.g., cachexia, anorexia, anorexia nervosa, nausea; vomiting, growth retardation, sarcopenia, muscle wasting, frailty, osteoporosis, bone loss, pain, anxiety, depression, or hypertension).

In some embodiments, the compounds of the present invention may be administered in combination with one or more other agents, including, but not limited to, orlistat, TZDs and other insulin sensitizers, FGF21 analogs, metformin, omega-3-acid ethyl esters (e.g., Lovaza), fibrates, HMG CoA-reductase inhibitors, ezetimibe, probucol, ursodeoxycholic acid, TGR5 agonists, FXR agonists, vitamin E, betaine, pentoxifylline, CB1 antagonists, carnitine, N-acetylcysteine, reduced glutathione, lorcaserin, combinations of naltrexone and bupropion, SGLT2 inhibitors (dapagliflozin, canaglyptophan), naphthalene, ... gliflozin, empagliflozin, tofogliflozin, ertugliflozin, ASP-1941, THR1474, TS-071, ISIS 388626 and LX4211 and those in WO2010023594), phentermine, topiramate, GLP-1 receptor agonists, GIP receptor agonists, dual GLP-1 receptor/glucagon receptor agonists (e.g., O PK88003, MEDI0382, JNJ-64565111, NN9277, BI456906), dual GLP-1 receptor/GIP receptor agonists [e.g., tirzepatide (LY3298176), NN9423], angiotensin receptor blockers, acetyl-CoA carboxylase (ACC) inhibitors, BCKDK inhibitors, ketohexokinase (KHK) inhibitors, ASK1 inhibitors, It may be co-administered with a branched-chain alpha keto acid dehydrogenase kinase inhibitor (BCKDK inhibitor), an inhibitor of CCR2 and/or CCR5, a PNPLA3 inhibitor, a DGAT1 inhibitor, a DGAT2 inhibitor, an FGF21 analog, an FGF19 analog, a PPAR agonist, an FXR agonist, an AMPK activator [e.g., ETC-1002 (bempedoic acid)], an SCD1 inhibitor, or an MPO inhibitor.

Exemplary GLP-1 receptor agonists include liraglutide, albiglutide, exenatide, albiglutide, lixisenatide, dulaglutide, semaglutide, HM15211, LY3298176, Medi-0382, NN-9924, TTP-054, TTP-273, epheglenatide, those described in WO2018109607, those described in PCT/IB2019/054867, filed June 11, 2019, and those described in PCT/IB2019/054961, filed June 13, 2019, including:
2-({4-[2-(4-chloro-2-fluorophenyl)-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-7-fluoro-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(4-chloro-2-fluorophenyl)-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(4-chloro-2-fluorophenyl)-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-7-fluoro-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-cyano-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(5-chloropyridin-2-yl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-3-(1,3-oxazol-2-ylmethyl)-3H-imidazo[4,5-b]pyridine-5-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(1-ethyl-1H-imidazol-5-yl)methyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-(1,3-oxazol-4-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-(pyridin-3-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-(1,3-oxazol-5-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(1-ethyl-1H-1,2,3-triazol-5-yl)methyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-(1,3-oxazol-2-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-chloro-2-fluorophenyl)-7-fluoro-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(4-cyano-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-(1,3-oxazol-2-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-7-fluoro-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-7-fluoro-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(4-cyano-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(5-chloropyridin-2-yl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(1-ethyl-1H-imidazol-5-yl)methyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2R)-2-(4-chloro-2-fluorophenyl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(1-ethyl-1H-imidazol-5-yl)methyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(5-chloropyridin-2-yl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2S)-2-(5-chloropyridin-2-yl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[(2R)-2-(5-chloropyridin-2-yl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-({4-[2-(5-chloropyridin-2-yl)-2-methyl-1,3-benzodioxol-4-yl]piperidin-1-yl}methyl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid, DIAST-X2;
2-[(4-{2-[(4-chloro-2-fluorobenzyl)oxy]pyridin-3-yl}piperidin-1-yl)methyl]-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-[(4-{2-[(4-chloro-2-fluorobenzyl)oxy]pyridin-3-yl}piperidin-1-yl)methyl]-1-(1,3-oxazol-2-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-[(4-{2-[(4-cyano-2-fluorobenzyl)oxy]pyridin-3-yl}piperidin-1-yl)methyl]-1-(1,3-oxazol-2-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-[(4-{2-[(4-cyano-2-fluorobenzyl)oxy]pyridin-3-yl}piperidin-1-yl)methyl]-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-[(4-{3-[(4-chloro-2-fluorobenzyl)oxy]pyrazin-2-yl}piperidin-1-yl)methyl]-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-(6-{6-[(4-cyano-2-fluorobenzyl)oxy]pyridin-2-yl}-6-azaspiro[2.5]oct-1-yl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-(6-{2-[(4-chloro-2-fluorobenzyl)oxy]-5-fluoropyrimidin-4-yl}-6-azaspiro[2.5]oct-1-yl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-(6-{2-[(4-chloro-2-fluorobenzyl)oxy]-5-fluoropyrimidin-4-yl}-6-azaspiro[2.5]oct-1-yl)-1-(1,3-oxazol-2-ylmethyl)-1H-benzimidazole-6-carboxylic acid;
2-(6-{6-[(4-cyano-2-fluorobenzyl)oxy]-5-fluoropyridin-2-yl}-6-azaspiro[2.5]oct-1-yl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-(6-{6-[(4-cyano-2-fluorobenzyl)oxy]-3-fluoropyridin-2-yl}-6-azaspiro[2.5]oct-1-yl)-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-[(4-{2-[(4-chloro-2-fluorobenzyl)oxy]pyrimidin-4-yl}piperidin-1-yl)methyl]-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-{[(2S)-4-{2-[(4-chloro-2-fluorobenzyl)oxy]-5-fluoropyrimidin-4-yl}-2-methylpiperazin-1-yl]methyl}-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid;
2-{[(2S)-4-{2-[(4-chloro-2-fluorobenzyl)oxy]pyrimidin-4-yl}-2-methylpiperazin-1-yl]methyl}-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid; and 2-[(4-{6-[(4-cyano-2-fluorobenzyl)oxy]pyridin-2-yl}piperidin-1-yl)methyl]-1-[(2S)-oxetan-2-ylmethyl]-1H-benzimidazole-6-carboxylic acid, and pharma- ceutically acceptable salts thereof.

Exemplary ACC inhibitors include 4-(4-[(1-isopropyl-7-oxo-1,4,6,7-tetrahydro-1'H-spiro[indazol-5,4'-piperidine]-1'-yl)carbonyl]-6-methoxypyridin-2-yl)benzoic acid, gemcabene, and filsocostat (GS-0976), and pharma- ceutically acceptable salts thereof.

Exemplary FXR agonists include tropifexor (2-[(1R,3R,5S)-3-({5-cyclopropyl-3-[2-(trifluoromethoxy)phenyl]-1,2-oxazol-4-yl}methoxy)-8-azabicyclo[3.2.1]octan-8-yl]-4-fluoro-1,3-benzothiazole-6-carboxylic acid), cilofexor (GS-9674), obeticholic acid, LY2562175, Met409, TERN-101, and EDP-305, and pharma- ceutically acceptable salts thereof.

Exemplary KHK inhibitors include [(1R,5S,6R)-3-{2-[(2S)-2-methylazetidin-1-yl]-6-(trifluoromethyl)pyrimidin-4-yl}-3-azabicyclo[3.1.0]hex-6-yl]acetic acid and pharma- ceutically acceptable salts thereof.

Exemplary DGAT2 inhibitors include (S)-2-(5-((3-ethoxypyridin-2-yl)oxy)pyridin-3-yl)-N-(tetrahydrofuran-3-yl)pyrimidine-5-carboxamide, including its crystalline solid forms (Form 1 and Form 2). See U.S. Pat. No. 10,071,992.

Exemplary BCKDK inhibitors are those described in U.S. Patent Application No. 62/868,057, filed June 28, 2019, and U.S. Patent Application No. 62/868,542, filed June 28, 2019, including the following:
5-(5-chloro-4-fluoro-3-methylthiophen-2-yl)-1H-tetrazole;
5-(5-chloro-3-difluoromethylthiophen-2-yl)-1H-tetrazole;
5-(5-fluoro-3-methylthiophen-2-yl)-1H-tetrazole;
5-(5-chloro-3-methylthiophen-2-yl)-1H-tetrazole;
5-(3,5-dichlorothiophen-2-yl)-1H-tetrazole;
5-(4-bromo-3-methylthiophen-2-yl)-1H-tetrazole;
5-(4-bromo-3-ethylthiophen-2-yl)-1H-tetrazole;
5-(4-chloro-3-ethylthiophen-2-yl)-1H-tetrazole;
3-chloro-5-fluorothieno[3,2-b]thiophene-2-carboxylic acid;
3-bromo-5-fluorothieno[3,2-b]thiophene-2-carboxylic acid;
3-(difluoromethyl)-5-fluorothieno[3,2-b]thiophene-2-carboxylic acid;
5,6-difluorothieno[3,2-b]thiophene-2-carboxylic acid; and 3,5-difluorothieno[3,2-b]thiophene-2-carboxylic acid;
or a pharma- ceutically acceptable salt thereof.

In some embodiments, the compounds of the present invention may be co-administered with one or more antidiabetic agents. Suitable antidiabetic agents include insulin, metformin, GLP-1 receptor agonists (as described herein above), acetyl-CoA carboxylase (ACC) inhibitors (as described herein above), SGLT2 inhibitors (as described herein above), monoacylglycerol O-acyltransferase inhibitors, phosphodiesterase (PDE)-10 inhibitors, AMPK activators [e.g., ETC-1002 (bempedoic acid)], sulfonylureas (e.g., acetohexamide, chlorpropamide, diabinese, glibenclamide, glipizide, glyburide, glimepiride, gliclazide, glipentide, gliquidone, glisolamide, tolazamide, and tolbutamide), meglitinides, α-amylase inhibitors (e.g., tendamistat, trestatin, and AL-3688). , α-glucoside hydrolase inhibitors (e.g., acarbose), α-glucosidase inhibitors (e.g., adiposine, camiglibose, emiglitate, miglitol, voglibose, pradimicin-Q, and salbostatin), PPARγ agonists (e.g., balaglitazone, ciglitazone, darglitazone, englitazone, isaglitazone, pioglitazone, tazone and rosiglitazone), PPARα/γ agonists (e.g., CLX-0940, GW-1536, GW-1929, GW-2433, KRP-297, L-796449, LR-90, MK-0767, and SB-219994), protein tyrosine phosphatase-1B (PTP-1B) inhibitors [e.g., trodusquemine, hirthiosal extract, and Zhang, S. et al., Drug Discovery 10:131-135, 1999, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2020, 2030, 2030, 2040, 2050, 2060, 2070, 2080, 2090, 2100, 2110, 2120, 2130, 2140, 2150, 2160, 2170, 2180, 2190, 2200, 2211, 2222, 2230, 2240, 2250, 2260, 2270, 2280, 2290, 2300, 2310, 2320, 2330, 2340, 2350, 2360, 2370, 23 Today, 12(9/10), 373-381 (2007)], SIRT-1 activators (e.g., resveratrol, GSK2245840 or GSK184072), dipeptidyl peptidase IV (DPP-IV) inhibitors (e.g., those in WO2005116014, sitagliptin, vildagliptin, alogliptin, dutogliptin, linagliptin and saxagliptin), insulin secretagogues, fatty acid oxidation inhibitors, A2 antagonists, c-jun amino-terminal kinase (JNK) inhibitors, glucocorticoids, steroids, steroid inhibitor ... glycogen phosphorylase activators (GKa), such as those described in WO2010103437, WO2010103438, WO2010013161, WO2007122482, TTP-399, TTP-355, TTP-547, AZD1656, ARRY403, MK-0599, TAK-329, AZD5658 or GKM-001, insulin, insulin mimetics, glycogen phosphorylase inhibitors (e.g. GSK1362885), VPAC2 receptor agonists, glucagon receptor modulators, such as those described in Demong, D. E. et al., Annual Reports in Medicinal Chemistry 2008, 43, 119-137; GPR119 modulators, in particular agonists, for example those described in WO2010140092, WO2010128425, WO2010128414, WO2010106457, Jones, R. M. et al., Annual Reports in Medicinal Chemistry 2008, 43, 119-137; et al., Annual Reports in Medicinal Chemistry 2009, 44, 149-170 (e.g. MBX-2982, GSK1292263, APD597 and PSN821), FGF21 derivatives or analogues, for example those described in Kharitonenkov, A. et al., Current Opinion in Investigational Drugs 2009, 10(4) 359-364, TGR5 (also called GPBAR1) receptor modulators, in particular agonists, for example those described in Zhong, M. et al., Annual Reports in Medicinal Chemistry 2009, 44, 149-170 (e.g. MBX-2982, GSK1292263, APD597 and PSN821). , Current Topics in Medicinal Chemistry, 2010, 10(4), 386-396 and INT777, GPR40 agonists, including but not limited to TAK-875, as described in Medina, J. C., Annual Reports in Medicinal Chemistry, 2008, 43, 75-85, GPR120 modulators, particularly agonists, high affinity nicotinic acid receptor (HM74A) activators, and SGLT1 inhibitors, including but not limited to GSK1614235. A further representative list of antidiabetic agents that can be combined with the compounds of the present invention can be found, for example, in WO2011005611, page 28, line 35 to page 30, line 19.

Other antidiabetic agents include inhibitors or modulators of the enzyme carnitine palmitoyltransferase, inhibitors of fructose 1,6-diphosphatase, inhibitors of aldose reductase, mineralocorticoid receptor inhibitors, inhibitors of TORC2, inhibitors of CCR2 and/or CCR5, inhibitors of PKC isoforms (e.g., PKCα, PKCβ, PKCγ), inhibitors of fatty acid synthase, inhibitors of serine palmitoyltransferase, inhibitors of GPR81 , GPR39, GPR43, GPR41, GPR105, Kv1.3, retinol binding protein 4, glucocorticoid receptors, modulators of somatostain receptors (e.g., SSTR1, SSTR2, SSTR3 and SSTR5), inhibitors or modulators of PDHK2 or PDHK4, inhibitors of MAP4K4, modulators of the IL1 family including IL1beta, modulators of RXRalpha. In addition, suitable antidiabetic agents include those mechanisms listed by Carpino, P. A., Goodwin, B. Expert Opin. Ther. Pat., 2010, 20(12), 1627-51.

The compounds of the invention may be co-administered with anti-heart failure agents such as ACE inhibitors (e.g., captopril, enalapril, fosinopril, lisinopril, perindopril, quinapril, ramipril, trandolapril), angiotensin II receptor blockers (e.g., candesartan, losartan, valsartan), angiotensin receptor neprilysin inhibitors (sacubitril/valsartan), the I _f channel blocker ivabradine, beta-adrenergic blockers (e.g., bisoprolol, metoprolol succinate, carvedilol), aldosterone antagonists (e.g., spironolactone, eplerenone), hydralazine and isosorbide dinitrate, diuretics (e.g., furosemide, bumetanide, torsemide, chlorothiazide, amiloride, hydrochlorothiazide, indapamide, metolazone, triamterene), or digoxin.

The compounds of the present invention are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction. They are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction and in treating chronic myocardial infarction. They are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction and in treating chronic myocardial infarction. They are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction and in treating chronic myocardial infarction. They are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction and in treating chronic myocardial infarction. They are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction and in treating chronic myocardial infarction. They are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction and in treating chronic myocardial infarction. They are useful in treating chronic myocardial infarction and in treating chronic myocardial infarction and in treating chronic myocardial infarction. It may be co-administered with cholesterol or lipid lowering agents including ACAT inhibitors; MTP inhibitors; lipoxygenase inhibitors; cholesterol absorption inhibitors (e.g., ezetimibe); nicotinic acid agonists (e.g., niacin, niacol, slo-niacin); omega-3 fatty acids (e.g., epanova, fish oil, eicosapentaenoic acid); cholesteryl ester transfer protein inhibitors (e.g., obiscetrapib) and PCSK9 modulators [e.g., alirocumab, evolocumab, bococizumab, ALN-PCS (incrisiran)].

The compounds of the present invention may be used in combination with antihypertensive agents, and such antihypertensive activity is readily determined by those skilled in the art according to standard assays (e.g., blood pressure measurements). Examples of suitable antihypertensive agents include alpha-adrenergic blockers; beta-adrenergic blockers; calcium channel blockers (e.g., diltiazem, verapamil, nifedipine, and amlodipine); vasodilators (e.g., hydralazine); diuretics (e.g., chlorothiazide, hydrochlorothiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methylchlorothiazide, trichloromethiazide, polythiazide, benzthiazide, ethacrynic acid, tricrynafen, chlorthalidone, torsemide, furosemide, musolimine, bumetanide, triamterene, amiloride, spironolactone); renin inhibitors; ACE inhibitors (e.g., capto, pril, zofenopril, fosinopril, enalapril, ceranopril, cilazapril, delapril, pentopril, quinapril, ramipril, lisinopril); AT-1 receptor antagonists (e.g., losartan, irbesartan, valsartan); ET receptor antagonists (e.g., sitaxsentan, atrasentan, and Nos. 5,612,359 and 6,043,265); dual ET/AII antagonists (e.g., compounds disclosed in WO 00/01389); neutral endopeptidase (NEP) inhibitors; vasopepsidase inhibitors (dual NEP-ACE inhibitors) (e.g., gemopatrilat and nitrate). An exemplary antianginal agent is ivabradine.

Examples of suitable calcium channel blockers (L-type or T-type) include diltiazem, verapamil, nifedipine and amlodipine, as well as mybefradil.

Examples of suitable cardiac glycosides include digitalis and ouabain.

In one embodiment, the compounds of the invention may be co-administered with one or more diuretics. Examples of suitable diuretics include (a) loop diuretics, such as furosemide (LASIX™, etc.), torsemide (DEMADEX™, etc.), bumetanide (BUMEX™, etc.), and ethacrynic acid (EDECRIN™, etc.); (b) thiazide diuretics, such as chlorothiazide (DIURIL™, ESIDRIX™, or HYDRODIURIL™, etc.), hydrochlorothiazide (MICROZIDE™ or ORETIC™, etc.), benzthiazide, hydroflumethiazide (SALURON™, etc.), benthiazide, benzo ... (c) phthalimidine diuretics, such as chlorthalidone (HYGROTON™, etc.) and metolazone (ZAROXOLYN™, etc.); (d) quinazoline diuretics, such as quinethazone; and (e) potassium-sparing diuretics, such as triamterene (DYRENIUM™, etc.) and amiloride (MIDAMOR™ or MODURETIC™, etc.).

In another embodiment, the compounds of the invention may be co-administered with a loop diuretic. In yet another embodiment, the loop diuretic is selected from furosemide and torsemide. In yet another embodiment, one or more compounds of formula I or pharma- ceutically acceptable salts thereof may be co-administered with furosemide. In yet another embodiment, one or more compounds of formula I or pharma- ceutically acceptable salts thereof may be co-administered with torsemide, which may be a controlled or modified release form of torsemide.

In another embodiment, the compound of the present invention may be co-administered with a thiazide diuretic. In yet another embodiment, the thiazide diuretic is selected from the group consisting of chlorothiazide and hydrochlorothiazide. In yet another embodiment, one or more compounds of Formula I or pharma- ceutically acceptable salts thereof may be co-administered with chlorothiazide. In yet another embodiment, one or more compounds of Formula I or pharma- ceutically acceptable salts thereof may be co-administered with hydrochlorothiazide.

In another embodiment, one or more compounds of Formula I or pharma- ceutically acceptable salts thereof may be co-administered with a phthalimidine diuretic. In yet another embodiment, the phthalimidine diuretic is chlorthalidone.

Examples of suitable mineralocorticoid receptor antagonists include spironolactone and eplerenone.

Examples of suitable phosphodiesterase inhibitors include PDE III inhibitors (such as cilostazol) and PDE V inhibitors (such as sildenafil).

Those skilled in the art will recognize that the compounds of the present invention may be used in conjunction with other cardiovascular or cerebrovascular procedures, including PCI, stenting, drug-eluting stents, stem cell therapy, and medical devices such as implantable pacemakers, defibrillators, or cardiac resynchronization therapy.

There is a potential for chemical interactions between the combined active ingredients, especially when provided as a single dosage unit. For this reason, when the compounds of the present invention and a second therapeutic agent are combined in a single dosage unit, they are formulated such that physical contact between the active ingredients is minimized (i.e., reduced) even when the active ingredients are combined in a single dosage unit. For example, one active ingredient may be enteric coated. By enteric coating one of the active ingredients, it is possible not only to minimize contact between the combined active ingredients, but also to control the release of one of these ingredients in the gastrointestinal tract, such that the ingredients are released in the intestine but not in the stomach. One of the active ingredients may be coated with a material that also serves to achieve sustained release throughout the gastrointestinal tract and minimize physical contact between the combined active ingredients. In addition, a sustained release component may be additionally enteric coated so that release of this component occurs only in the intestine. Yet another approach would involve formulating a combination product in which one component is coated with a sustained and/or enteric release polymer to further separate the active ingredients, and the other component is also coated with a polymer such as low viscosity grades of hydroxypropylmethylcellulose (HPMC) or other suitable materials as known in the art. The polymer coating serves to form an additional barrier to interaction with the other component.

These and other techniques for minimizing contact between the components of the combination products of the present invention, whether administered in a single dosage form or in separate forms but administered simultaneously by the same mode, will be readily apparent to those of skill in the art upon reading this disclosure.

In combination therapy treatment, both the compound of the invention and the other drug therapy are administered to a mammal (e.g., a human, male or female) by conventional methods. The compounds of formula I or salts thereof are adapted for therapeutic use as agents that antagonize (including inhibit) MC4R in mammals, particularly humans, and are therefore useful in the treatment of a variety of conditions in which such an action is implicated, such as those described herein.

Diseases/disorders/conditions that may be treated according to the present invention include, but are not limited to, cachexia (e.g., cachexia associated with cancer, AIDS, CHF and/or CKD); anorexia/anorexia nervosa (e.g., anorexia in the elderly, anorexia associated with chemotherapy and/or radiation therapy); nausea; vomiting; weight loss (e.g., involuntary weight loss); failure to thrive; sarcopenia; muscle wasting; frailty; osteoporosis; bone disorders (e.g., bone loss); pain; neuropathic pain; anxiety; depression; hypertension; malnutrition; obesity; sexual dysfunction; and inflammatory diseases.

Administration of the compounds of the invention can be via any method that delivers the compounds of the invention systemically and/or locally. These methods include oral routes, parenteral, intraduodenal routes, buccal, intranasal, and the like. Generally, the compounds of the invention are administered orally, although parenteral administration (e.g., intravenous, intramuscular, subcutaneous, or intramedullary) can be utilized, for example, when oral administration is inappropriate for the target or when the patient is unable to ingest the drug.

For administration to human patients, the oral daily dose of the compounds herein may be, for example, in the range of 0.01 mg to 5000 mg, depending, of course, on the mode and frequency of administration, the disease state, and the age and condition of the patient, etc. Oral daily doses in the range of 1 mg to 2000 mg (e.g., 3 mg to 2000 mg) may be used. Further oral daily doses are in the range of 5 mg to 1000 mg. For convenience, the compounds of the present invention may be administered in unit dosage form. If desired, the total daily dose may be increased using the unit dosage form in multiple doses per day. The unit dosage form may be, for example, a tablet or capsule containing about 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 250, 300, 500, or 1000 mg of the compound of the invention. The total daily dose may be administered in single or divided doses and, at the physician's discretion, may fall outside of the typical ranges given herein.

For administration to human patients, the daily infusion dose of the compounds herein may range from 1 mg to 2000 mg, depending, of course, on the mode and frequency of administration, the disease state, and the age and condition of the patient, etc. Further daily infusion doses are in the range of 5 mg to 1000 mg. The total daily dose may be administered in single or divided doses and, at the physician's discretion, may fall outside the typical ranges noted herein.

In accordance with the methods of treatment of the present invention, a compound of the present invention or a combination of a compound of the present invention and at least one additional pharmaceutical agent (herein referred to as a "combination") is administered to a subject in need of such treatment, preferably in the form of a pharmaceutical composition. In the combination aspect of the present invention, the compound of the present invention and at least one other pharmaceutical agent (e.g., another anti-cachexia or anti-anorexia agent) may be administered separately or in a pharmaceutical composition containing both. It is generally preferred that such administration is oral.

When a combination of a compound of the invention and at least one other pharmaceutical agent is administered together, such administration may be sequential in time or simultaneous. In some embodiments, simultaneous administration of drug combinations is used. In separate or sequential administration, the compound of the invention and the additional pharmaceutical agent may be administered in any order, and each of them may be administered at an independent frequency or dosage regimen. In some embodiments, such administration is oral. In some embodiments, such administration can be oral and simultaneous. When the compound of the invention and the additional pharmaceutical agent are administered sequentially, administration of each may be by the same method or by different methods.

According to the methods of the invention, the compounds or combinations of the invention can be administered in the form of pharmaceutical compositions. Thus, the compounds or combinations of the invention can be administered to a patient separately or together in any conventional oral, rectal, transdermal, parenteral (e.g., intravenous, intramuscular or subcutaneous), intracisternal, intravaginal, intraperitoneal, topical (e.g., powders, ointments, creams, sprays or lotions), buccal or nasal dosage form (e.g., sprays, drops or inhalants).

The compounds or combinations of the present invention may be administered alone or in admixture with one or more suitable pharmaceutical excipients, adjuvants, excipients or carriers known in the art and selected with respect to the intended route of administration and standard pharmaceutical practice. The compounds or combinations of the present invention may be formulated to provide immediate, delayed, modulated, sustained, pulsed or controlled release dosage forms depending on the specifics of the desired route of administration and release profile to meet the therapeutic needs.

Pharmaceutical compositions contain a compound or combination of the invention in an amount generally within the range of about 1% to about 75%, 80%, 85%, 90% or even 95% (by weight) of the composition, usually within the range of about 1%, 2% or 3% to about 50%, 60% or 70%, more often within the range of about 1%, 2% or 3% to less than 50%, for example within the range of about 25%, 30% or 35%.

Methods for preparing various pharmaceutical compositions with specific amounts of active compounds are known to those skilled in the art. See, for example, Remington, J. P., The Science and Practice of Pharmacy, Lippincott Williams and Wilkins, Baltimore, Md., 20th Edition, 2000.

Compositions suitable for parenteral injection generally include pharma- ceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions, or emulsions, and sterile powders for reconstitution into sterile injectable solutions or dispersions. Examples of suitable aqueous and nonaqueous carriers or excipients (including solvents and vehicles) include water, ethanol, polyols (propylene glycol, polyethylene glycol, glycerol, etc.), suitable mixtures thereof, triglycerides, including vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. A preferred carrier is Miglyol® brand caprylic/capric esters (e.g., Miglyol® 812, Miglyol® 829, Miglyol® 840) with glycerin or propylene glycol, available from Condea Vista Co., Cranford, N.J. Proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.

These compositions for parenteral injection may also contain additives such as preservatives, wetting agents, emulsifying agents, and dispersing agents. Prevention of microbial contamination of the compositions can be accomplished using various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example, sugars, sodium chloride, and the like. Prolonged absorption of injectable pharmaceutical compositions can be brought about by the use of agents capable of delaying absorption, for example, aluminum monostearate and gelatin.

Solid dosage forms for oral administration include capsules, tablets, chewable tablets, candies, pills, powders and multiparticulate preparations (granules). In such solid dosage forms, the compounds or combinations of the present invention are admixed with at least one inert additive, excipient or carrier. Suitable additives, excipients or carriers include materials such as sodium citrate or dicalcium phosphate, and/or (a) one or more fillers or extenders (e.g., microcrystalline cellulose (available from FMC Corp. as Avicel™), starch, lactose, sucrose, mannitol, silicic acid, xylitol, sorbitol, dextrose, calcium hydrogen phosphate, dextrin, alpha-cyclodextrin, beta-cyclodextrin, polyethylene glycol, medium chain fatty acids, titanium oxide, magnesium oxide, aluminum oxide, etc.); (b) one or more binders (e.g., carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxypropylmethyl ... (c) one or more humectants (e.g., glycerol, etc.); (d) one or more disintegrating agents (e.g., agar, calcium carbonate, potato or tapioca starch, alginic acid, certain complex silicates, sodium carbonate, sodium lauryl sulfate, sodium starch glycolate (available as Explotab™ from Edward Mendell Co.), cross-linked polyvinylpyrrolidone, croscarmellose sodium type A (available as Ac-di-sol™), potassium polyacrylin (polyacrylin), etc.); (e) one or more solution retardants (e.g., paraffin, etc.); (f) one or more absorption accelerators (e.g., quaternary ammonium compounds, etc.); (g) one or more wetting agents (e.g., cetyl alcohol, glycerol monostearate, etc.); (h) one or more adsorbents (e.g., kaolin, bentonite, etc.); and/or (i) one or more lubricants (e.g., talc, calcium stearate, magnesium stearate, stearic acid, polyoxyl stearate, cetanol, hydrogenated castor oil, sucrose fatty acid esters, dimethylpolysiloxane, microcrystalline wax, yellow wax, white wax, solid polyethylene glycol, sodium lauryl sulfate, etc.). In the case of capsules and tablets, the dosage form may also include a buffering agent.

Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar and high molecular weight polyethylene glycols and the like.

Solid dosage forms such as tablets, dragees, capsules and granules may be prepared with coatings and shells, such as enteric coatings and others well known in the art. They may contain opacifying agents and may be of a composition such that they release the compound of the invention and/or additional pharmaceutical agents in a delayed manner. Examples of embedding compositions that may be used are polymeric substances and waxes. The drug may also be in microencapsulated form, if appropriate, with one or more of the excipients mentioned above.

In tablets, the active agent will typically comprise less than 50% (by weight) of the formulation, e.g., less than about 10%, such as 5% or 2.5% by weight. The main part of the formulation will include fillers, excipients, disintegrants, lubricants, and may include flavorings. The composition of these excipients is well known in the art. Frequently, the filler/excipient will comprise a mixture of two or more of the following ingredients: microcrystalline cellulose, mannitol, lactose (all types), starch, and dicalcium phosphate. The filler/excipient mixture will typically comprise less than 98%, preferably less than 95%, e.g., 93.5%, of the formulation. Preferred disintegrants include Ac-di-sol™, Explotab™, starch, and sodium lauryl sulfate. When present, the disintegrant will usually comprise less than 10% or less than 5%, e.g., about 3%, of the formulation. A preferred lubricant is magnesium stearate. When present, lubricants will typically comprise less than 5% or less than 3%, for example about 1%, of the formulation.

Tablets may be manufactured by standard tabletting processes, such as direct compression or wet, dry or melt granulation, melt congealing processes and extrusion. Tablet cores may be single or multi-layered and may be coated with suitable protective films known in the art.

Liquid dosage forms for oral administration include pharma- ceutically acceptable emulsions, solutions, suspensions, syrups, and elixirs. In addition to the compounds or combinations of the present invention, liquid dosage forms may contain inert excipients commonly used in the art, such as water or other solvents, solubilizing and emulsifying agents, such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (e.g., cottonseed oil, peanut oil, corn germ oil, olive oil, castor oil, sesame seed oil, etc.), Miglyol® (available from CONDEA Vista Co., Cranford, N.J.), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycol, and sorbitan fatty acid esters, or mixtures of these substances.

Besides such inert excipients, the composition may also include additives such as wetting agents, emulsifying and suspending agents, sweetening, flavoring and perfuming agents, etc.

Oral liquid forms of the compounds or combinations of the present invention include solutions in which the active compounds are completely dissolved. Examples of solvents include all pharma- ceutical precedent solvents suitable for oral administration, especially those in which the compounds of the present invention show good solubility, such as polyethylene glycol, polypropylene glycol, edible oils, and glyceryl and glyceride-based systems. Glyceryl and glyceride-based systems include, for example, the following branded products (and corresponding generic products): Captex™ 355EP (glyceryl tricaprylate/caprate, manufactured by Abitec, Columbus Ohio), Crodamol™ GTC/C (medium chain triglyceride, manufactured by Croda, Cowick, Ohio), and others. Hall, UK) or Labrafac™ CC (medium chain triglycerides, manufactured by Gattefosse), Captex™ 500P (glyceryl triacetate, i.e. triacetin, manufactured by Abitec), Capmul™ MCM (medium chain mono- and diglycerides, manufactured by Abitec), Migyol™ 812 (caprylic/capric triglyceride, manufactured by Condea, Cranford, UK). N.J.), Migyol™ 829 (caprylic/capric/succinic triglyceride, ex Condea), Migyol™ 840 (propylene glycol dicaprylate/dicaprate, ex Condea), Labrafil™ M1944CS (oleoyl macrogol-6 glyceride, ex Gattefosse), Peceol™ (glyceryl monooleate, ex Gattefosse) and Maisine™ 35-1 (glyceryl monooleate, ex Gattefosse). Of particular interest are the medium chain (about _C8 to _C10 ) triglyceride oils. These solvents frequently constitute the majority of the composition, i.e., more than about 50%, usually more than about 80%, for example, more than about 95% or 99%. Adjuvants and additives may be included along with the solvents, primarily taste masking agents, palatability and flavoring agents, antioxidants, stabilizers, texture and viscosity modifiers, and solubilizers.

Suspensions may further comprise, in addition to a compound or combination of the present invention, a carrier such as a suspending agent, e.g., ethoxylated isostearyl alcohol, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar, and tragacanth, or mixtures of these substances.

Compositions for rectal or vaginal administration preferably include suppositories, which may be prepared by mixing the compounds or combinations of the present invention with suitable non-irritating excipients or carriers, such as cocoa butter, polyethylene glycol or a suppository wax, which are solid at normal room temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity, thereby releasing the active ingredient.

Dosage forms for topical administration of the compounds or combinations of the invention include ointments, creams, lotions, powders and sprays. The drug is admixed with a pharma- ceutically acceptable excipient, diluent or carrier, and any preservatives, buffers or propellants that may be required.

Some of the compounds of the present invention may have poor solubility in water, e.g., less than about 1 μg/mL. Thus, liquid compositions in solubilizing non-aqueous solvents such as the medium chain triglyceride oils discussed above are preferred dosage forms for these compounds.

Solid amorphous dispersions, including dispersions formed by spray drying processes, are also preferred dosage forms for the poorly soluble compounds of the present invention. By "solid amorphous dispersion" is meant a solid material in which at least a portion of the poorly soluble compound is in amorphous form and dispersed in a water-soluble polymer. By "amorphous" is meant that the poorly soluble compound is not crystalline. By "crystalline" is meant that the compound exhibits three-dimensional long-range order of at least 100 repeat units in each dimension. Thus, the term amorphous is intended to include materials that have no inherent order, as well as materials that may have a small degree of order, but that order is less than three-dimensional and/or short-range. Amorphous materials may be characterized by techniques known in the art, such as powder X-ray diffraction (PXRD) crystallography, solid-state NMR, or thermal techniques such as differential scanning calorimetry (DSC), to name a few.

Preferably, at least a majority (i.e., at least about 60 wt%) of the poorly soluble compound in the solid amorphous dispersion is amorphous. The compound can exist within the solid amorphous dispersion in relatively pure amorphous domains or regions, as a solid solution of the compound homogeneously distributed throughout the polymer, or any combination of these states or intermediate states between them. Preferably, the solid amorphous dispersion is substantially homogeneous, such that the amorphous compound is dispersed as homogeneously as possible throughout the polymer. As used herein, "substantially homogeneous" means that the proportion of the compound present in the relatively pure amorphous domains or regions within the solid amorphous dispersion is relatively small, approximately less than 20 wt%, preferably less than 10 wt% of the total amount of drug.

Water-soluble polymers suitable for use in solid amorphous dispersions should be inert, in the sense that they do not chemically react in a deleterious manner with the poorly soluble compound, are pharma- ceutically acceptable, and have at least some solubility in aqueous solutions at physiologically relevant pH (e.g., 1-8). The polymers can be neutral or ionizable, and should have an aqueous solubility of at least 0.1 mg/mL over at least a portion of the pH range from 1 to 8.

Water-soluble polymers suitable for use in the present invention may be cellulosic or non-cellulosic. The polymers may be neutral or ionizable in aqueous solution. Of these, ionizable and cellulosic polymers are preferred, with ionizable cellulosic polymers being more preferred.

Exemplary water-soluble polymers include hydroxypropyl methylcellulose acetate succinate (HPMCAS), hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose phthalate (HPMCP), carboxymethylethylcellulose (CMEC), cellulose acetate phthalate (CAP), cellulose acetate trimellitate (CAT), polyvinylpyrrolidone (PVP), hydroxypropyl cellulose (HPC), methylcellulose (MC), block copolymers of ethylene oxide and propylene oxide (PEO/PPO, also known as poloxamers), and mixtures thereof. Particularly preferred polymers include HPMCAS, HPMC, HPMCP, CMEC, CAP, CAT, PVP, poloxamers, and mixtures thereof. Most preferred is HPMCAS. See European Patent Application Publication No. 0 901 786 A2, the disclosure of which is incorporated herein by reference.

The solid amorphous dispersions may be prepared according to any process for forming a solid amorphous dispersion that results in at least a majority (at least 60%) of the poorly soluble compound being in the amorphous state. Such processes include mechanical, thermal and solvent processes. Exemplary mechanical processes include milling and extrusion; melt processes, including high temperature melting, solvent-modified fusion and melt-solidification processes; and solvent processes, including non-solvent precipitation, spray coating and spray drying. See, for example, the following U.S. patents, the relevant disclosures of which are incorporated herein by reference: 5,456,923 and 5,939,099, which describe forming a dispersion by an extrusion process; 5,340,591 and 4,673,564, which describe forming a dispersion by a milling process; and 5,707,646 and 4,894,235, which describe forming a dispersion by a melt-solidification process. In a preferred process, the solid amorphous dispersion is formed by spray drying, as disclosed in EP 0 901 786 A2. In this process, the compound and polymer are dissolved in a solvent, such as acetone or methanol, and then the solvent is rapidly removed from the solution by spray drying to form the solid amorphous dispersion. The solid amorphous dispersion can be prepared to contain up to about 99 wt% of the compound, for example, 1 wt%, 5 wt%, 10 wt%, 25 wt%, 50 wt%, 75 wt%, 95 wt%, or 98 wt%, as desired.

The solid dispersion may be used as a dosage form by itself or may serve as a manufacturing use product (MUP) in the preparation of other dosage forms such as capsules, tablets, liquids or suspensions. An example of an aqueous suspension is an aqueous suspension of 1:1 (w/w) compound/HPMCAS-HF spray dried dispersion containing 2.5 mg/mL of compound in 2% polysorbate-80. Solid dispersions for use in tablets or capsules will generally be mixed with other additives or adjuvants typically found in such dosage forms. For example, an exemplary filler for a capsule contains 2:1 (w/w) compound/HPMCAS-MF spray dried dispersion (60%), lactose (fast flow) (15%), microcrystalline cellulose (e.g., Avicel.sup.(R0-102) (15.8%), sodium starch (7%), sodium lauryl sulfate (2%) and magnesium stearate (1%).

HPMCAS polymers are available in low, medium and high grades as Aqoat®-LF, Aqoat®-MF and Aqoat®-HF from Shin-Etsu Chemical Co., Ltd., Tokyo, Japan. Higher MF and HF grades are generally preferred.

Advantageously, the compounds (or combinations) of the present invention can be carried in drinking water such that a therapeutic dosage of the compound is ingested with the daily water supply. The compounds can be metered directly into the drinking water, preferably in the form of a liquid, water-soluble concentrate (such as an aqueous solution of a water-soluble salt).

These compounds may be administered to non-human animals, for example, for the indications detailed above. The exact dosage of each active ingredient administered will vary depending on any number of factors, including, but not limited to, the type of animal and type of condition being treated, the age of the animal, and the route of administration.

In combination with a compound of formula I or a salt thereof
The dosages of the combined pharmaceutical agents used in the conjugation with are those effective for the indication being treated. Such dosages can be determined by standard assays such as those referenced above and provided herein. The combined agents can be administered simultaneously or sequentially in any order.

These dosages are based on an average human subject weighing approximately 60 kg to 70 kg. A physician will be readily able to determine dosages for subjects whose weight falls outside this range, such as infants and the elderly.

Dosage regimens may be adjusted to provide the optimum desired response. For example, a single bolus may be administered, several divided doses may be administered over time, or the dose may be proportionally reduced or increased as dictated by the exigencies of the therapeutic situation. It is particularly advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form, as used herein, refers to physically discrete units suitable as unitary dosages for the mammalian subject to be treated, each unit containing a predetermined amount of active compound calculated to produce the desired therapeutic effect together with the required pharmaceutical carrier. The specifications for the dosage unit forms of the present invention are dictated by and directly depend on (a) the unique characteristics of the chemotherapeutic agent and the particular therapeutic or prophylactic effect to be achieved, and (b) the limitations inherent in the art of compounding such active compounds for the treatment of susceptibility in an individual.

Thus, one of skill in the art will know, based on the disclosure provided herein, that doses and dosing regimens will be adjusted according to methods well known in the therapeutic arts. That is, the maximum tolerated dose can be readily established, and the effective amount that provides a detectable therapeutic benefit to the patient can be determined, as can the primary requirement for administering each agent to provide a detectable therapeutic benefit to the patient. Thus, although certain doses and dosing regimens are exemplified herein, these examples are not intended to be limiting of the doses and dosing regimens that may be provided to a patient in practicing the present invention.

It should be noted that dosage values may vary with the type and severity of the condition to be alleviated and may include single or multiple doses. It should be further understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the composition, and that the dosage ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed compositions. For example, doses may be adjusted based on pharmacokinetic or pharmacodynamic parameters, which may include toxic effects and/or clinical effects such as laboratory values. Thus, the present invention encompasses intrapatient dose escalation as determined by one of skill in the art. Determining appropriate dosages and regimens for administration of chemotherapeutic agents is well known in the relevant art and will be understood to be encompassed by those of skill in the art given the teachings disclosed herein.

The present invention further includes the use of a compound of formula I or a pharma- ceutically acceptable salt thereof for use as a medicament (such as a unit dose tablet or capsule). In another embodiment, the present invention includes the use of a compound of formula I or a pharma- ceutically acceptable salt thereof for the manufacture of a medicament (such as a unit dose tablet or capsule) for treating one or more of the conditions previously identified in the section above discussing methods of treatment.

The pharmaceutical compositions of the invention may be prepared, packaged, or sold in bulk as a single unit dose or as a plurality of single unit doses. As used herein, a "unit dose" is a discrete amount of the pharmaceutical composition comprising a predetermined amount of the active ingredient. The amount of the active ingredient is generally equal to the dosage of the active ingredient that would be administered to a subject or a convenient fraction of such a dosage, such as, for example, one-half or one-third of such a dosage.

These agents and compounds of the invention can be combined with a pharma- ceutically acceptable vehicle, such as saline, Ringer's solution, dextrose solution, and the like. The particular dosing regimen, i.e., dosage, timing, and repetition, will depend on the particular individual and that individual's medical history.

Acceptable carriers, additives, or stabilizers are nontoxic to the recipient at the dosages and concentrations employed and include buffers such as phosphates, citrates, and other organic acids; salts such as sodium chloride; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzylammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; It may include proteins such as serum albumin, gelatin, or Ig; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates, including glucose, mannose, or dextrin; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose, or sorbitol; salt-forming counterions such as sodium; metal complexes (e.g., Zn-protein complexes); and/or non-ionic surfactants such as TWEEN™, PLURONICS™, or polyethylene glycol (PEG).

Liposomes containing these agents and/or compounds of the invention are prepared by methods known in the art, such as those described in U.S. Pat. Nos. 4,485,045 and 4,544,545. Liposomes with enhanced circulation time are disclosed in U.S. Pat. No. 5,013,556. Particularly useful liposomes can be produced by the reverse phase evaporation method using a lipid composition comprising phosphatidylcholine, cholesterol and PEG-derivatized phosphatidylethanolamine (PEG-PE). Liposomes are extruded through filters of defined pore size to yield liposomes with the desired diameter.

These agents and/or compounds of the invention may be encapsulated in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization, for example, hydroxymethylcellulose or gelatin microcapsules and poly-(methyl methacrylate) microcapsules, in colloidal drug delivery systems (e.g., liposomes, albumin microspheres, microemulsions, nanoparticles and nanocapsules) or macroemulsions, respectively. Such techniques are disclosed in Remington, The Science and Practice of Pharmacy, 20th Edition, Mack Publishing (2000).

Sustained release preparations may be used. Suitable examples of sustained release preparations include semipermeable matrices of solid hydrophobic polymers containing the compound of the invention, which matrices are in the form of shaped articles, e.g., films or microcapsules. Examples of sustained release matrices include polyesters, hydrogels [e.g., poly(2-hydroxyethyl-methacrylate) or poly(vinyl alcohol)], polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and 7L-ethyl glutamate, non-degradable ethylene-vinyl acetate, degradable lactic acid-glycolic acid copolymers, such as those used in LUPRON DEPOT™ (injectable microspheres composed of lactic acid-glycolic acid copolymer and leuprolide acetate), sucrose acetate isobutyrate, and poly-D-(−)-3-hydroxybutyric acid.

Formulations to be used for intravenous administration must be sterile. This is readily accomplished, for example, by filtration through sterile filtration membranes. The compounds of the invention are generally placed into a container having a sterile access port, for example, an intravenous solution bag or vial having a stopper pierceable by a hypodermic injection needle.

Suitable emulsions may be prepared using commercially available fat emulsions, such as Intralipid™, Liposyn™, Infonutrol™, Lipofundin™ and Lipiphysan™. The active ingredient may either be dissolved in a premixed emulsion composition or, alternatively, dissolved in an emulsion formed upon mixing of oil (e.g., soybean oil, safflower oil, cottonseed oil, sesame oil, corn oil or almond oil) and phospholipids (e.g., egg phospholipids, soybean phospholipids or soybean lecithin) with water. It will be appreciated that other ingredients, such as glycerol or glucose, may be added to adjust the isotonicity of the emulsion. Suitable emulsions will typically contain up to 20% oil, e.g., between 5 and 20%. The fat emulsion may contain fat droplets between 0.1 and 1.0 μm, particularly 0.1 and 0.5 μm, and have a pH in the range of 5.5 to 8.0.

The emulsion composition can be prepared by mixing the compound of the present invention with Intralipid™ or its components (soybean oil, egg phospholipids, glycerol and water).

Compositions for inhalation or insufflation include solutions and suspensions in pharma- ceutically acceptable, aqueous or organic solvents or mixtures thereof, as well as powders. Liquid or solid compositions may contain suitable pharma- ceutically acceptable additives as specified above. In some embodiments, compositions are administered by the oral or nasal respiratory route for local or systemic effect. Compositions, preferably in sterile, pharma- ceutically acceptable solvents, may be nebulized by the use of gases. Nebulized solutions may be inhaled directly from the nebulizing device or the nebulizing device may be attached to a face mask, tent or intermittent positive pressure respirator. Solution, suspension or powder compositions may be administered, preferably orally or intranasally, from a device that delivers the formulation in an appropriate manner.

The compound particles herein may be formulated in a form suitable for oral, buccal, intranasal, parenteral (e.g., intravenous, intramuscular or subcutaneous) or rectal administration, or for administration by inhalation. The compounds of the invention may also be formulated for sustained delivery.

Methods of preparing various pharmaceutical compositions with a particular amount of active ingredient are known or will be apparent to one of skill in the art in light of this disclosure. For examples of methods of preparing pharmaceutical compositions, see Remington, The Science and Practice of Pharmacy, 20th Edition (Lippincott Williams & Wilkins, 2000).

Pharmaceutical compositions according to the invention may contain 0.1% to 95%, preferably 1% to 70%, of a compound of the invention. In any event, the composition administered will contain a quantity of a compound according to the invention in an amount effective to treat the disease/condition of the subject being treated.

Since the present invention has an aspect relating to the treatment of diseases/conditions described herein with active ingredient compounds that can be administered separately, the present invention also relates to combining separate pharmaceutical compositions in kit form. The kit comprises two separate pharmaceutical compositions: a compound of formula I or a pharma- ceutically acceptable salt or prodrug thereof or a salt of such compound or prodrug, and a second compound as described above. The kit includes a means for containing the separate compositions, such as a container, a divided bottle, or a divided foil packet. Typically, the kit includes instructions for administration of the separate components. The kit form is particularly advantageous when the separate components are preferably administered in different dosage forms (e.g., oral and parenteral), at different dosage intervals, or when titration of the individual components of the combination is desired by the prescribing physician.

An example of such a kit is the so-called blister pack. Blister packs are well known in the packaging industry and are widely used for packaging pharmaceutical unit dosage forms (tablets, capsules, etc.). A blister pack generally consists of a sheet of relatively rigid material covered with a foil of a preferably transparent plastic material. During the packaging process, recesses are formed in the plastic foil. The recesses have the size and shape in which the tablets or capsules are packed. The tablets or capsules are then placed in the recesses and the sheet of relatively rigid material is sealed against the plastic foil, on the face of the foil opposite to the direction in which the recesses were formed. As a result, the tablets or capsules are sealed in the recesses between the plastic foil and the sheet. Preferably, the strength of the sheet is such that the tablets or capsules can be removed from the blister pack by manually applying pressure to the recesses, whereby an opening is formed in the sheet at the place of the recesses. The tablets or capsules can then be removed through said opening.

It may be desirable to provide a memory aid to the kit, for example in the form of numbers next to the tablets or capsules that correspond to the numbers of the days in the regimen on which the tablets or capsules so designated should be taken. Another example of such a memory aid is a calendar printed on a card, for example as follows: "First week, Monday, Tuesday, etc...Second week, Monday, Tuesday,..." etc. Other variations of memory aids will be readily apparent. A "daily dose" can be a single tablet or capsule or several pills or capsules to be taken on a given day. Also, a daily dose of a compound of the invention may consist of one tablet or capsule, while a daily dose of a second compound may consist of several tablets or capsules, or vice versa. The memory aid should reflect this.

In another specific embodiment of the invention, a dispenser designed to dispense the daily doses one at a time in the order of their intended use is provided. Preferably, the dispenser is equipped with a memory aid to further facilitate compliance with the regimen. An example of such a memory aid is a mechanical counter that indicates the number of daily doses that have been dispensed. Another example of such a memory aid is a battery-powered microchip memory coupled with a liquid crystal display or, for example, an audible reminder signal that reads out the date the previous daily dose was taken and/or reminds the user of the date when the next dose should be taken.

Also, since the present invention has aspects relating to the diseases/conditions described herein that employ combinations of active ingredients that can be administered together, the present invention also relates to combining separate pharmaceutical compositions in a single dosage form such as, but not limited to, a single tablet or capsule, a bilayer or multilayer tablet or capsule, or by the use of segregated components or compartments within a tablet or capsule.

The active ingredient may be delivered as a solution in an aqueous or non-aqueous vehicle with or without additional solvents, co-solvents, additives or complexing agents selected from pharma- ceutically acceptable excipients, additives, vehicles or carriers.

The active ingredient may be formulated as a solid dispersion or as a self-emulsifying drug delivery system (SEDDS) with the addition of pharma- ceutically acceptable excipients.

The active ingredient may be formulated as an immediate release or controlled (e.g., suspended, delayed or sustained) release tablet or capsule. Alternatively, the active ingredient may be delivered alone as the active ingredient within the capsule shell, without the addition of additional additives.

The following illustrates the synthesis of various compounds of the present invention. Additional compounds within the scope of the present invention can be prepared using the methods illustrated in these examples, either alone or in combination with techniques generally known in the art. All starting materials in these preparations and examples are either commercially available or can be prepared by methods known in the art or as described herein.

Reactions were carried out in air or under an inert atmosphere (nitrogen or argon) when oxygen- or moisture-sensitive reagents or intermediates were used. When appropriate, the reactor was dried under dynamic vacuum using a heat gun, and anhydrous solvents (Sure-Seal™ products from Aldrich Chemical Company, Milwaukee, Wisconsin, or DriSolv™ products from EMD Chemicals, Gibbstown, NJ) were used. In some cases, commercially available solvents were passed through columns packed with 4 Å molecular sieves until the following water QC criteria were reached: a) less than 100 ppm for dichloromethane, toluene, N,N-dimethylformamide, and tetrahydrofuran; b) less than 180 ppm for methanol, ethanol, 1,4-dioxane, and diisopropylamine. In very sensitive reactions, the solvents were further treated with sodium metal, calcium hydride or molecular sieves and distilled immediately before use. Other commercially available solvents and reagents were used without further purification. In syntheses that refer to procedures in other examples or methods, reaction conditions (reaction times and temperatures) may vary. Products were generally dried under vacuum before being carried forward to further reactions or sent for biological testing.

Where indicated, reactions were heated by microwave irradiation using a Biotage Initiator or a Personal Chemistry Emries Optimizer microwave. Reaction progress was monitored using thin layer chromatography (TLC), liquid chromatography-mass spectrometry (LCMS), high performance liquid chromatography (HPLC) and/or gas chromatography-mass spectrometry (GCMS) analysis. TLC was performed on precoated silica gel plates with fluorescent indicators (254 nm excitation wavelength) and visualized under UV light and/or with iodine, potassium permanganate, cobalt(II) chloride, phosphomolybdic acid and/or ceric ammonium molybdate stains. LCMS data was acquired on an Agilent 1100 series instrument using a Leap Technologies autosampler, a Gemini C18 column, an acetonitrile/water gradient, and either trifluoroacetic acid, formic acid or ammonium hydroxide modifiers. Column eluents were analyzed using a Waters ZQ mass spectrometer scanning from 100 to 1200 Da in both positive and negative ion mode. Other similar instruments were also used. HPLC data were generally acquired on an Agilent 1100 series instrument using the indicated columns, acetonitrile/water gradients, and either trifluoroacetic acid or ammonium hydroxide modifiers. GCMS data were acquired using a Hewlett-Packard 6890 oven with an HP6890 injector, HP-1 column (12 m×0.2 mm×0.33 μm), and helium carrier gas. Samples were analyzed on an HP5973 mass selective detector scanning from 50 to 550 Da using electron ionization. Purification was performed by medium pressure liquid chromatography (MPLC) using an Isco Combiflash Companion, AnaLogix IntelliFlash 280, Biotage SP1, or Biotage Isolela One instrument and pre-packed Isco Redisep or Biotage Snap Silica cartridges. Chiral purification was performed by chiral supercritical fluid chromatography (SFC) typically using Berger or Thar instruments; columns such as ChiralPak-AD, -AS, -IC, ChiralCel-OD or -OJ columns; and _CO2 mixtures with methanol, ethanol, 2-propanol or acetonitrile, alone or modified with trifluoroacetic acid or propan-2-amine. UV detection was used to trigger fraction collection. For syntheses that refer to procedures in other examples or methods, purification may vary: generally, the solvents and solvent ratios used for the eluents/gradients were selected to provide appropriate _RfS or retention times.

Mass spectrometry data are reported from LCMS analysis. Mass spectrometry (MS) was performed via atmospheric pressure chemical ionization (APCI), electrospray ionization (ESI), electron impact ionization (EI) or electron scattering (ES) ionization sources. Proton magnetic resonance spectroscopy ( ¹ H NMR) chemical shifts are reported in parts per million downfield from tetramethylsilane and were recorded on Varian, Bruker or Jeol analyzers at 300, 400, 500 or 600 MHz. Chemical shifts are expressed in parts per million (ppm, δ) referenced to deuterated solvent residual peaks (chloroform, 7.26 ppm; CD ₂ HOD, 3.31 ppm; acetonitrile-d ₂ , 1.94 ppm; dimethylsulfoxide-d ₅ , 2.50 ppm; DHO, 4.79 ppm). Peak shapes are described as follows: s, singlet; d, doublet; t, triplet; q, quartet; quin, quintet; m, multiplet; brs, broad singlet; app, apparent. Analytical SFC data were generally acquired on a Berger analytical instrument as described above. Optical rotation data were acquired on a PerkinElmer Model 343 polarimeter using a 1 dm cell. Microanalysis was performed by Quantitative Technologies Inc. and was within 0.4% of calculated values.

Unless otherwise noted, chemical reactions were carried out at room temperature (approximately 23 degrees Celsius).

Unless otherwise noted, all reactants were obtained commercially and used without further purification or were prepared using methods known in the literature.

The terms "concentrated," "evaporated," and "concentrated in vacuum" refer to removal of solvent at reduced pressure in a rotary evaporator with a bath temperature below 60° C. The abbreviations "min" and "h" stand for "minutes" and "hours," respectively. The term "TLC" refers to thin layer chromatography, "room or ambient temperature" means a temperature between 18° C. and 25° C., "GCMS" refers to gas chromatography-mass spectrometry, "LCMS" refers to liquid chromatography-mass spectrometry, "UPLC" refers to ultra-performance liquid chromatography, "HPLC" refers to high performance liquid chromatography, and "SFC" refers to supercritical fluid chromatography.

Hydrogenation can be carried out in a Parr shaker under pressurized hydrogen gas or in a Thales-nano H cube flow hydrogenator with full hydrogen and a flow rate between 1 and 2 mL/min at the specified temperature.

HPLC, UPLC, LCMS, GCMS, and SFC retention times were measured using the methods noted in the procedures.

In some examples, chiral separation was performed to separate the enantiomers or diastereoisomers of certain compounds of the invention (in some examples, the separated enantiomers are designated ENT-1 and ENT-2 according to their order of elution; similarly, the separated diastereoisomers are designated DIAST-1 and DIAST-2 according to their order of elution). In some examples, the optical rotation of the enantiomers was measured using a polarimeter. The enantiomer with clockwise rotation was designated the (+)-enantiomer and the enantiomer with counterclockwise rotation was designated the (-)-enantiomer according to its observed rotation data (or its specific rotation data). Racemates are designated either by the absence of a depicted or written stereochemistry or by the presence of (+/-) adjacent to the structure; in the latter case, the designated stereochemistry represents only one of the two enantiomers that make up the racemic mixture.

The compounds and intermediates described below were named using the naming conventions provided by ACD/ChemSketch 2017.2.1, file version C40H41, build 99535 (Advanced Chemistry Development, Inc., Toronto, Ontario, Canada). The naming conventions provided by ACD/ChemSketch 2017.2.1 are well known to those skilled in the art, and the naming conventions provided by ACD/ChemSketch 2017.2.1 are generally believed to conform to the IUPAC (International Union of Pure and Applied Chemistry) recommendations for the nomenclature of organic compounds and the CAS index rules.

The ¹ H NMR spectra of many of the compounds herein indicate mixtures of rotamers due to the presence of amide and/or carbamate functionalities and are tabulated to reflect the presence of more than one rotamer.

PREPARATIVE EXAMPLES Preparations P1 to P33 describe exemplary preparations of some of the starting materials or intermediates used in the preparation of certain compounds of the invention.

Preparation Example P1
2-(5-chloro-2-methoxypyridin-4-yl)propanoic acid (P1)

ステップ１． メチル（５－クロロ－２－メトキシピリジン－４－イル）アセテート（Ｃ１）の合成。
テトラヒドロフラン中のリチウムジイソプロピルアミドの溶液（２Ｍ；１．９Ｌ、３．８ｍｏｌ）を、テトラヒドロフラン（１．４Ｌ）中の５－クロロ－２－メトキシ－４－メチルピリジン（１９７ｇ、１．２５ｍｏｌ）の－３０℃溶液に滴下方式にて添加した。反応混合物を－３０℃で１時間にわたって撹拌した後に、炭酸ジメチル（３３８ｇ、３．７５ｍｏｌ）を滴下添加し；添加の終了時に、反応混合物を２５℃に加温し、１時間にわたって撹拌した。次いで、これを塩酸（０．５Ｍ、７Ｌ、３．５ｍｏｌ）に注ぎ入れ、酢酸エチル（２×１．５Ｌ）で抽出し；合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲルクロマトグラフィー（勾配：石油エーテル中０％から２０％酢酸エチル）により精製して、Ｃ１を黄色油として得た。収量：２０３ｇ、０．９４１ｍｏｌ、７５％。LCMS m/z 216.1 (塩素同位体パターンが観察された) [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ8.10 (s, 1H), 6.82 (s, 1H), 3.90 (s, 3H),
3.79 (s, 2H), 3.71 (s, 3H).

Step 1. Synthesis of methyl (5-chloro-2-methoxypyridin-4-yl)acetate (C1).
A solution of lithium diisopropylamide in tetrahydrofuran (2M; 1.9 L, 3.8 mol) was added dropwise to a −30° C. solution of 5-chloro-2-methoxy-4-methylpyridine (197 g, 1.25 mol) in tetrahydrofuran (1.4 L). The reaction mixture was stirred at −30° C. for 1 h before dimethyl carbonate (338 g, 3.75 mol) was added dropwise; at the end of the addition, the reaction mixture was warmed to 25° C. and stirred for 1 h. It was then poured into hydrochloric acid (0.5 M, 7 L, 3.5 mol) and extracted with ethyl acetate (2×1.5 L); the combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered and concentrated in vacuo. Purification by silica gel chromatography (gradient: 0% to 20% ethyl acetate in petroleum ether) afforded C1 as a yellow oil. Yield: 203 g, 0.941 mol, 75%. LCMS m/z 216.1 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.10 (s, 1H), 6.82 (s, 1H), 3.90 (s, 3H),
3.79 (s, 2H), 3.71 (s, 3H).

Step 2. Synthesis of methyl 2-(5-chloro-2-methoxypyridin-4-yl)propanoate (C2).
To a −78° C. solution of C1 (175 g, 0.812 mol) in tetrahydrofuran (1.2 L) was added a solution of sodium bis(trimethylsilyl)amide in tetrahydrofuran (2 M; 455 mL, 0.910 mol) in a dropwise manner. The reaction mixture was stirred at −78° C. for 1 h, whereupon a solution of iodomethane (172.6 g, 1.216 mol) in tetrahydrofuran (100 mL) was added dropwise at −78° C. and stirring was continued at this temperature for 2 h. The reaction mixture was then poured into saturated aqueous ammonium chloride solution (500 mL) and extracted with ethyl acetate (2×100 mL); the combined organic layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated in vacuo to provide C2 as a brown oil. NMR and LCMS analysis showed that this material was contaminated with some of the dimethylated by-product methyl 2-(5-chloro-2-methoxypyridin-4-yl)-2-methylpropanoate. Yield: 136 g, .about.0.592 mol, .about.73%. LCMS m/z 230.1 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ), product peaks only: δ 8.10 (s, 1H), 6.76 (s, 1H), 4.10 (q, J = 7.2 Hz, 1H), 3.89 (s, 3H),
3.69 (s, 3H), 1.48 (d, J = 7.2 Hz, 3H).

Step 3. Synthesis of 2-(5-chloro-2-methoxypyridin-4-yl)propanoic acid (P1).
To a 25° C. solution of C2 (168 g, 0.732 mol) in tetrahydrofuran (1 L) was added a solution of lithium hydroxide monohydrate (61.4 g, 0.146 mol) in water (300 mL) in a dropwise manner at 25° C. The mixture was stirred for 2 h whereupon it was concentrated in vacuo. The aqueous residue was poured into water (500 mL) and washed with tert-butyl methyl ether (2×500 mL). The aqueous layer was then adjusted to pH 4 by adding 3 M hydrochloric acid and extracted with ethyl acetate (2×500 mL); the combined ethyl acetate layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated under reduced pressure to provide P1 as a white solid. Yield: 122 g, 0.566 mol, 77%. LCMS m/z 216.1 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.10 (s, 1H), 6.79 (s, 1H), 4.06 (q, J =
7.1 Hz, 1H), 3.89 (s, 3H), 1.48 (d, J = 7.2 Hz, 3H).

Preparation Examples P2 and P3
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)propanoic acid (P2) and (2S)-2-(5-chloro-2-methoxypyridin-4-yl)propanoic acid (P3)

Ｐ１（５．００ｇ、２３．２ｍｍｏｌ）の、その構成要素の鏡像異性体への分離を、超臨界流体クロマトグラフィー（カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＩＧ、３０×２５０ｍｍ、５μｍ；移動相：９５：５ 二酸化炭素／メタノール；流速：８０ｍＬ／分；背圧：１２０バール）により行った。第１に溶離する鏡像異性体、静置すると固化した油状物をＰ２として、第２に溶離する鏡像異性体をＰ３として指定した。

Separation of P1 (5.00 g, 23.2 mmol) into its constituent enantiomers was carried out by supercritical fluid chromatography (column: Chiral Technologies Chiralpak IG, 30×250 mm, 5 μm; mobile phase: 95:5 carbon dioxide/methanol; flow rate: 80 mL/min; back pressure: 120 bar). The first eluting enantiomer, an oil that solidified on standing, was designated P2 and the second eluting enantiomer was designated P3.

The absolute stereochemistry indicated was assigned by X-ray crystal structure determination of 15, synthesized using this lot of P2 (see Example 15, Alternative Step 3 below).
P2-Yield: 2.4 g, 11.1 mmol, 48%. ¹ H NMR (400 MHz, chloroform-d) δ 8.13 (s, 1H), 6.75 (s, 1H), 4.12 (q, J = 7.2 Hz, 1H), 3.91 (s, 3H),
1.53 (d, J = 7.2 Hz, 3H). Retention time: 3.98 min (Analytical conditions: Column: Chiral Technologies Chiralpak IG, 4.6 x 250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: methanol; Gradient: 5% B over 1.00 min, then 5% to 60% B over 8 min; Flow rate: 3.0 mL/min; Back pressure: 120 bar).
P3 - Yield: 2.4 g, 11.1 mmol, 48%. Retention time: 4.22 min (same analytical conditions as used for P2).

Preparation Example P4
Lithium 2-(6-methoxy-2-methylpyrimidin-4-yl)propanoate (P4)

ステップ１． ジメチル（６－メトキシ－２－メチルピリミジン－４－イル）（メチル）プロパンジオエート（Ｃ３）およびメチル２－（６－メトキシ－２－メチルピリミジン－４－イル）プロパノエート（Ｃ４）の合成。
水素化ナトリウム（鉱油中６０％；１．１４ｇ、２８．５ｍｍｏｌ）を、Ｎ，Ｎ－ジメチルホルムアミド（２５ｍＬ）中のジメチルメチルプロパンジオエート（５．５３ｇ、３７．８ｍｍｏｌ）の溶液に添加した。３０分後に、４－クロロ－６－メトキシ－２－メチルピリミジン（３．００ｇ、１８．９ｍｍｏｌ）を添加し、その後すぐに、反応混合物を１００℃で１６時間にわたって加熱した。次いで、これを水（１５０ｍＬ）で希釈し、酢酸エチル（３×５０ｍＬ）で抽出し；合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮し、シリカゲルクロマトグラフィー（勾配：石油エーテル中０％から１０％酢酸エチル）により精製して、生成物（２．６０ｇ）を黄色油として得た。ＮＭＲおよびＬＣＭＳ分析を基に、これは、Ｃ３およびＣ４の不純な混合物であると判断され、これをそのまま、次のステップに持ち込んだ。LCMS m/z 211.1および269.2
[M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄), 特徴的ピーク: δ 6.68 (s), 6.60
(s), 3.96 (s), 3.94 (s), 3.81 (q, J = 7.2 Hz), 3.75 (s), 3.68 (s), 2.54 (s),
2.52 (s), 1.79 (s), 1.47 (d, J = 7.3 Hz).

Step 1. Synthesis of dimethyl (6-methoxy-2-methylpyrimidin-4-yl)(methyl)propanedioate (C3) and methyl 2-(6-methoxy-2-methylpyrimidin-4-yl)propanoate (C4).
Sodium hydride (60% in mineral oil; 1.14 g, 28.5 mmol) was added to a solution of dimethyl methylpropanedioate (5.53 g, 37.8 mmol) in N,N-dimethylformamide (25 mL). After 30 min, 4-chloro-6-methoxy-2-methylpyrimidine (3.00 g, 18.9 mmol) was added whereupon the reaction mixture was heated at 100° C. for 16 h. It was then diluted with water (150 mL) and extracted with ethyl acetate (3×50 mL); the combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, concentrated in vacuo, and purified by silica gel chromatography (gradient: 0% to 10% ethyl acetate in petroleum ether) to give the product (2.60 g) as a yellow oil. Based on NMR and LCMS analysis, this was determined to be an impure mixture of C3 and C4, which was carried on directly to the next step. LCMS m/z 211.1 and 269.2
[M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ), characteristic peaks: δ 6.68 (s), 6.60
(s), 3.96 (s), 3.94 (s), 3.81 (q, J = 7.2 Hz), 3.75 (s), 3.68 (s), 2.54 (s),
2.52 (s), 1.79 (s), 1.47 (d, J = 7.3 Hz).

Step 2. Synthesis of lithium 2-(6-methoxy-2-methylpyrimidin-4-yl)propanoate (P4).
A solution of C3 and C4 (from the previous step; 2.60 g, ∼18.9 mmol) and lithium hydroxide monohydrate (1.22 g, 29.1 mmol) in a mixture of tetrahydrofuran (45 mL) and water (15 mL) was stirred at 45° C. for 3 h. After the reaction mixture was concentrated in vacuo, the residue was lyophilized to provide P4 as a white solid. Yield: 2.3 g, 11 mmol, 58% for two steps. LCMS m/z 197.1 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 6.66 (s, 1H), 3.94 (s, 3H), 3.61 (q, J =
7.3 Hz, 1H), 2.53 (s, 3H), 1.44 (d, J = 7.2 Hz, 3H).

Preparation Example P5
2-[6-(difluoromethoxy)pyridin-3-yl]propanoic acid (P5)

ステップ１． ２－（ジフルオロメトキシ）－５－ヨードピリジン（Ｃ５）の合成。
ナトリウムクロロ（ジフルオロ）アセテート（４．６２ｇ、３０．３ｍｍｏｌ）および炭酸カリウム（５．５８ｇ、４０．４ｍｍｏｌ）を、Ｎ，Ｎ－ジメチルホルムアミド（１００ｍＬ）中の５－ヨードピリジン－２－オール（４．４６ｇ、２０．２ｍｍｏｌ）の２５℃溶液に添加し、反応混合物を５０℃で１６時間にわたって撹拌した。次いで、これを水（５００ｍＬ）で希釈し、酢酸エチル（３×１００ｍＬ）で抽出し、合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲル上でのクロマトグラフィー（勾配：石油エーテル中０％から８％酢酸エチル）は、Ｃ５を油状物として提供した。収量：２．１０ｇ、７．７５ｍｍｏｌ、３８％。¹H NMR (400 MHz, クロロホルム-d) δ 8.39 (br d, J = 2.2 Hz, 1H), 7.97 (dd, J = 8.6, 2.3 Hz, 1H), 7.40
(t, J_HF = 72.6 Hz, 1H), 6.74 (br d, J = 8.6 Hz, 1H).

Step 1. Synthesis of 2-(difluoromethoxy)-5-iodopyridine (C5).
Sodium chloro(difluoro)acetate (4.62 g, 30.3 mmol) and potassium carbonate (5.58 g, 40.4 mmol) were added to a 25° C. solution of 5-iodopyridin-2-ol (4.46 g, 20.2 mmol) in N,N-dimethylformamide (100 mL) and the reaction mixture was stirred at 50° C. for 16 h. It was then diluted with water (500 mL) and extracted with ethyl acetate (3×100 mL) and the combined organic layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated in vacuo. Chromatography on silica gel (gradient: 0% to 8% ethyl acetate in petroleum ether) provided C5 as an oil. Yield: 2.10 g, 7.75 mmol, 38%. ^1H NMR (400 MHz, chloroform-d) δ 8.39 (br d, J = 2.2 Hz, 1H), 7.97 (dd, J = 8.6, 2.3 Hz, 1H), 7.40
(t, J _HF = 72.6 Hz, 1H), 6.74 (br d, J = 8.6 Hz, 1H).

Step 2. Synthesis of diethyl [6-(difluoromethoxy)pyridin-3-yl]propanedioate (C6).
A mixture of C5 (1.9 g, 7.0 mmol), diethylpropanedioate (1.68 g, 10.5 mmol), copper(I) iodide (133 mg, 0.698 mmol), pyridine-2-carboxylic acid (172 mg, 1.40 mmol), and cesium carbonate (7.42 g, 22.8 mmol) in tetrahydrofuran (50 mL) was stirred at 80° C. for 16 h, whereupon the reaction mixture was diluted with ethyl acetate (100 mL) and washed with aqueous ammonium chloride (100 mL). The aqueous layer was extracted with ethyl acetate (2×50 mL) and the combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Purification using silica gel chromatography (gradient: 0% to 15% ethyl acetate in petroleum ether) afforded C6 as a colorless oil (2.4 g). By ¹ H NMR analysis, this material contained residual diethylpropanedioate; a portion of this sample was carried directly into the next step. LCMS m/z 304.0 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d), product peak only: δ 8.14 (br s, 1H),
7.90 (br d, J = 8.4 Hz, 1H), 7.45 (t, J _HF = 72.9 Hz, 1H), 6.92 (d, J
= 8.4 Hz, 1H), 4.59 (s, 1H), 4.26 - 4.17 (m, 4H, presumed; partially obscured by residual diethylpropanedioate), 1.31 - 1.24 (m, 6H, presumed; partially obscured by residual diethylpropanedioate).

Step 3. Synthesis of diethyl[6-(difluoromethoxy)pyridin-3-yl](methyl)propanedioate (C7).
To a solution of C6 (from the previous step; .about.750 mg, 2.2 mmol) in N,N-dimethylformamide (15 mL) was added potassium carbonate (1.03 g, 7.45 mmol). Iodomethane (527 mg, 3.71 mmol) was added dropwise and the reaction mixture was stirred at 25° C. for 4 h. This was then combined with a similar reaction carried out using C6 (.about.250 mg, 0.73 mmol), poured into water (200 mL) and extracted with ethyl acetate (2×50 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate and concentrated in vacuo; chromatography on silica gel (gradient: 0% to 15% ethyl acetate in petroleum ether) provided C7 as an oil. Combined yield: 738 mg, 2.33 mmol, 80% for two steps. LCMS m/z 318.2 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.20 (br s, 1H), 7.81 (br d, J = 8.7 Hz, 1H), 7.45 (t, J _HF
= 72.9 Hz, 1H), 6.90 (d, J = 8.7 Hz, 1H), 4.30 - 4.18 (m, 4H), 1.87 (s, 3H),
1.27 (t, J = 7.1 Hz, 6H).

Step 4. Synthesis of 2-[6-(difluoromethoxy)pyridin-3-yl]propanoic acid (P5).
To a 25° C. solution of C7 (738 mg, 2.33 mmol) in tetrahydrofuran (10 mL) was added a solution of lithium hydroxide (279 mg, 11.6 mmol) in water (3 mL). The reaction mixture was stirred at 25° C. for 16 h whereupon it was diluted with water (100 mL) and washed with dichloromethane (3×50 mL). The organic layers were discarded. The aqueous layer was adjusted to pH 5 by adding 5 M hydrochloric acid before being extracted with dichloromethane (3×50 mL); the combined organic layers were concentrated in vacuo to give P5 as a solid. Yield: 337 mg, 1.55 mmol, 67%. LCMS m/z 218.1 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.15 (d, J = 2.5 Hz, 1H), 7.83 (dd, J =
8.5, 2.5 Hz, 1H), 7.51 (t, J _HF = 73.2 Hz, 1H), 6.94 (d, J = 8.5 Hz,
1H), 3.78 (q, J = 7.2 Hz, 1H), 1.49 (d, J = 7.2 Hz, 3H).

Preparation Example P6
2-(5-Fluoro-2-methoxypyridin-4-yl)propanoic acid (P6)

ステップ１． ジベンジル（５－フルオロ－２－メトキシピリジン－４－イル）プロパンジオエート（Ｃ８）の合成。
この反応を３つの並列バッチで行った。テトラヒドロフラン（１．５Ｌ）中のジベンジルプロパンジオエート（６０７ｇ、２．１３ｍｏｌ）の２５℃溶液に、ピリジン－２－カルボン酸（３５．０ｇ、２８４ｍｍｏｌ）、続いて、ヨウ化銅（Ｉ）（２７．１ｇ、１４２ｍｍｏｌ）、次いで、新たに粉砕された炭酸セシウム（１．３９ｋｇ、４．２７ｍｏｌ）を添加した。反応混合物を７０℃に加熱した後に、これを、テトラヒドロフラン（８００ｍＬ）中の５－フルオロ－４－ヨード－２－メトキシピリジン（３６０ｇ、１．４２ｍｏｌ）の溶液で滴下方式にて処理し、その後すぐに、撹拌を７０℃で１６時間にわたって継続した。

Step 1. Synthesis of dibenzyl (5-fluoro-2-methoxypyridin-4-yl)propanedioate (C8).
The reaction was carried out in three parallel batches. To a 25° C. solution of dibenzylpropanedioate (607 g, 2.13 mol) in tetrahydrofuran (1.5 L) was added pyridine-2-carboxylic acid (35.0 g, 284 mmol), followed by copper(I) iodide (27.1 g, 142 mmol), then freshly ground cesium carbonate (1.39 kg, 4.27 mol). After heating the reaction mixture to 70° C., it was treated dropwise with a solution of 5-fluoro-4-iodo-2-methoxypyridine (360 g, 1.42 mol) in tetrahydrofuran (800 mL), whereupon stirring was continued at 70° C. for 16 h.

The three reaction mixtures were now combined, cooled to 25° C., and filtered through diatomaceous earth. The filter pads were rinsed with ethyl acetate (3×500 mL), and the combined filtrates were concentrated in vacuo, keeping the internal temperature below 40° C. The residue was dissolved in ethyl acetate (2 L), washed successively with saturated aqueous ammonium chloride (500 mL) and saturated aqueous sodium chloride (500 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure at 40° C. Chromatography on silica gel (gradient: 1% to 8% ethyl acetate in petroleum ether) afforded C8 (1.87 kg) as a yellow oil. By ¹ H NMR analysis, this material was contaminated with dibenzylpropanedioate; a portion of this was used in the next step. LCMS m/z 410.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d), product peak only: δ 8.01 (d, J = 1.3
Hz, 1H), 7.40 - 7.25 (m, 10H, estimated; partially obscured by residual dibenzylpropanedioate), 6.83 (d, J = 4.8 Hz, 1H), 5.20 (AB quartet, J _AB = 12.2 Hz, Δν _AB = 11.9 Hz, 4H), 5.00 (s, 1H), 3.89
(s, 3H).

Step 2. Synthesis of dibenzyl (5-fluoro-2-methoxypyridin-4-yl)(methyl)propanedioate (C9).
The reaction was carried out in two parallel batches. A solution of C8 (from the previous step; 575 g, 1.31 mol) in acetonitrile (1.5 L) was stirred in an ice-water bath for 20 minutes, whereupon potassium carbonate (582 g, 4.21 mol) was added. Stirring was continued for another 10 minutes. Iodomethane (302 g, 2.13 mol) was then added to the reaction mixture at 0° C., and the reaction was allowed to proceed until LCMS analysis indicated conversion to C9. After combining the two reaction mixtures, they were filtered through diatomaceous earth and the filter cake was washed with acetonitrile (2×1 L). The combined filtrate was concentrated at 40° C., and the residue was partitioned between ethyl acetate (2 L) and water (500 mL). The aqueous layer was extracted with ethyl acetate (2×1 L), and the combined organic layers were washed with saturated aqueous sodium chloride solution (1 L), dried over sodium sulfate, filtered, and concentrated under reduced pressure at 40° C. The resulting crude product was dissolved in petroleum ether (1.5 L) and stirred at 0° C. for 2 h; the solid was collected by filtration. The filtrate was concentrated in vacuo and the residue was dissolved in petroleum ether (500 mL) and then cooled to 0° C. to provide an additional solid, which was isolated by filtration. The two solids were combined, suspended in petroleum ether (800 mL) and stirred at 20° C. for 16 h. It was then collected by filtration to give C9 as a yellow solid. Yield: 670 g, 1.58 mol, 60% for two steps. LCMS m/z 423.8 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.94 (d, J = 2.6 Hz, 1H), 7.36 - 7.20 (m, 10H), 6.54 (d, J = 5.1
Hz, 1H), 5.18 (s, 4H), 3.87 (s, 3H), 1.85 (s, 3H).

Step 3. Synthesis of 2-(5-fluoro-2-methoxypyridin-4-yl)propanoic acid (P6).
The reaction was carried out in four parallel batches. To a 25° C. solution of C9 (200 g, 472 mmol) in ethyl acetate (1 L) was added 10% palladium on carbon (wet; 40 g). The mixture was degassed under vacuum and then purged with nitrogen; this evacuation-purge cycle was performed a total of three times. The mixture was again degassed under vacuum and then purged with hydrogen; this evacuation-purge cycle was also performed a total of three times. The mixture was hydrogenated (30 psi) at 50° C. for 16 h. The four reaction mixtures were combined and filtered through a pad of diatomaceous earth, and the filtrate was concentrated in vacuo at 45° C. Chromatography on silica gel (gradient: 10% to 20% ethyl acetate in petroleum ether) provided P6 as a white solid. Combined yield: 270 g, 1.36 mmol, 72%. LCMS m/z 199.7 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.98 (d, J = 1.7 Hz, 1H), 6.70 (d, J = 4.9 Hz, 1H), 3.97 (q, J =
7.3 Hz, 1H), 3.89 (s, 3H), 1.53 (d, J = 7.3 Hz, 3H).

Preparations P7 and P8
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)propanoic acid (P7) and (2S)-2-(5-fluoro-2-methoxypyridin-4-yl)propanoic acid (P8)

Ｐ６（７００ｇ、３．５１ｍｏｌ）の、その構成要素の鏡像異性体への分離を、超臨界流体クロマトグラフィー（カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＡＤ－Ｈ、５０×２５０ｍｍ、５μｍ；移動相：９：１ 二酸化炭素／２－プロパノール；流速：２５０ｍＬ／分；背圧：１２０バール）により行った。第１に溶離する鏡像異性体をＰ７として、第２に溶離する鏡像異性体をＰ８として指定し；両方を固体として単離した。
Ｐ７－収量：２６０ｇ、１．３０ｍｏｌ、３７％。保持時間：３．１７分（分析条件。カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＡＤ－Ｈ、４．６×２５０ｍｍ、５μｍ；移動相Ａ：二酸化炭素；移動相Ｂ：２－プロパノール；勾配：Ｂ５％を１．００分間にわたって、次いで、８分かけてＢ５％から６０％へ；流速：３．０ｍＬ／分；背圧：１２０バール）。
Ｐ８－収量：４００ｇ、２．０１ｍｏｌ、５７％。保持時間：３．３６分（Ｐ７で使用されたものと同一の分析条件）。

Separation of P6 (700 g, 3.51 mol) into its constituent enantiomers was carried out by supercritical fluid chromatography (column: Chiral Technologies Chiralpak AD-H, 50×250 mm, 5 μm; mobile phase: 9:1 carbon dioxide/2-propanol; flow rate: 250 mL/min; back pressure: 120 bar). The first eluting enantiomer was designated as P7 and the second eluting enantiomer as P8; both were isolated as solids.
P7 - Yield: 260 g, 1.30 mol, 37%. Retention time: 3.17 min (Analytical conditions: Column: Chiral Technologies Chiralpak AD-H, 4.6 x 250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: 2-propanol; Gradient: 5% B over 1.00 min, then 5% to 60% B over 8 min; Flow rate: 3.0 mL/min; Back pressure: 120 bar).
P8 - Yield: 400 g, 2.01 mol, 57%. Retention time: 3.36 min (same analytical conditions as used for P7).

The absolute stereochemistry indicated for P7 and P8 was assigned based on comparison with a sample of P7 synthesized in an alternative preparation of P7 (#1); the configuration of that material was established by X-ray crystallographic studies of the derived compound 14 (see below).
Retention time for P7 from preparative examples P7 and P8: 2.86 min.
Retention time for P7 from an alternative preparation of P7 (#1): 2.86 min.
Retention times for racemic mixture of P7 and P8: 2.87 and 3.16 min.
These three analyses were performed using the same analytical method: [Column: Chiral Technologies Chiralpak IG, 4.6 x 250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: methanol; Gradient: 5% B over 1 min, then 5% to 60% B over 7 min; Flow rate: 3 mL/min; Back pressure: 120 bar].

Alternative Preparation of P7 (#1)
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)propanoic acid (P7)

ステップ１． ジナトリウム（５－フルオロ－２－メトキシピリジン－４－イル）（メチル）プロパンジオエート（Ｃ１０）の合成。
１．０Ｍ、ｐＨ８．０緩衝液を次の方式で調製した：水（９００ｍＬ）中の２－アミノ－２－（ヒドロキシメチル）プロパン－１，３－ジオール（Ｔｒｉｓ；１２１ｇ、１．００ｍｏｌ）の溶液を、塩酸（３７．５重量％、およそ４０ｍＬ）を添加することによりｐＨ８．０に調節し、次いで、水を添加することにより１Ｌの体積にした。

Step 1. Synthesis of disodium (5-fluoro-2-methoxypyridin-4-yl)(methyl)propanedioate (C10).
A 1.0 M, pH 8.0 buffer solution was prepared in the following manner: a solution of 2-amino-2-(hydroxymethyl)propane-1,3-diol (Tris; 121 g, 1.00 mol) in water (900 mL) was adjusted to pH 8.0 by adding hydrochloric acid (37.5 wt %, approximately 40 mL) and then brought to a volume of 1 L by adding water.

A hydrogenation reactor was charged with palladium hydroxide on carbon (10%; 5.00 g). To this was added a solution of C9 (50.0 g, 118 mmol) in toluene (50 mL, 1 volume); additional toluene (50 mL) was used to rinse the flask, which was also added to the reaction mixture. A mixture of aqueous sodium hydroxide (2.0 M, 118 mL, 236 mmol), the above pH 8.0 buffer (1.0 M; 250 mL, 250 mmol), and water (132 mL) was added, and the resulting mixture was purged with nitrogen (3.5 bar), followed by hydrogen (3.5 bar); this purging process was performed a total of three times. After the mixture was brought to 20° C. with stirring at 100 rpm, it was pressurized with hydrogen to 3.45 bar, whereupon the stirring speed was increased to 750 rpm. Hydrogenation was allowed to proceed for 4 h at 20° C. after which the stirring speed was reduced to 250 rpm and the reaction was purged three times with nitrogen (3.5 bar). The catalyst was removed by filtration and the reactor was rinsed with water (100 mL), which was then used to wash the filter cake. The aqueous phase of the combined filtrate (590 mL, pH 8.2), containing C10, was carried directly onto the next step. LCMS m/z 244.2 [M+H] ⁺ .

Step 2. Synthesis of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)propanoic acid (P7).
A 2L jacketed vessel equipped with an overhead stirrer (set at 20° C. jacket temperature) was charged with C10 (aqueous solution from the previous step; ∼118 mmol) and the stirring speed was set at 200 rpm. Then Bordetella bronchiseptica AMDase lyophilized cell-free extract powder (1.75 gm) in water (17.5 mL) [This arylmalonate decarboxylase (AMDase) from Bordetella bronchiseptica is a wild-type enzyme described in the literature with accession number Q05115, which was recombinantly expressed in E. coli and charged as a lyophilized cell-free extract powder. References: S. K., et al., J. Am. Chem. Soc. 1999, 143:1311-1323, 1999, 1999, 1999, 1999, 1999, 1999, 1999, 1999, 1999, 1999, 1999, 1999, 1990, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 19 ... A solution of 1,2-dichlorophenyl ether (Gassmeyer et al., ChemCatChem, 2016, 8, 916-921; K. Okrasa et al., Angew. Chem. Int. Ed. 2009, 48, 7691-7694) was charged to the reactor along with a water rinse (5 mL) of the enzyme vessel. After 15 hours, the stirring speed was reduced to 100 rpm and the pH of the reaction mixture was adjusted to pH 6.0 by sequential addition of hydrochloric acid (4.0 M, 5 mL portions, 38 mL). At this point, the mixture was stirred for 1.5 hours to allow gas evolution to subside, whereupon it was acidified to a pH of 2.0 or less by further addition of hydrochloric acid (4.0 M, 85 mL total). tert-Butyl methyl ether (300 mL) was added and stirring was continued at 200 rpm for 15 minutes. The mixture was then filtered through diatomaceous earth (25 g) using a Buchner funnel and filter paper; the reactor was rinsed with tert-butyl methyl ether (100 mL), which was then used to wash the filter cake. The aqueous layer of the combined filtrate was extracted in the same manner with tert-butyl methyl ether (300 mL). The combined organic layers were dried over sodium sulfate (50 g) and filtered; the filter cake was washed with tert-butyl methyl ether (25 mL). The combined filtrate was concentrated in vacuo at 30° C. to provide an oil that solidified under vacuum drying overnight to give P7 as an off-white solid. Yield: 18.88 g, 94.8 mmol, 80% for two steps. ^1H NMR (400 MHz, chloroform-d) δ 11.4 - 10.3 (br s, 1H), 7.98 (d, J = 1.6 Hz, 1H), 6.70 (d, J = 4.9
Hz, 1H), 3.97 (q, J = 7.2 Hz, 1H), 3.89 (s, 3H), 1.53 (d, J = 7.2 Hz, 3H).

P7 (18.6 g, 93.4 mmol) from the previous step and P7 (24.9 g, 125 mmol) from a similar reaction of C10 with AMDase were combined to give a slightly pink solid with an enantiomeric excess of 98.5%. ^1H NMR (400 MHz, methanol- _d4 ) δ 7.94 (d, J = 1.9 Hz, 1H), 6.74 (d, J = 5.0
Hz, 1H), 3.93 (q, J = 7.3 Hz, 1H), 3.87 (s, 3H), 1.48 (d, J = 7.3 Hz, 3H).Retention time: 2.86 min [Column: Chiral Technologies Chiralpak IG, 4.6 x 250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: methanol; Gradient: 5% B over 1 min, then 5% to 60% B over 7 min; Flow rate: 3 mL/min; Back pressure: 120 bar].

The indicated absolute stereochemistry of P7 was assigned based on conversion of this lot of P7 to Example 14; the absolute stereochemistry of 14 was established by single crystal X-ray analysis (see below).

Alternative Preparation of P7 (#2)
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)propanoic acid (P7)

ステップ１． ジベンジル（５－フルオロ－２－メトキシピリジン－４－イル）プロパンジオエート（Ｃ８）の合成。
テトラヒドロフラン（１．２６Ｌ；５体積）中のピリジン－２－カルボン酸（２４．６ｇ、０．２００ｍｏｌ）、ヨウ化銅（Ｉ）（１９．１ｇ、０．１００ｍｏｌ）、および炭酸セシウム（９７７ｇ、３．００ｍｏｌ）の混合物を６０℃から７０℃の内部温度に加熱し、その後すぐに、テトラヒドロフラン（２５０ｍＬ、１体積）中の５－フルオロ－４－ヨード－２－メトキシピリジン（２５３ｇ、１．００ｍｏｌ）およびジベンジルプロパンジオエート（４２６ｇ、１．５０ｍｏｌ）の溶液を添加した。反応混合物を６０℃から７０℃で、およそ３から６時間にわたって加熱した後に、これを１５℃から３０℃に冷却させ、珪藻土（２５０ｇ）を通して濾過した。濾過ケーキをテトラヒドロフラン（５００ｍＬ、２体積）で洗浄し、Ｃ８を含有する合わせた濾液をそのまま、次のステップで使用した。代表的な¹H NMR (500 MHz, クロロホルム-d) δ 8.00 (d, J = 1.3 Hz, 1H), 7.40 - 7.24 (m, 10H, 推定; 残留ジベンジルプロパンジオエートにより一部不明確), 6.82 (d, J = 4.8 Hz, 1H), 5.20 (AB四重線, J_AB = 12.3 Hz, Δν_AB = 14.9 Hz, 4H), 4.99 (s, 1H), 3.88
(s, 3H).

Step 1. Synthesis of dibenzyl (5-fluoro-2-methoxypyridin-4-yl)propanedioate (C8).
A mixture of pyridine-2-carboxylic acid (24.6 g, 0.200 mol), copper(I) iodide (19.1 g, 0.100 mol), and cesium carbonate (977 g, 3.00 mol) in tetrahydrofuran (1.26 L; 5 volumes) was heated to an internal temperature of 60° C. to 70° C., whereupon a solution of 5-fluoro-4-iodo-2-methoxypyridine (253 g, 1.00 mol) and dibenzylpropanedioate (426 g, 1.50 mol) in tetrahydrofuran (250 mL, 1 volume) was added. After the reaction mixture was heated at 60° C. to 70° C. for approximately 3 to 6 hours, it was allowed to cool to 15° C. to 30° C. and filtered through diatomaceous earth (250 g). The filter cake was washed with tetrahydrofuran (500 mL, 2 volumes) and the combined filtrate containing C8 was used directly in the next step. Representative ^1H NMR (500 MHz, chloroform-d) δ 8.00 (d, J = 1.3 Hz, 1H), 7.40 - 7.24 (m, 10H, estimated; partially obscured by residual dibenzylpropanedioate), 6.82 (d, J = 4.8 Hz, 1H), 5.20 (AB quartet, J _AB = 12.3 Hz, Δν _AB = 14.9 Hz, 4H), 4.99 (s, 1H), 3.88
(s, 3H).

Step 2. Synthesis of dibenzyl (5-fluoro-2-methoxypyridin-4-yl)(methyl)propanedioate (C9).
Iodomethane (284 g, 2.00 mol) was added slowly to a 10° C.-20° C. mixture of cesium carbonate (977 g, 3.00 mol) and a solution of C8 (from the previous step, solution in tetrahydrofuran; ≦1.00 mol). After the reaction mixture was stirred at 10° C.-20° C. for approximately 10-12 hours, it was filtered through diatomaceous earth (250 g). The filter cake was washed with tetrahydrofuran (500 mL, 1.2 vol) and the combined filtrate was concentrated to 1-2 vol. The resulting mixture was diluted with propan-2-yl acetate (1.25 L, 3.1 vol), washed successively with water (750 mL, 1.8 vol), aqueous ammonium chloride (20%; 750 mL), and aqueous sodium chloride (20%; 750 mL), and concentrated in vacuo. The remaining solvent was exchanged with heptane and precipitation proceeded from heptane (2-3 volumes) at 15-25° C. The resulting solid was collected by filtration and triturated with a mixture of heptane (450 mL) and propan-2-yl acetate (50 mL) to give C9 as a solid. Three batches of chemistry in steps 1 and 2 were performed and the final lot of C9 was combined. Yield: 675 g, 1.59 mol, approximately 53% for the two steps. Representative ¹ H NMR (500 MHz, DMSO-d ₆ ) δ 8.15 (d, J = 2.0 Hz, 1H), 7.39 - 7.21 (m,
10H), 6.75 (d, J = 5.0 Hz, 1H), 5.21 (s, 4H), 3.81 (s, 3H), 1.81 (s, 3H).

Step 3. Synthesis of disodium (5-fluoro-2-methoxypyridin-4-yl)(methyl)propanedioate (C10).
Buffer solution [pH 8.0; 2-amino-2-(hydroxymethyl)propane-1,3-diol (Tris; 121 g, 1.00 mol) in water (1 L, 5 vol.), and concentrated hydrochloric acid (46 mL, 0.23 vol.)] and palladium hydroxide on carbon (10%, 20 g) were added to a 15° C. to 25° C. mixture of C9 (200 g, 0.472 mol) in toluene (400 mL, 2 vol.). A solution of sodium hydroxide (38.8 g, 0.970 mol) in water (1 L, 5 vol.) was added whereupon the mixture was stirred for approximately 10 to 20 minutes. The reactor was purged with nitrogen and then with hydrogen, and the reaction mixture was stirred under a bag of hydrogen (approximately 10 L) at 15° C. to 30° C. until HPLC analysis indicated that no more than 0.5% C9 was present (approximately 22 hours). (Retention time: 11.44 min. HPLC conditions: Column: Agilent Technologies ZORBAX Eclipse Plus C18, 4.6×100 mm, 3.5 μm; Mobile phase A: 0.1% phosphoric acid in water; Mobile phase B: acetonitrile; Gradient: 5% B over 3 min, then 5% to 100% B over 9 min, then 100% B over 3 min; Flow rate: 1.5 mL/min.) The reaction mixture was filtered and the filter cake was washed with water (2.6 vol.); the aqueous layer of the filtrate, containing C10, was carried directly into the next step.

Step 4. Synthesis of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)propanoic acid (P7).
A mixture of AMDase (7 g) in water (70 mL, 0.35 vol) and C10 (-0.472 mol as solution in water from the previous step) was stirred at 15°C to 30°C until HPLC analysis indicated that -0.5% C10 was present (approximately 16 h). [Retention time: 5.80 min. Identical HPLC conditions as described in step 3, synthesis of disodium (5-fluoro-2-methoxypyridin-4-yl)(methyl)propanedioate (C10)]. Hydrochloric acid (4.0 M) was then added slowly until the pH of the reaction mixture reached 6.0, whereupon stirring was continued for 1.5 h. The pH was then adjusted to -2.0 (range, 1.5 to 2.0) by further addition of hydrochloric acid (4.0 M). After addition of tert-butyl methyl ether (1.2 L, 6 vol), the mixture was filtered through diatomaceous earth (100 g) and the aqueous phase of the filtrate was extracted with tert-butyl methyl ether (800 mL, 4 vol). The combined organic layers were washed with aqueous sodium chloride (15%; 600 mL, 3 vol) and concentrated to 2-2.5 vol at a temperature of 45° C. or less and a pressure of −0.08 MPa or less. n-Heptane (600 mL, 3 vol) was added and the mixture was concentrated to 3-5 vol at a temperature of 45° C. or less and a pressure of −0.08 MPa or less; this heptane dilution/concentration was performed a total of three times. The resulting mixture was stirred at 0° C. to 10° C. for approximately 1-2 h before the precipitate was collected by filtration to provide P7 as an off-white solid with an enantiomeric excess of 99.8%. Yield: 80.0 g, 0.402 mol, 85% for two steps. Representative ^1H NMR (500 MHz, chloroform-d) δ 11.68 (v br s, 1H), 7.99 (br s, 1H), 6.70 (d, J = 4.9 Hz, 1H), 3.97
(q, J = 7.2 Hz, 1H), 3.88 (s, 3H), 1.52 (d, J = 7.3 Hz, 3H).

Preparation Example P9
2-[5-(difluoromethyl)-2-methoxypyridin-4-yl]propanoic acid (P9)

ステップ１． メチル２－（５－ブロモ－２－メトキシピリジン－４－イル）プロパノエート（Ｃ１１）の合成。
テトラヒドロフラン中のナトリウムビス（トリメチルシリル）アミドの溶液（２Ｍ；１ｍＬ、２ｍｍｏｌ）を、テトラヒドロフラン（５０ｍＬ）中のメチル（５－ブロモ－２－メトキシピリジン－４－イル）アセテート（４１５ｍｇ、１．６０ｍｍｏｌ）の－７８℃溶液に滴下添加した。反応混合物を－７８℃で１時間にわたって撹拌した後に、ヨードメタンの溶液（０．５ｍＬ、８ｍｍｏｌ）を滴下添加した。添加の完了時に、反応混合物を－３０℃に加温し、その温度で３時間にわたって撹拌し、その後すぐに、これを塩化アンモニウム水溶液で希釈し、酢酸エチル（３×５０ｍＬ）で抽出した。合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、温度を４５℃未満に保ちながら真空で濃縮した。シリカゲルクロマトグラフィー（溶離液：１：３ 酢酸エチル／石油エーテル）により精製して、Ｃ１１を無色の油状物として提供した。収量：３７６ｍｇ、１．３７ｍｍｏｌ、８６％。LCMS m/z 276.0 (臭素同位体パターンが観察された) [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ 8.23 (s, 1H), 6.76 (s, 1H), 4.10 (q, J =
7.1 Hz, 1H), 3.89 (s, 3H), 3.69 (s, 3H), 1.48 (d, J = 7.2 Hz, 3H).

Step 1. Synthesis of methyl 2-(5-bromo-2-methoxypyridin-4-yl)propanoate (C11).
A solution of sodium bis(trimethylsilyl)amide in tetrahydrofuran (2 M; 1 mL, 2 mmol) was added dropwise to a −78° C. solution of methyl (5-bromo-2-methoxypyridin-4-yl)acetate (415 mg, 1.60 mmol) in tetrahydrofuran (50 mL). The reaction mixture was stirred at −78° C. for 1 h before a solution of iodomethane (0.5 mL, 8 mmol) was added dropwise. Upon completion of the addition, the reaction mixture was warmed to −30° C. and stirred at that temperature for 3 h whereupon it was diluted with aqueous ammonium chloride and extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered and concentrated in vacuo while keeping the temperature below 45° C. Purification by silica gel chromatography (eluent: 1:3 ethyl acetate/petroleum ether) provided C11 as a colorless oil. Yield: 376 mg, 1.37 mmol, 86%. LCMS m/z 276.0 (bromine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.23 (s, 1H), 6.76 (s, 1H), 4.10 (q, J =
7.1 Hz, 1H), 3.89 (s, 3H), 3.69 (s, 3H), 1.48 (d, J = 7.2 Hz, 3H).

Step 2. Synthesis of methyl 2-(5-ethenyl-2-methoxypyridin-4-yl)propanoate (C12).
A mixture of C11 (376 mg, 1.37 mmol), potassium vinyltrifluoroborate (460 mg, 3.43 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (201 mg, 0.275 mmol), and potassium phosphate (872 mg, 4.11 mmol) in N,N-dimethylformamide (20 mL) was stirred at 100° C. for 16 h. The reaction mixture was then filtered; the filtrate was poured into water and extracted with ethyl acetate (2×30 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, concentrated in vacuo, and purified by chromatography on silica gel (gradient: 0% to 30% ethyl acetate in petroleum ether) to give C12 as a colorless oil. Yield: 188 mg, 0.850 mmol, 62%. LCMS m/z 222.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.21 (s, 1H), 6.81 (dd, J = 17.3, 10.9 Hz, 1H), 6.63 (s, 1H), 5.56
(br d, J = 17.3 Hz, 1H), 5.32 (br d, J = 10.8 Hz, 1H), 3.95 - 3.87 (m, 1H),
3.93 (s, 3H), 3.67 (s, 3H), 1.46 (d, J = 7.1 Hz, 3H).

Step 3. Synthesis of methyl 2-(5-formyl-2-methoxypyridin-4-yl)propanoate (C13).
A solution of C12 (195 mg, 0.881 mmol) in dichloromethane (10 mL) was cooled to −78° C. and then treated with a stream of ozone-enriched oxygen until the blue color persisted. After 5 min, a stream of dry nitrogen was bubbled through the reaction mixture until the blue color disappeared, whereupon triphenylphosphine (439 mg, 1.67 mmol) was added. The resulting mixture was warmed to 25° C. and stirred for 2 h, at which point it was combined with a similar reaction carried out using C12 (63 mg, 0.28 mmol) and concentrated in vacuo. The residue was purified using silica gel chromatography (gradient: 0% to 30% ethyl acetate in petroleum ether) to provide C13 as a colorless oil. Combined yield: 124 mg, 0.555 mmol, 48%. LCMS m/z 224.0 [M+H] ⁺ .

Step 4. Synthesis of methyl 2-[5-(difluoromethyl)-2-methoxypyridin-4-yl]propanoate (C14).
To a solution of C13 (124 mg, 0.555 mmol) in dichloromethane (5 mL) was added [bis(2-methoxyethyl)amino]sulfur trifluoride (614 mg, 2.78 mmol). After the reaction mixture was stirred at 25° C. for 16 h, it was poured into saturated aqueous sodium bicarbonate (50 mL) and extracted with dichloromethane (50 mL). The organic layer was washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 20% ethyl acetate in petroleum ether) provided C14 as a colorless oil. Yield: 110 mg, 0.449 mmol, 81%. LCMS m/z 246.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.28 (s, 1H), 6.87 (s, 1H), 6.76 (t, J _HF = 54.5 Hz, 1H),
4.11 (q, J = 6.9 Hz, 1H), 4.03 (s, 3H), 3.69 (s, 3H), 1.52 (d, J = 7.0 Hz, 3H).

Step 5. Synthesis of 2-[5-(difluoromethyl)-2-methoxypyridin-4-yl]propanoic acid (P9).
To a solution of C14 (145 mg, 0.591 mmol) in methanol (10 mL) was added a solution of lithium hydroxide (43 mg, 1.8 mmol) in water (4 mL) and the reaction mixture was stirred at 20° C. for 4 h whereupon it was concentrated in vacuo and washed with tert-butyl methyl ether (2×5 mL). The aqueous layer was adjusted to pH 5 by adding 2 M hydrochloric acid and then extracted with ethyl acetate (3×10 mL). The combined ethyl acetate layers were washed with water (3×10 mL) and saturated aqueous sodium chloride solution (20 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure to provide P9 as a yellow oil. Yield: 132 mg, 0.571 mmol, 97%. LCMS m/z 232.1 [M+H] ⁺ . ^1H NMR (400 MHz, methanol-d ₄ ) δ 8.26 (s, 1H), 6.96 (t, J _HF =
54.4 Hz, 1H), 6.84 (s, 1H), 4.12 (q, J = 7.2 Hz, 1H), 3.94 (s, 3H), 1.48 (d, J
= 7.2 Hz, 3H).

Preparation Example P10
2-Fluoro-2-(2-methoxypyridin-4-yl)propanoic acid (P10)

ステップ１． ジメチル（２－メトキシピリジン－４－イル）プロパンジオエート（Ｃ１５）の合成。
テトラヒドロフラン（３０ｍＬ）中の２－メトキシ－４－メチルピリジン（５．００ｇ、４０．６ｍｍｏｌ）の－１０℃溶液に、リチウムジイソプロピルアミド（テトラヒドロフラン中２Ｍ溶液；８１．２ｍＬ、１６２ｍｍｏｌ）を添加した。反応混合物を－１０℃で１．５時間にわたって撹拌した後に、炭酸ジメチル（１４．６ｇ、１６２ｍｍｏｌ）を添加し、撹拌を－１０℃で１．５時間にわたって継続した。次いで、反応混合物を２５℃に加温し、１６時間にわたって撹拌し、その後すぐに、これを、塩化アンモニウム水溶液を添加することによりクエンチした。得られた混合物を酢酸エチル（３×３０ｍＬ）で抽出し、合わせた有機層を硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲル上でのクロマトグラフィー（勾配：石油エーテル中０％から２０％酢酸エチル）により精製して、Ｃ１５を黄色油として提供した。収量：４．９２ｇ、２０．６ｍｍｏｌ、５１％。LCMS m/z 240.1 [M+H]⁺. ¹H NMR (400 MHz, クロロホルム-d) δ 8.17 (d, J = 5.0 Hz, 1H), 6.95 (d, J = 4.8 Hz, 1H), 6.80 (s, 1H),
4.59 (s, 1H), 3.96 (s, 3H), 3.77 (s, 6H).

Step 1. Synthesis of dimethyl (2-methoxypyridin-4-yl)propanedioate (C15).
To a −10° C. solution of 2-methoxy-4-methylpyridine (5.00 g, 40.6 mmol) in tetrahydrofuran (30 mL) was added lithium diisopropylamide (2 M solution in tetrahydrofuran; 81.2 mL, 162 mmol). After the reaction mixture was stirred at −10° C. for 1.5 h, dimethyl carbonate (14.6 g, 162 mmol) was added and stirring was continued at −10° C. for 1.5 h. The reaction mixture was then warmed to 25° C. and stirred for 16 h whereupon it was quenched by the addition of aqueous ammonium chloride. The resulting mixture was extracted with ethyl acetate (3×30 mL) and the combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo. Purification by chromatography on silica gel (gradient: 0% to 20% ethyl acetate in petroleum ether) provided C15 as a yellow oil. Yield: 4.92 g, 20.6 mmol, 51%. LCMS m/z 240.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.17 (d, J = 5.0 Hz, 1H), 6.95 (d, J = 4.8 Hz, 1H), 6.80 (s, 1H),
4.59 (s, 1H), 3.96 (s, 3H), 3.77 (s, 6H).

Chromatographic purification also afforded the mono-acylated product, methyl (2-methoxypyridin-4-yl)acetate. Yield: 1.29 g, 7.12 mmol, 18%. LCMS m/z 182.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.11 (br d, J = 5.3 Hz, 1H), 6.81 (dd, J = 5.4, 1.5 Hz, 1H), 6.68 -
6.66 (m, 1H), 3.93 (s, 3H), 3.71 (s, 3H), 3.57 (s, 2H).

Step 2. Synthesis of dimethyl (2-methoxypyridin-4-yl)(methyl)propanedioate (C16).
Sodium bis(trimethylsilyl)amide (2M solution in tetrahydrofuran; 14.0 mL, 28.0 mmol) was added to a −78° C. solution of C15 (4.47 g, 18.7 mmol) in tetrahydrofuran (30 mL). The reaction mixture was stirred at −78° C. for 1 h before iodomethane (1.40 mL, 22.5 mmol) was added. The reaction mixture was then warmed to −40° C. and stirred for 2 h, warmed to 25° C. and stirred for an additional 16 h whereupon it was quenched with aqueous ammonium chloride. The resulting mixture was extracted with ethyl acetate (2×30 mL) and the combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 10% ethyl acetate in petroleum ether) afforded C16 as a yellow oil. Yield: 3.29 g, 13.0 mmol, 70%. LCMS m/z 254.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.15 (d, J = 5.5 Hz, 1H), 6.88 (br d, J = 5.5 Hz, 1H), 6.74 (br s,
1H), 3.95 (s, 3H), 3.78 (s, 6H), 1.83 (s, 3H).

Step 3. Synthesis of 2-(2-methoxypyridin-4-yl)propanoic acid (C17).
A solution of C16 (3.28 g, 13.0 mmol) and lithium hydroxide (1.24 g, 51.8 mmol) in a mixture of tetrahydrofuran (20 mL) and water (10 mL) was stirred at 45° C. for 5 h. LCMS analysis indicated conversion to C17: LCMS m/z 182.1 [M+H] ⁺ , and the reaction mixture was concentrated in vacuo to provide C17 as a white solid (2.40 g). This material was used as is in the next step.

Step 4. Synthesis of methyl 2-(2-methoxypyridin-4-yl)propanoate (C18).
A mixture of C17 (from the previous step; 2.40 g, ∼13.0 mmol) and sulfuric acid (2.5 mL) in methanol (25 mL) was stirred at 60 °C for 16 h. The reaction mixture was then concentrated in vacuo, washed with aqueous sodium bicarbonate, and extracted with ethyl acetate (2 x 20 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated under reduced pressure to give C18 as a colorless oil. Yield: 1.56 g, 7.99 mmol, 61% for two steps. LCMS m/z 196.2 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.10 (d, J = 5.4 Hz, 1H), 6.81 (dd, J = 5.4, 1.5 Hz, 1H), 6.67 (br
s, 1H), 3.93 (s, 3H), 3.67 (s, 3H), 3.66 (q, J = 7.1 Hz, 1H), 1.47 (d, J = 7.2
Hz, 3H).

Step 5. Synthesis of methyl 2-fluoro-2-(2-methoxypyridin-4-yl)propanoate (C19).
To a −78° C. solution of C18 (500 mg, 2.56 mmol) in tetrahydrofuran (13 mL) was added lithium bis(trimethylsilyl)amide (3.33 mL of a 1 M solution in tetrahydrofuran, 3.33 mmol). The reaction mixture was stirred at −78° C. for 30 minutes before a solution of N-(benzenesulfonyl)-N-fluorobenzenesulfonamide (969 mg, 3.07 mmol) in tetrahydrofuran (2 mL) was added. The reaction mixture was stirred at −10° C. for 3 hours whereupon it was quenched with aqueous ammonium chloride and extracted with ethyl acetate (3×20 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo; silica gel chromatography (gradient: 0% to 10% ethyl acetate in petroleum ether) afforded C19 as a yellow oil. Yield: 400 mg, 1.88 mmol, 73%. LCMS m/z 214.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.18 (d, J = 5.4 Hz, 1H), 7.00 (dd, J = 5.5, 1.6 Hz, 1H), 6.88 (br
d, J = 1.5 Hz, 1H), 3.96 (s, 3H), 3.78 (s, 3H), 1.89 (d, J _HF = 22.3
Hz, 3H).

Step 6. Synthesis of 2-fluoro-2-(2-methoxypyridin-4-yl)propanoic acid (P10).
A solution of C19 (400 mg, 1.88 mmol) and lithium hydroxide (89.9 mg, 3.75 mmol) in a mixture of tetrahydrofuran (10 mL) and water (2 mL) was stirred at 45 °C for 4 h. The reaction mixture was then concentrated in vacuo, diluted with water (12 mL), and adjusted to pH 6 by adding 3 M hydrochloric acid. The resulting mixture was extracted with ethyl acetate (2 x 20 mL), and the combined organic layers were dried over sodium sulfate, filtered, and concentrated under reduced pressure to provide P10 as a yellow oil. Yield: 300 mg, 1.51 mmol, 80%. LCMS m/z 200.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 9.9 - 9.4 (br s, 1H), 8.21 (d, J = 5.6 Hz, 1H), 7.08 (dd, J = 5.6,
1.6 Hz, 1H), 6.95 (br s, 1H), 3.95 (s, 3H), 1.92 (d, J _HF = 22.2 Hz,
3H).

Preparation Example P11
2-[3-(difluoromethoxy)-5-methoxyphenyl]propanoic acid (P11)

ステップ１． １－（ジフルオロメトキシ）－３－メトキシ－５－メチルベンゼン（Ｃ２０）の合成。
水酸化カリウム水溶液（２０％溶液；６０．９ｇ、２１７ｍｍｏｌ）および［ブロモ（ジフルオロ）メチル］（トリメチル）シラン（１１．３ｍＬ、７２．７ｍｍｏｌ）を、ジクロロメタン（５０ｍＬ）中の３－メトキシ－５－メチルフェノール（５．００ｇ、３６．２ｍｍｏｌ）の０℃溶液に順次に添加した。反応混合物を０℃で４．５時間にわたって撹拌した後に、これを水（５０ｍＬ）で希釈し、ジクロロメタン（３×１００ｍＬ）で抽出した。合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮し、シリカゲル上でのクロマトグラフィー（勾配：石油エーテル中０％から５％酢酸エチル）により精製して、Ｃ２０を無色の油状物として得た。収量：６．２７ｇ、３３．３ｍｍｏｌ、９２％。¹H NMR (400 MHz, メタノール-d₄) δ 6.76 (t, J_HF = 74.4 Hz, 1H),
6.60 (br s, 1H), 6.53 (br s, 1H), 6.49 - 6.46 (m, 1H), 3.76 (s, 3H), 2.30 (s,
3H).

Step 1. Synthesis of 1-(difluoromethoxy)-3-methoxy-5-methylbenzene (C20).
Aqueous potassium hydroxide (20% solution; 60.9 g, 217 mmol) and [bromo(difluoro)methyl](trimethyl)silane (11.3 mL, 72.7 mmol) were added sequentially to a 0° C. solution of 3-methoxy-5-methylphenol (5.00 g, 36.2 mmol) in dichloromethane (50 mL). After the reaction mixture was stirred at 0° C. for 4.5 h, it was diluted with water (50 mL) and extracted with dichloromethane (3×100 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, concentrated in vacuo, and purified by chromatography on silica gel (gradient: 0% to 5% ethyl acetate in petroleum ether) to afford C20 as a colorless oil. Yield: 6.27 g, 33.3 mmol, 92%. ^1H NMR (400 MHz, methanol- _d4 ) δ 6.76 (t, _JHF = 74.4 Hz, 1H),
6.60 (br s, 1H), 6.53 (br s, 1H), 6.49 - 6.46 (m, 1H), 3.76 (s, 3H), 2.30 (s,
3H).

Step 2. Synthesis of 1-(bromomethyl)-3-(difluoromethoxy)-5-methoxybenzene (C21).
A mixture of C20 (3.00 g, 15.9 mmol), 2,2'-azobisisobutyronitrile (262 mg, 1.60 mmol), and N-bromosuccinimide (2.84 g, 15.9 mmol) in tetrachloromethane (90 mL) was stirred at 80°C for 8 h. Concentration in vacuo provided C21 as a yellow oil. Yield: 4.0 g, 15 mmol, 94%. ^1H NMR (400 MHz, methanol- _d4 ), product peak only, characteristic peak: δ 6.84 (s, 1H),
6.77 (s, 1H), 6.63 - 6.60 (m, 1H), 4.50 (s, 2H), 3.81 (s, 3H).

Step 3. Synthesis of [3-(difluoromethoxy)-5-methoxyphenyl]acetonitrile (C22).
To a solution of C21 (4.0 g, 15 mmol) in acetonitrile (150 mL) were added potassium carbonate (3.11 g, 22.5 mmol) and trimethylsilyl cyanide (2.2 g, 22 mmol) sequentially. The resulting mixture was stirred at 80° C. for 16 h, at which point LCMS analysis indicated the presence of C22: LCMS m/z 214.1 [M+H] ⁺ . The reaction mixture was concentrated under reduced pressure, diluted with water (50 mL), and extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, concentrated in vacuo, and purified using silica gel chromatography (gradient: 0% to 30% ethyl acetate in petroleum ether) to afford C22 as a yellow oil. Yield: 1.20 g, 5.63 mmol, 38%. ^1H NMR (400 MHz, methanol- _d4 ) δ 6.84 (t, _JHF = 73.9 Hz, 1H),
6.81 (br s, 1H), 6.73 (br s, 1H), 6.68 - 6.66 (m, 1H), 3.89 (s, 2H), 3.82 (s,
3H).

Step 4. Synthesis of 2-[3-(difluoromethoxy)-5-methoxyphenyl]propanenitrile (C23).
C22 (3.00 g, 14.1 mmol) was converted to C23 using the procedure described for the synthesis of C16 from C15 in Preparation P10. Silica gel chromatography (gradient: 0% to 5% ethyl acetate in petroleum ether) provided C23 as a yellow oil. Yield: 1.00 g, 4.40 mmol, 31%. LCMS m/z 228.1 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 6.85 (t, J _HF = 73.9 Hz, 1H),
6.84 - 6.82 (m, 1H), 6.77 - 6.74 (m, 1H), 6.69 - 6.66 (m, 1H), 4.11 (q, J = 7.2
Hz, 1H), 3.82 (s, 3H), 1.60 (d, J = 7.3 Hz, 3H).

Step 5. Synthesis of ethyl 2-[3-(difluoromethoxy)-5-methoxyphenyl]propanoate (C24).
Thionyl chloride (5.3 mL, 73 mmol) was added dropwise to a 0° C. solution of C23 (900 mg, 3.96 mmol) in ethanol (40 mL). The reaction mixture was stirred at 85° C. for 16 h whereupon it was diluted with water (50 mL) and extracted with ethyl acetate (3×30 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 6% ethyl acetate in petroleum ether) provided C24 (700 mg, 2.55 mmol, 64%) as a yellow oil. Yield: 700 mg, 2.55 mmol, 64%. LCMS m/z 275.1 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 6.80 (t, J _HF = 74.2 Hz, 1H),
6.74 - 6.71 (m, 1H), 6.65 (br s, 1H), 6.59 (dd, J = 2.2, 2.2 Hz, 1H), 4.19 -
4.05 (m, 2H), 3.79 (s, 3H), 3.72 (q, J = 7.2 Hz, 1H), 1.44 (d, J = 7.2 Hz, 3H),
1.20 (t, J = 7.1 Hz, 3H).

Step 6. Synthesis of 2-[3-(difluoromethoxy)-5-methoxyphenyl]propanoic acid (P11).
To a solution of C24 (700 mg, 2.55 mmol) in tetrahydrofuran (30 mL) was added a solution of lithium hydroxide monohydrate (535 mg, 12.8 mmol) in water (10 mL). After the reaction mixture was stirred at 25° C. for 16 hours, it was concentrated in vacuo, diluted with water (20 mL), and washed with dichloromethane (3×25 mL). The organic layers were discarded. The aqueous layer was adjusted to a pH of approximately 2 using 2 M hydrochloric acid; it was then extracted with dichloromethane (3×25 mL). The combined organic layers were washed with saturated aqueous sodium chloride solution (10 mL), dried over sodium sulfate, filtered, and concentrated under reduced pressure to give P11 as a yellow oil. Yield: 628 mg, 2.55 mmol, quantitative. LCMS m/z 247.1 [M+H] ⁺ . ^1H NMR (400 MHz, methanol-d ₄ ) δ 6.79 (t, J _HF = 74.2 Hz, 1H),
6.77 - 6.73 (m, 1H), 6.69 - 6.66 (m, 1H), 6.59 (dd, J = 2.2, 2.2 Hz, 1H), 3.79
(s, 3H), 3.69 (q, J = 7.2 Hz, 1H), 1.44 (d, J = 7.2 Hz, 3H).

Preparation Example P12
2-[5-Fluoro-2-(trifluoromethoxy)pyridin-4-yl]propanoic acid (P12)

ステップ１． ジエチル（５－フルオロ－２－メトキシピリジン－４－イル）プロパンジオエート（Ｃ２５）の合成。
５－フルオロ－４－ヨード－２－メトキシピリジン（３．４５ｇ、１３．６ｍｍｏｌ）とジエチルプロパンジオエート（３．２８ｇ、２０．５ｍｍｏｌ）との反応を、調製例Ｐ５においてＣ５からのＣ６の合成について記述されている方法を使用して行った。シリカゲルクロマトグラフィー（勾配：石油エーテル中０％から１５％酢酸エチル）を使用して精製して、Ｃ２５を無色の油状物として得た。収量：２．８０ｇ、９．８２ｍｍｏｌ、７２％。LCMS m/z 286.1 [M+H]⁺. ¹H NMR (400 MHz, クロロホルム-d) δ 8.00 (br s, 1H), 6.84 (br d, J = 4.8 Hz, 1H), 4.87 (s, 1H), 4.30 -
4.21 (m, 4H), 3.90 (s, 3H), 1.28 (t, J = 7.1 Hz, 6H).

Step 1. Synthesis of diethyl (5-fluoro-2-methoxypyridin-4-yl)propanedioate (C25).
The reaction of 5-fluoro-4-iodo-2-methoxypyridine (3.45 g, 13.6 mmol) with diethylpropanedioate (3.28 g, 20.5 mmol) was carried out using the method described for the synthesis of C6 from C5 in Preparation P5. Purification using silica gel chromatography (gradient: 0% to 15% ethyl acetate in petroleum ether) afforded C25 as a colorless oil. Yield: 2.80 g, 9.82 mmol, 72%. LCMS m/z 286.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.00 (br s, 1H), 6.84 (br d, J = 4.8 Hz, 1H), 4.87 (s, 1H), 4.30 -
4.21 (m, 4H), 3.90 (s, 3H), 1.28 (t, J = 7.1 Hz, 6H).

Step 2. Synthesis of diethyl (5-fluoro-2-methoxypyridin-4-yl)(methyl)propanedioate (C26).
To a solution of C25 (2.80 g, 9.82 mmol) in acetonitrile (100 mL) was added potassium carbonate (4.07 g, 29.4 mmol), followed by dropwise addition of iodomethane (2.09 g, 14.7 mmol). The reaction mixture was stirred at 25° C. for 2 days, whereupon LCMS analysis indicated conversion to C26: LCMS m/z 300.1 [M+H] ⁺ . The reaction mixture was poured into water (1 L) and extracted with ethyl acetate (2×100 mL); the combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo to provide C26 as a yellow oil. Yield: 2.25 g, 7.52 mmol, 77%. ^1H NMR (400 MHz, chloroform-d) δ 7.95 (d, J = 2.7 Hz, 1H), 6.58 (d, J = 5.2 Hz, 1H), 4.30 - 4.22 (m,
4H), 3.90 (s, 3H), 1.81 (s, 3H), 1.27 (t, J = 7.1 Hz, 6H).

Step 3. Synthesis of diethyl (5-fluoro-2-hydroxypyridin-4-yl)(methyl)propanedioate (C27).
Trimethylsilyl iodide (7.52 g, 37.6 mmol) was added dropwise to a solution of C26 (2.25 g, 7.52 mmol) in acetonitrile (100 mL) and the reaction mixture was stirred at 100° C. for 4 h, at which point LCMS analysis indicated conversion to C27: LCMS m/z 286.1 [M+H] ⁺ . The reaction mixture was poured into aqueous sodium bicarbonate (100 mL) and the resulting mixture was extracted with ethyl acetate (3×100 mL). The combined organic layers were washed with aqueous sodium dithionite (200 mL), filtered, concentrated in vacuo, and purified by silica gel chromatography (gradient: 0% to 15% methanol in dichloromethane) to provide C27 as a white solid. Yield: 685 mg, 2.40 mmol, 32%. ^1H NMR (400 MHz, chloroform-d) δ 7.29 - 7.26 (m, 1H, estimated; partially obscured by solvent peaks),
6.43 (d, J = 6.4 Hz, 1H), 4.35 - 4.19 (m, 4H), 1.80 (s, 3H), 1.27 (t, J = 7.1
Hz, 6H).

Step 4. Synthesis of diethyl [5-fluoro-2-(trifluoromethoxy)pyridin-4-yl](methyl)propanedioate (C28).
A solution of 1-trifluoromethyl-1,2-benziodoxol-3-(1H)-one (759 mg, 2.40 mmol) and C27 (685 mg, 2.40 mmol) in nitromethane (20 mL) was stirred at 100° C. for 16 h. After removal of the solvent in vacuo, the residue was purified by chromatography on silica gel (gradient: 0% to 20% ethyl acetate in petroleum ether) to give C28 as a colorless oil. Yield: 283 mg, 0.801 mmol, 33%. LCMS m/z 354.0 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.13 (d, J = 2.3 Hz, 1H), 6.93 (d, J = 5.0 Hz, 1H), 4.34 - 4.22 (m,
4H), 1.85 (s, 3H), 1.28 (t, J = 7.1 Hz, 6H).

Step 5. Synthesis of 2-[5-fluoro-2-(trifluoromethoxy)pyridin-4-yl]propanoic acid (P12).
To a solution of C28 (300 mg, 0.849 mmol) in tetrahydrofuran (10 mL) was added a solution of lithium hydroxide (102 mg, 4.26 mmol) in water (3 mL) at 25° C. After the reaction mixture was stirred at 25° C. for 16 h, it was combined with a similar reaction carried out using C28 (50 mg, 0.14 mmol), diluted with water (100 mL), and washed with dichloromethane (3×50 mL). The organic layers were discarded. The aqueous layer was adjusted to pH 5 by adding 5 M hydrochloric acid and extracted with dichloromethane (3×50 mL); the combined dichloromethane layers were concentrated in vacuo to provide P12 as a white solid. Combined yield: 230 mg, 0.909 mmol, 92%. LCMS m/z 254.0 [M+H] ⁺ . ^1H NMR (400 MHz, methanol- _{d 4} ) δ 8.17 (d, J = 1.5 Hz, 1H), 7.20 (d, J = 4.8
Hz, 1H), 4.05 (q, J = 7.3 Hz, 1H), 1.53 (d, J = 7.3 Hz, 3H).

Preparation Example P13
2-[2-(difluoromethoxy)-5-fluoropyridin-4-yl]propanoic acid (P13)

ステップ１． メチル２－（５－フルオロ－２－メトキシピリジン－４－イル）プロパノエート（Ｃ２９）の合成。
硫酸（０．２ｍＬ）を、メタノール（２０ｍＬ）中のＰ６（１．８０ｇ、９．０４ｍｍｏｌ）の溶液に添加し、反応混合物を７０℃で１２時間にわたって撹拌し、その後すぐに、これを減圧下で濃縮した。残渣を、ｐＨが８に達するまで、飽和炭酸水素ナトリウム水溶液（３０ｍＬ）で処理し、次いで、これを酢酸エチル（３×３０ｍＬ）で抽出した。合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮して、Ｃ２９を無色の油状物として提供した。収量：１．８５ｇ、８．６８ｍｍｏｌ、９６％。LCMS m/z 214.1 [M+H]⁺. ¹H NMR (400 MHz, クロロホルム-d) δ 7.94 (br s, 1H), 6.65 (d, J = 5.0 Hz, 1H), 3.93 (q, J = 7.3 Hz,
1H), 3.89 (s, 3H), 3.69 (s, 3H), 1.49 (d, J = 7.3 Hz, 3H).

Step 1. Synthesis of methyl 2-(5-fluoro-2-methoxypyridin-4-yl)propanoate (C29).
Sulfuric acid (0.2 mL) was added to a solution of P6 (1.80 g, 9.04 mmol) in methanol (20 mL) and the reaction mixture was stirred at 70° C. for 12 h whereupon it was concentrated under reduced pressure. The residue was treated with saturated aqueous sodium bicarbonate (30 mL) until pH reached 8, and then it was extracted with ethyl acetate (3×30 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo to provide C29 as a colorless oil. Yield: 1.85 g, 8.68 mmol, 96%. LCMS m/z 214.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.94 (br s, 1H), 6.65 (d, J = 5.0 Hz, 1H), 3.93 (q, J = 7.3 Hz,
1H), 3.89 (s, 3H), 3.69 (s, 3H), 1.49 (d, J = 7.3 Hz, 3H).

Step 2. Synthesis of methyl 2-(5-fluoro-2-hydroxypyridin-4-yl)propanoate (C30).
A solution of C29 (700 mg, 3.28 mmol) and trimethylsilyl iodide (1.97 g, 9.85 mmol) in acetonitrile (10 mL) was stirred at 80° C. for 4 h. After the reaction mixture was concentrated in vacuo, the residue was purified using silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) to give C30 as a light brown oil. Yield: 550 mg, 2.76 mmol, 84%. LCMS m/z 200.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.99 (d, J = 3.5 Hz, 1H), 6.93 (d, J = 5.8 Hz, 1H), 3.99 (q, J =
7.2 Hz, 1H), 3.75 (s, 3H), 1.58 (d, J = 7.2 Hz, 3H).

Step 3. Synthesis of methyl 2-[2-(difluoromethoxy)-5-fluoropyridin-4-yl]propanoate (C31).
A mixture of C30 (580 mg, 2.91 mmol) and sodium chloro(difluoro)acetate (888 mg, 5.82 mmol) in acetonitrile (10.0 mL) was stirred at 100° C. for 12 h. The reaction mixture was then concentrated in vacuo and subjected to silica gel chromatography (gradient: 0% to 30% ethyl acetate in petroleum ether) to provide C31 as a colorless oil. Yield: 550 mg, 2.21 mmol, 76%. LCMS m/z 250.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.99 (d, J = 1.3 Hz, 1H), 7.36 (t, J _HF = 72.9 Hz, 1H),
6.86 (d, J = 4.8 Hz, 1H), 3.99 (q, J = 7.3 Hz, 1H), 3.72 (s, 3H), 1.53 (d, J =
7.3Hz, 3H).

Step 4. Synthesis of 2-[2-(difluoromethoxy)-5-fluoropyridin-4-yl]propanoic acid (P13).
A solution of lithium hydroxide monohydrate (455 mg, 10.8 mmol) in water (5 mL) was added to a solution of C31 (1.00 g, 4.01 mmol) in tetrahydrofuran (10 mL). The reaction mixture was stirred at 25° C. for 10 h whereupon it was concentrated under reduced pressure and the aqueous residue was washed with dichloromethane (3×10 mL). The aqueous layer was then adjusted to pH 7 by adding 1 M hydrochloric acid, and the resulting mixture was extracted with ethyl acetate (3×30 mL). The combined ethyl acetate layers were concentrated in vacuo to provide P13 as a colorless oil. Yield: 830 mg, 3.53 mmol, 88%. LCMS m/z 236.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.99 (br s, 1H), 7.35 (t, J _HF = 72.8 Hz, 1H), 6.86 (d, J
= 4.8 Hz, 1H), 3.98 (q, J = 7.2 Hz, 1H), 1.52 (d, J = 7.3 Hz, 3H).

Preparation Example P14
2-[2-(dimethylamino)-5-fluoropyridin-4-yl]propanoic acid (P14)

ステップ１． ｔｅｒｔ－ブチル（２－クロロ－５－フルオロピリジン－４－イル）アセテート（Ｃ３２）の合成。
リチウムジイソプロピルアミド（テトラヒドロフラン中２Ｍ溶液；５０．５ｍＬ、１０１ｍｍｏｌ）を、テトラヒドロフラン（２００ｍＬ）中の２－クロロ－５－フルオロ－４－メチルピリジン（４．９０ｇ、３３．７ｍｍｏｌ）の－７８℃溶液に添加した。反応混合物を－５０℃で１時間にわたって撹拌した後に、これを－７８℃に冷却し、テトラヒドロフラン（３０ｍＬ）中の二炭酸ジ－ｔｅｒｔ－ブチル（８．５１ｍＬ、３７．０ｍｍｏｌ）の溶液を添加した。次いで、反応混合物を－３０℃に加温し、２時間にわたって撹拌し、水（１００ｍＬ）で希釈した。得られた混合物を酢酸エチル（３×５０ｍＬ）で抽出し；合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲルクロマトグラフィー（勾配：石油エーテル中０％から１０％酢酸エチル）は、Ｃ３２を油状物として提供した。収量：４．９０ｇ、１９．９ｍｍｏｌ、５９％。LCMS m/z 246.1 (塩素同位体パターンが観察された) [M+H]⁺. ¹H NMR (400 MHz, クロロホルム-d) δ 8.21 (br s, 1H), 7.29 (d, J = 5.2 Hz, 1H), 3.59 (s, 2H), 1.46 (s,
9H).

Step 1. Synthesis of tert-butyl (2-chloro-5-fluoropyridin-4-yl)acetate (C32).
Lithium diisopropylamide (2M solution in tetrahydrofuran; 50.5 mL, 101 mmol) was added to a −78° C. solution of 2-chloro-5-fluoro-4-methylpyridine (4.90 g, 33.7 mmol) in tetrahydrofuran (200 mL). After the reaction mixture was stirred at −50° C. for 1 h, it was cooled to −78° C. and a solution of di-tert-butyl dicarbonate (8.51 mL, 37.0 mmol) in tetrahydrofuran (30 mL) was added. The reaction mixture was then warmed to −30° C., stirred for 2 h, and diluted with water (100 mL). The resulting mixture was extracted with ethyl acetate (3×50 mL); the combined organic layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 10% ethyl acetate in petroleum ether) provided C32 as an oil. Yield: 4.90 g, 19.9 mmol, 59%. LCMS m/z 246.1 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.21 (br s, 1H), 7.29 (d, J = 5.2 Hz, 1H), 3.59 (s, 2H), 1.46 (s,
9H).

Step 2. Synthesis of tert-butyl 2-(2-chloro-5-fluoropyridin-4-yl)propanoate (C33).
Conversion of C32 (4.60 g, 18.7 mmol) to C33 was accomplished using the method described for the synthesis of C16 from C15 in Preparation P10. Silica gel chromatography (gradient 0% to 20% ethyl acetate in petroleum ether) provided C33 as an oil. Yield: 4.40 g, 16.9 mmol, 90%. LCMS m/z 262.1 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.19 (br s, 1H), 7.28 (d, J = 5.1 Hz, 1H), 3.87 (q, J = 7.3 Hz,
1H), 1.48 (d, J = 7.2 Hz, 3H), 1.42 (s, 9H).

Step 3. Synthesis of 2-[2-(dimethylamino)-5-fluoropyridin-4-yl]propanoic acid (P14).
A mixture of C33 (3.00 g, 11.6 mmol), dimethylamine (2 M solution in tetrahydrofuran; 8.66 mL, 17.3 mmol), tris(dibenzylideneacetone)dipalladium(0) (1.06 g, 1.16 mmol), 2-dicyclohexylphosphino-2′,6′-diisopropoxybiphenyl (RuPhos; 1.08 g, 2.31 mmol), and sodium tert-butoxide (3.33 g, 34.7 mmol) in toluene (100 mL) was stirred at 100° C. for 16 hours. After the reaction mixture was concentrated in vacuo, it was diluted with water and washed with dichloromethane (3×30 mL). The aqueous layer was then adjusted to pH 5 by adding 5 M hydrochloric acid and extracted with ethyl acetate (2×50 mL). The combined ethyl acetate layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Chromatography on silica gel (gradient: 0% to 10% methanol in dichloromethane) gave P14 as a grey solid. Yield: 700 mg, 3.30 mmol, 28%. LCMS m/z 213.1 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 7.87 (d, J = 2.1 Hz, 1H), 6.57 (d, J = 4.9
Hz, 1H), 3.90 (q, J = 7.2 Hz, 1H), 3.04 (s, 6H), 1.48 (d, J = 7.2 Hz, 3H).

Preparation Example P15
Lithium 2-(5-chloro-2-methoxypyrimidin-4-yl)propanoate (P15)

ステップ１． ジメチル（２，５－ジクロロピリミジン－４－イル）（メチル）プロパンジオエート（Ｃ３４）の合成。
水素化ナトリウム（鉱油中６０％分散体；１．３１ｇ、３３ｍｍｏｌ）を、テトラヒドロフラン（４０ｍＬ）中のジメチルメチルプロパンジオエート（４．７８ｇ、３２．７ｍｍｏｌ）の０℃溶液にゆっくりと添加した。反応混合物を０℃で３０分間にわたって撹拌し、その後すぐに、テトラヒドロフラン（１０ｍＬ）中の２，４，５－トリクロロピリミジン（５．００ｇ、２７．３ｍｍｏｌ）の溶液を０℃で滴下添加した。撹拌を０℃で３０分間にわたって継続し、その時点で、反応混合物を２５℃にゆっくりと加温し、その温度で３０分間にわたって撹拌した。飽和塩化アンモニウム水溶液（１００ｍＬ）の添加後に、混合物を酢酸エチル（３×１００ｍＬ）で抽出した。合わせた有機層を水および飽和塩化ナトリウム水溶液で順次に洗浄し、次いで、２，４，５－トリクロロピリミジン（５００ｍｇ、２．７３ｍｍｏｌ）を使用して行われた同様の反応からの有機層と合わせ、硫酸ナトリウム上で乾燥させ、濾過し、温度を４０℃未満に保ちながら真空で濃縮した。シリカゲルクロマトグラフィー（勾配：石油エーテル中１０％から１３％酢酸エチル）は、Ｃ３４を無色の油状物として提供した。合わせた収量：６．８２ｇ、２３．３ｍｍｏｌ、７８％。LCMS m/z 293.0 (ジクロロ同位体パターンが観察された) [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ 8.74 (s, 1H), 3.79 (s, 6H), 1.90 (s, 3H).

Step 1. Synthesis of dimethyl (2,5-dichloropyrimidin-4-yl)(methyl)propanedioate (C34).
Sodium hydride (60% dispersion in mineral oil; 1.31 g, 33 mmol) was added slowly to a 0° C. solution of dimethyl methylpropanedioate (4.78 g, 32.7 mmol) in tetrahydrofuran (40 mL). The reaction mixture was stirred at 0° C. for 30 minutes whereupon a solution of 2,4,5-trichloropyrimidine (5.00 g, 27.3 mmol) in tetrahydrofuran (10 mL) was added dropwise at 0° C. Stirring was continued at 0° C. for 30 minutes at which point the reaction mixture was slowly warmed to 25° C. and stirred at that temperature for 30 minutes. After addition of saturated aqueous ammonium chloride solution (100 mL), the mixture was extracted with ethyl acetate (3×100 mL). The combined organic layers were washed successively with water and saturated aqueous sodium chloride solution, then combined with an organic layer from a similar reaction carried out using 2,4,5-trichloropyrimidine (500 mg, 2.73 mmol), dried over sodium sulfate, filtered, and concentrated in vacuo while keeping the temperature below 40° C. Silica gel chromatography (gradient: 10% to 13% ethyl acetate in petroleum ether) provided C34 as a colorless oil. Combined yield: 6.82 g, 23.3 mmol, 78%. LCMS m/z 293.0 (dichloro isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.74 (s, 1H), 3.79 (s, 6H), 1.90 (s, 3H).

Step 2. Synthesis of dimethyl (5-chloro-2-methoxypyrimidin-4-yl)(methyl)propanedioate (C35).
A solution of sodium methoxide in methanol (30% solution; 4.66 g, 26 mmol) was added dropwise to a solution of C34 (6.32 g, 21.6 mmol) in methanol (120 mL). After the reaction mixture was stirred at 25° C. for 2 h, it was concentrated in vacuo while keeping the temperature below 40° C., diluted with water (50 mL), and extracted with ethyl acetate (2×100 mL). The organic layer was combined with that from a similar reaction carried out using C34 (500 mg, 1.71 mmol), washed successively with water and saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient: 11% to 15% ethyl acetate in petroleum ether) afforded C35 as a colorless oil. Combined yield: 4.00 g, 13.9 mmol, 60%. LCMS m/z 289.0 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.53 (s, 1H), 3.95 (s, 3H), 3.79 (s, 6H),
1.88 (s, 3H).

Step 3. Synthesis of lithium 2-(5-chloro-2-methoxypyrimidin-4-yl)propanoate (P15).
A solution of lithium hydroxide monohydrate (1.65 g, 39.3 mmol) in water (20 mL) was added dropwise to a solution of C35 (3.78 g, 13.1 mmol) in tetrahydrofuran (60 mL). The reaction mixture was stirred at 35° C. for 3 h, whereupon it was concentrated in vacuo. The resulting aqueous mixture was washed with dichloromethane and then purified by reverse phase chromatography (column: C18; gradient: 0% to 10% acetonitrile in water) to provide P15 as a white solid. Yield: 1.87 g, 8.40 mmol, 64%. LCMS m/z 217.1 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.37 (s, 1H), 4.05 (q, J = 7.2 Hz, 1H),
4.00 (s, 3H), 1.55 (d, J = 7.2 Hz, 3H).

Preparation Example P16
2-[2-(difluoromethoxy)-6-methoxypyridin-4-yl]propanoic acid (P16)

ステップ１． メチル２－（ジフルオロメトキシ）－６－メトキシピリジン－４－カルボキシレート（Ｃ３６）の合成。
メチル２－ヒドロキシ－６－メトキシピリジン－４－カルボキシレート（９００ｍｇ、４．９１ｍｍｏｌ）を、調製例Ｐ５において５－ヨードピリジン－２－オールからのＣ５の合成について記述されている方法を使用して、Ｃ３６に変換した。シリカゲル上でのクロマトグラフィー（勾配：石油エーテル中０％から８％酢酸エチル）は、Ｃ３６を無色の油状物として提供した。収量：７２０ｍｇ、３．０９ｍｍｏｌ、６３％。LCMS m/z 234.1 [M+H]⁺. ¹H NMR (400 MHz, クロロホルム-d) δ 7.39 (t, J_HF = 73.0 Hz, 1H), 7.10 (br s, 1H), 7.00 (br
s, 1H), 3.94 (s, 3H), 3.93 (s, 3H).

Step 1. Synthesis of methyl 2-(difluoromethoxy)-6-methoxypyridine-4-carboxylate (C36).
Methyl 2-hydroxy-6-methoxypyridine-4-carboxylate (900 mg, 4.91 mmol) was converted to C36 using the method described for the synthesis of C5 from 5-iodopyridin-2-ol in Preparation P5. Chromatography on silica gel (gradient: 0% to 8% ethyl acetate in petroleum ether) provided C36 as a colorless oil. Yield: 720 mg, 3.09 mmol, 63%. LCMS m/z 234.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.39 (t, J _HF = 73.0 Hz, 1H), 7.10 (br s, 1H), 7.00 (br
s, 1H), 3.94 (s, 3H), 3.93 (s, 3H).

Step 2. Synthesis of 2-(difluoromethoxy)-6-methoxypyridine-4-carboxylic acid (C37).
C36 (1.10 g, 4.72 mmol) was hydrolyzed to give C37 as a white solid using the method described for the synthesis of P11 from C24 in Preparation P11. Yield: 980 mg, 4.47 mmol, 95%. LCMS m/z 220.1 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.41 (t, J _HF = 72.8 Hz, 1H), 7.15 (d, J = 1.1 Hz, 1H),
7.05 (d, J = 1.0 Hz, 1H), 3.95 (s, 3H).

Step 3. Synthesis of methyl [2-(difluoromethoxy)-6-methoxypyridin-4-yl]acetate (C38).
A solution of C37 (980 mg, 4.47 mmol) in thionyl chloride (6.49 mL, 89.0 mmol) was stirred at 70° C. for 2.5 hours, whereupon it was concentrated under reduced pressure. The resulting acyl chloride was dissolved in a mixture of tetrahydrofuran (8 mL) and acetonitrile (8 mL), which was then cooled to 0° C. and treated with freshly distilled triethylamine (0.87 mL, 6.2 mmol) followed by (diazomethyl)(trimethyl)silane (2 M solution in diethyl ether; 3.35 mL, 6.70 mmol). The reaction mixture was stirred at 0° C. for 8 hours, whereupon it was diluted with diethyl ether (25 mL) and washed successively with 10% aqueous citric acid (5 mL), saturated aqueous sodium bicarbonate (15 mL), and saturated aqueous sodium chloride (25 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated under reduced pressure to provide the crude diazoketone. This material was suspended in methanol (10 mL) in an ultrasonic bath; a solution of silver benzoate (512 mg, 2.24 mmol) in triethylamine (1.86 mL, 13.3 mmol) was slowly added at room temperature while the reaction mixture was sonicated. After 30 min, the volatiles were removed in vacuo and the residue was purified using chromatography on silica gel (gradient: 0% to 10% ethyl acetate in petroleum ether) to provide C38 as a colorless oil. Yield: 340 mg, 1.38 mmol, 31%. LCMS m/z 248.0 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.40 (t, J _HF = 73.4 Hz, 1H), 6.45 (br s, 1H), 6.40 (br
s, 1H), 3.88 (s, 3H), 3.71 (s, 3H), 3.57 (s, 2H).

Step 4. Synthesis of methyl 2-[2-(difluoromethoxy)-6-methoxypyridin-4-yl]propanoate (C39).
To a −78° C. solution of C38 (230 mg, 0.930 mmol) in tetrahydrofuran (20 mL) was added sodium bis(trimethylsilyl)amide (2 M solution in tetrahydrofuran; 0.56 mL, 1.1 mmol) and the reaction mixture was stirred at −78° C. for 1 h. Iodomethane (57.9 μL, 0.93 mmol) was then added and stirring was continued at −78° C. for 2 h. After addition of saturated aqueous ammonium chloride (10 mL), the mixture was combined with a similar reaction carried out using C38 (100 mg, 0.405 mmol) and extracted with ethyl acetate (3×20 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered and concentrated in vacuo; silica gel chromatography (gradient: 0% to 4% ethyl acetate in petroleum ether) afforded C39 as a colorless oil. Combined yield: 150 mg, 0.574 mmol, 43%. LCMS m/z 262.1 [M+H] ⁺ . ^1H NMR (400 MHz, methanol-d ₄ ) δ 7.51 (t, J _HF = 73.3 Hz, 1H),
6.50 (br d, J = 1 Hz, 1H), 6.43 (br d, J = 1 Hz, 1H), 3.88 (s, 3H), 3.78 (q, J
= 7.2 Hz, 1H), 3.68 (s, 3H), 1.44 (d, J = 7.2 Hz, 3H).

Step 5. Synthesis of 2-[2-(difluoromethoxy)-6-methoxypyridin-4-yl]propanoic acid (P16).
Hydrolysis of C39 (130 mg, 0.498 mmol) was carried out using the method described for the synthesis of P12 from C28 in Preparation P12 to provide P16 as a colorless oil. Yield: 101 mg, 0.409 mmol, 82%. LCMS m/z 248.0 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 7.51 (t, J _HF = 73.3 Hz, 1H),
6.53 (br d, J = 1.1 Hz, 1H), 6.46 (br d, J = 1.1 Hz, 1H), 3.88 (s, 3H), 3.72
(q, J = 7.1 Hz, 1H), 1.44 (d, J = 7.2 Hz, 3H).

Preparation Examples P17 and P18
tert-Butyl 7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate (P17) and di-tert-butyl 7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1,1'-dicarboxylate (P18)

ステップ１． ２－クロロ－３－ヨード－６－メチルピリジン（Ｃ４０）の合成。
水（５．０Ｌ）および塩酸（５．０Ｍ；３．３Ｌ、１６．５ｍｏｌ）中の２－クロロ－６－メチルピリジン－３－アミン（４００ｇ、２．８０ｍｏｌ）の０℃混合物に、水（８００ｍＬ）中の亜硝酸ナトリウム（２９０ｇ、４．２０ｍｏｌ）の溶液を、内部反応温度を５℃未満に維持する速度で、滴下方式にて添加した。反応混合物を氷冷下で３０分間にわたって撹拌し、次いで、－５℃に冷却し、その後すぐに、ｔｅｒｔ－ブチルメチルエーテル（３．０Ｌ）を添加し、続いて、水（８００ｍＬ）中のヨウ化カリウム（９２９ｇ、５．６０ｍｏｌ）の溶液を滴下添加し、その間、内部反応温度を１０℃未満に維持した。次いで、反応混合物を２５℃にゆっくりと加温させ、撹拌を２５℃で１６時間にわたって継続した。ｐＨを、２Ｍ水酸化ナトリウム水溶液を添加することにより、９に調節した後に、混合物を酢酸エチル（３×２．０Ｌ）で抽出し；合わせた有機層を、亜硫酸ナトリウム水溶液で２回、飽和塩化ナトリウム水溶液で１回洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲルクロマトグラフィー（勾配：石油エーテル中０％から５％酢酸エチル）により精製して、Ｃ４０を白色の固体として得た。収量：６１０ｇ、２．４１ｍｏｌ、８６％。LCMS m/z 253.9 (塩素同位体パターンが観察された) [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ 8.13 (d, J = 7.9 Hz, 1H), 6.96 (d, J = 7.9
Hz, 1H), 2.44 (s, 3H).

Step 1. Synthesis of 2-chloro-3-iodo-6-methylpyridine (C40).
To a 0° C. mixture of 2-chloro-6-methylpyridin-3-amine (400 g, 2.80 mol) in water (5.0 L) and hydrochloric acid (5.0 M; 3.3 L, 16.5 mol) was added dropwise a solution of sodium nitrite (290 g, 4.20 mol) in water (800 mL) at a rate to maintain the internal reaction temperature below 5° C. The reaction mixture was stirred under ice cooling for 30 minutes and then cooled to −5° C. whereupon tert-butyl methyl ether (3.0 L) was added followed by the dropwise addition of a solution of potassium iodide (929 g, 5.60 mol) in water (800 mL) while maintaining the internal reaction temperature below 10° C. The reaction mixture was then allowed to warm slowly to 25° C. and stirring was continued at 25° C. for 16 hours. After adjusting the pH to 9 by adding 2M aqueous sodium hydroxide, the mixture was extracted with ethyl acetate (3×2.0 L); the combined organic layers were washed twice with aqueous sodium sulfite and once with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo. Purification by silica gel chromatography (gradient: 0% to 5% ethyl acetate in petroleum ether) afforded C40 as a white solid. Yield: 610 g, 2.41 mol, 86%. LCMS m/z 253.9 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.13 (d, J = 7.9 Hz, 1H), 6.96 (d, J = 7.9
Hz, 1H), 2.44 (s, 3H).

Step 2. Synthesis of 1-benzyl-3-[(trimethylsilyl)ethynyl]pyrrolidin-3-ol (C41).
A solution of n-butyllithium in tetrahydrofuran (2.5 M; 3.75 L, 9.4 mol) was added dropwise to a −78° C. solution of ethynyl(trimethyl)silane (1.01 kg, 10.3 mol) in tetrahydrofuran (4.0 L). The reaction mixture was stirred at −78° C. for 1 h whereupon a solution of 1-benzylpyrrolidin-3-one (1.50 kg, 8.56 mol) in tetrahydrofuran (1.5 L) was added dropwise. After completion of the addition, the reaction mixture was warmed to 20° C. and stirred at 20° C. for 16 h, followed by pouring into aqueous ammonium chloride solution. The resulting mixture was extracted with ethyl acetate (2×2.0 L) and the combined organic layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and concentrated in vacuo to provide C41 as a yellow oil. Yield: 2.25 kg, 8.23 mol, 96%. LCMS m/z 274.2 [M+H] ⁺ . ^1H NMR (400 MHz, methanol-d ₄ ) δ 7.37 - 7.28 (m, 4H), 7.28 - 7.22 (m, 1H),
3.66 (AB quartet, J _AB =
12.7 Hz, Δν _AB = 12.2 Hz, 2H), 2.89 - 2.77 (m, 3H), 2.65 (ddd, J = 9.4, 7.9, 5.5
Hz, 1H), 2.30 - 2.21 (m, 1H), 2.12 - 2.03 (m, 1H), 0.14 (s, 9H).

Step 3. Synthesis of 1-benzyl-3-ethynylpyrrolidin-3-ol (C42).
A mixture of C41 (2.77 kg, 10.1 mol) and potassium carbonate (2.80 kg, 20.3 mol) in methanol (10 L) was stirred at 25° C. for 3 h whereupon the reaction mixture was filtered and the filtrate was concentrated in vacuo. The residue was diluted with ethyl acetate (10 L) before being filtered. The filtrate was concentrated under reduced pressure to give C42 as a black oil (2.30 kg). This material was taken directly into the next step. LCMS m/z 202.2 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ), characteristic peaks: δ 7.37 - 7.28 (m, 4H), 7.28 - 7.22 (m, 1H), 3.66 (AB quartet, J _AB = 12.7 Hz, Δν _AB =
12.7 Hz, 2H), 2.89 - 2.78 (m, 3H), 2.65 (ddd, J = 9.4, 7.9, 5.7 Hz, 1H), 2.27
(ddd, J = 13.3, 7.9, 6.8 Hz, 1H), 2.14 - 2.04 (m, 1H).

Step 4. Synthesis of 1-benzyl-3-ethynylpyrrolidin-3-yl acetate (C43).
To a 0° C. solution of C42 (from the previous step; 2.30 kg, 10.1 mol.) and triethylamine (3.17 L, 22.7 mol) in dichloromethane (10 L) was added acetyl chloride (1.35 kg, 17.2 mol) in a dropwise fashion. The reaction mixture was then stirred at 25° C. for 30 minutes whereupon water (10 L) was added. The resulting mixture was extracted with dichloromethane (2×3.0 L) and the combined organic layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and concentrated in vacuo to provide C43 as a brown oil (2.82 kg). A portion of this material was used in the next step. LCMS m/z 244.2 [M+H] ⁺ . ^1H NMR (400 MHz, methanol-d ₄ ) δ 7.38 - 7.23 (m, 5H), 3.65 (s, 2H), 3.05
(s, 2H), 3.03 (s, 1H), 2.77 (ddd, J = 9.5, 7.4, 6.1 Hz, 1H), 2.66 (ddd, J =
9.5, 7.4, 6.5 Hz, 1H), 2.46 (ddd, J = 13.6, 7.4, 6.1 Hz, 1H), 2.40 - 2.31 (m,
1H), 2.02 (s, 3H).

Step 5. Synthesis of 1-benzyl-3-ethynyl-N-[(4-methoxyphenyl)methyl]pyrrolidin-3-amine (C44).
A mixture of C43 (from the previous step; .about.1.20 kg, 4.30 mol), 1-(4-methoxyphenyl)methanamine (1.35 kg, 9.84 mmol), and copper(I) chloride (48.8 g, 0.493 mol) in tetrahydrofuran (6.0 L) was degassed under vacuum and then purged with nitrogen; this evacuation-purge cycle was performed a total of three times. The reaction mixture was then stirred at reflux for 45 minutes whereupon it was concentrated in vacuo. This material was combined with that from three similar reactions carried out using C43 (from the previous step; .about.3.2 mol using 900 g of C43 in three reactions) and purified by chromatography on silica gel (gradient: 0% to 50% ethyl acetate in petroleum ether) to provide C44 as a brown oil. Combined yield: 620 g, 1.93 mol, 26% for three steps. LCMS m/z 321.3 [M+H] ⁺ . ^1H NMR (400 MHz, methanol-d ₄ ) δ 7.36 - 7.21 (m, 7H), 6.85 (br d, J = 8.7
Hz, 2H), 3.81 - 3.69 (m, 2H), 3.77 (s, 3H), 3.65 (AB quartet, J _AB = 12.7 Hz, Δν _AB = 9.9 Hz, 2H), 2.88 (s, 1H), 2.82 -
2.67 (m, 2H), 2.79 (AB quartet, J _AB
= 9.8 Hz, Δν _AB = 37.8 Hz, 2H), 2.27 (ddd, J = 13.4, 7.7, 6.0 Hz, 1H), 2.09 - 2.01
(m, 1H).

Step 6. Synthesis of 1-benzyl-3-[(2-chloro-6-methylpyridin-3-yl)ethynyl]-N-[(4-methoxyphenyl)methyl]pyrrolidin-3-amine (C45).
A mixture of C44 (426 g, 1.33 mol), C40 (303 g, 1.20 mmol), dichlorobis(triphenylphosphine)palladium(II) (46.6 g, 66.4 mmol), and copper(I) iodide (12.6 g, 66.2 mmol) in triethylamine (2.0 L) was degassed under vacuum and then purged with nitrogen; this evacuation-purging cycle was performed a total of three times. The reaction mixture was stirred at reflux for 16 hours whereupon it was filtered; the filtrate was concentrated in vacuo and combined with material from two similar reactions carried out using C40 (12.17 g, 48.0 mmol; 146 g, 0.576 mol). The resulting mixture was purified by silica gel chromatography (gradient: 20% to 50% ethyl acetate in petroleum ether) to give C45 as a black oil. Combined yield: 420 g, 0.942 mol, 52%. LCMS m/z 446.2 [M+H] ⁺ . ^1H NMR (400 MHz, methanol- _{d 4} ) δ 7.80 (d, J = 7.8 Hz, 1H), 7.39 - 7.20 (m,
8H), 6.86 (d, J = 8.6 Hz, 2H), 3.87 (AB quartet, J _AB = 12.0 Hz, Δν _AB = 29.6 Hz, 2H), 3.76 (s, 3H), 3.70
(AB quartet, J _AB = 13.0
Hz, Δν _AB = 9.3 Hz, 2H), 3.00 (d, AB quartet component, J = 9.9 Hz, 1H), 2.87 - 2.77 (m, 3H), 2.51 (s, 3H), 2.44 - 2.33
(m, 1H), 2.21 - 2.10 (m, 1H).

Step 7. Synthesis of 1-benzyl-3-[2-(2-chloro-6-methylpyridin-3-yl)ethyl]-N-[(4-methoxyphenyl)methyl]pyrrolidin-3-amine (C46).
A mixture of C45 (40.0 g, 89.7 mmol) and platinum(IV) oxide (4.09 g, 18.0 mmol) in methanol (400 mL) was hydrogenated (60 psi) at 25° C. for 3 h. The reaction mixture was then filtered and the filtrate was concentrated in vacuo to provide C46 as a black oil. Yield: 40.5 g, estimated quantitative. LCMS m/z 450.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ), characteristic peaks: δ 7.61 (d, J = 7.7 Hz, 1H), 7.38 - 7.23 (m, 7H), 7.17 (d, J = 7.7 Hz,
1H), 6.88 (br d, J = 8.7 Hz, 2H), 3.78 (s, 3H), 3.64 (AB quartet, J _AB = 12.0 Hz, Δν _AB =
21.6 Hz, 2H), 3.64 (s, 2H), 2.46 (s, 3H).

Step 8. Synthesis of 1'-benzyl-1-[(4-methoxyphenyl)methyl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] (C47).
A mixture of C46 (400 g, 0.89 mol), palladium(II) acetate (9.97 g, 44.4 mmol), 2-dicyclohexylphosphino-2',6'-diisopropoxybiphenyl (RuPhos; 41.5 g, 88.9 mmol) and sodium tert-butoxide (170 g, 1.77 mol) in 1,4-dioxane (4.0 L) was stirred at 90° C. for 10 h, whereupon the reaction mixture was filtered and the filtrate was concentrated in vacuo. The residue was partitioned between ethyl acetate (2 L) and water (2 L) before the aqueous layer was extracted with ethyl acetate (1 L). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, concentrated in vacuo and subjected to silica gel chromatography (gradient: 0% to 10% ethyl acetate in petroleum ether) to afford C47 as a white solid. Yield: 195 g, 0.472 mol, 53%. LCMS m/z 414.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.38 - 7.21 (m, 5H, estimated; partially obscured by solvent peaks),
7.17 (d, J = 8.2 Hz, 2H), 7.03 (d, J = 7.2 Hz, 1H), 6.77 (d, J = 8.2 Hz, 2H),
6.32 (d, J = 7.3 Hz, 1H), 5.07 - 4.92 (m, 2H), 3.77 (s, 3H), 3.54 (br AB quartet, J _AB = 13 Hz, Δν _AB = 40
Hz, 2H), 2.95 (d, J = 10.2 Hz, 1H), 2.92 - 2.83 (m, 1H), 2.83 - 2.73 (m, 1H),
2.73 - 2.63 (m, 1H), 2.43 - 2.31 (m, 1H), 2.29 - 2.08 (m, 2H), 2.23 (s, 3H),
2.03 - 1.73 (m, 3H).

Step 9. Synthesis of 1'-benzyl-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] (C48).
To a 0° C. solution of C47 (190 g, 0.459 mol) in dichloromethane (1.5 L) was added trifluoroacetic acid (523 g, 4.59 mol) and the reaction mixture was stirred at 25° C. for 3 hours. It was then concentrated in vacuo; the residue was diluted with ethyl acetate (1.5 L), washed with saturated aqueous sodium carbonate (1.0 L) and the aqueous layer was extracted with ethyl acetate (2×300 mL). The combined organic layers were concentrated in vacuo and purified by silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) to give C48 as a brown oil (179 g). This material was carried on to the next step as is. LCMS m/z 294.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 9.1 - 8.3 (br s, 1H), 7.41 - 7.35 (m, 2H), 7.35 - 7.28 (m, 2H),
7.28 - 7.22 (m, 2H, estimated; partially obscured by solvent peak), 6.35 (d, J = 7.3 Hz, 1H), 3.72
(s, 2H), 2.96 - 2.85 (m, 1H), 2.80 - 2.62 (m, 5H), 2.42 (s, 3H), 2.05 (ddd, J =
13.1, 8.1, 5.0 Hz, 1H), 1.98 - 1.81 (m, 3H).

Step 10. Synthesis of tert-butyl 7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P17) and di-tert-butyl 7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (P18).
A mixture of C48 (from previous step; 179 g, ∼0.459 mol), di-tert-butyl dicarbonate (199.7 g, 915 mmol), and palladium hydroxide (17.9 g, 127 mmol) in methanol (2.0 L) and ethyl acetate (2.0 L) was hydrogenated at 55 psi and 25 °C for 18 h. The reaction mixture was then filtered through a pad of diatomaceous earth and the filtrate was concentrated in vacuo. Silica gel chromatography (gradient: 0% to 50% dichloromethane in ethyl acetate) provided both P17 and P18 as white solids.
P17 - Yield: 101 g, 0.333 mol, 73% over two steps. LCMS m/z 304.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 7.20 (d, J = 7.3 Hz, 1H), 6.44 (d, J = 7.4
Hz, 1H), 3.62 - 3.44 (m, 2H), 3.37 - 3.3 (m, 2H, estimated; partially obscured by solvent peak),
2.84 - 2.66 (m, 2H), 2.27 (s, 3H), 2.05 - 1.92 (m, 2H), 1.92 - 1.76 (m, 2H),
[1.48 (s) and 1.46 (s), total 9H].
P18 - Yield: 21.3 g, 52.8 mmol, 12% over two steps. LCMS m/z 404.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 7.49 (d, J = 7.7 Hz, 1H), 7.02 (br d, J =
7.7 Hz, 1H), [3.85 (d, J = 11.3 Hz) and 3.75 (d, J = 11.2 Hz), total 1H], 3.62 - 3.47 (m, 2H), 3.40 - 3.24 (m, 1H, estimated; partially obscured by solvent peak), 2.89 - 2.73 (m, 2H), 2.54 - 2.27 (m, 1H), 2.44 (s, 3H), 2.13 -
1.82 (m, 3H), 1.46 (s, 9H), [1.43 (s) and 1.43 (s), total 9H].

Preparation Examples P19 and P20
tert-Butyl (2S)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate (P19) and tert-butyl (2R)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate (P20)

二炭酸ジ－ｔｅｒｔ－ブチル（３．９７ｇ、１８．２ｍｍｏｌ）を、メタノール（２０ｍＬ）および酢酸エチル（２５ｍＬ）の混合物中のＣ４８（４．４５ｇ、１５．２ｍｍｏｌ）の溶液に添加した。炭素上の水酸化パラジウム（９００ｍｇ）の添加後に、反応混合物を８０ｐｓｉで１８時間にわたって水素化し、その時点で、ＬＣＭＳ分析は、Ｐ１９／Ｐ２０への完全な変換を指し示した：LCMS m/z 304.2 [M+H]⁺.反応混合物を濾過し、濾液を減圧下で濃縮し；残渣を酢酸エチルに溶解し、飽和炭酸水素ナトリウム溶液および飽和塩化ナトリウム水溶液で順次に洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮した。構成要素の鏡像異性体の分離を、超臨界流体クロマトグラフィー｛カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＩＢ、３０×２５０ｍｍ、５μｍ；移動相 ９：１ 二酸化炭素／［０．２％（メタノール中７Ｍアンモニア）を含有するエタノール］；流速：８０ｍＬ／分；背圧：１００バール｝により行った。第１に溶離する鏡像異性体をＰ１９として、第２に溶離する鏡像異性体をＰ２０として指定した。両方を固体として単離した。
Ｐ１９－収量：１．６０ｇ、５．２７ｍｍｏｌ、３５％。保持時間：３．７５分［分析条件。カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＩＢ、４．６×２５０ｍｍ、５μｍ；移動相Ａ：二酸化炭素；移動相Ｂ：０．２％（メタノール中７Ｍアンモニア）を含有するエタノール；勾配：Ｂ５％を１分間にわたって、次いで、８分かけてＢ５％から６０％へ；流速：３．０ｍＬ／分；背圧：１２０バール］。
Ｐ２０－収量：１．５０ｇ、４．９４ｍｍｏｌ、３２％。保持時間：３．９６分（Ｐ１９で使用されたものと同一の分析条件）。

Di-tert-butyl dicarbonate (3.97 g, 18.2 mmol) was added to a solution of C48 (4.45 g, 15.2 mmol) in a mixture of methanol (20 mL) and ethyl acetate (25 mL). After addition of palladium hydroxide on carbon (900 mg), the reaction mixture was hydrogenated at 80 psi for 18 h, at which point LCMS analysis indicated complete conversion to P19/P20: LCMS m/z 304.2 [M+H] ⁺ . The reaction mixture was filtered and the filtrate was concentrated under reduced pressure; the residue was dissolved in ethyl acetate, washed successively with saturated sodium bicarbonate solution and saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated in vacuo. Separation of the constituent enantiomers was performed by supercritical fluid chromatography {column: Chiral Technologies Chiralpak IB, 30 x 250 mm, 5 μm; mobile phase 9:1 carbon dioxide/[ethanol containing 0.2% (7 M ammonia in methanol)]; flow rate: 80 mL/min; back pressure: 100 bar}. The first eluting enantiomer was designated as P19 and the second eluting enantiomer as P20. Both were isolated as solids.
P19 - Yield: 1.60 g, 5.27 mmol, 35%. Retention time: 3.75 min [Analytical conditions. Column: Chiral Technologies Chiralpak IB, 4.6 x 250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: ethanol containing 0.2% (7 M ammonia in methanol); Gradient: 5% B over 1 min, then 5% to 60% B over 8 min; Flow rate: 3.0 mL/min; Back pressure: 120 bar].
P20 - Yield: 1.50 g, 4.94 mmol, 32%. Retention time: 3.96 min (same analytical conditions as used for P19).

The absolute stereochemistry indicated was assigned based on the conversion of this batch of P19 to P23 in the alternative preparation of P23 (#1) below. The absolute configuration of P23 was established by its use in the synthesis of 14, which was analyzed by single crystal X-ray crystallography (see below).

Preparation Example P21
Di-tert-butyl 6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1,1'-dicarboxylate (P21)

ジクロロメタン（２００ｍＬ）中のＰ１８（２０ｇ、５０ｍｍｏｌ）の０℃溶液に、１，３－ジブロモ－５，５－ジメチルイミダゾリジン－２，４－ジオン（７．０９ｇ、２４．８ｍｍｏｌ）を３０分かけて６回で添加した。反応混合物を０℃で１時間にわたって撹拌し、その後すぐに、これを飽和亜硫酸ナトリウム水溶液（２００ｍＬ）で処理し、ジクロロメタン（３×１００ｍＬ）で抽出した。合わせた有機層を飽和炭酸水素ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲルクロマトグラフィー（勾配：石油エーテル中０％から４０％酢酸エチル）は、Ｐ２１を白色の固体として提供した。収量：２２．８ｇ、４７．２ｍｍｏｌ、９４％。LCMS m/z 384.1 (臭素同位体パターンが観察された) {[M - (2-メチルプロパ-1-エンおよびCO₂)]+H}⁺. ¹H
NMR (400 MHz, クロロホルム-d) δ 7.51 (br s, 1H), [3.89 (d, J = 11.0 Hz)および3.73 (d, J = 11.0 Hz), 合計1H], 3.65 - 3.51 (m, 1H), 3.46 (d, J =
11.0 Hz, 1H), 3.38 - 3.26 (m, 1H), [2.87 - 2.56 (m)および2.15 - 1.70 (m), 合計6H],
2.57 (s, 3H), [1.46 (s)および1.45
(s), 合計18H].

To a 0° C. solution of P18 (20 g, 50 mmol) in dichloromethane (200 mL) was added 1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione (7.09 g, 24.8 mmol) in six portions over 30 min. The reaction mixture was stirred at 0° C. for 1 h whereupon it was treated with saturated aqueous sodium sulfite (200 mL) and extracted with dichloromethane (3×100 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate, dried over sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 40% ethyl acetate in petroleum ether) provided P21 as a white solid. Yield: 22.8 g, 47.2 mmol, 94%. LCMS m/z 384.1 (bromine isotope pattern observed) {[M - (2-methylprop-1-ene and CO ₂ )] + H} ⁺ . ¹ H
NMR (400 MHz, chloroform-d) δ 7.51 (br s, 1H), [3.89 (d, J = 11.0 Hz) and 3.73 (d, J = 11.0 Hz), summed 1H], 3.65 - 3.51 (m, 1H), 3.46 (d, J =
11.0 Hz, 1H), 3.38 - 3.26 (m, 1H), [2.87 - 2.56 (m) and 2.15 - 1.70 (m), total 6H],
2.57 (s, 3H), [1.46 (s) and 1.45
(s), 18H in total].

Preparation Example P22
tert-Butyl 6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate (P22)

１，３－ジブロモ－５，５－ジメチルイミダゾリジン－２，４－ジオン（２．４７ｇ、８．６４ｍｍｏｌ）を、ジクロロメタン（６９ｍＬ）中のＰ１７（５．２５ｇ、１７．３ｍｍｏｌ）の０℃溶液に２０分かけて少しずつ添加した。反応混合物を０℃で４５分間にわたって撹拌した後に、ＬＣＭＳ分析は、Ｐ２２への変換を指し示した：LCMS m/z 384.3 (臭素同位体パターンが観察された) [M+H]⁺.０℃で１時間後に、反応混合物を飽和亜硫酸ナトリウム水溶液（１００ｍＬ）で処理し、混合物をジクロロメタンで抽出した。有機層を飽和炭酸水素ナトリウム水溶液および飽和塩化ナトリウム水溶液で順次に洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮して、Ｐ２２を固体として提供した。収量：６．６０ｇ、１７．３ｍｍｏｌ、定量的。¹H NMR (400 MHz, メタノール-d₄) δ 7.40 (br s, 1H), 3.61 - 3.43 (m, 2H), 3.37
- 3.3 (m, 2H, 推定; 水ピークにより大部分が不明確), 2.85 - 2.67 (m, 2H), 2.37
(s, 3H), 2.06 - 1.92 (m, 2H), 1.92 - 1.75 (m, 2H), [1.47 (s)および1.46 (s), 合計9H].

1,3-Dibromo-5,5-dimethylimidazolidine-2,4-dione (2.47 g, 8.64 mmol) was added portionwise over 20 min to a 0° C. solution of P17 (5.25 g, 17.3 mmol) in dichloromethane (69 mL). After stirring the reaction mixture at 0° C. for 45 min, LCMS analysis indicated conversion to P22: LCMS m/z 384.3 (bromine isotope pattern observed) [M+H] ⁺ . After 1 h at 0° C., the reaction mixture was treated with saturated aqueous sodium sulfite (100 mL) and the mixture was extracted with dichloromethane. The organic layer was washed successively with saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo to provide P22 as a solid. Yield: 6.60 g, 17.3 mmol, quantitative. ^1H NMR (400 MHz, methanol- _d4 ) δ 7.40 (br s, 1H), 3.61 - 3.43 (m, 2H), 3.37
- 3.3 (m, 2H, estimated; mostly obscured by water peak), 2.85 - 2.67 (m, 2H), 2.37
(s, 3H), 2.06 - 1.92 (m, 2H), 1.92 - 1.75 (m, 2H), [1.47 (s) and 1.46 (s), total 9H].

Preparations P23 and P24
tert-Butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate (P23) and tert-butyl (2R)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate (P24)

１，３－ジブロモ－５，５－ジメチルイミダゾリジン－２，４－ジオン（５．６５ｇ、１９．８ｍｍｏｌ）を、ジクロロメタン（１５０ｍＬ）中のＰ１７（１０．０ｇ、３２．９ｍｍｏｌ）の０℃溶液に少しずつ添加し、反応混合物を０℃から５℃で１時間にわたって撹拌し、その時点で、ＬＣＭＳ分析は、臭素化が起きたことを指し示した：LCMS m/z 382.3 [M+H]⁺.飽和亜硫酸ナトリウム水溶液（２０ｍＬ）、続いて、水（５０ｍＬ）を添加し；得られた水層をジクロロメタン（２×５０ｍＬ）で抽出した。合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮し；シリカゲルクロマトグラフィー（勾配：ヘプタン中０％から１００％酢酸エチル）により、Ｐ２３およびＰ２４のラセミ混合物を薄黄色の泡状物（１１．８ｇ）として得た。これを、Ｐ１７（７．４０ｇ、２４．４ｍｍｏｌ）を使用して行われた同様の反応の生成物と合わせて、薄黄色の泡状物（２０．９ｇ、５４．６ｍｍｏｌ、合わせた収率９５％）を提供し、超臨界流体クロマトグラフィー［カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｃｅｌ ＯＪ、５０×２５０ｍｍ、５μｍ；移動相 ４：１ 二酸化炭素／（１：１ メタノール／アセトニトリル）；流速：２５０ｍＬ／分；背圧：１２０バール］により、その構成要素の鏡像異性体に分離した。第１に溶離する鏡像異性体をＰ２３として指定し、第２に溶離する鏡像異性体をＰ２４として指定した。

1,3-Dibromo-5,5-dimethylimidazolidine-2,4-dione (5.65 g, 19.8 mmol) was added portionwise to a 0° C. solution of P17 (10.0 g, 32.9 mmol) in dichloromethane (150 mL) and the reaction mixture was stirred at 0° C. to 5° C. for 1 h, at which point LCMS analysis indicated that bromination had occurred: LCMS m/z 382.3 [M+H] ⁺ . Saturated aqueous sodium sulfite (20 mL) was added, followed by water (50 mL); the resulting aqueous layer was extracted with dichloromethane (2×50 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo; silica gel chromatography (gradient: 0% to 100% ethyl acetate in heptane) afforded a racemic mixture of P23 and P24 as a light yellow foam (11.8 g). This was combined with the product of a similar reaction carried out using P17 (7.40 g, 24.4 mmol) to give a pale yellow foam (20.9 g, 54.6 mmol, 95% combined yield) which was separated into its component enantiomers by supercritical fluid chromatography [column: Chiral Technologies Chiralcel OJ, 50×250 mm, 5 μm; mobile phase 4:1 carbon dioxide/(1:1 methanol/acetonitrile); flow rate: 250 mL/min; back pressure: 120 bar]. The first eluting enantiomer was designated as P23 and the second eluting enantiomer was designated as P24.

The absolute stereochemistry indicated was assigned based on the conversion of this batch of P23 to P28 (see Preparation P28) and then to Example 14; the absolute stereochemistry of 14 was established by single crystal X-ray analysis (see below).
P23 was isolated as a yellow oil that solidified on standing - combined yield: 9.37 g, 24.5 mmol, 43%. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.37 (s, 1H), 7.02 - 6.96 (m, 1H), [3.55 -
3.40 (m), 3.36 - 3.26 (m, estimated; partially obscured by water peak), and 3.24 - 3.13 (m), total 4H],
2.75 - 2.55 (m, 2H), 2.31 (s, 3H), 1.95 - 1.78 (m, 2H), 1.76 - 1.60 (m, 2H),
[1.40 (s) and 1.38 (s), total 9H].
Retention time: 4.01 min [Analytical conditions. Column: Chiral Technologies Chiralcel OJ-H, 4.6×250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: methanol containing 0.2% (7 M ammonia in methanol); Gradient: 5% B over 1 min, then 5% to 60% B over 8 min; Flow rate: 3.0 mL/min; Back pressure: 120 bar].
P24 - Combined yield: 11.8 g, which contained ethanol; corrected estimate: 28.4 mmol, 50%. ¹ H NMR (400 MHz, DMSO-d ₆ ), characteristic peaks: δ 7.37 (s, 1H), 7.01 - 6.96 (m, 1H), 2.75 - 2.55 (m, 2H), 2.31 (s,
3H), 1.95 - 1.78 (m, 2H), 1.76 - 1.60 (m, 2H), [1.40 (s) and 1.38 (s), total 9H]. Retention time: 4.32 min (same analytical conditions as used for P23).

Alternative Preparation of P23 (#1)
tert-Butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P23)

１，３－ジブロモ－５，５－ジメチルイミダゾリジン－２，４－ジオン（６２５ｍｇ、２．１９ｍｍｏｌ）を、ジクロロメタン（２０ｍＬ）中のＰ１９（調製例Ｐ１９およびＰ２０からの材料；１．１０ｇ、３．６３ｍｍｏｌ）の０℃溶液に少しずつ添加した。反応混合物を室温で１時間にわたって撹拌した後に、ＬＣＭＳ分析は、Ｐ２３への変換を指し示した：LCMS m/z 384.2 (臭素同位体パターンが観察された) [M+H]⁺.次いで、飽和亜硫酸ナトリウム水溶液を添加し、得られた混合物をジクロロメタンで抽出した。有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮し、シリカゲルクロマトグラフィー（勾配：ヘプタン中１０％から４０％酢酸エチル）を使用して精製して、Ｐ２３を白色の固体として得た。収量：１．２５ｇ、３．２７ｍｍｏｌ、９０％。¹H NMR (400 MHz, クロロホルム-d) δ 7.33 (s, 1H), 5.15 - 5.01 (br s, 1H), 3.59 - 3.45 (m, 2H), 3.43 -
3.25 (m, 2H), 2.81 - 2.66 (m, 2H), 2.43 (s, 3H), 2.01 - 1.74 (m, 4H), 1.48 -
1.43 (br s, 9H).

1,3-Dibromo-5,5-dimethylimidazolidine-2,4-dione (625 mg, 2.19 mmol) was added portionwise to a 0° C. solution of P19 (material from Preparations P19 and P20; 1.10 g, 3.63 mmol) in dichloromethane (20 mL). After stirring the reaction mixture at room temperature for 1 h, LCMS analysis indicated conversion to P23: LCMS m/z 384.2 (bromine isotope pattern observed) [M+H] ⁺ . Saturated aqueous sodium sulfite was then added and the resulting mixture was extracted with dichloromethane. The organic layer was washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, concentrated in vacuo, and purified using silica gel chromatography (gradient: 10% to 40% ethyl acetate in heptane) to give P23 as a white solid. Yield: 1.25 g, 3.27 mmol, 90%. ^1H NMR (400 MHz, chloroform-d) δ 7.33 (s, 1H), 5.15 - 5.01 (br s, 1H), 3.59 - 3.45 (m, 2H), 3.43 -
3.25 (m, 2H), 2.81 - 2.66 (m, 2H), 2.43 (s, 3H), 2.01 - 1.74 (m, 4H), 1.48 -
1.43 (br s, 9H).

The absolute stereochemistry of this sample of P23 was assigned by comparison with samples from preparations P23 and P24 as indicated:
Retention time of P23 from an alternative preparation of P23 (#1): 4.08 min. Retention times of racemic mixture of P23 and P24: 4.07 and 4.36 min.
Retention time of P23 from Prep. Examples P23 and P24: 4.01 min. Retention time of P24 from Prep. Examples P23 and P24: 4.32 min. These four analyses were performed using the same analytical method: [Column: Chiral Technologies Chiralcel OJ-H, 4.6×100 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: methanol containing 0.2% (7M ammonia in methanol); Gradient: 5% B over 1 min, then 5% to 60% B over 8 min; Flow rate: 3.0 mL/min.].

Alternative Preparation of P23 (#2)
tert-Butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P23)

ステップ１． （２－クロロ－６－メチルピリジン－３－イル）メタノール（Ｃ４９）の合成。
ナトリウムビス（２－メトキシエトキシ）アルミニウムヒドリド溶液（７０％；１．０５ｋｇ、２．５当量）を、トルエン（２．５Ｌ）中の２－クロロ－６－メチルピリジン－３－カルボン酸（２５０ｇ、１．４６ｍｏｌ）の－５℃から５℃溶液に添加した。反応混合物を－５℃から５℃で１９時間にわたって撹拌した後に、これを、水（１．２５Ｌ）中の水酸化ナトリウム（１４５．７ｇ、３．６４２ｍｏｌ、２．５０当量）の溶液で処理し、その間、内部温度を０℃から１０℃未満に維持した。次いで、得られた混合物を２５℃に加温し；１５分後に、水層をプロパン－２－イルアセテート（２×１．２５Ｌ）で抽出した。これらの２つの抽出物をトルエン層と合わせ、シリカゲル（１２５ｇ）を通して濾過した。濾過ケーキをプロパン－２－イルアセテート（１２５ｍＬ）ですすぎ、合わせた濾液を４０℃から４５℃の温度で８体積まで濃縮して、Ｃ４９をトルエン中溶液（１．６０２ｋｇ、重量で１１．２％Ｃ４９）として得た；この溶液のバルクを次のステップで使用した。推定収量：１７９．４ｇ、１．１３８ｍｏｌ、７８％。¹H NMR (400 MHz, DMSO-d₆) δ 7.81 (d, J = 7.8 Hz, 1H), 7.29 (d, J = 7.7
Hz, 1H), 5.48 (t, J = 5.6 Hz, 1H), 4.50 (d, J = 5.6 Hz, 2H), 2.43 (s, 3H).

Step 1. Synthesis of (2-chloro-6-methylpyridin-3-yl)methanol (C49).
Sodium bis(2-methoxyethoxy)aluminum hydride solution (70%; 1.05 kg, 2.5 equiv.) was added to a −5° C. to 5° C. solution of 2-chloro-6-methylpyridine-3-carboxylic acid (250 g, 1.46 mol) in toluene (2.5 L). After the reaction mixture was stirred at −5° C. to 5° C. for 19 hours, it was treated with a solution of sodium hydroxide (145.7 g, 3.642 mol, 2.50 equiv.) in water (1.25 L) while maintaining the internal temperature below 0° C. to 10° C. The resulting mixture was then warmed to 25° C.; after 15 minutes, the aqueous layer was extracted with propan-2-yl acetate (2×1.25 L). These two extracts were combined with the toluene layer and filtered through silica gel (125 g). The filter cake was rinsed with propan-2-yl acetate (125 mL) and the combined filtrate was concentrated to 8 volumes at 40° C. to 45° C. to give C49 as a solution in toluene (1.602 kg, 11.2% C49 by weight); the bulk of this solution was used in the next step. Estimated yield: 179.4 g, 1.138 mol, 78%. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.81 (d, J = 7.8 Hz, 1H), 7.29 (d, J = 7.7
Hz, 1H), 5.48 (t, J = 5.6 Hz, 1H), 4.50 (d, J = 5.6 Hz, 2H), 2.43 (s, 3H).

Step 2. Synthesis of (2-chloro-6-methylpyridin-3-yl)methyl methanesulfonate (C50).
Triethylamine (134.2 g, 1.326 mol) was added to a solution of C49 in toluene (from the previous step; 1.537 kg, containing 11.2% C49, 172.1 g, 1.09 mol). The solution was cooled to -5 to 5°C and then treated dropwise with methanesulfonyl chloride (128.5 g, 1.122 mol) while maintaining the internal temperature at -5 to 5°C. After the reaction mixture was stirred at this temperature for 2 hours, triethylamine (22.7 g, 0.224 mol) was added again, followed by the dropwise addition of methanesulfonyl chloride (25.7 g, 0.224 mol). Stirring was continued at -5°C to 5°C for 1 h, whereupon the reaction mixture was treated with water (805 mL) while maintaining the internal temperature below 25°C, and then stirred at 25°C for 15 min. The organic layer was washed with water (805 mL) and concentrated to provide C50 as a solution in toluene (861 g). This solution was used directly in the next step. ^1H NMR (400 MHz, DMSO- _d6 ) δ 7.92 (d, J = 7.7 Hz, 1H), 7.36 (d, J = 7.7
Hz, 1H), 5.30 (s, 2H), 3.29 (s, 3H), 2.48 (s, 3H).

Step 3. Synthesis of 2-chloro-3-(iodomethyl)-6-methylpyridine (C51).
Sodium iodide (230 g, 1.53 mol) was dissolved in acetone (1.13 kg) at 25° C.; to this solution was added a solution of C50 in toluene (from the previous step; 861 g, 1.09 mol or less of C50). After the reaction mixture was stirred at 25° C. for 1 h, a solution of sodium metabisulfite (57.86 g, 0.3044 mol) in water (1.45 L) was added and stirring was continued for 30 min. The organic layer was separated, diluted with toluene (417 mL) and concentrated to 5 volumes to provide C51 as a solution in toluene (1.110 kg, 22.93% C51 by weight). This solution was used as is in the next step. Estimated yield: 254.5 g, 0.9514 mol, 87% for two steps. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.90 (d, J = 7.7 Hz, 1H), 7.26 (d, J = 7.8
Hz, 1H), 4.55 (s, 2H), 2.41 (s, 3H).

Step 4. Synthesis of [(2-chloro-6-methylpyridin-3-yl)methyl](triphenyl)phosphonium iodide (C52).
A solution of C51 in toluene (from the previous step; 1.110 kg, 22.93% C51 by weight, 254.5 g, 0.9514 mol) was diluted with acetonitrile (1.29 L) and treated with triphenylphosphine (262 g, 0.999 mol). After the reaction mixture was stirred at 25° C. for 4 h, it was cooled to 10° C., stirred at that temperature for 16 h, and filtered. The filter cake was washed with toluene (255 mL) and dried at 45° C. for 4 h to give C52 as a solid. Yield: 412.6 g, 0.7788 mol, 56% for 4 steps. Purity: 99.7% by HPLC. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.97 - 7.90 (m, 3H), 7.80 - 7.71 (m, 8H),
7.71 - 7.66 (m, 4H), 7.44 (dd, J = 7.8, 2.4 Hz, 1H), 7.20 (d, J = 7.8 Hz, 1H),
5.15 (d, J _HP = 15.0 Hz, 2H), 2.40 (d, J = 2.4 Hz, 3H).

Step 5. Synthesis of diethyl 1-benzylpyrrolidine-3,3-dicarboxylate (C53).
A solution of ethyl 1-benzylpyrrolidine-3-carboxylate (700 g, 3.00 mol) in tetrahydrofuran (4.20 L) was added dropwise over 5 hours to a −80° C. to −70° C. solution of lithium diisopropylamide (2.0 M, 2.40 L, 4.80 mol). Stirring was continued at −80° C. to −70° C. for 2 hours whereupon ethyl chloroformate (423.5 g, 3.90 mol) was added over 3 hours while the reaction temperature was maintained at −80° C. to −70° C. After stirring the reaction mixture at −80° C. to −70° C. for 2 hours, the temperature was adjusted to −50° C. to −40° C. and the reaction was quenched by the addition of a solution of acetic acid (288 g, 4.80 mol) in tetrahydrofuran (1.40 L) while the temperature was maintained at −50° C. to −40° C. The resulting mixture was warmed to 15-25° C. and partitioned between water (3.50 L) and 2-methyltetrahydrofuran (7.0 L). After stirring the mixture at 15-25° C. for 30 minutes, the aqueous layer was extracted with 2-methyltetrahydrofuran (7.0 L) and the combined organic layers were washed with a solution of acetic acid (288 g, 4.80 mol) in water (4.2 L) and then with an aqueous solution of sodium sulfate (10%; 2×3.50 kg). The organic layer was concentrated in vacuo to 2-3 volumes, keeping the temperature below 50° C. Ethanol (4.90 L, 7 volumes) was added and the solution was again concentrated in vacuo to 2-3 volumes, keeping the temperature below 50° C. This ethanol addition/concentration was performed a total of three times, with a final round using 2.80 L of ethanol followed by concentration to 4-5 volumes. This provided C53 as a solution in ethanol (3.148 kg, 24.23% C53 by weight). A portion of this solution was used in the next step. Estimated yield: 762.8 g, 2.498 mol, 83%. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.35 - 7.20 (m, 5H), 4.12 (q, J = 7.1 Hz,
4H), 3.57 (s, 2H), 2.90 (s, 2H), 2.55 (t, J = 6.9 Hz, 2H), 2.29 (t, J = 6.8 Hz,
2H), 1.14 (t, J = 7.1 Hz, 6H).

Step 6. Synthesis of diethylpyrrolidine-3,3-dicarboxylate, L-tartrate salt (C54).
Ethanol (720 mL, 6 vol) was added to a solution of C53 (120 g, 0.393 mol) in ethanol (from the previous step; approximately 500 mL). After addition of wet palladium on carbon (10%; 12 g), the reaction vessel was evacuated and charged with argon three times, then evacuated and charged with hydrogen three times. Hydrogenation was then carried out at 40-50 psi and 40-50° C. for 24 h. The resulting mixture was filtered through diatomaceous earth (50 g); the filter cake was washed with ethanol (240 mL, 2 vol) and the combined filtrate was concentrated in vacuo to 2.5-3.5 vol, keeping the temperature below 45° C. This solution was added to a 40-50° C. solution of L-tartaric acid (76.7 g, 0.511 mol) in water (85 mL, 0.7 vol) and ethanol (465 mL) over 2 h. The mixture was stirred at 40-50° C. for 1 h, after which C54 seeds (0.4 g; see below) were added at 45° C. The mixture was cooled to 10° C. over 6 h, then stirred at 10° C. for 4 h; filtered to provide a filter cake that was washed with ethanol (2 vol.) and dried at 40° C. for 20 h to give C54 as a solid. Yield: 127.4 g, 0.3487 mol, 89%. HPLC purity: 99.1%. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 4.16 (q, J = 7.1 Hz, 4H), 4.03 (s, 2H),
3.49 (s, 2H), 3.08 (t, J = 7.1 Hz, 2H), 2.32 (t, J = 7.1 Hz, 2H), 1.18 (t, J =
7.1Hz, 6H).
The seed material used above was obtained from another run of the same synthesis of C54, where solid C54 was formed directly upon cooling.

Step 7. Synthesis of 1-tert-butyl 3,3-diethylpyrrolidine-1,3,3-tricarboxylate (C55).
Di-tert-butyl dicarbonate (19.7 g, 90.3 mmol) was added in a dropwise fashion to a 20° C.-30° C. mixture of C54 (88.12 g, 0.2412 mol) and triethylamine (73.33 g, 0.7247 mol) in dichloromethane (881 mL, 10 volumes). After periodic HPLC analysis, additional di-tert-butyl dicarbonate (19.2 g, 88.0 mmol and 19.3 g, 88.4 mmol) was added dropwise. After stirring the reaction mixture at 20° C.-30° C. for 18 h, the pH was adjusted to 7 by the addition of hydrochloric acid (1 M; 309 g) and stirring was continued for 15 min. The organic layer was stirred with aqueous sodium sulfate (10%; 485.30 g) at 20° C. to 30° C. for 15 min, then the organic layer was concentrated in vacuo to 1 to 2 volumes while maintaining the temperature below 40° C. Dimethyl sulfoxide (71.7 g) was added to give C55 as a solution in dimethyl sulfoxide (154.2 g, 48.9% C55 by weight). The bulk of this material was carried on to the next step. Estimated yield: 75.4 g, 0.239 mol, 99%. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 4.16 (q, J = 7.1 Hz, 4H), 3.67 (br s, 2H),
3.34 - 3.26 (m, 2H), 2.37 - 2.28 (m, 2H), 1.39 (s, 9H), 1.17 (br t, J = 7.1 Hz,
6H).

Step 8. Synthesis of (3R)-1-(tert-butoxycarbonyl)-3-(ethoxycarbonyl)pyrrolidine-3-carboxylic acid (C56).
ECS-esterase 03 enzyme (Bacillus stearothermophilus, recombinant from Escherichia coli, (EC 3.1.1.1); 0.540 g) was added to phosphate buffer (0.1 M; pH = 6.92, 580 mL, 8.2 volumes) at 20°C to 30°C. A solution of C55 (72.2 g, 0.229 mol) in dimethyl sulfoxide (from the previous step; approximately 148 g) was added; additional dimethyl sulfoxide (9 mL) was used to rinse the initial vessel, which was also added to the reaction mixture. The initial reaction pH was 7.08; after stirring for 1 hour at 20°C to 30°C, the pH decreased to 6.58. The pH was maintained at 7.5 by adding aqueous sodium hydroxide (2M; 121 mL, 0.242 mol) over 24 hours using a pH automatic titrator. Hydrochloric acid (6M; 52 mL, 0.312 mol) was added to a pH of 2.39; then ethyl acetate (435 mL, 6.0 vol) was added and the mixture was stirred at 20°C to 30°C for 30 minutes. Filtered through diatomaceous earth (18.0 g) to provide a filter cake, which was rinsed with ethyl acetate (2 x 75 mL). The combined filtrate was stirred at 20°C to 30°C for 30 minutes, then the aqueous layer was stirred with ethyl acetate (217 mL, 3.0 vol) for 30 minutes. The combined organic layers were washed twice with water (360 mL, 5.0 vol) by stirring for 30 minutes. The resulting solution was concentrated in vacuo to 1-2 volumes while maintaining the temperature below 40° C., then diluted with toluene (360 mL); this concentration/dilution procedure was performed a total of three times to provide C56 as a solution in toluene (418.3 g, 15.67% C56 by weight). Estimated yield: 65.6 g, 0.228 mol, quantitative. ¹ H NMR (400 MHz, chloroform-d) δ 7.99 (v br s, 1H), 4.22 (q, J = 7.1 Hz, 2H), [3.88 (br s) and 3.83 (br s), total 2H], 3.51 - 3.38 (m, 2H), 2.41 (t, J = 7.1 Hz, 2H), 1.44 (s, 9H),
1.26 (br t, J = 7 Hz, 3H).

Step 9. Synthesis of 1-tert-butyl 3-ethyl (3S)-3-{[(benzyloxy)carbonyl]amino}pyrrolidine-1,3-dicarboxylate (C57).
Toluene (170 mL, 1.2 vol) was added to a solution of C56 in toluene (3.8 vol, containing 28.9% C56 by weight, 146.4 g, 0.5096 mol); the solution was heated to 80° C. to 90° C. To this was added slowly over 2 hours a mixture of triethylamine (77.4 g, 0.765 mol) and diphenyl phosphorazidate (140.3 g, 0.5098 mol) in toluene (732 mL, 5 vol). The reaction mixture was stirred at 80° C. to 90° C. for 3 hours whereupon it was cooled to 50° C. and treated dropwise over 2 hours with a solution of benzyl alcohol (55.12 g, 0.5097 mol) in toluene (290 mL, 2 vol). After the reaction mixture was stirred at 100° C. for 16 hours, it was cooled to 15-25° C. and partitioned between toluene (1.46 L, 10 volumes) and water (2.20 L, 15 volumes) by stirring for 30 minutes. The organic layer was washed sequentially with aqueous potassium carbonate (10%; 3×1.46 L) and water (2×750 mL). It was then concentrated in vacuum to 1-2 volumes while maintaining the temperature below 50° C. and diluted with tetrahydrofuran (1.0 L); this concentration/dilution procedure was performed a total of three times, whereupon the mixture was concentrated in vacuum to 4-5 volumes while maintaining the temperature below 50° C. This gave C57 as a solution in tetrahydrofuran (595.8 g, 19.14% C57 by weight). Estimated yield: 114 g, 0.290 mol, 57%. ^1H NMR (400 MHz, chloroform-d) δ 7.40 - 7.28 (m, 5H), 5.25 (v br s, 1H), 5.10 (br s, 2H), 4.28 -
4.12 (m, 2H), 3.91 - 3.76 (m, 1H), 3.71 - 3.38 (m, 3H), 2.54 - 2.15 (m, 2H),
1.45 (s, 9H), 1.27 - 1.16 (m, 3H).

Step 10. Synthesis of tert-butyl (3S)-3-{[(benzyloxy)carbonyl]amino}-3-(hydroxymethyl)pyrrolidine-1-carboxylate (C58).
A solution of lithium borohydride in tetrahydrofuran (2 M; 511 mL, 1.02 mol) was added over 2 hours to a 0° C.-10° C. solution of C57 in tetrahydrofuran (835.6 g, containing 19.20% C57 by weight, 160.4 g, 0.4087 mol). The reaction mixture was stirred at 0° C.-10° C. for 15 hours before it was cooled to −5° C.-5° C. and treated dropwise with hydrochloric acid (0.5 M; 2.08 L, 1.04 mol, 13 volumes) to a pH of 7. The mixture was then warmed to 20° C.-30° C., diluted with ethyl acetate (1.60 L, 10 volumes) and stirred for 10 minutes whereupon the organic layer was concentrated in vacuo to 2-3 volumes while maintaining the temperature below 50° C. The resulting mixture was diluted with acetonitrile (880 mL) and concentrated in vacuo to 2-3 volumes while maintaining the temperature below 50° C.; this dilution/concentration procedure was performed a total of three times. The mixture was then heated to 40° C.-50° C. and stirred for 1 hour, whereupon it was cooled to 15° C.-25° C. over 4 hours. Water (164 mL) was added dropwise at 15° C.-25° C. over 2 hours, and the mixture was stirred at 15° C.-25° C. for 12 hours. The resulting solid was collected by filtration and dried in vacuum at a temperature below 50° C. for 40 hours to give C58 as a solid. Yield: 123.2 g, 0.3516 mol, 86%. HPLC purity: 99.8%. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 7.40 - 7.27 (m, 5H), 4.99 (s, 2H), 4.93
(t, J = 5.8 Hz, 1H), 3.58 - 3.45 (m, 3H), 3.31 - 3.21 (m, 3H), 2.10 - 1.85 (m,
2H), 1.38 (s, 9H).

Step 11. Synthesis of tert-butyl (3S)-3-{[(benzyloxy)carbonyl]amino}-3-formylpyrrolidine-1-carboxylate (C59).
A solution of C58 (125 g, 0.357 mol) and dimethylsulfoxide (144.5 g, 1.849 mol) in dichloromethane (2.02 L) was stirred at 35° C. to 45° C. for 2 hours; Karl Fischer analysis indicated a water content of 0.029%. The solution was concentrated in vacuum to 3 to 4 volumes at 35° C. to 45° C. and then diluted with dichloromethane (1.80 L). Another Karl Fischer analysis revealed a water content of 0.034%. The solution was concentrated in vacuum to 6 to 7 volumes at 35° C. to 45° C. whereupon triethylamine (112.3 g, 1.110 mol) was added at 20° C. to 30° C. and the reaction mixture was cooled to −5 to 0° C. and stirred at that temperature for 15 minutes. Sulfur trioxide pyridine complex (141.3 g, 0.8878 mol) was added portionwise over 2 h; stirring was then continued at −5° C. to 0° C. for 16 h, at which point the reaction mixture was warmed to 35° C. to 45° C. and concentrated to 2 to 3 volumes. After the mixture was cooled to 20° C. to 30° C., it was partitioned between ethyl acetate (945 mL) and water (675 mL), and the aqueous layer was extracted with ethyl acetate (675 mL). The combined organic layers were washed successively with hydrochloric acid (1 M; 675 mL), water (675 mL), and saturated aqueous sodium bicarbonate solution (675 mL), then concentrated to dryness at 30° C. to 40° C. to provide C59 as an oil. Yield: 118.7 g, 0.3407 mol, 95%. HPLC purity: 91.2%. ^1H NMR (400 MHz, chloroform-d) δ 9.59 (s, 1H), 7.42 - 7.29 (m, 5H), 5.39 (br s, 1H), 5.12 (s, 2H),
3.85 - 3.70 (m, 1H), 3.63 - 3.43 (m, 3H), 2.44 - 2.04 (m, 2H), 1.45 (s, 9H).

Step 12. Synthesis of tert-butyl (3R)-3-{[(benzyloxy)carbonyl]amino}-3-[(E)-2-(2-chloro-6-methylpyridin-3-yl)ethenyl]pyrrolidine-1-carboxylate (C60) and tert-butyl (3R)-3-{[(benzyloxy)carbonyl]amino}-3-[(Z)-2-(2-chloro-6-methylpyridin-3-yl)ethenyl]pyrrolidine-1-carboxylate (C61).
A mixture of C59 (237.1 g, 0.6805 mol) and C52 (393.6 g, 0.7429 mol) in dimethylsulfoxide (2.40 L, 10 vol) was treated with potassium carbonate (188.7 g, 1.365 mol) and heated at 60° C. for 2 hours. Then propan-2-yl acetate (1.54 L, 6.5 vol), water (6.40 L, 27 vol), and aqueous sodium sulfate (10%; 710 mL, 3.0 vol) were added and the mixture was stirred at 25° C. for 20 minutes. The organic layer was washed three times with aqueous sodium sulfate (10%; 1.30 L, 5.5 vol) by stirring each mixture for 20 minutes before separation. It was then washed in the same manner with aqueous sodium bicarbonate (7%; 1.30 L, 5.5 vol) and concentrated in vacuo to 1 to 2 volumes at a temperature of 50° C. or less. Propan-2-yl acetate (1.06 L) was added and the mixture was concentrated in vacuo to 1-2 volumes at a temperature below 50° C. Propan-2-yl acetate (480 mL) was added followed by dropwise addition of methylcyclohexane (1.66 L) at 20° C. to 30° C. The resulting mixture was stirred at 20° C. to 30° C. for 1 hour before it was cooled to −15° C. to −5° C. and stirred at that temperature for 16 hours. The slurry was filtered at −15° C. to −5° C. and the filter cake was washed with a mixture of propan-2-yl acetate and methylcyclohexane (ratio 3:7, 710 mL) at −15° C. to −5° C. The combined filtrate was concentrated in vacuo, diluted with methylcyclohexane (20 volumes) and chromatographed on silica gel (gradient: 14% to 25% ethyl acetate in methylcyclohexane) to give a mixture of C60 and C61 as an oil. This material was determined to consist of three to four isomers/rotamers by ¹ H NMR analysis. Yield: 268.1 g, 0.5680 mol, 83%. HPLC purity: 99.7% or higher. ¹ H NMR (400 MHz, DMSO-d ₆ ), characteristic peaks: δ [8.00 (d, J = 7.9 Hz) and 7.59 (d, J = 7.6 Hz), total 1H], [7.85 (s) and 7.41
(s), total 1H], [7.38 - 7.25 (m),
7.22 (br d, J = 7.2 Hz), and 7.16
(d, J = 7.7 Hz), total 6H], [6.62
(d, component of AB quartet, J = 16.1 Hz) and 6.34 (d, J = 12.3 Hz), sum 1H], [6.49 (br d, component of AB quartet, J = 16.0 Hz), 5.88 (d, J = 12.3 Hz), and 5.87 (d, J = 12.3 Hz), sum 1H], [5.04 (AB quartet, J _AB = 12.7 Hz, Δν _AB = 16.4 Hz), 4.74 (d, component of AB quartet, J = 12.4 Hz), and 4.70 - 4.62 (m), sum 2H], 3.83 - 3.68 (m, 1H), 3.32 - 3.16 (m, 3H), [2.43 (s) and 2.36 (s), total 3H], 2.27 - 2.12 (m, 1H), 2.00 - 1.85 (m, 1H), [1.40 (s), 1.39 (s),
1.37 (s), and 1.34 (s), total 9H].

Step 13. Synthesis of tert-butyl (3S)-3-{[(benzyloxy)carbonyl]amino}-3-[2-(2-chloro-6-methylpyridin-3-yl)ethyl]pyrrolidine-1-carboxylate (C62).
The reaction vessel, containing a mixture of C60 and C61 (283.0 g, 0.5996 mol) and rhodium on alumina (5%; 14.15 g) in methanol (1.98 L), was evacuated and charged with argon three times, then evacuated and charged with hydrogen three times. Hydrogenation was then carried out at 30-40 psi and 20° C.-25° C. for 40 hours. After filtering the reaction mixture through diatomaceous earth (424 g), the filter cake was washed with methanol (5 vol.); the combined filtrate was concentrated in vacuum at 35° C.-45° C. The resulting material was treated with toluene (5 vol.) and concentrated in vacuum at 50° C.-60° C.; this toluene addition/concentration procedure was carried out a total of three times to provide C62. Yield: 254.4 g, 0.5367 mol, 90%. HPLC purity: 97.1%. ^1H NMR (400 MHz, chloroform-d) δ 7.41 - 7.28 (m, 6H), 6.99 (br d, J = 7.6 Hz, 1H), 5.06 (s, 2H),
4.91 - 4.79 (m, 1H), 3.62 (d, J = 11.7 Hz, 1H), 3.57 - 3.36 (m, 2H), 3.36 -
3.26 (m, 1H), 2.74 - 2.55 (m, 2H), 2.48 (s, 3H), [2.48 - 2.40 (m), 2.39 - 2.07
(m) and 2.05 - 1.82 (m), total 4H], 1.45 (br s, 9H).

Step 14. Synthesis of tert-butyl (2S)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P19).
A solution of C62 in toluene (947.73 g, containing 19% C62 by weight, 180 g, 0.380 mol) was diluted with toluene (1.17 L, 6.5 vol) and treated sequentially with 2-dicyclohexylphosphino-2',6'-diisopropoxybiphenyl (RuPhos; 35.44 g, 75.95 mmol) and potassium phosphate (145.1 g, 0.6836 mol). The resulting mixture was purged with nitrogen three times whereupon tris(dibenzylideneacetone)dipalladium(0) (34.78 g, 37.98 mmol) was added and three more rounds of nitrogen purging were performed. The reaction mixture was stirred at 75° C. to 85° C. for 24 h. Potassium phosphate (16.2 g, 0.117 mol) was added and stirring was continued at 75° C. to 85° C. for an additional 16 h. After cooling the reaction mixture to 20-30° C., potassium tert-butoxide (76.7 g, 0.684 mol) was added and the reaction mixture was stirred at 75-85° C. for 2 hours. It was then cooled and partitioned between water (2.25 L) and ethyl acetate (2.25 L); after stirring at 20-30° C. for 30 minutes, the mixture was filtered through diatomaceous earth (180 g) and the filter cake was washed with ethyl acetate (1.80 L). The organic layer of the combined filtrate was washed successively with water (2×2.25 L) and aqueous sodium sulfate (10%; 2.25 L), then extracted three times with aqueous citric acid (0.5 M; 1.072 kg, 1.4 equiv.). The combined citric acid layer was washed with ethyl acetate (2×1.07 L) and then adjusted to pH 7 by adding aqueous sodium hydroxide (30%; 596 g) at 20-30° C. The aqueous layer was extracted with ethyl acetate (3×1.07 L) and the three organic layers were subsequently combined to provide P19 as a solution in ethyl acetate (3.218 kg, 2.7% P19 by weight); the bulk of this material was carried on to the next step. Estimated yield: 86.9 g, 0.286 mol, 75%. HPLC purity: 98.9%. ¹ H NMR (400 MHz, chloroform-d) δ 7.11 (d, J = 7.3 Hz, 1H), 6.41 (d, J = 7.4 Hz, 1H), 4.90 (br s,
1H), 3.59 - 3.43 (m, 2H), [3.40 (d, component of the AB quartet, J = 11.1 Hz) and 3.36
- 3.25 (m), total 2H], 2.80 - 2.65
(m, 2H), 2.31 (s, 3H), 2.00 - 1.75 (m, 4H), [1.45 (s) and 1.44 (s), total 9H].

Step 15. Synthesis of tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P23).
1,3-Dibromo-5,5-dimethylimidazolidine-2,4-dione (45.60 g, 0.1595 mol) was added to a 0° C.-5° C. solution of P19 in ethyl acetate (from the previous step; 2986 g, containing 2.7% P19, 80.6 g, 0.266 mol). After the reaction mixture was stirred at 0° C.-5° C. for 1 h, it was quenched by adding aqueous sodium sulfite (10%; 203 g) and water (456 mL) and the resulting mixture was stirred at 10° C.-20° C. for 20 min. The aqueous layer was extracted twice with ethyl acetate (415 mL, 5.1 vol) by stirring at 10° C.-20° C. for 20 min; then the combined organic layers were stirred with aqueous sodium sulfate (10%; 456 g) for 20 min. The organic layer was concentrated in vacuum below 50° C. to 1-2 volumes, followed by dilution with methanol (480 mL, 6 volumes). This concentration/dilution procedure was performed a total of three times, and the final solution was concentrated in vacuum below 50° C. to 5-6 volumes. The resulting solution was cooled to 15° C. to 25° C., water (415 mL) was added slowly at 15° C. to 25° C. over 2 hours, and then stirring was performed at 15° C. to 25° C. for 14 hours. Filtration provided a filter cake, which was washed with a mixture of methanol and water (1:1, 2×200 mL), and then dried under vacuum at 45° C. for 48 hours to obtain P23 as a solid. Yield: 99.50 g, 0.2603 mol, 98%. HPLC purity: 99.7%. LCMS m/z 384.1 (bromine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, DMSO-d ₆ )
δ 7.37 (s, 1H), 7.03 - 6.97 (m,
1H), 3.55 - 3.43 (m, 1H), 3.3 - 3.25 (m, 1H, estimated; partially obscured by water peak),
3.24 - 3.13 (m, 2H), 2.75 - 2.55 (m, 2H), 2.30 (s, 3H), 1.95 - 1.77 (m, 2H),
1.76 - 1.59 (m, 2H), [1.40 (s) and 1.38 (s), total 9H].

Obtaining Powder X-ray Diffraction (PXRD) Data for Crystalline P23 A sample of P23 [prepared as described in step 15 of Alternate Preparation (#2) above] was sent for powder X-ray diffraction (PXRD) analysis and found to be a crystalline material.

Powder X-ray diffraction analysis was performed using a Bruker AXS D8 Endeavor diffractometer equipped with a copper (Cu) radiation source. The divergence slit was set to 15 mm continuous illumination. Diffracted radiation was detected by a PSD-LynxEye detector with the detector PSD aperture set to 4.123 degrees. The X-ray tube voltage and amperage were set to 40 kV and 40 mA, respectively. In addition, an energy dispersive detector, nickel filter was used. Data was collected on a theta-theta goniometer at Cu wavelengths from 3.0 to 40.0 degrees 2 theta using a step width of 0.0100 degrees and a step time of 1.0 seconds. The anti-scatter screen was set at a fixed distance of 1.5 mm. Samples were prepared by placing them in a silicon low background sample holder and rotating at 15 revolutions per minute during collection. Data was collected using Bruker DIFFRAC Plus software and analysis was performed with EVA diffract plus software. PXRD data files were not processed prior to peak searching. Preliminary peak assignments were made using the peak search algorithm in the EVA software, with peaks selected as thresholded at 1. Adjustments were made manually, the output of the automatic assignment was visually verified, and peak positions were adjusted to the peak maximum to ensure validity. Peaks with a relative intensity of 3% or greater were generally selected. Peaks that were not resolved or consistent with noise were typically not selected. Typical errors associated with peak positions from PXRD as stated in the USP are a maximum of +/- 0.2° 2-theta (USP-941).

One representative diffraction pattern was observed for the crystalline form of P23 and is provided in Figure 3. A list of the diffraction peaks, expressed in degrees 2θ and relative intensities, from the PXRD from a sample of crystalline P23 with a relative intensity of 3.0% or greater is provided below in Table X-P23.

In some embodiments, the present invention provides a compound that is tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate or a salt thereof. In some embodiments, the present invention provides a compound that is tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate. In some further embodiments, the present invention provides a crystalline form of tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate. In some further embodiments, the crystalline form of tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits a powder X-ray diffraction pattern including at least one characteristic peak in terms of 2θ, such as those listed in Table X-P23.

In some embodiments, the crystalline form of tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern with at least two characteristic peaks in 2θ, such as those listed in Table X-P23. In some embodiments, the crystalline form of tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern with at least three characteristic peaks in 2θ, such as those listed in Table X-P23. In some embodiments, the crystalline form of tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern including at least 4 (e.g., 4, 5, 6, 7, 8, 9, or 10) characteristic peaks in 2θ such as those listed in Table X-P23. In some embodiments, the crystalline form of tert-butyl (2S)-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern substantially as shown in FIG. 3.

Preparation Example P25
Di-tert-butyl 7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (P25)

ステップ１． ジ－ｔｅｒｔ－ブチル６－エテニル－７－メチル－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１，１’－ジカルボキシレート（Ｃ６３）の合成。
Ｎ，Ｎ－ジメチルホルムアミド（５００ｍＬ）中のＰ２１（１５．０ｇ、３１．１ｍｍｏｌ）、ビニルトリフルオロホウ酸カリウム（１０．４ｇ、７７．６ｍｍｏｌ）、［１，１’－ビス（ジフェニルホスフィノ）フェロセン］ジクロロパラジウム（ＩＩ）（２．２７ｇ、３．１０ｍｍｏｌ）、およびリン酸カリウム（１９．８ｇ、９３．３ｍｍｏｌ）の混合物を９５℃で１６時間にわたって撹拌し、その後すぐに、反応混合物を濾過し；濾液を水（４Ｌ）に注ぎ入れ、酢酸エチル（２×８００ｍＬ）で抽出した。合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。残渣を、Ｐ２１（５．００ｇ、１０．４ｍｍｏｌ）を使用して行われた同様の反応の生成物と合わせた後に、これをシリカゲル上でのクロマトグラフィー（勾配：石油エーテル中０％から２０％酢酸エチル）により精製して、Ｃ６３を白色の固体として得た。合わせた収量：１７．１ｇ、３８．９ｍｍｏｌ、９４％。LCMS m/z 430.3 [M+H]⁺. ¹H NMR (400 MHz, クロロホルム-d) δ 7.46 (br s, 1H), 6.83 (dd, J = 17.4, 11.1 Hz, 1H), 5.59 (br d, J =
17.4 Hz, 1H), 5.37 - 5.24 (m, 1H), [3.90 (d, J = 11.0 Hz)および3.72 (d, J = 11.0 Hz), 合計1H], 3.64 - 3.41 (m, 2H), 3.38 - 3.24 (m,
1H), [2.86 - 2.64 (m), 2.62 - 2.39 (m),および2.16 - 1.72 (m), 合計9H],
1.45 (s, 18H).

Step 1. Synthesis of di-tert-butyl 6-ethenyl-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (C63).
A mixture of P21 (15.0 g, 31.1 mmol), potassium vinyltrifluoroborate (10.4 g, 77.6 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (2.27 g, 3.10 mmol), and potassium phosphate (19.8 g, 93.3 mmol) in N,N-dimethylformamide (500 mL) was stirred at 95° C. for 16 hours, whereupon the reaction mixture was filtered; the filtrate was poured into water (4 L) and extracted with ethyl acetate (2×800 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was combined with the product of a similar reaction carried out using P21 (5.00 g, 10.4 mmol) before being purified by chromatography on silica gel (gradient: 0% to 20% ethyl acetate in petroleum ether) to give C63 as a white solid. Combined yield: 17.1 g, 38.9 mmol, 94%. LCMS m/z 430.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.46 (br s, 1H), 6.83 (dd, J = 17.4, 11.1 Hz, 1H), 5.59 (br d, J =
17.4 Hz, 1H), 5.37 - 5.24 (m, 1H), [3.90 (d, J = 11.0 Hz) and 3.72 (d, J = 11.0 Hz), total 1H], 3.64 - 3.41 (m, 2H), 3.38 - 3.24 (m,
1H), [2.86 - 2.64 (m), 2.62 - 2.39 (m), and 2.16 - 1.72 (m), total 9H],
1.45 (s, 18H).

Step 2. Synthesis of di-tert-butyl 6-formyl-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (C64).
A solution of C63 (17.0 g, 39.6 mmol) in dichloromethane (200 mL) was cooled to −78° C. and a stream of ozone-enriched oxygen was introduced until the blue color persisted. After an additional 5 min, a stream of dry nitrogen was bubbled through the reaction mixture until the blue color disappeared, whereupon triphenylphosphine (20.7 g, 78.9 mmol) was added. The resulting mixture was warmed to 25° C. and stirred for 2 h, at which point LCMS analysis indicated the presence of C64: LCMS m/z 454.3 [M+Na ⁺ ]. After concentrating the reaction mixture in vacuo, the residue was purified using silica gel chromatography (gradient: 0% to 50% ethyl acetate in petroleum ether) to provide C64 as a colorless gum. Yield: 9.98 g, 23.1 mmol, 58%.

Step 3. Synthesis of di-tert-butyl 7-methyl-6-[(2-methylhydrazinylidene)methyl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (C65).
A solution of methylhydrazine sulfate (3.20 g, 22.2 mmol) and triethylamine (7.78 mL, 55.8 mmol) in methanol (50 mL) was stirred at 25° C. for 5 min, whereupon a solution of C64 (7.98 g, 18.5 mmol) in methanol (20 mL) was added. After the reaction mixture was stirred at 25° C. for 1 h, the precipitate was collected by filtration to give C65 as a white solid. Yield: 7.60 g, 16.5 mmol, 89%. LCMS m/z 460.3 [M+H] ⁺ .

Step 4. Synthesis of di-tert-butyl 7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (P25).
To a solution of C65 (6.70 g, 14.6 mmol) in a mixture of 2,2,2-trifluoroethanol (35 mL) and dichloromethane (35 mL) was added di-tert-butyl azodicarboxylate (4.36 g, 18.9 mmol), followed by [bis(trifluoroacetoxy)iodo]benzene (33.2 g, 77.2 mmol). The reaction mixture was stirred at 25° C. for 30 min whereupon it was poured into saturated aqueous sodium sulfite (300 mL) and extracted with dichloromethane (2×100 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo; silica gel chromatography (gradient: 0% to 20% ethanol in dichloromethane) provided P25 as a white solid. Yield: 2.10 g, 4.32 mmol, 30%. LCMS m/z 508.3 [M+Na ⁺ ]. ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.11 (s, 1H), 4.44 (s, 3H), [3.93 (d, J =
11.3 Hz) and 3.86 (d, J = 11.1
Hz), total 1H], 3.68 - 3.56 (m,
1H), 3.56 - 3.46 (m, 1H), 3.46 - 3.3 (m, 1H, estimated; partially obscured by solvent peak),
2.92 - 2.81 (m, 2H), 2.73 (s, 3H), [2.69 - 2.58 (m) and 2.58 - 2.47 (m), total 1H],
2.15 - 1.88 (m, 3H), 1.48 (br s, 18H).

Preparation Example P26
(2S)-7-Methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P26)

ステップ１． ジ－ｔｅｒｔ－ブチル（２Ｒ）－７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１，１’－ジカルボキシレート（Ｃ６６）およびジ－ｔｅｒｔ－ブチル（２Ｓ）－７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１，１’－ジカルボキシレート（Ｃ６７）の分離。
Ｐ２５（２．３７ｇ、４．８８ｍｍｏｌ）の、その構成要素のジアステレオマーへの分離を、超臨界流体クロマトグラフィー｛カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｃｅｌ ＯＪ－Ｈ、２１．２×２５０ｍｍ、５μｍ；移動相 ９：１ 二酸化炭素／［０．２％（メタノール中７Ｍアンモニア）を含有するメタノール］；流速：８０ｍＬ／分；背圧：１２０バール｝を使用して行った。第１に溶離するジアステレオマーをＣ６６として指定し、第２に溶離するジアステレオマーをＣ６７として指定した。
Ｃ６６を固体として単離した。収量：１．０１ｇ、２．０８ｍｍｏｌ、４３％。保持時間：２．６８分［分析条件。カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｃｅｌ ＯＪ－Ｈ、４．６×２５０ｍｍ、５μｍ；移動相Ａ：二酸化炭素；移動相Ｂ：０．２％（メタノール中７Ｍアンモニア）を含有するメタノール；勾配：Ｂ５％を１．０分間にわたって、次いで、８．０分かけてＢ５％から６０％へ；流速：３．０ｍＬ／分；背圧：１２０バール］。
Ｃ６７を油状物として単離した。収量：１．００ｇ、２．０６ｍｍｏｌ、４２％。保持時間：３．３３分（Ｃ６６で使用されたものと同一の分析条件）。
絶対立体化学の割り当てについては、以下を参照されたい。

Step 1. Separation of di-tert-butyl (2R)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (C66) and di-tert-butyl (2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1,1′-dicarboxylate (C67).
Separation of P25 (2.37 g, 4.88 mmol) into its constituent diastereomers was carried out using supercritical fluid chromatography {column: Chiral Technologies Chiralcel OJ-H, 21.2×250 mm, 5 μm; mobile phase 9:1 carbon dioxide/[methanol containing 0.2% (7 M ammonia in methanol)]; flow rate: 80 mL/min; back pressure: 120 bar}. The first eluting diastereomer was designated as C66 and the second eluting diastereomer was designated as C67.
C66 was isolated as a solid. Yield: 1.01 g, 2.08 mmol, 43%. Retention time: 2.68 min. [Analytical conditions. Column: Chiral Technologies Chiralcel OJ-H, 4.6×250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: methanol containing 0.2% (7 M ammonia in methanol); Gradient: 5% B over 1.0 min, then 5% to 60% B over 8.0 min; Flow rate: 3.0 mL/min; Back pressure: 120 bar].
C67 was isolated as an oil. Yield: 1.00 g, 2.06 mmol, 42%. Retention time: 3.33 min (same analytical conditions as used for C66).
For absolute stereochemical assignment, see below.

Step 2. Synthesis of (2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P26).
A solution of C67 (150 mg, 0.309 mmol) in a mixture of dichloromethane (1.0 mL) and 1,1,1,3,3,3-hexafluoropropan-2-ol (1.0 mL) was treated with a solution of hydrogen chloride in 1,4-dioxane (4 M; 0.309 mL, 1.24 mmol). After stirring the reaction mixture at room temperature for 2 h, LCMS analysis indicated conversion to P26: LCMS m/z 286.3 [M+H] ⁺ . The reaction mixture was concentrated in vacuo to give P26 as a solid. Yield: 105 mg, 0.293 mmol, 95%.

The absolute stereochemistry indicated was established in the following manner. This batch of P26 was used to prepare 3 and 4 in the alternative syntheses of Examples 3 and 4. Correlations between those batches of 3 and 4 and the same compounds prepared from precursors of known absolute stereochemistry (see Examples 3 and 4) are provided in the alternative syntheses of Examples 3 and 4.

Alternative Preparation of P26 (2S)-7-Methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P26)

ステップ１． ｔｅｒｔ－ブチル（２Ｓ）－７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－カルボキシレート（Ｃ６８）の合成。
１，４－ジオキサン（１０ｍＬ）中の４，４，４’，４’，５，５，５’，５’－オクタメチル－２，２’－ビ－１，３，２－ジオキサボロラン（２９９ｍｇ、１．１８ｍｍｏｌ）、Ｐ２３（３００ｍｇ、０．７８５ｍｍｏｌ）、［１，１’－ビス（ジフェニルホスフィノ）フェロセン］ジクロロパラジウム（ＩＩ）、ジクロロメタン錯体（３２．０ｍｇ、３９．２μｍｏｌ）、およびオーブン乾燥酢酸カリウム（３０８ｍｇ、３．１４ｍｍｏｌ）の混合物を、これに窒素を５分間にわたって吹き込むことにより脱気した。次いで、反応バイアルを密封し、アルミニウムブロック内で、１００℃で２時間にわたって加熱し、その後すぐに、これを室温に冷却させた。５－ブロモ－２－メチル－２Ｈ－テトラゾール（１３４ｍｇ、０．８２２ｍｍｏｌ）、ジクロロビス（トリフェニルホスフィン）パラジウム（ＩＩ）（２７．５ｍｇ、３９．２μｍｏｌ）、および炭酸ナトリウムの脱気水溶液（２．０Ｍ；０．９８１ｍＬ、１．９６ｍｍｏｌ）を添加し、反応混合物を、窒素を５分間にわたって吹き込んで再び脱気した。次いで、これを９０℃で１８時間にわたって撹拌し、室温に冷却し、酢酸エチルで希釈し、珪藻土を通して濾過した。濾液の有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮し；ＬＣＭＳ分析は、Ｃ６８の存在を指し示した：LCMS m/z 386.3 [M+H]⁺.シリカゲルクロマトグラフィー（勾配：ヘプタン中２０％から５０％酢酸エチル）は、Ｃ６８を薄黄色油として提供した。収量：２８０ｍｇ、０．７２６ｍｍｏｌ、９２％。このバッチのＣ６８を、下記の実施例３および４において使用した。

Step 1. Synthesis of tert-butyl (2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C68).
A mixture of 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi-1,3,2-dioxaborolane (299 mg, 1.18 mmol), P23 (300 mg, 0.785 mmol), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), dichloromethane complex (32.0 mg, 39.2 μmol), and oven-dried potassium acetate (308 mg, 3.14 mmol) in 1,4-dioxane (10 mL) was degassed by bubbling nitrogen through it for 5 min. The reaction vial was then sealed and heated in an aluminum block at 100° C. for 2 h, whereupon it was allowed to cool to room temperature. 5-Bromo-2-methyl-2H-tetrazole (134 mg, 0.822 mmol), dichlorobis(triphenylphosphine)palladium(II) (27.5 mg, 39.2 μmol), and degassed aqueous sodium carbonate (2.0 M; 0.981 mL, 1.96 mmol) were added and the reaction mixture was degassed again by bubbling nitrogen through it for 5 min. It was then stirred at 90° C. for 18 h, cooled to room temperature, diluted with ethyl acetate, and filtered through diatomaceous earth. The organic layer of the filtrate was washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo; LCMS analysis indicated the presence of C68: LCMS m/z 386.3 [M+H] ⁺ . Silica gel chromatography (gradient: 20% to 50% ethyl acetate in heptane) provided C68 as a pale yellow oil. Yield: 280 mg, 0.726 mmol, 92%. This batch of C68 was used in Examples 3 and 4 below.

Step 2. Synthesis of (2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P26).
A mixture of C68 (185 mg, 0.480 mmol) and a solution of hydrogen chloride in 2-propanol (1.25 M; 1.9 mL, 2.4 mmol) was heated to 50° C. for 1 h. The reaction mixture was concentrated in vacuo to provide P26 as a solid, which was used without further purification. Yield: 170 mg, 0.47 mmol, 98%.

Preparation Example P27
[(2S)-1'-(tert-butoxycarbonyl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-6-yl]boronic acid (P27)

Ｐ２３（１９．５ｇ、５１．０ｍｍｏｌ）、酢酸カリウム（１２．５ｇ、１２７ｍｍｏｌ）、ナトリウムｔｅｒｔ－ブトキシド（４９．０ｍｇ、０．５１０ｍｍｏｌ）、クロロ（２－ジシクロヘキシルホスフィノ－２’，４’，６’－トリイソプロピル－１，１’－ビフェニル）［２－（２’－アミノ－１，１’－ビフェニル）］パラジウム（ＩＩ）［ＸＰｈｏｓ Ｐｄ Ｇ２；４０１ｍｇ、０．５１０ｍｍｏｌ）、および２－ジシクロヘキシルホスフィノ－２’，４’，６’－トリイソプロピルビフェニル（ＸＰｈｏｓ；７２９ｍｇ、１．５３ｍｍｏｌ）の混合物を含有する反応容器を窒素でパージした。次いで、メタノール（２００ｍＬ）、エタン－１，２－ジオール（２０ｍＬ）、およびテトラヒドロキシジボロン（１１．４ｇ、１２７ｍｍｏｌ）を添加し、その後すぐに、窒素を反応混合物に１０分間にわたって吹き込んだ。反応混合物を２時間にわたって５０℃の内部温度に加熱し、室温に、次いで、０℃に冷却し、水酸化ナトリウム水溶液（４Ｍ；８０ｍＬ）を添加することによりｐＨ１４に調節した｛注意：ガス発生｝。得られた混合物を室温で３０分間にわたって撹拌し、濾過し；濾液を真空で濃縮し、ｔｅｒｔ－ブチルメチルエーテルで２回抽出した。次いで、合わせた有機層を水酸化ナトリウム水溶液（２Ｍ；２×１００ｍＬ）で抽出した。すべての水層を合わせ、撹拌混合物を、固体が沈殿するまで（これはおよそ９のｐＨで起こった）、塩酸（４Ｍ；およそ２０ｍＬ）で滴下処理した。混合物を室温でさらに３０分間にわたって撹拌した後に、これを酢酸エチルで４回抽出した。合わせた酢酸エチル層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮して、Ｐ２７を薄黄色の粉末として提供した。収量：１２．５ｇ、３６．０ｍｍｏｌ、７１％。LCMS m/z 348.4 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄), 特徴的ピーク: δ 7.74 (br s, 1H), 3.46 - 3.35 (m, 2H), 2.92 - 2.72 (m, 2H), 2.48 (s,
3H), 2.12 - 1.83 (m, 4H), [1.47 (s)および1.46 (s), 合計9H].

A reaction vessel containing a mixture of P23 (19.5 g, 51.0 mmol), potassium acetate (12.5 g, 127 mmol), sodium tert-butoxide (49.0 mg, 0.510 mmol), chloro(2-dicyclohexylphosphino-2′,4′,6′-triisopropyl-1,1′-biphenyl)[2-(2′-amino-1,1′-biphenyl)]palladium(II) [XPhos Pd G2; 401 mg, 0.510 mmol), and 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (XPhos; 729 mg, 1.53 mmol) was purged with nitrogen. Methanol (200 mL), ethane-1,2-diol (20 mL), and tetrahydroxydiboron (11.4 g, 127 mmol) were then added whereupon nitrogen was bubbled through the reaction mixture for 10 min. The reaction mixture was heated to an internal temperature of 50° C. for 2 h, cooled to room temperature and then to 0° C., and adjusted to pH 14 by addition of aqueous sodium hydroxide (4 M; 80 mL) {Caution: gas evolution}. The resulting mixture was stirred at room temperature for 30 min, filtered; the filtrate was concentrated in vacuo and extracted twice with tert-butyl methyl ether. The combined organic layers were then extracted with aqueous sodium hydroxide (2 M; 2×100 mL). All aqueous layers were combined and the stirred mixture was treated dropwise with hydrochloric acid (4 M; approximately 20 mL) until a solid precipitated (this occurred at a pH of approximately 9). The mixture was stirred at room temperature for an additional 30 min before it was extracted four times with ethyl acetate. The combined ethyl acetate layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered and concentrated in vacuo to provide P27 as a pale yellow powder. Yield: 12.5 g, 36.0 mmol, 71%. LCMS m/z 348.4 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ), characteristic peaks: δ 7.74 (br s, 1H), 3.46 - 3.35 (m, 2H), 2.92 - 2.72 (m, 2H), 2.48 (s,
3H), 2.12 - 1.83 (m, 4H), [1.47 (s) and 1.46 (s), total 9H].

Preparation Example P28
(2S)-7-Methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P28)

ステップ１． ｔｅｒｔ－ブチル（２Ｓ）－７－メチル－６－（ピリミジン－２－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－カルボキシレート（Ｃ６９）の合成。
窒素を、１，４－ジオキサン（２０ｍＬ）中のオーブン乾燥酢酸カリウム（２．０７ｇ、２１．１ｍｍｏｌ）、Ｐ２３（調製例Ｐ２３およびＰ２４からの材料；２．０２ｇ、５．２８ｍｍｏｌ）、５，５，５’，５’－テトラメチル－２，２’－ビ－１，３，２－ジオキサボリナン（１．７９ｇ、７．９２ｍｍｏｌ）、および［１，１’－ビス（ジフェニルホスフィノ）フェロセン］ジクロロパラジウム（ＩＩ）、ジクロロメタン錯体（２１６ｍｇ、０．２６４ｍｍｏｌ）の混合物に、５分間にわたって吹き込んだ。次いで、反応混合物を１０５℃のアルミニウムブロック内で２時間にわたって加熱し、その後すぐに、これを室温に冷却させ、次いで、２－ブロモピリミジン（８４０ｍｇ、５．２８ｍｍｏｌ）、追加の［１，１’－ビス（ジフェニルホスフィノ）フェロセン］ジクロロパラジウム（ＩＩ）、ジクロロメタン錯体（２１６ｍｇ、０．２６４ｍｍｏｌ）、および炭酸ナトリウム水溶液（２．０Ｍ；７．９３ｍＬ、１５．９ｍｍｏｌ）で処理した。この反応混合物を窒素でスパージした後に、これを１８時間にわたって１００℃に加熱し、その時点で、ＬＣＭＳ分析は、Ｃ６９への変換を指し示した：LCMS m/z 382.4 [M+H]⁺.反応混合物を冷却し、塩化アンモニウム水溶液と酢酸エチルとの間で分配し、次いで、混合物全体を、珪藻土のパッドを通して濾過した。フィルターパッドを水および酢酸エチルの両方ですすぎ、合わせた濾液の水層を酢酸エチル（２×３０ｍＬ）で抽出した。すべての有機層を合わせた後に、それらを水（１００ｍＬ）および飽和塩化ナトリウム水溶液で順次に洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮した。残渣（２．９ｇ）を酢酸エチル（１０ｍＬ）に溶解し、ＳｉｌｉａＭｅｔＳチオール（ＳｉｌｉＣｙｃｌｅ、Ｒ５１０３０Ｂ；２ｇ）で処理し；得られた混合物を還流状態で１０分間にわたって加熱し、次いで、室温に冷却した。珪藻土のパッドを通して濾過して、濾液を提供し、これを減圧下で濃縮して、Ｃ６９を褐色のゴム状物（２ｇ）として得た。この材料をさらに精製せずに次のステップで用いた。

Step 1. Synthesis of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C69).
Nitrogen was bubbled through a mixture of oven-dried potassium acetate (2.07 g, 21.1 mmol), P23 (material from Preparations P23 and P24; 2.02 g, 5.28 mmol), 5,5,5',5'-tetramethyl-2,2'-bi-1,3,2-dioxaborinane (1.79 g, 7.92 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), dichloromethane complex (216 mg, 0.264 mmol) in 1,4-dioxane (20 mL) for 5 minutes. The reaction mixture was then heated in an aluminum block at 105° C. for 2 hours, whereupon it was allowed to cool to room temperature and then treated with 2-bromopyrimidine (840 mg, 5.28 mmol), additional [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II), dichloromethane complex (216 mg, 0.264 mmol), and aqueous sodium carbonate (2.0 M; 7.93 mL, 15.9 mmol). After sparging the reaction mixture with nitrogen, it was heated to 100° C. for 18 hours, at which point LCMS analysis indicated conversion to C69: LCMS m/z 382.4 [M+H] ⁺ . The reaction mixture was cooled and partitioned between aqueous ammonium chloride and ethyl acetate, and the entire mixture was then filtered through a pad of diatomaceous earth. The filter pad was rinsed with both water and ethyl acetate, and the aqueous layer of the combined filtrate was extracted with ethyl acetate (2×30 mL). After all the organic layers were combined, they were washed successively with water (100 mL) and saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated in vacuum. The residue (2.9 g) was dissolved in ethyl acetate (10 mL) and treated with SiliaMetS thiol (SiliCycle, R51030B; 2 g); the resulting mixture was heated at reflux for 10 minutes and then cooled to room temperature. Filtration through a pad of diatomaceous earth provided a filtrate that was concentrated under reduced pressure to give C69 as a brown gum (2 g). This material was used in the next step without further purification.

Step 2. Synthesis of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P28).
A solution of hydrogen chloride was prepared by slowly adding acetyl chloride (1.50 mL, 21.1 mmol) to 2-propanol (4 mL). In a separate flask, C69 (from the previous step; 2 g; ∼5.28 mmol) was dissolved in a mixture of propan-2-yl acetate (15 mL) and 2-propanol (15 mL); this required heating at 50° C. Once a solution was obtained, hydrogen chloride solution was added slowly to it and the reaction mixture was heated at 50° C. for 2 hours. It was then allowed to cool slowly to room temperature with stirring; stirring was continued at room temperature for 18 hours. The resulting solid was collected by vacuum filtration under nitrogen to provide P28 as a hygroscopic solid. Yield: 750 mg, 2.12 mmol, 40% for two steps. LCMS m/z 282.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 8.91 (d, J = 4.9 Hz, 2H), 8.58 (s, 1H),
7.43 (t, J = 4.9 Hz, 1H), 3.76 - 3.66 (m, 1H), 3.66 - 3.52 (m, 2H), 3.46 (d, AB quartet component, J = 12.5 Hz, 1H), 3.12 - 2.95 (m,
2H), 2.90 (s, 3H), 2.49 - 2.38 (m, 1H), 2.37 - 2.25 (m, 1H), 2.24 - 2.06 (m,
2H).

The absolute stereochemistry indicated was assigned based on the conversion of this lot of P28 to Example 14; the absolute stereochemistry of 14 was established by single crystal X-ray analysis (see Example 14 below).

Preparation Example P29
tert-Butyl 4,7-dimethyl-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P29)

ステップ１． ｔｅｒｔ－ブチル３－アミノ－３－（プロパ－２－エン－１－イル）ピロリジン－１－カルボキシレート（Ｃ７０）の合成。
ｔｅｒｔ－ブチル３－オキソピロリジン－１－カルボキシレート（５００ｍｇ、２．７０ｍｍｏｌ）、およびメタノール中のアンモニアの溶液（７Ｍ；３．９ｍＬ、２７ｍｍｏｌ）の混合物を、室温で３０分間にわたって撹拌した。次いで、これに、メタノール中の４，４，５，５－テトラメチル－２－（プロパ－２－エン－１－イル）－１，３，２－ジオキサボロラン（９０７ｍｇ、５．４０ｍｍｏｌ）の溶液を滴下方式にて添加し、反応混合物を室温で１８時間にわたって撹拌した。揮発物を真空で除去し、残渣をシリカゲルクロマトグラフィー（勾配：ジクロロメタン中０％から１０％メタノール）に掛けて、Ｃ７０を提供した。収量：２００ｍｇ、０．８８４ｍｍｏｌ、３３％。¹H NMR (400 MHz, クロロホルム-d) δ 5.91 - 5.76 (m, 1H), 5.20 (m, 1H), 5.15 (br d, J = 11 Hz, 1H), 3.53
- 3.38 (m, 2H), 3.32 - 3.08 (m, 2H), 2.28 (d, J = 7.5 Hz, 2H), 1.89 - 1.79 (m,
1H), 1.73 - 1.63 (m, 1H), 1.46 (s, 9H).

Step 1. Synthesis of tert-butyl 3-amino-3-(prop-2-en-1-yl)pyrrolidine-1-carboxylate (C70).
A mixture of tert-butyl 3-oxopyrrolidine-1-carboxylate (500 mg, 2.70 mmol) and a solution of ammonia in methanol (7 M; 3.9 mL, 27 mmol) was stirred at room temperature for 30 minutes. To this was then added a solution of 4,4,5,5-tetramethyl-2-(prop-2-en-1-yl)-1,3,2-dioxaborolane (907 mg, 5.40 mmol) in methanol in a dropwise manner and the reaction mixture was stirred at room temperature for 18 hours. The volatiles were removed in vacuo and the residue was chromatographed on silica gel (gradient: 0% to 10% methanol in dichloromethane) to provide C70. Yield: 200 mg, 0.884 mmol, 33%. ^1H NMR (400 MHz, chloroform-d) δ 5.91 - 5.76 (m, 1H), 5.20 (m, 1H), 5.15 (br d, J = 11 Hz, 1H), 3.53
- 3.38 (m, 2H), 3.32 - 3.08 (m, 2H), 2.28 (d, J = 7.5 Hz, 2H), 1.89 - 1.79 (m,
1H), 1.73 - 1.63 (m, 1H), 1.46 (s, 9H).

Step 2. Synthesis of tert-butyl 3-[(3-chloro-6-methylpyridin-2-yl)amino]-3-(prop-2-en-1-yl)pyrrolidine-1-carboxylate (C71).
A vial containing a mixture of 2,3-dichloro-6-methylpyridine (100 mg, 0.617 mmol), C70 (168 mg, 0.742 mmol), palladium(II) acetate (6.93 mg, 30.9 μmol), 2-dicyclohexylphosphino-2′,6′-diisopropoxybiphenyl (RuPhos; 28.8 mg, 61.7 μmol), and sodium tert-butoxide (119 mg, 1.24 mmol) in 1,4-dioxane (8 mL) was sparged with nitrogen, sealed, and heated at 80° C. overnight. LCMS analysis indicated conversion to C71: LCMS m/z 352.3 (chlorine isotope pattern observed) [M+H] ⁺ , whereupon the reaction mixture was cooled to room temperature and partitioned between water and dichloromethane. The aqueous layer was extracted with dichloromethane, and the combined organic layers were washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, concentrated in vacuo, and subjected to silica gel chromatography (gradient: 0% to 50% ethyl acetate in heptane) to provide C71 as an oil that solidified upon standing. Yield: 121 mg, 0.344 mmol, 56%. ¹ H NMR (400 MHz, chloroform-d) δ 7.29 (d, J = 8.1 Hz, 1H), 6.42 - 6.34 (m, 1H), 5.82 - 5.68 (m, 1H),
5.11 - 5.03 (m, 1H), 5.03 - 4.93 (m, 1H), 3.79 - 3.69 (m, 1H), [3.62 (d, component of AB quartet, J = 11.6 Hz), 3.56 (d, component of AB quartet, J = 11.4 Hz), and 3.54 - 3.36 (m), total 3H], 2.95 - 2.83 (m, 1H), 2.76 - 2.63 (m, 1H), 2.45 - 2.28 (m, 1H),
2.34 (s, 3H), 2.08 - 1.96 (m, 1H), 1.50 - 1.41 (br s, 9H).

Step 3. Synthesis of tert-butyl 4,7-dimethyl-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P29).
A mixture of C71 (40 mg, 0.11 mmol), tris(dibenzylideneacetone)dipalladium(0) (5.20 mg, 5.68 μmol), N-cyclohexyl-N-methylcyclohexanamine (111 mg, 0.568 mmol), and tri-tert-butylphosphine (1.15 mg, 5.68 μmol) in N,N-dimethylformamide (1.0 mL) was degassed and then heated at 80° C. for 2 h. Heat was increased to 120° C. and the reaction mixture was maintained at that temperature for 3 days. LCMS analysis indicated conversion to P29: LCMS m/z 316.3 [M+H] ⁺ . After the reaction mixture was cooled to room temperature, it was partitioned between ethyl acetate and water, and the aqueous layer was extracted twice with ethyl acetate. The combined organic layers were washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo; silica gel chromatography (gradient: 0% to 100% ethyl acetate in heptane) afforded P29. Yield: 30 mg, 95 μmol, 86%. ¹ H NMR (400 MHz, chloroform-d), characteristic peak: δ 7.13 (d, J = 7.5
Hz, 1H), 6.40 (d, J = 7.5 Hz, 1H), 5.27 (br s, 1H), 5.06 - 4.99 (br s, 1H),
3.58 - 3.40 (m, 3H), 3.31 - 3.21 (m, 1H), 2.31 (s, 3H), [1.96 (s) and 1.96 (s), total 3H], [1.46 (s) and 1.44
(s), 9H in total].

Preparation Example P30
tert-Butyl 1-benzyl-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate (P30)

ステップ１． １，１’－ジベンジル－７－メチル－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］（Ｃ７２）の合成。
Ｃ４３の、Ｃ７２への変換を、１－（４－メトキシフェニル）メタンアミンの代わりに１－フェニルメタンアミンを利用することにより、調製例Ｐ１７およびＰ１８においてＣ４３からのＣ４７の合成について記述されている方法を使用して行った。シリカゲルクロマトグラフィー（勾配：ジクロロメタン中０％から１０％メタノール）は、Ｃ７２を提供した。Ｃ７２を提供する環化ステップについての収量：５８０ｍｇ、１．５１ｍｍｏｌ、６９％。

Step 1. Synthesis of 1,1′-dibenzyl-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine] (C72).
Conversion of C43 to C72 was accomplished using the method described for the synthesis of C47 from C43 in Preparations P17 and P18 by utilizing 1-phenylmethanamine instead of 1-(4-methoxyphenyl)methanamine. Silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) provided C72. Yield for the cyclization step to provide C72: 580 mg, 1.51 mmol, 69%.

Step 2. Synthesis of tert-butyl 1-benzyl-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (P30).
A mixture of C72 (550 mg, 1.43 mmol), palladium on carbon (50 mg, 0.143 mmol), and di-tert-butyl dicarbonate (376 mg, 1.72 mmol) in methanol (20 mL) was hydrogenated at 75 psi overnight. The reaction mixture was filtered through diatomaceous earth and the filtrate was concentrated in vacuo; silica gel chromatography (gradient: 0% to 100% ethyl acetate in heptane) afforded P30 as a white semi-solid. Yield: 482 mg, 1.22 mmol, 85%. ¹ H NMR (400 MHz, chloroform-d) δ 7.29 - 7.07 (m, 6H, estimated; partially obscured by solvent peaks),
6.39 (d, J = 7.2 Hz, 1H), 5.15 - 4.99 (m, 1H), 4.97 - 4.78 (m, 1H), 3.58 - 3.19
(m, 4H), 2.87 - 2.71 (m, 2H), 2.31 - 2.16 (m, 1H), 2.24 (s, 3H), 2.07 - 1.95
(m, 1H), 1.92 - 1.79 (m, 1H), 1.75 - 1.63 (m, 1H), [1.45 (s) and 1.43 (s), total 9H].

Preparation Example P31
6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] (P31)

ステップ１． １，１’－ジベンジル－６－ブロモ－７－メチル－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］（Ｃ７３）の合成。
１，３－ジブロモ－５，５－ジメチルイミダゾリジン－２，４－ジオン（５３２ｍｇ、１．８６ｍｍｏｌ）を、ジクロロメタン（１６ｍＬ）中のＣ７２（１．１９ｇ、３．１０ｍｍｏｌ）の０℃溶液に少しずつ添加した。１時間後のＬＣＭＳ分析は、Ｃ７３への変換を指し示した：LCMS m/z 462.2 (臭素同位体パターンが観察された) [M+H]⁺.反応混合物をジクロロメタン（２０ｍＬ）で希釈し、飽和亜硫酸ナトリウム水溶液、飽和炭酸水素ナトリウム水溶液、および飽和塩化ナトリウム水溶液で順次に洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲルクロマトグラフィー（勾配：ヘプタン中０％から５０％酢酸エチル）により、Ｃ７３を油状物として得た。収量：９８０ｍｇ、２．１２ｍｍｏｌ、６８％。¹H NMR (400 MHz, クロロホルム-d) δ 7.32 - 7.12 (m, 11H, 推定; 溶媒ピークにより一部不明確),
5.03 (AB四重線, J_AB = 16.3
Hz, Δν_AB = 26.6 Hz, 2H), 3.54 (AB四重線, J_AB = 13.1 Hz, Δν_AB = 41.8 Hz, 2H), 2.93 (d, J = 10.2
Hz, 1H), 2.88 (ddd, J = 8.5, 8.5, 3.4 Hz, 1H), 2.84 - 2.75 (m, 1H), 2.74 - 2.65
(m, 1H), 2.40 - 2.32 (m, 1H), 2.29 (s, 3H), 2.19 (d, J = 10.2 Hz, 1H), 2.12 (ddd,
J = 13.4, 8.3, 8.3 Hz, 1H), 1.99 (ddd, J = 13.7, 8.8, 5.2 Hz, 1H), 1.93 - 1.85
(m, 1H), 1.81 (ddd, J = 13.4, 7.3, 3.5 Hz, 1H).

Step 1. Synthesis of 1,1′-dibenzyl-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine] (C73).
1,3-Dibromo-5,5-dimethylimidazolidine-2,4-dione (532 mg, 1.86 mmol) was added portionwise to a 0° C. solution of C72 (1.19 g, 3.10 mmol) in dichloromethane (16 mL). LCMS analysis after 1 h indicated conversion to C73: LCMS m/z 462.2 (bromine isotope pattern observed) [M+H] ⁺ .The reaction mixture was diluted with dichloromethane (20 mL), washed sequentially with saturated aqueous sodium sulfite, saturated aqueous sodium bicarbonate, and saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 50% ethyl acetate in heptane) afforded C73 as an oil. Yield: 980 mg, 2.12 mmol, 68%. ^1H NMR (400 MHz, chloroform-d) δ 7.32 - 7.12 (m, 11H, estimated; partially obscured by solvent peak),
5.03 (AB quartet, J _AB = 16.3
Hz, Δν _AB = 26.6 Hz, 2H), 3.54 (AB quartet, J _AB = 13.1 Hz, Δν _AB = 41.8 Hz, 2H), 2.93 (d, J = 10.2
Hz, 1H), 2.88 (ddd, J = 8.5, 8.5, 3.4 Hz, 1H), 2.84 - 2.75 (m, 1H), 2.74 - 2.65
(m, 1H), 2.40 - 2.32 (m, 1H), 2.29 (s, 3H), 2.19 (d, J = 10.2 Hz, 1H), 2.12 (ddd,
J = 13.4, 8.3, 8.3 Hz, 1H), 1.99 (ddd, J = 13.7, 8.8, 5.2 Hz, 1H), 1.93 - 1.85
(m, 1H), 1.81 (ddd, J = 13.4, 7.3, 3.5 Hz, 1H).

Step 2. Synthesis of 1,1′-dibenzyl-7-methyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine] (C74).
A reaction vial was charged with 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi-1,3,2-dioxaborolane (148 mg, 0.583 mmol), C73 (180 mg, 0.389 mmol), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), dichloromethane complex (31.8 mg, 38.9 μmol), and oven-dried potassium acetate (153 mg, 1.56 mmol) in 1,4-dioxane (5 mL). Nitrogen was bubbled through the reaction mixture for 5 min whereupon the vial was sealed and heated in an aluminum block at 100° C. for 2 h. LCMS analysis indicated the presence of C74: LCMS m/z 510.4 [M+H] ⁺ . After the reaction mixture was cooled to room temperature, it was diluted with ethyl acetate and filtered through a pad of diatomaceous earth. The filtrate was concentrated in vacuo to provide C74, which was used as is in the next step.

Step 3. Synthesis of 1,1′-dibenzyl-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine] (C75).
Dichlorobis(triphenylphosphine)palladium(II) (5.24 mg, 7.46 μmol), an aqueous solution of potassium phosphate (2.0 M; 0.466 mL, 0.932 mmol), and 3-bromo-5-(difluoromethyl)-1-methyl-1H-1,2,4-triazole (P33; 79.1 mg, 0.373 mmol) were added to a solution of C74 (from the previous step; ∼0.389 mmol) in tetrahydrofuran (5 mL). After sparging the reaction mixture with nitrogen, the reaction vessel was sealed and heated in an aluminum block at 70° C. for 1 h. The temperature was then increased to 100° C. and heating was continued overnight. 3-Bromo-5-(difluoromethyl)-1-methyl-1H-1,2,4-triazole (P33; 79.1 mg, 0.373 mmol) was added again and heating was continued for an additional 6 h whereupon the reaction mixture was cooled and partitioned between ethyl acetate and water. The aqueous layer was extracted twice with ethyl acetate and the combined organic layers were washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 100% ethyl acetate in heptane) provided C75. Yield: 105 mg, 0.204 mmol, 52% for two steps. LCMS m/z 515.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.69 (s, 1H), 7.33 - 7.19 (m, 9H, estimated; partially obscured by solvent peaks),
7.18 - 7.12 (m, 1H), 6.85 (t, J _HF = 52.6 Hz, 1H), 5.14 (AB quartet, J _AB = 16.3 Hz, Δν _AB =
17.6 Hz, 2H), 4.05 (s, 3H), 3.54 (AB quartet, J _AB = 13.0 Hz, Δν _AB = 38.8 Hz, 2H), 2.97 (d, J = 10.2
Hz, 1H), 2.93 - 2.81 (m, 2H), 2.81 - 2.72 (m, 1H), 2.53 (s, 3H), 2.41 - 2.32
(m, 1H), 2.22 (d, J = 10.2 Hz, 1H), 2.15 (ddd, J = 13.5, 8.3, 8.2 Hz, 1H), 2.06
- 1.97 (m, 1H), 1.96 - 1.88 (m, 1H), 1.84 (ddd, J = 13.4, 7.3, 3.4 Hz, 1H).

Step 4. Synthesis of 6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine] (P31).
Palladium on carbon (10%, water-wet; 20 mg) was added to a solution of C75 (105 mg, 0.204 mmol) in methanol (5 mL) containing a drop of formic acid, and the resulting mixture was hydrogenated at room temperature and 70 psi overnight. After filtration, the filtrate was concentrated in vacuo to provide P31 as a pale yellow solid. Yield: 63 mg, 0.19 mmol, 93%. LCMS m/z 335.2 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.20 (s, 1H), 6.86 (t, J _HF = 52.4 Hz, 1H), 4.10 (s, 3H),
3.78 - 3.51 (m, 3H), 3.41 (d, J = 12.3 Hz, 1H), 2.99 - 2.85 (m, 2H), 2.83 (s,
3H), 2.29 - 2.19 (m, 2H), 2.19 - 2.01 (m, 2H).

Preparation Example P32
(2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P32)

ステップ１． ｔｅｒｔ－ブチル（２Ｓ）－６－［５－（ジフルオロメチル）－１－メチル－１Ｈ－１，２，４－トリアゾール－３－イル］－７－メチル－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－カルボキシレート（Ｃ７６）の合成。
Ｐ２６の代替調製例においてＰ２３からのＣ６８の合成について記述されている方法を使用し、Ｐ２３（２２０ｍｇ、０．５７５ｍｍｏｌ）および３－ブロモ－５－（ジフルオロメチル）－１－メチル－１Ｈ－１，２，４－トリアゾール（Ｐ３３；１２８ｍｇ、０．６０４ｍｍｏｌ）を使用して、Ｃ７６を調製した。シリカゲルクロマトグラフィー（勾配：ヘプタン中２０％から５０％酢酸エチル）により、Ｃ７６を白色の固体として得た。収量：１１０ｍｇ、０．２５３ｍｍｏｌ、４４％。LCMS m/z 435.4 [M+H]⁺.

Step 1. Synthesis of tert-butyl (2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C76).
C76 was prepared using P23 (220 mg, 0.575 mmol) and 3-bromo-5-(difluoromethyl)-1-methyl-1H-1,2,4-triazole (P33; 128 mg, 0.604 mmol) using the method described for the synthesis of C68 from P23 in the alternative preparation of P26. Silica gel chromatography (gradient: 20% to 50% ethyl acetate in heptane) afforded C76 as a white solid. Yield: 110 mg, 0.253 mmol, 44%. LCMS m/z 435.4 [M+H] ⁺ .

Step 2. Synthesis of (2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride salt (P32).
A mixture of C76 (110 mg, 0.253 mmol) in a solution of hydrogen chloride in 2-propanol (1.25 M, 1.0 mL, 1.2 mmol) was heated at 50° C. for 1 h. LCMS analysis indicated the formation of P32: LCMS m/z 335.3 [M+H] ⁺ . Concentration in vacuo afforded P32 as a solid. Yield: 74 mg, 0.182 mmol, 72%.

Preparation Example P33
3-Bromo-5-(difluoromethyl)-1-methyl-1H-1,2,4-triazole (P33)

［ビス（２－メトキシエチル）アミノ］硫黄トリフルオリド（４７．０ｍＬ、２５５ｍｍｏｌ）を、ジクロロメタン（４００ｍＬ）中の３－ブロモ－１－メチル－１Ｈ－１，２，４－トリアゾール－５－カルバルデヒド（２４．２ｇ、１２７ｍｍｏｌ）の０℃混合物に滴下方式にて添加し；反応混合物を２０℃に加温させ、２０℃で１６時間にわたって撹拌した。炭酸水素ナトリウム水溶液の滴下添加後に、得られた混合物をジクロロメタン（３×３００ｍＬ）で抽出した。合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲル上でのクロマトグラフィー（勾配：石油エーテル中５０％から７０％ジクロロメタン）により、３－ブロモ－５－（ジフルオロメチル）－１－メチル－１Ｈ－１，２，４－トリアゾール（Ｐ３３）を薄黄色油（１７．７ｇ）として得た。この材料を、３－ブロモ－１－メチル－１Ｈ－１，２，４－トリアゾール－５－カルバルデヒド（１２．０ｇ、６３．２ｍｍｏｌ）を使用して行われた同様の反応の生成物と合わせ；減圧下で濃縮して、Ｐ３３を白色の固体として提供した。合わせた収量：２５．２ｇ、１１９ｍｍｏｌ、６３％。LCMS m/z 212 (臭素同位体パターンが観察された) [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ 7.06 (t, J_HF = 52.2 Hz, 1H),
4.01 (s, 3H).

[Bis(2-methoxyethyl)amino]sulfur trifluoride (47.0 mL, 255 mmol) was added dropwise to a 0° C. mixture of 3-bromo-1-methyl-1H-1,2,4-triazole-5-carbaldehyde (24.2 g, 127 mmol) in dichloromethane (400 mL); the reaction mixture was allowed to warm to 20° C. and stirred at 20° C. for 16 hours. After dropwise addition of aqueous sodium bicarbonate, the resulting mixture was extracted with dichloromethane (3×300 mL). The combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo. Chromatography on silica gel (gradient: 50% to 70% dichloromethane in petroleum ether) gave 3-bromo-5-(difluoromethyl)-1-methyl-1H-1,2,4-triazole (P33) as a pale yellow oil (17.7 g). This material was combined with the product of a similar reaction carried out using 3-bromo-1-methyl-1H-1,2,4-triazole-5-carbaldehyde (12.0 g, 63.2 mmol); concentrated under reduced pressure to provide P33 as a white solid. Combined yield: 25.2 g, 119 mmol, 63%. LCMS m/z 212 (bromine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 7.06 (t, J _HF = 52.2 Hz, 1H),
4.01 (s, 3H).

(Examples 1 and 2)
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-1 (1) and (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-2 (2)

ステップ１． ７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］、二塩酸塩（Ｃ７７）の合成。
１，４－ジオキサン中の塩化水素の溶液（４．０Ｍ；０．５８７ｍＬ、２．３５ｍｍｏｌ）を、ジクロロメタン（１ｍＬ）および１，１，１，３，３，３－ヘキサフルオロプロパン－２－オール（１ｍＬ）の混合物中のＰ２５（２８５ｍｇ、０．５８７ｍｍｏｌ）の溶液に添加した。反応混合物を室温で２時間にわたって撹拌した後に、ＬＣＭＳ分析は、Ｃ７７の存在を指し示した：LCMS m/z 286.3 [M+H]⁺.揮発物を真空で除去して、Ｃ７７を白色の固体として得た。収量：２１０ｍｇ、０．５８６ｍｍｏｌ、定量的。

Step 1. Synthesis of 7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (C77).
A solution of hydrogen chloride in 1,4-dioxane (4.0 M; 0.587 mL, 2.35 mmol) was added to a solution of P25 (285 mg, 0.587 mmol) in a mixture of dichloromethane (1 mL) and 1,1,1,3,3,3-hexafluoropropan-2-ol (1 mL). After stirring the reaction mixture at room temperature for 2 h, LCMS analysis indicated the presence of C77: LCMS m/z 286.3 [M+H] ⁺ . The volatiles were removed in vacuo to give C77 as a white solid. Yield: 210 mg, 0.586 mmol, quantitative.

Step 2. Synthesis of (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]propan-1-one, DIAST-1 (1) and (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]propan-1-one, DIAST-2 (2).
To a solution of P2 (65.7 mg, 0.305 mmol) in acetonitrile (1 mL) was added pyridinium trifluoromethanesulfonate (140 mg, 0.611 mmol) and the mixture was stirred until it went into solution. 1,1'-carbonyldiimidazole (49.4 mg, 0.305 mmol) was added in one portion and the reaction mixture was stirred at room temperature for 45 min whereupon a solution of C77 (104 mg, 0.290 mmol) in acetonitrile (2 mL) was introduced. After the reaction mixture was stirred at room temperature for 3 h, it was diluted with aqueous ammonium chloride and the resulting mixture was extracted three times with ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered and concentrated in vacuo. Silica gel chromatography (gradient: 20% to 100% ethyl acetate in heptane) afforded a mixture of 1 and 2 as a white solid (105 mg), LCMS m/z 483.3 (chlorine isotope pattern observed) [M+H] ⁺ . Separation of the diastereomers was achieved by supercritical fluid chromatography [column: Chiral Technologies Chiralpak IB, 21×250 mm, 5 μm; mobile phase 85:15 carbon dioxide/(0.2% ammonium hydroxide in methanol); flow rate: 75 mL/min; back pressure: 200 bar]; the first eluting diastereomer was identified as 1{(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′- The first eluting diastereomer was designated as 2{(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1} and the second eluting diastereomer as 2{(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2}.
1 - Yield: 7.2 mg, 15 μmol, 5%. LCMS m/z 483.2 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ [8.15 (s) and 8.14 (s), total 1H],
[7.87 (s) and 7.83 (s), total 1H], [6.81 (s) and 6.75 (s), total 1H],
[4.39 (s) and 4.39 (s), total 3H], [4.31 (q, J = 6.8 Hz) and 4.22 (q, J = 6.9 Hz), total 1H], 3.90 (s, 3H), [3.9 - 3.81 (m) and 3.76 - 3.52 (m), total 3H], [3.48 (d, component of AB quartet, J = 12.3 Hz) and 3.35
(d, J = 10.7 Hz), total 1H], [2.93
- 2.72 (m) and 2.6 - 2.46 (m), total 2H], [2.60 (s) and 2.58 (s), total 3H],
2.16 - 1.84 (m, 3H), 1.80 - 1.72 (m, 1H), [1.43 (d, J = 6.8 Hz) and 1.42 (d, J = 6.9 Hz), total 3H]. Retention time: 2.32 min. [Analytical conditions. Column: Chiral Technologies Chiralpak IB, 4.6 x 100 mm, 5 μm; Mobile phase 3:2 carbon dioxide/(0.2% ammonium hydroxide in methanol); Flow rate: 1.5 mL/min; Back pressure: 120 bar].
2- Yield: 7.9 mg, 16 μmol, 6%. LCMS m/z 483.2 [M+H] ⁺ . Retention time: 2.53 min (same analytical conditions as used in 1).

(Examples 3 and 4)
2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-1 (3) and 2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-2 (4)

トリフルオロ酢酸（２ｍＬ）を、ジクロロメタン（１０ｍＬ）中のＣ６８（２８０ｍｇ、０．７２６ｍｍｏｌ）の溶液に添加し、反応混合物を室温で２時間にわたって撹拌した。次いで、これを真空で濃縮し、酢酸エチルで２回蒸発させて、脱保護された材料を暗褐色油（２００ｍｇ）、LCMS m/z 286.3 [M+H]⁺として得た。この油の一部（３５ｍｇ）およびＰ４（２４．９ｍｇ、０．１２３ｍｍｏｌ）をジクロロメタン（３ｍＬ）に溶解し、Ｏ－（７－アザベンゾトリアゾール－１－イル）－Ｎ，Ｎ，Ｎ’，Ｎ’－テトラメチルウロニウムヘキサフルオロホスフェート（ＨＡＴＵ；７０．０ｍｇ、０．１８４ｍｍｏｌ）およびトリエチルアミン（５１．３μＬ、０．３６８ｍｍｏｌ）、続いて、溶解を補助するためのＮ，Ｎ－ジメチルホルムアミド（２滴）で処理した。反応混合物を室温で終夜撹拌した後に、これをジクロロメタンで希釈し、炭酸水素ナトリウム水溶液および飽和塩化ナトリウム水溶液で順次に洗浄し、濾過し、乾燥させ、減圧下で濃縮した。構成要素のジアステレオマーの分離を、超臨界流体クロマトグラフィー［カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＩＡ、２１×２５０ｍｍ、５μｍ；移動相：７：３ 二酸化炭素／（メタノール中０．５％水酸化アンモニウム）；流速：７５ｍＬ／分；背圧：１２０バール］を使用して行い；第１に溶離するジアステレオマーを３｛２－（６－メトキシ－２－メチルピリミジン－４－イル）－１－［（２Ｓ）－７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］プロパン－１－オン、ＤＩＡＳＴ－１｝として、第２に溶離するジアステレオマーを４｛２－（６－メトキシ－２－メチルピリミジン－４－イル）－１－［（２Ｓ）－７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］プロパン－１－オン、ＤＩＡＳＴ－２｝として指定した。
３－収量：３．１ｍｇ、６．７μｍｏｌ、５％。LCMS m/z 464.3 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ [7.86 (s)および7.85 (s), 合計1H],
[6.65 (s)および6.61 (s), 合計1H], [4.39 (s)および4.39 (s), 合計3H],
[4.05 (q, J = 7.0 Hz), 4.01 - 3.89 (m), 3.88 - 3.55 (m), 3.59 (s),および3.53 (s), 合計5H], [3.98 (s)および3.96
(s), 合計3H], 2.95 - 2.75 (m,
2H), [2.60 (s), 2.58 (s),および2.55
(s), 合計6H], 2.19 - 1.71 (m,
4H), [1.46 (d, J = 7.1 Hz)および1.44
(d, J = 7.1 Hz), 合計3H].保持時間：２．４７分［分析条件。カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＩＡ、４．６×１００ｍｍ、５μｍ；移動相：６５：３５ 二酸化炭素／（０．５％水酸化アンモニウムを含有するメタノール）；流速：１．５ｍＬ／分；背圧：１２０バール］。
４－収量：３．６ｍｇ、７．８μｍｏｌ、６％。LCMS m/z 486.3 [M+Na⁺].保持時間：２．９２分（３で使用されたものと同一の分析条件）。

Trifluoroacetic acid (2 mL) was added to a solution of C68 (280 mg, 0.726 mmol) in dichloromethane (10 mL) and the reaction mixture was stirred at room temperature for 2 h. It was then concentrated in vacuo and evaporated twice with ethyl acetate to give the deprotected material as a dark brown oil (200 mg), LCMS m/z 286.3 [M+H] ⁺ . A portion of this oil (35 mg) and P4 (24.9 mg, 0.123 mmol) were dissolved in dichloromethane (3 mL) and treated with O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU; 70.0 mg, 0.184 mmol) and triethylamine (51.3 μL, 0.368 mmol), followed by N,N-dimethylformamide (2 drops) to aid dissolution. After the reaction mixture was stirred at room temperature overnight, it was diluted with dichloromethane, washed successively with aqueous sodium bicarbonate and saturated aqueous sodium chloride, filtered, dried and concentrated under reduced pressure. Separation of the constituent diastereomers was achieved using supercritical fluid chromatography [column: Chiral Technologies Chiralpak IA, 21×250 mm, 5 μm; mobile phase: 7:3 carbon dioxide/(0.5% ammonium hydroxide in methanol); flow rate: 75 mL/min; back pressure: 120 bar]; the first eluting diastereomer was identified as 3{2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′ -yl]propan-1-one, DIAST-1} and the second eluting diastereomer was designated as 4{2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2}.
3- Yield: 3.1 mg, 6.7 μmol, 5%. LCMS m/z 464.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ [7.86 (s) and 7.85 (s), total 1H],
[6.65 (s) and 6.61 (s), total 1H], [4.39 (s) and 4.39 (s), total 3H],
[4.05 (q, J = 7.0 Hz), 4.01 - 3.89 (m), 3.88 - 3.55 (m), 3.59 (s), and 3.53 (s), total 5H], [3.98 (s) and 3.96
(s), total 3H], 2.95 - 2.75 (m,
2H), [2.60 (s), 2.58 (s), and 2.55
(s), total 6H], 2.19 - 1.71 (m,
4H), [1.46 (d, J = 7.1 Hz) and 1.44
(d, J = 7.1 Hz), total 3H]. Retention time: 2.47 min [Analytical conditions. Column: Chiral Technologies Chiralpak IA, 4.6 x 100 mm, 5 μm; Mobile phase: 65:35 carbon dioxide/(methanol containing 0.5% ammonium hydroxide); Flow rate: 1.5 mL/min; Back pressure: 120 bar].
4 - Yield: 3.6 mg, 7.8 μmol, 6%. LCMS m/z 486.3 [M+Na ⁺ ]. Retention time: 2.92 min (same analytical conditions as used in 3).

Alternative synthesis of examples 3 and 4 2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]propan-1-one, DIAST-1 (3) and 2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]propan-1-one, DIAST-2 (4)

Ｎ，Ｎ－ジメチルホルムアミド（３ｍＬ）中のＰ２６（調製例Ｐ２６からの材料；１０５ｍｇ、０．２９３ｍｍｏｌ）、Ｐ４（６９．０ｍｇ、０．３５２ｍｍｏｌ）、１－［３－（ジメチルアミノ）プロピル］－３－エチルカルボジイミド塩酸塩（ＥＤＣＩ；１６９ｍｇ、０．８８２ｍｍｏｌ）、１Ｈ－ベンゾトリアゾール－１－オール（１１９ｍｇ、０．８８１ｍｍｏｌ）およびＮ，Ｎ－ジイソプロピルエチルアミン（０．２５５ｍＬ、１．４６ｍｍｏｌ）の溶液を２５℃で１６時間にわたって撹拌した。次いで、反応混合物を水（４０ｍＬ）で希釈し、酢酸エチル（３×３０ｍＬ）で抽出し、合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲルクロマトグラフィー（勾配：ジクロロメタン中０％から１０％メタノール）の後に、超臨界流体クロマトグラフィー［カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｃｅｌ ＯＪ、３０×２５０ｍｍ、５μｍ；移動相：８５：１５ 二酸化炭素／（０．２％プロパン－２－アミンを含有する２－プロパノール）；流速：８０ｍＬ／分；背圧：１００バール］を使用する２つのジアステレオマーの分離を続けた。第１に溶離するジアステレオマーを３｛２－（６－メトキシ－２－メチルピリミジン－４－イル）－１－［（２Ｓ）－７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］プロパン－１－オン、ＤＩＡＳＴ－１｝として、第２に溶離するジアステレオマーを４｛２－（６－メトキシ－２－メチルピリミジン－４－イル）－１－［（２Ｓ）－７－メチル－６－（２－メチル－２Ｈ－テトラゾール－５－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］プロパン－１－オン、ＤＩＡＳＴ－２｝として指定した。
３－収量：３０ｍｇ、６５μｍｏｌ、２２％。LCMS m/z 464.2 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ [7.86 (s)および7.84 (s), 合計1H],
[6.65 (s)および6.61 (s), 合計1H], [4.39 (s)および4.39 (s), 合計3H],
[4.04 (q, J = 7.0 Hz), 4.00 - 3.89 (m), 3.88 - 3.60 (m), 3.59 (s),および3.53 (s), 合計5H], [3.97 (s)および3.96
(s), 合計3H], [2.94 - 2.74 (m)および2.67 - 2.59 (m), 合計2H], [2.60 (s), 2.58 (s),および2.55 (s), 合計6H],
[2.16 - 2.06 (m)および2.06 - 1.71
(m), 合計4H], [1.46 (d, J = 7.1
Hz)および1.44 (d, J = 7.1 Hz), 合計3H].保持時間：４．９２分（分析条件。カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｃｅｌ ＯＪ、４．６×２５０ｍｍ、５μｍ；移動相Ａ：二酸化炭素；移動相Ｂ：０．２％プロパン－２－アミンを含有する２－プロパノール；勾配：Ｂ５％を１．００分間にわたって、次いで、８．００分かけてＢ５％から６０％へ；流速：３．０ｍＬ／分；背圧：１２０バール）。
４－収量：３０ｍｇ、６５μｍｏｌ、２２％。LCMS m/z 464.2 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ 7.85 (s, 1H), [6.62 (s)および6.59 (s), 合計1H], [4.40 (s)および4.39
(s), 合計3H], [4.04 (q, J = 7.1
Hz), 3.98 - 3.85 (m), 3.77 - 3.60 (m), 3.58 (d, AB四重線の成分, J = 10.6 Hz),および3.55
- 3.48 (m), 合計5H], [3.96 (s)および3.91 (s), 合計3H], 2.92 - 2.76 (m, 2H), [2.59 (s), 2.57 (s), 2.56 (s),および2.37 (s), 合計6H], [2.21 - 2.09 (m), 2.08 - 2.01 (m),および2.01 - 1.78 (m), 合計4H],
[1.47 (d, J = 6.9 Hz)および1.42
(d, J = 7.0 Hz), 合計3H].保持時間：５．０５分（３で使用されたものと同一の分析条件）。

A solution of P26 (material from Preparation P26; 105 mg, 0.293 mmol), P4 (69.0 mg, 0.352 mmol), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (EDCI; 169 mg, 0.882 mmol), 1H-benzotriazol-1-ol (119 mg, 0.881 mmol) and N,N-diisopropylethylamine (0.255 mL, 1.46 mmol) in N,N-dimethylformamide (3 mL) was stirred for 16 h at 25° C. The reaction mixture was then diluted with water (40 mL) and extracted with ethyl acetate (3×30 mL) and the combined organic layers were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) was followed by separation of the two diastereomers using supercritical fluid chromatography [column: Chiral Technologies Chiralcel OJ, 30×250 mm, 5 μm; mobile phase: 85:15 carbon dioxide/(2-propanol containing 0.2% propan-2-amine); flow rate: 80 mL/min; back pressure: 100 bar]. The first eluting diastereomer was designated as 3{2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-1} and the second eluting diastereomer was designated as 4{2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-2}.
3 - Yield: 30 mg, 65 μmol, 22%. LCMS m/z 464.2 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ [7.86 (s) and 7.84 (s), total 1H],
[6.65 (s) and 6.61 (s), total 1H], [4.39 (s) and 4.39 (s), total 3H],
[4.04 (q, J = 7.0 Hz), 4.00 - 3.89 (m), 3.88 - 3.60 (m), 3.59 (s), and 3.53 (s), total 5H], [3.97 (s) and 3.96
(s), total 3H], [2.94 - 2.74 (m) and 2.67 - 2.59 (m), total 2H], [2.60 (s), 2.58 (s), and 2.55 (s), total 6H],
[2.16 - 2.06 (m) and 2.06 - 1.71
(m), total 4H], [1.46 (d, J = 7.1
Hz) and 1.44 (d, J = 7.1 Hz), sum 3H]. Retention time: 4.92 min (analytical conditions: Column: Chiral Technologies Chiralcel OJ, 4.6 x 250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: 2-propanol containing 0.2% propan-2-amine; Gradient: 5% B over 1.00 min, then 5% to 60% B over 8.00 min; Flow rate: 3.0 mL/min; Back pressure: 120 bar).
4 - Yield: 30 mg, 65 μmol, 22%. LCMS m/z 464.2 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ 7.85 (s, 1H), [6.62 (s) and 6.59 (s), total 1H], [4.40 (s) and 4.39
(s), total 3H], [4.04 (q, J = 7.1
Hz), 3.98 - 3.85 (m), 3.77 - 3.60 (m), 3.58 (d, component of the AB quadruplet, J = 10.6 Hz), and 3.55
- 3.48 (m), total 5H], [3.96 (s) and 3.91 (s), total 3H], 2.92 - 2.76 (m, 2H), [2.59 (s), 2.57 (s), 2.56 (s), and 2.37 (s), total 6H], [2.21 - 2.09 (m), 2.08 - 2.01 (m), and 2.01 - 1.78 (m), total 4H],
[1.47 (d, J = 6.9 Hz) and 1.42
(d, J = 7.0 Hz), total 3H]. Retention time: 5.05 min (same analytical conditions as used in 3).

The assignment of the two diastereomers as 3 and 4 was made based on the similarity of the ¹ H NMR spectrum of this first eluting enantiomer (3) to samples of 3 from Examples 3 and 4 above. Further support was provided by comparison of the chromatographic retention time of this batch of 3 with the products from Examples 3 and 4 above:
Retention time of 3 from alternative syntheses of Examples 3 and 4: 2.28 min. Retention time of 3 from Examples 3 and 4: 2.46 min. Retention time of 4 from Examples 3 and 4: 2.91 min. These analyses were performed using the same analytical method: [Column: Chiral Technologies Chiralpak IA, 4.6×100 mm, 5 μm; Mobile phase: 65:35 carbon dioxide/(methanol containing 0.5% ammonium hydroxide); Flow rate: 1.5 mL/min; Back pressure: 120 bar].

The biological activity (K _i ) of each example from these two experiments was also consistent with the assigned assignments (data from individual batches summarized in Table 2):
Example 3 from Examples 3 and 4: 0.36 nM
Example 3 from an alternative synthesis of Examples 3 and 4: 1.2 nM
Example 4 from Examples 3 and 4: 25 nM
Example 4 from an alternative synthesis of Examples 3 and 4: 34 nM

(Examples 5 and 6)
2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-1 (5) and 2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-2 (6)

ジクロロメタン（１０ｍＬ）中のＰ２８（５０ｍｇ、０．１４ｍｍｏｌ）、Ｐ５（３０．６ｍｇ、０．１４１ｍｍｏｌ）、Ｎ，Ｎ－ジイソプロピルエチルアミン（０．１２ｍＬ、０．６９ｍｍｏｌ）、および２，４，６－トリプロピル－１，３，５，２，４，６－トリオキサトリホスフィナン２，４，６－トリオキシド（酢酸エチル中５０％溶液；０．２５ｍＬ、０．４２ｍｍｏｌ）の混合物を２５℃で１６時間にわたって撹拌し、その後すぐに、これを水（２０ｍＬ）で希釈し、ジクロロメタン（２×２０ｍＬ）で抽出した。合わせた有機層を炭酸水素ナトリウム水溶液（３０ｍＬ）および飽和塩化ナトリウム水溶液（３０ｍＬ）で順次に洗浄し、硫酸ナトリウム上で乾燥させ、濾過し、真空で濃縮した。シリカゲル上でのクロマトグラフィー（勾配：ジクロロメタン中０％から１０％メタノール）により、５および６の混合物を得；これらのジアステレオマーを、逆相ＨＰＬＣ（カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＩＥ；５０×２５０ｍｍ；１０μｍ；移動相：９５：５ エタノール／アセトニトリル；流速：６０ｍＬ／分）を使用して分離した。第１に溶離するジアステレオマーを５｛２－［６－（ジフルオロメトキシ）ピリジン－３－イル］－１－［（２Ｓ）－７－メチル－６－（ピリミジン－２－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］プロパン－１－オン、ＤＩＡＳＴ－１｝として指定し、第２に溶離するジアステレオマーを６｛２－［６－（ジフルオロメトキシ）ピリジン－３－イル］－１－［（２Ｓ）－７－メチル－６－（ピリミジン－２－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］プロパン－１－オン、ＤＩＡＳＴ－２｝として指定し；両方を白色の固体として単離した。
５－収量：１０ｍｇ、２１μｍｏｌ、１５％。LCMS m/z 481.3 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ [8.82 (d, J = 4.9 Hz)および8.81 (d, J = 4.9 Hz), 合計2H], [8.19 (d, J = 2.5 Hz)および8.12 (d, J = 2.5 Hz), 合計1H], 7.88 - 7.76 (m, 2H), [7.52 (t, J_HF
= 73.2 Hz)および7.43 (t, J_HF
= 73.1 Hz), 合計1H], [7.31 (t, J
= 4.9 Hz)および7.31 (t, J = 4.9
Hz), 合計1H], [6.96 (d, J = 8.5
Hz)および6.89 (d, J = 8.5 Hz), 合計1H], [4.07 (q, J = 6.9 Hz), 4.03 - 3.91
(m), 3.74 - 3.63 (m), 3.60 (d, AB四重線の成分, J = 12.1 Hz), 3.58 - 3.51 (m), 3.44 (d, J = 12.4 Hz)および3.40 (d, J = 10.6 Hz), 合計5H], 2.92 - 2.77 (m, 2H), [2.58 (s)および2.54 (s), 合計3H], [2.22 - 2.10 (m), 2.08 - 1.93 (m)および1.93 - 1.77 (m), 合計4H],
[1.46 (d, J = 6.9 Hz)および1.42
(d, J = 6.9 Hz), 合計3H].保持時間：７．１２分（分析条件。カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｐａｋ ＡＹ－Ｈ；４．６×２５０ｍｍ；移動相：９５：５：０．１ エタノール／アセトニトリル／ジエチルアミン；流速：０．６ｍＬ／分）。
６－収量：９．８ｍｇ、２０μｍｏｌ、１４％。LCMS m/z 481.3 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ [8.81 (d, J = 4.9 Hz)および8.80 (d, J = 4.9 Hz), 合計2H], [8.21 (d, J = 2.5 Hz)および8.16 (d, J = 2.5 Hz), 合計1H], 7.90 - 7.78 (m, 2H), [7.54 (t, J_HF
= 73.2 Hz)および7.53 (t, J_HF
= 73.2 Hz), 合計1H], [7.31 (t, J
= 4.9 Hz)および7.30 (t, J = 4.9
Hz), 合計1H], [6.98 (d, J = 8.5
Hz)および6.96 (d, J = 8.5 Hz), 合計1H], [4.08 (q, J = 6.9 Hz)および4.00 (q, J = 6.9 Hz), 合計1H], [3.95 - 3.87 (m), 3.78 - 3.54 (m),
3.51 (AB四重線, J_AB =
12.3 Hz, Δν_AB = 33.2 Hz),および3.39
(d, J = 10.7 Hz), 合計4H], [2.94
- 2.71 (m)および2.62 - 2.49 (m), 合計2H], [2.57 (s)および2.54 (s), 合計3H],
[2.16 - 2.04 (m)および2.02 - 1.84
(m), 合計3H], 1.78 - 1.70 (m,
1H), [1.45 (d, J = 7.0 Hz)および1.42
(d, J = 7.0 Hz), 合計3H].保持時間：１０．６６分（５で使用されたものと同一の分析条件）。

A mixture of P28 (50 mg, 0.14 mmol), P5 (30.6 mg, 0.141 mmol), N,N-diisopropylethylamine (0.12 mL, 0.69 mmol), and 2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphinane 2,4,6-trioxide (50% solution in ethyl acetate; 0.25 mL, 0.42 mmol) in dichloromethane (10 mL) was stirred at 25° C. for 16 h, whereupon it was diluted with water (20 mL) and extracted with dichloromethane (2×20 mL). The combined organic layers were washed successively with aqueous sodium bicarbonate (30 mL) and saturated aqueous sodium chloride (30 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Chromatography on silica gel (gradient: 0% to 10% methanol in dichloromethane) gave a mixture of 5 and 6; these diastereomers were separated using reverse-phase HPLC (column: Chiral Technologies Chiralpak IE; 50×250 mm; 10 μm; mobile phase: 95:5 ethanol/acetonitrile; flow rate: 60 mL/min). The first eluting diastereomer was designated as 5{2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1} and the second eluting diastereomer was designated as 6{2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2}; both were isolated as white solids.
5 - Yield: 10 mg, 21 μmol, 15%. LCMS m/z 481.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol- _{d 4} ) δ [8.82 (d, J = 4.9 Hz) and 8.81 (d, J = 4.9 Hz), summed 2H], [8.19 (d, J = 2.5 Hz) and 8.12 (d, J = 2.5 Hz), summed 1H], 7.88 - 7.76 (m, 2H), [7.52 (t, J _HF
= 73.2 Hz) and 7.43 (t, J _HF
= 73.1 Hz), total 1H], [7.31 (t, J
= 4.9 Hz) and 7.31 (t, J = 4.9
Hz), total 1H], [6.96 (d, J = 8.5
Hz) and 6.89 (d, J = 8.5 Hz), total 1H], [4.07 (q, J = 6.9 Hz), 4.03 - 3.91
(m), 3.74 - 3.63 (m), 3.60 (d, component of the AB quadruplet, J = 12.1 Hz), 3.58 - 3.51 (m), 3.44 (d, J = 12.4 Hz) and 3.40 (d, J = 10.6 Hz), summed 5H], 2.92 - 2.77 (m, 2H), [2.58 (s) and 2.54 (s), summed 3H], [2.22 - 2.10 (m), 2.08 - 1.93 (m) and 1.93 - 1.77 (m), summed 4H],
[1.46 (d, J = 6.9 Hz) and 1.42
(d, J = 6.9 Hz), total 3H]. Retention time: 7.12 min (analytical conditions: column: Chiral Technologies Chiralpak AY-H; 4.6 x 250 mm; mobile phase: 95:5:0.1 ethanol/acetonitrile/diethylamine; flow rate: 0.6 mL/min).
6 - Yield: 9.8 mg, 20 μmol, 14%. LCMS m/z 481.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol- _{d 4} ) δ [8.81 (d, J = 4.9 Hz) and 8.80 (d, J = 4.9 Hz), summed 2H], [8.21 (d, J = 2.5 Hz) and 8.16 (d, J = 2.5 Hz), summed 1H], 7.90 - 7.78 (m, 2H), [7.54 (t, J _HF
= 73.2 Hz) and 7.53 (t, J _HF
= 73.2 Hz), total 1H], [7.31 (t, J
= 4.9 Hz) and 7.30 (t, J = 4.9
Hz), total 1H], [6.98 (d, J = 8.5
Hz) and 6.96 (d, J = 8.5 Hz), total 1H], [4.08 (q, J = 6.9 Hz) and 4.00 (q, J = 6.9 Hz), total 1H], [3.95 - 3.87 (m), 3.78 - 3.54 (m),
3.51 (AB quartet, J _AB =
12.3 Hz, Δν _AB = 33.2 Hz), and 3.39
(d, J = 10.7 Hz), total 4H], [2.94
- 2.71 (m) and 2.62 - 2.49 (m), total 2H], [2.57 (s) and 2.54 (s), total 3H],
[2.16 - 2.04 (m) and 2.02 - 1.84
(m), total 3H], 1.78 - 1.70 (m,
1H), [1.45 (d, J = 7.0 Hz) and 1.42
(d, J = 7.0 Hz), total 3H]. Retention time: 10.66 min (same analytical conditions as used in 5).

(Examples 7 and 8)
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-1 (7) and 1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-2 (8).

１，１’－カルボニルジイミダゾール（２４０ｍｇ、１．４８ｍｍｏｌ）を、アセトニトリル（５ｍＬ）中の２－［４－（トリフルオロメチル）フェニル］プロパン酸（３２３ｍｇ、１．４８ｍｍｏｌ）の溶液に少量ずつ添加した。反応混合物を室温で４５分間にわたって撹拌した後に、アセトニトリル（２ｍＬ）中のＰ２８（５００ｍｇ、１．４１ｍｍｏｌ）およびＮ，Ｎ－ジイソプロピルエチルアミン（０．５０４ｍＬ、２．８９ｍｍｏｌ）の混合物を添加した。撹拌を室温で１８時間にわたって継続し、その後すぐに、反応混合物を酢酸エチルで抽出した。合わせた有機層を飽和炭酸水素ナトリウム水溶液および飽和塩化ナトリウム水溶液で順次に洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮した。残渣を、超臨界流体クロマトグラフィー｛カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｃｅｌ ＯＪ、３０×２５０ｍｍ、５μｍ；移動相 ８５：１５ 二酸化炭素／［０．２％（メタノール中７Ｍアンモニア）を含有するメタノール］；流速：８０ｍＬ／分；背圧：１００バール｝により、その構成要素のジアステレオマーに分離した。第１に溶離するジアステレオマーを７｛１－［（２Ｓ）－７－メチル－６－（ピリミジン－２－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］－２－［４－（トリフルオロメチル）フェニル］プロパン－１－オン、ＤＩＡＳＴ－１｝として指定し、第２に溶離するジアステレオマーを８｛１－［（２Ｓ）－７－メチル－６－（ピリミジン－２－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］－２－［４－（トリフルオロメチル）フェニル］プロパン－１－オン、ＤＩＡＳＴ－２｝として指定し；両方を固体として単離した。
７－収量：２５０ｍｇ、０．５１９ｍｍｏｌ、３７％。LCMS m/z 482.4 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ [8.80 (d, J = 4.9 Hz)および8.79 (d, J = 4.9 Hz), 合計2H], [7.83 (s)および7.75 (s), 合計1H],
7.68 - 7.62 (m, 2H), [7.54 (d, AB四重線の成分, J = 8.1 Hz)および7.49
(d, AB四重線の成分, J = 8.1 Hz), 合計2H], [7.28 (t, J = 4.9 Hz)および7.28 (t, J = 4.9 Hz), 合計1H], [4.10 (q, J = 6.9 Hz)および4.00 (q, J = 6.9 Hz), 合計1H], [3.92 - 3.83 (m)および3.71 (ddd, J = 12.5, 8.5, 6.2 Hz), 合計1H], [3.62 - 3.46 (m), 3.46 (d, AB四重線の成分, J = 12.3 Hz),および3.26 (d, J = 10.7 Hz), 合計3H], [2.91 - 2.75 (m), 2.68 - 2.58 (m),および2.35 - 2.25 (m), 合計2H], [2.56 (s)および2.53
(s), 合計3H], [2.13 - 1.99 (m)および1.99 - 1.81 (m), 合計3H], 1.66 - 1.58 (m, 1H), [1.45 (d, J = 6.9 Hz)および1.42 (d, J = 6.9 Hz), 合計3H].保持時間：４．２８分［カラム：Ｃｈｉｒａｌ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｈｉｒａｌｃｅｌ ＯＪ、４．６×２５０ｍｍ、５μｍ；移動相Ａ：二酸化炭素；移動相Ｂ：０．２％（メタノール中７Ｍアンモニア）を含有するメタノール；勾配：Ｂ５％を１．０分間にわたって、次いで、８．０分かけてＢ５％から６０％へ；流速：３．０ｍＬ／分；背圧：１２０バール］。
８－収量：２６０ｍｇ、０．５４０ｍｍｏｌ、３８％。LCMS m/z 482.4 [M+H]⁺. ¹H NMR (400 MHz, メタノール-d₄) δ [8.80 (d, J = 4.9 Hz)および8.79 (d, J = 4.9 Hz), 合計2H], [7.82 (s)および7.81 (s), 合計1H],
[7.64 (d, AB四重線の成分, J = 8.1 Hz)および7.57 (d, AB四重線の成分, J = 8.2 Hz), 合計2H],
[7.52 (d, AB四重線の成分, J = 8.1 Hz)および7.47 (d, AB四重線の成分, J = 8.2 Hz), 合計2H],
[7.29 (t, J = 4.9 Hz)および7.28
(t, J = 4.9 Hz), 合計1H], [4.09
(q, J = 6.9 Hz)および4.03 (q, J =
6.9 Hz), 合計1H], [3.96 - 3.87
(m)および3.46 - 3.37 (m), 合計1H], [3.73 - 3.63 (m), 3.52 (AB四重線, J_AB = 12.3 Hz, Δν_AB =
62.6 Hz),および3.27 (d, J = 10.6
Hz), 合計3H]. 2.90 - 2.71 (m,
2H), [2.57 (s)および2.53 (s), 合計3H], [2.15 - 2.05 (m), 2.04 - 1.90 (m),および1.89 - 1.70 (m), 合計4H], [1.45 (d, J = 6.9 Hz)および1.43 (d, J = 6.9 Hz), 合計3H].保持時間：４．７４分（７で使用されたものと同一の分析条件）。

1,1'-Carbonyldiimidazole (240 mg, 1.48 mmol) was added in portions to a solution of 2-[4-(trifluoromethyl)phenyl]propanoic acid (323 mg, 1.48 mmol) in acetonitrile (5 mL). The reaction mixture was stirred at room temperature for 45 minutes before a mixture of P28 (500 mg, 1.41 mmol) and N,N-diisopropylethylamine (0.504 mL, 2.89 mmol) in acetonitrile (2 mL) was added. Stirring was continued at room temperature for 18 hours whereupon the reaction mixture was extracted with ethyl acetate. The combined organic layers were washed successively with saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue was separated into its constituent diastereomers by supercritical fluid chromatography {column: Chiral Technologies Chiralcel OJ, 30×250 mm, 5 μm; mobile phase 85:15 carbon dioxide/[methanol containing 0.2% (7M ammonia in methanol)]; flow rate: 80 mL/min; back pressure: 100 bar}. The first eluting diastereomer was designated as 7{1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-1} and the second eluting diastereomer was designated as 8{1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-2}; both were isolated as solids.
7 - Yield: 250 mg, 0.519 mmol, 37%. LCMS m/z 482.4 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol- _{d 4} ) δ [8.80 (d, J = 4.9 Hz) and 8.79 (d, J = 4.9 Hz), total 2H], [7.83 (s) and 7.75 (s), total 1H],
7.68 - 7.62 (m, 2H), [7.54 (d, component of the AB quartet, J = 8.1 Hz) and 7.49
(d, AB quadruplet component, J = 8.1 Hz), sum 2H], [7.28 (t, J = 4.9 Hz) and 7.28 (t, J = 4.9 Hz), sum 1H], [4.10 (q, J = 6.9 Hz) and 4.00 (q, J = 6.9 Hz), sum 1H], [3.92 - 3.83 (m) and 3.71 (ddd, J = 12.5, 8.5, 6.2 Hz), sum 1H], [3.62 - 3.46 (m), 3.46 (d, AB quadruplet component, J = 12.3 Hz), and 3.26 (d, J = 10.7 Hz), sum 3H], [2.91 - 2.75 (m), 2.68 - 2.58 (m), and 2.35 - 2.25 (m), total 2H], [2.56 (s) and 2.53
(s), total 3H], [2.13 - 1.99 (m) and 1.99 - 1.81 (m), total 3H], 1.66 - 1.58 (m, 1H), [1.45 (d, J = 6.9 Hz) and 1.42 (d, J = 6.9 Hz), total 3H].Retention time: 4.28 min [Column: Chiral Technologies Chiralcel OJ, 4.6 x 250 mm, 5 μm; Mobile phase A: carbon dioxide; Mobile phase B: methanol containing 0.2% (7M ammonia in methanol); Gradient: 5% B over 1.0 min, then 5% to 60% B over 8.0 min; Flow rate: 3.0 mL/min; Back pressure: 120 bar].
8 - Yield: 260 mg, 0.540 mmol, 38%. LCMS m/z 482.4 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol- _{d 4} ) δ [8.80 (d, J = 4.9 Hz) and 8.79 (d, J = 4.9 Hz), summed 2H], [7.82 (s) and 7.81 (s), summed 1H],
[7.64 (d, component of the AB quartet, J = 8.1 Hz) and 7.57 (d, component of the AB quartet, J = 8.2 Hz), total 2H],
[7.52 (d, component of the AB quartet, J = 8.1 Hz) and 7.47 (d, component of the AB quartet, J = 8.2 Hz), total 2H],
[7.29 (t, J = 4.9 Hz) and 7.28
(t, J = 4.9 Hz), total 1H], [4.09
(q, J = 6.9 Hz) and 4.03 (q, J =
6.9 Hz), total 1H], [3.96 - 3.87
(m) and 3.46 - 3.37 (m), total 1H], [3.73 - 3.63 (m), 3.52 (AB quartet, J _AB = 12.3 Hz, Δν _AB =
62.6 Hz), and 3.27 (d, J = 10.6
Hz), total 3H]. 2.90 - 2.71 (m,
2H), [2.57 (s) and 2.53 (s), sum 3H], [2.15 - 2.05 (m), 2.04 - 1.90 (m), and 1.89 - 1.70 (m), sum 4H], [1.45 (d, J = 6.9 Hz) and 1.43 (d, J = 6.9 Hz), sum 3H]. Retention time: 4.74 min (analytical conditions identical to those used in 7).

(Examples 9, 10, 11, and 12)
1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-1 (9), 1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-2 (10), 1 -(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-3 (11), and 1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-4 (12).

ステップ１． １－（４，７－ジメチル－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル）－２－（４－フルオロフェニル）エタン－１－オン（Ｃ７８）の合成。
トリフルオロ酢酸（０．５ｍＬ）を、ジクロロメタン（３ｍＬ）中のＰ２９（３０ｍｇ、９５μｍｏｌ）の溶液に添加し、反応混合物を室温で１時間にわたって撹拌した。真空での濃縮による揮発物の除去後に、残渣を酢酸エチルおよびヘプタンと２回共蒸発させ、次いで、ジクロロメタン（５ｍＬ）に溶解した。この溶液に、トリエチルアミン（１３．３μＬ、９５．４μｍｏｌ）、（４－フルオロフェニル）酢酸（１４．７ｍｇ、９５．４μｍｏｌ）、およびＯ－（７－アザベンゾトリアゾール－１－イル）－Ｎ，Ｎ，Ｎ’，Ｎ’－テトラメチルウロニウムヘキサフルオロホスフェート（ＨＡＴＵ；３６．２ｍｇ、９５．２μｍｏｌ）を添加した。反応混合物を室温で１時間にわたって撹拌した後に、これを真空で濃縮し、シリカゲル上でのクロマトグラフィー（勾配：ジクロロメタン中０％から１０％メタノール）により精製して、Ｃ７８をオフホワイト色の粉末として得た。収量：３４ｍｇ、定量的。LCMS m/z 352.2 [M+H]⁺.

Step 1. Synthesis of 1-(4,7-dimethyl-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidin]-1′-yl)-2-(4-fluorophenyl)ethan-1-one (C78).
Trifluoroacetic acid (0.5 mL) was added to a solution of P29 (30 mg, 95 μmol) in dichloromethane (3 mL) and the reaction mixture was stirred at room temperature for 1 h. After removal of volatiles by concentration in vacuum, the residue was coevaporated twice with ethyl acetate and heptane and then dissolved in dichloromethane (5 mL). To this solution were added triethylamine (13.3 μL, 95.4 μmol), (4-fluorophenyl)acetic acid (14.7 mg, 95.4 μmol), and O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU; 36.2 mg, 95.2 μmol). After stirring the reaction mixture at room temperature for 1 h, it was concentrated in vacuum and purified by chromatography on silica gel (gradient: 0% to 10% methanol in dichloromethane) to give C78 as an off-white powder. Yield: 34 mg, quantitative. LCMS m/z 352.2 [M+H] ⁺ .

Step 2. 1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-1 (9), 1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-2 (10), 1-( Synthesis of 4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-3 (11), and 1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-4 (12).
A solution of C78 (22 mg, 63 μmol) in methanol (3 mL) was treated with palladium on carbon (10%; 5 mg) and hydrogenated at 50 psi overnight. The reaction mixture was then filtered, concentrated in vacuo, and subjected to supercritical fluid chromatography (column: Chiral Technologies Chiralcel OJ-H, 5 μm; mobile phase A: carbon dioxide; mobile phase B: methanol containing 0.2% ammonium hydroxide; gradient: 3% to 5% B; flow rate: 75 mL/min; back pressure: 200 bar) to separate the four diastereomers. The first eluting diastereomer was designated as 9 {1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-1}, the second eluting diastereomer was designated as 10 {1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-2}, and the third eluting diastereomer was designated as 10 {1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-3}. The first eluting diastereomer was designated as 11 {1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-3} and the fourth eluting diastereomer was designated as 12 {1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-4}.
9 - Yield: 1.2 mg, 3.4 μmol, 5%. LCMS m/z 354.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.31 - 7.21 (m, 2H, estimated; partially obscured by solvent peaks),
7.21 - 7.16 (m, 1H), 7.05 - 6.94 (m, 2H), [6.48 (d, J = 7.5 Hz) and 6.47 (d, J = 7.5 Hz), total 1H], [3.77 - 3.52 (m) and 3.44 (d, components of the AB quartet, J = 12.1 Hz), total 4H],
[3.62 (s) and 3.39 (s), total 2H], [2.90 - 2.77 (m) and 2.61 - 2.48 (m), total 1H], 2.33 (s, 3H), 2.13 - 2.03 (m, 1H), 2.02 - 1.94 (m, 1H), 1.89 -
1.74 (m, 1H), [1.33 (d, J = 6.7 Hz) and 1.28 (d, J = 6.7 Hz), summed 3H]. Retention time: 2.77 min. (analytical conditions: column: Chiral Technologies Chiralcel OJ-H, 4.6 x 100 mm, 5 μm; mobile phase: 85:15 carbon dioxide/(methanol containing 0.2% ammonium hydroxide); flow rate: 1.5 mL/min; back pressure: 120 bar).
10 - Yield: 1.3 mg, 3.7 μmol, 6%. LCMS m/z 354.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.30 - 7.19 (m, 3H, estimated; partially obscured by solvent peaks),
7.06 - 6.98 (m, 2H), [6.48 (d, J = 7.4 Hz) and 6.47 (d, J = 7.4 Hz), total 1H], [3.75 - 3.55 (m) and 3.50 - 3.40 (m), total 6H],
2.95 - 2.82 (m, 1H), 2.33 (s, 3H), [2.13 - 1.79 (m) and 1.74 - 1.66 (m, estimated; partially obscured by water peak), total 4H], 1.36 - 1.30 (m, 3H). Retention time: 2.92 min (analytical conditions identical to those used in 9).
11 - Yield: 1.3 mg, 3.7 μmol, 6%. LCMS m/z 354.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.29 - 7.21 (m, 2H, estimated; partially obscured by solvent peaks),
7.21 - 7.15 (m, 1H), 7.05 - 6.93 (m, 2H), [6.48 (d, J = 7.5 Hz) and 6.47 (d, J = 7.5 Hz), total 1H], [3.74 - 3.52 (m) and 3.45 (d, components of the AB quartet, J = 12.0 Hz), total 4H],
[3.62 (s) and 3.39 (s), total 2H], [2.90 - 2.78 (m) and 2.61 - 2.49 (m), total 1H], [2.33 (s) and 2.32
(s), total 3H], 2.10 - 2.04 (m,
1H), 2.00 - 1.94 (m, 1H), 1.88 - 1.74 (m, 1H), [1.32 (d, J = 6.7 Hz) and 1.28 (d, J = 6.7 Hz), total 3H]. Retention time: 3.48 min (analytical conditions identical to those used in 9).
12 - Yield: 2.1 mg, 5.9 μmol, 9%. LCMS m/z 354.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 7.29 - 7.20 (m, 3H, estimated; partially obscured by solvent peaks),
7.06 - 6.98 (m, 2H), [6.48 (d, J = 7.4 Hz) and 6.46 (d, J = 7.4 Hz), total 1H], [3.74 - 3.55 (m) and 3.50 - 3.40 (m), total 6H],
2.95 - 2.82 (m, 1H), 2.32 (s, 3H), [2.12 - 1.78 (m) and 1.74 - 1.66 (m, estimated; partially obscured by water peak), total 4H], 1.36 - 1.30 (m, 3H). Retention time: 4.14 min (analytical conditions identical to those used in 9).
By comparison of ^{the 1} H NMR data, 9 and 11 are enantiomers of each other. Similarly, 10 and 12 constitute a pair of enantiomers.

Example 13
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]propan-1-one (13)

ジクロロメタン（１０ｍＬ）中のＣ６８（２８０ｍｇ、０．７２６ｍｍｏｌ）の溶液をトリフルオロ酢酸（２ｍＬ）で処理し、反応混合物を室温で２時間にわたって撹拌した。次いで、これを真空で濃縮し、酢酸エチルから２回蒸発させて、脱保護された基質を暗褐色油（２００ｍｇ）として提供し；この材料の一部をその後のカップリングで使用した。

A solution of C68 (280 mg, 0.726 mmol) in dichloromethane (10 mL) was treated with trifluoroacetic acid (2 mL) and the reaction mixture was stirred at room temperature for 2 h. It was then concentrated in vacuo and evaporated twice from ethyl acetate to provide the deprotected substrate as a dark brown oil (200 mg); a portion of this material was used in the subsequent coupling.

To a solution of P7 (36.4 mg, 0.183 mmol) in acetonitrile (3 mL) was added pyridinium trifluoromethanesulfonate (88.0 mg, 0.384 mmol) followed by 1,1'-carbonyldiimidazole (31.1 mg, 0.192 mmol). After stirring the mixture at room temperature for 45 min, a portion of the deprotected material from above (73 mg, .about.0.18 mmol) was added as a solution in acetonitrile (3 mL) and the reaction mixture was stirred at room temperature overnight. It was then partitioned between dichloromethane and dilute aqueous ammonium chloride; the organic layer was washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) followed by supercritical fluid chromatography [column: Chiral Technologies Chiralpak IA, 21×250 mm, 5 μm; mobile phase: 7:3 carbon dioxide/(0.5% ammonium hydroxide in methanol); flow rate: 75 mL/min; back pressure: 120 bar] provided (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]propan-1-one (13). Yield: 13.6 mg, 29.1 μmol, approximately 16%. LCMS m/z 489.3 [M+Na ⁺ ]. Retention time: 2.6 min [Analytical conditions. Column: Chiral Technologies Chiralpak IA, 4.6×100 mm, 5 μm; Mobile phase: 65:35 carbon dioxide/(methanol containing 0.5% ammonium hydroxide); Flow rate: 1.5 mL/min; Back pressure: 120 bar].

(Example 14)
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]propan-1-one (14)

トリフルオロメタンスルホン酸ピリジニウム（１．０２ｇ、４．４５ｍｍｏｌ）を、アセトニトリル（１０ｍＬ）中のＰ７（Ｐ７の代替調製例（＃１）のステップ２からの材料；４２２ｍｇ、２．１２ｍｍｏｌ）の溶液に添加した。得られた溶液に、１，１’－カルボニルジイミダゾール（３６０ｍｇ、２．２２ｍｍｏｌ）を一度に添加し、反応混合物を室温で４５分間にわたって撹拌し、その後すぐに、アセトニトリル（５ｍＬ）中のＰ２８（調製例Ｐ２８のステップ２からの材料；７５０ｍｇ、２．１２ｍｍｏｌ）の溶液を一度に添加した。反応物を室温でさらに３時間にわたって撹拌した後に、これを飽和塩化アンモニウム水溶液で希釈し、酢酸エチルで３回抽出した。合わせた有機層を飽和炭酸水素ナトリウム水溶液および飽和塩化ナトリウム水溶液で順次に洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮し；シリカゲルクロマトグラフィー（勾配：ヘプタン中３０％から１００％酢酸エチル）により、（２Ｒ）－２－（５－フルオロ－２－メトキシピリジン－４－イル）－１－［（２Ｓ）－７－メチル－６－（ピリミジン－２－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル］プロパン－１－オン（１４）を白色の固体として得た。

Pyridinium trifluoromethanesulfonate (1.02 g, 4.45 mmol) was added to a solution of P7 (material from step 2 of Alternate Preparation of P7 (#1); 422 mg, 2.12 mmol) in acetonitrile (10 mL). To the resulting solution was added 1,1′-carbonyldiimidazole (360 mg, 2.22 mmol) in one portion and the reaction mixture was stirred at room temperature for 45 minutes whereupon a solution of P28 (material from step 2 of Preparation P28; 750 mg, 2.12 mmol) in acetonitrile (5 mL) was added in one portion. The reaction was stirred at room temperature for an additional 3 hours before it was diluted with saturated aqueous ammonium chloride and extracted three times with ethyl acetate. The combined organic layers were washed successively with saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo; silica gel chromatography (gradient: 30% to 100% ethyl acetate in heptane) afforded (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]propan-1-one (14) as a white solid.

The absolute stereochemistry indicated was assigned based on the single crystal X-ray structure analysis performed on 14 derived from the crystallization of this lot (see below).
Yield: 670 mg, 1.45 mmol, 68%. LCMS m/z 463.4 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol- _{d 4} ) δ [8.81 (d, J = 4.9 Hz) and 8.80 (d, J = 4.9 Hz), summed 2H], [7.99 (d, J = 1.6 Hz) and 7.98 (d, J = 1.7 Hz), summed 1H], [7.84 (s) and 7.81 (s), summed 1H],
[7.30 (t, J = 4.9 Hz) and 7.29
(t, J = 4.9 Hz), total 1H], [6.78
(d, J = 4.9 Hz) and 6.73 (d, J =
4.9 Hz), total 1H], [4.27 (q, J =
6.9 Hz) and 4.19 (q, J = 6.9 Hz),
Total 1H], [3.93 - 3.83 (m) and 3.76 - 3.67 (m), Total 1H], [3.88 (s) and 3.88
(s), total 3H], [3.67 - 3.57 (m),
3.53 (AB quartet, J _AB =
12.3 Hz, Δν _AB = 34.7 Hz), and 3.39
(d, component of the AB quadruplet, J = 10.6 Hz), total 3H], [2.94 - 2.72 (m) and 2.63 - 2.54 (m), total 2H], [2.57 (s) and 2.55
(s), total 3H], 2.15 - 1.83 (m,
3H), 1.83 - 1.74 (m, 1H), [1.45 (d, J = 6.8 Hz) and 1.43 (d, J = 6.8 Hz), total 3H].
Recrystallization from a 3:2 mixture of ethyl acetate and heptane provided material with a diastereomeric excess of 99.1%; further recrystallization from acetonitrile afforded single crystals used for X-ray structure determination.

Single Crystal X-Ray Structure Determination of 14 Single Crystal X-Ray Analysis Data collection was carried out at room temperature on a Bruker D8 Quest diffractometer. Data collection consisted of Omega and Phi scans.

The structure was solved with intrinsic phases using the SHELX software suite in the triclinic class group P1. The structure was then refined by full-matrix least-squares fitting. All non-hydrogen atoms were located and refined using anisotropic displacement parameters.

The hydrogen atoms located at the nitrogens were found from the Fourier difference distribution and refined at restricted distances. The remaining hydrogen atoms were placed at the calculated positions and attached to their carrier atoms. The final refinement included isotropic displacement parameters on all hydrogen atoms.

Analysis of the absolute structure using a likelihood method (Hooft, 2008) was performed using PLATON (Spek). The results indicate that the absolute structure has been correctly assigned. This method calculates a 100% probability that the structure has been correctly assigned. The Hooft parameter is reported as 0.05 with an esd (estimated standard deviation) of (10) and the Parson parameter is reported as 0.04 with an esd of (10).

The final R-index was 4.5%. The final difference Fourier revealed no missing or misplaced electron density.

Relevant crystallographic, data collection, and refinement information is summarized in Table A. Atomic coordinates, bond distances, bond angles, and displacement parameters are listed in Tables B-D.
Software and References
SHELXTL, Version 5.1, Bruker AXS, 1997.
PLATON, AL Spek, J. Appl. Cryst. 2003,
36, 7-13.
MERCURY, C.F. Macrae, P.R. Edington, P.
McCabe, E. Pidcock, GP Shields, R. Taylor, M. Towler and J. van de Streek, J. Appl. Cryst. 2006, 39, 453-457.
OLEX2, OV Dolomanov, LJ Bourhis, R.
J. Gildea, J. A. K. Howard and H. Puschmann, J. Appl.
Cryst. 2009, 42, 339-341.
RWW Hooft, LH Straver and AL Spek, J. Appl. Cryst. 2008, 41, 96-103.
HD Flack, Acta Cryst. 1983, A39,
867-881.

Therefore, the absolute stereochemistry of compound Example 14 was determined by single crystal X-ray crystallography. Figure 1 is the resulting single crystal X-ray structure (ORTEP drawing) of crystalline compound Example 14: (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one.

In some embodiments, the present invention provides a crystalline form of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one. In some further embodiments, the crystalline form of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one is as described (or prepared) in Example 14.

Alternative synthesis of Example 14 (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]propan-1-one (14)

ステップ１． ｔｅｒｔ－ブチル（２Ｓ）－６－（５，５－ジメチル－１，３，２－ジオキサボリナン－２－イル）－７－メチル－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－カルボキシレート（Ｃ７９）の合成。
ジ（１－アダマンチル）－ｎ－ブチルホスフィン（ｃａｔａＣＸｉｕｍ（登録商標）Ａ；２．２１ｇ、６．１６ｍｍｏｌ）、続いて、酢酸パラジウム（ＩＩ）（０．４６１ｍｇ、２．０５ｍｍｏｌ）を、２－メチルテトラヒドロフラン（１７０ｍＬ）に添加し；触媒混合物を、各操作間に１０から２０分間にわたってアルゴンでスパージした。混合物を還流状態で１時間にわたって加熱し、次いで、５０℃以下に冷却した。

Step 1. Synthesis of tert-butyl (2S)-6-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C79).
Di(1-adamantyl)-n-butylphosphine (cataCXium® A; 2.21 g, 6.16 mmol) was added to 2-methyltetrahydrofuran (170 mL) followed by palladium(II) acetate (0.461 mg, 2.05 mmol); the catalyst mixture was sparged with argon for 10 to 20 minutes between each run. The mixture was heated at reflux for 1 hour and then cooled to below 50° C.

In a separate reactor, P23 (98.2% by mass; 80.0 g, 205 mmol), 5,5,5',5'-tetramethyl-2,2'-bi-1,3,2-dioxaborinane (60.3 g, 267 mmol), potassium acetate (97% by mass; 62.4 g, 617 mmol), and water (2.37 mL, 132 mmol) were added to 2-methyltetrahydrofuran (220 mL). The sides of the reactor were rinsed with 2-methyltetrahydrofuran (100 mL) and the resulting mixture was sparged with argon for approximately 1 hour. The catalyst mixture was then added via cannula over less than 2 minutes and the reaction mixture was heated to reflux at a rate of 1°C/min. After 4 hours at reflux, it was cooled to 10°C, maintained at that temperature overnight, and rapidly treated dropwise over 15 minutes with aqueous sodium hydroxide (1.0 M; 410 mL, 410 mmol). The internal temperature was maintained below 17° C. during the addition. The resulting mixture was warmed to 20° C., diluted with tert-butyl methyl ether (180 mL) and mixed well for 5 minutes, whereupon the aqueous layer was confirmed to be at pH 10. Aqueous sodium hydroxide (1.0 M; 480 mL, 480 mmol) was added to the organic layer in four portions over 4 minutes; after stirring for 5 minutes the organic layer was separated and similarly extracted with aqueous sodium hydroxide (1.0 M; 480 mL, 480 mmol). The combined sodium hydroxide extracts were mixed with toluene (240 mL) and treated in portions with hydrochloric acid (12.2 M; 62.3 mL, 760 mmol) at a rate that maintained the temperature below 30° C. The pH of the resulting mixture was 14; additional hydrochloric acid (12.2 M; 34 mL, 415 mmol) was added to adjust the pH to 10. After stirring the mixture for 5 min, the aqueous layer was extracted with toluene (2×240 mL) and the toluene layers were combined to give C79 as a solution in toluene. The bulk of this material was used in the next step. Estimated yield: 73.2 g (by quantitative NMR), 176 mmol, 86% yield, as a solution in toluene.

Step 2. Synthesis of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C69).
To a solution of C79 in toluene (from the previous step; 509 mL, containing 72.7 g, 175 mmol of C79) was added aqueous sodium hydroxide (1 M; 530 mL, 530 mmol), followed by 2-bromopyrimidine (39.0 g, 245 mmol). The resulting mixture was sparged with argon for 30 minutes whereupon 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos; 1.27 g, 2.19 mmol) and palladium(II) acetate (394 mg, 1.76 mmol) were added. The reaction mixture was heated at 50° C. for 3.5 hours before it was cooled to 20° C., stirred overnight, and filtered. The filter cake was rinsed with toluene (150 mL) and the combined filtrate organic layer was washed with water by stirring for 5 minutes and then allowing the mixture to settle for 30 minutes; the solids in the mixture were kept with the organic layer and subjected to short path distillation at 100 mbar and 60° C. The mixture was distilled until approximately 275 mL remained, whereupon it was cooled to 20° C. at a rate of 1° C./min. The mixture was stirred for 30 minutes during which time solids were observed, after which heptane (727 mL) was slowly added dropwise over 30 minutes. The resulting solution was stirred for 10 minutes, heated to 60° C. at a rate of 1° C./min, stirred at 60° C. for 90 minutes, whereupon it was cooled to 20° C. at a rate of 1° C./min and stirred for 3 days. Following filtration, the solid cake was rinsed twice with the filtrate and once with heptane (220 mL) to provide C69 as a solid. Yield: 63.85g, 167.4mmol, 96%. HPLC purity: 99.4%. ¹ H NMR (600 MHz, DMSO-d ₆ ) δ 8.80 (d, J = 4.8 Hz, 2H), 7.90 (s, 1H),
7.27 (t, J = 4.8 Hz, 1H), [7.25 (br s) and 7.24 (br s), total 1H],
3.56 - 3.49 (m, 1H), 3.37 - 3.30 (m, 1H), 3.28 - 3.21 (m, 2H), 2.80 - 2.73 (m,
1H), 2.73 - 2.65 (m, 1H), 2.59 (s, 3H), 1.99 - 1.84 (m, 2H), 1.82 - 1.69 (m,
2H), [1.41 (s) and 1.39 (s), total 9H].

Obtaining Powder X-ray Diffraction (PXRD) Data for Crystalline C69 A sample of C69 (prepared as described in step 2 above) was submitted for powder X-ray diffraction (PXRD) analysis and found to be a crystalline material.

Powder X-ray diffraction analysis was performed using a Bruker AXS D8 Endeavor diffractometer equipped with a copper (Cu) radiation source. The divergence slit was set to 15 mm continuous illumination. Diffracted radiation was detected by a PSD-LynxEye detector with the detector PSD aperture set to 4.123 degrees. The X-ray tube voltage and amperage were set to 40 kV and 40 mA, respectively. In addition, an energy dispersive detector, nickel filter was used. Data was collected on a theta-theta goniometer at Cu wavelengths from 3.0 to 40.0 degrees 2 theta using a step width of 0.0100 degrees and a step time of 1.0 seconds. The anti-scatter screen was set at a fixed distance of 1.5 mm. Samples were prepared by placing them in a silicon low background sample holder and rotating at 15 revolutions per minute during collection. Data was collected using Bruker DIFFRAC Plus software and analysis was performed with EVA diffract plus software. PXRD data files were not processed prior to peak searching. Preliminary peak assignments were made using the peak search algorithm in the EVA software, with peaks selected as thresholded at 1. Adjustments were made manually to ensure validity; the output of the automatic assignment was visually verified and peak positions were adjusted to the peak maximum. Peaks with a relative intensity of 3% or greater were generally selected. Peaks that were not resolved or consistent with noise were typically not selected. Typical errors associated with peak positions from PXRD as stated in the USP are a maximum of +/- 0.2° 2-theta (USP-941).

One representative diffraction pattern was observed for the crystalline form of C69 and is provided in Figure 4. A list of the diffraction peaks, expressed in degrees 2θ and relative intensities, from the PXRD from a sample of crystalline C69 with a relative intensity of 3.0% or greater is provided below in Table X-C69.

In some embodiments, the present invention provides a compound that is tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate or a salt thereof. In some embodiments, the present invention provides a compound that is tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate. In some further embodiments, the present invention provides a crystalline form of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate. In some further embodiments, the crystalline form of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits a powder X-ray diffraction pattern including at least one characteristic peak in terms of 2θ, such as those listed in Table X-C69.

In some embodiments, the crystalline form of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern with at least two characteristic peaks in 2θ, such as those listed in Table X-C69. In some embodiments, the crystalline form of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern with at least three characteristic peaks in 2θ, such as those listed in Table X-C69. In some embodiments, the crystalline form of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern including at least 4 (e.g., 4, 5, 6, 7, 8, 9, or 10) characteristic peaks in 2θ such as those listed in Table X-C69. In some embodiments, the crystalline form of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-carboxylate exhibits an X-ray powder diffraction pattern substantially as shown in FIG. 4.

Step 3. Synthesis of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine] (P28, free base).
A solution of C69 (96% by mass; 50.0 g, 126 mmol) in water (100 mL) and 2-propanol (150 mL) was added over 10 min to an 80° C. mixture of water (150 mL) and concentrated sulfuric acid (14.5 mL, 272 mmol). After the reaction mixture was stirred at 80° C. for 4 h, it was cooled to 25° C. and then subjected to short path distillation at 120° C. and atmospheric pressure. Once the mixture was distilled to a volume of approximately 200 mL, the temperature was reduced to 50° C., activated carbon (Darco G-60; 10 g) was added, and stirring was continued at 50° C. for 1.5 h. The mixture was then cooled to 25° C. and filtered using a 10 μm filter. The filter cake was rinsed with water (100 mL) and the combined filtrate was diluted with 2-propanol (20 mL); the resulting mixture at pH 0.86 was basified to the point of turbidity, which was then clarified by adding 6 M aqueous sodium hydroxide (approximately 75 mL). The resulting pH was 9.32. The mixture was treated dropwise with additional 6 M aqueous sodium hydroxide (approximately 20 drops) to a pH of 9.6 to 9.7, at which point turbidity persisted. Stirring was continued for 45 minutes, whereupon additional 6 M aqueous sodium hydroxide (up to a total of approximately 80 mL, 480 mmol) was added and stirring was continued at 20° C. for 30 minutes. The mixture was then heated to 50° C. at a rate of 1° C./min, stirred for 1.5 hours, and cooled to 20° C. at a rate of 1° C./min. After stirring for 1.5 h, the mixture was filtered; the filter cake was rinsed with aqueous sodium hydroxide (1 M; 100 mL, 100 mmol) and dried overnight in vacuum at 50° C. to provide P28, free base. Yield: 30.87 g, 98.1% P28 by quantitative NMR, 108 mmol, 86%. ¹ H NMR (600 MHz, DMSO-d ₆ ) δ 8.79 (d, J = 4.8 Hz, 2H), 7.88 (s, 1H),
7.25 (t, J = 4.8 Hz, 1H), 7.01 (s, 1H), 2.99 (ddd, J = 11.0, 8.4, 6.4 Hz, 1H),
2.79 (ddd, J = 10.9, 8.6, 5.6 Hz, 1H), 2.75 - 2.68 (m, 3H), 2.61 (d, J = 11.3
Hz, 1H), 2.58 (s, 3H), 1.80 - 1.68 (m, 3H), 1.65 (ddd, J = 12.7, 8.6, 6.4 Hz,
1H).

Obtaining Powder X-ray Diffraction (PXRD) Data for Crystalline P28 A sample of P28 (prepared as described in step 3 above) was submitted for powder X-ray diffraction (PXRD) analysis and found to be a crystalline material.

Powder X-ray diffraction analysis was performed using a Bruker AXS D8 Endeavor diffractometer equipped with a copper (Cu) radiation source. The divergence slit was set to 15 mm continuous illumination. Diffracted radiation was detected by a PSD-LynxEye detector with the detector PSD aperture set at 4.123 degrees. The X-ray tube voltage and amperage were set to 40 kV and 40 mA, respectively. In addition, an energy dispersive detector, nickel filter was used. Data were collected on a theta-theta goniometer at Cu wavelengths from 3.0 to 40.0 degrees 2 theta using a step width of 0.0100 degrees and a step time of 1.0 seconds. The anti-scatter screen was set at a fixed distance of 1.5 mm. Samples were prepared by placing them in a silicon low background sample holder and rotating at 15 revolutions per minute during collection. Data was collected using Bruker DIFFRAC Plus software and analysis was performed with EVA diffract plus software. PXRD data files were not processed prior to peak searching. Preliminary peak assignments were made using the peak search algorithm in the EVA software, with peaks selected as thresholded at 1. Adjustments were made manually to ensure validity; the output of the automatic assignment was visually verified and peak positions were adjusted to the peak maximum. Peaks with a relative intensity of 3% or greater were generally selected. Peaks that were not resolved or consistent with noise were typically not selected. Typical errors associated with peak positions from PXRD as stated in the USP are a maximum of +/- 0.2° 2-theta (USP-941).

One representative diffraction pattern was observed for the crystalline form of P28 and is provided in Figure 5. A list of the diffraction peaks, expressed in degrees 2θ and relative intensities, from the PXRD from a sample of crystalline P28 with a relative intensity of 3.0% or greater is provided below in Table X-P28.

In some embodiments, the present invention provides a compound that is (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] or a salt thereof. In some embodiments, the present invention provides a compound that is (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]. In some further embodiments, the present invention provides a crystalline form of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]. In some further embodiments, the crystalline form of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] exhibits a powder X-ray diffraction pattern including at least one characteristic peak in 2θ, such as those listed in Table X-P28.

In some embodiments, the crystalline form of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] exhibits an X-ray powder diffraction pattern with at least two characteristic peaks in 2θ, such as those listed in Table X-P28. In some embodiments, the crystalline form of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] exhibits an X-ray powder diffraction pattern with at least three characteristic peaks in 2θ, such as those listed in Table X-P28. In some embodiments, the crystalline form of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] exhibits an X-ray powder diffraction pattern including at least 4 (e.g., 4, 5, 6, 7, 8, 9, or 10) characteristic peaks in 2θ such as those listed in Table X-P28. In some embodiments, the crystalline form of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine] exhibits an X-ray powder diffraction pattern substantially as shown in FIG. 5.

Step 4. Synthesis of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one (14).
A slurry of P7 (19.1 g, 95.9 mmol) in 2-methyltetrahydrofuran (200 mL) was treated with P28, free base (98.1% by mass, 25 g, 87.2 mmol), followed by N,N-diisopropylethylamine (19 mL, 110 mmol). 2,4,6-Tripropyl-1,3,5,2,4,6-trioxatriphosphinane 2,4,6-trioxide (50% solution by weight in ethyl acetate; 65 mL, 110 mmol) was added over 15 min at a rate to maintain the internal reaction temperature below 30° C. After stirring the reaction mixture for 100 min, aqueous sodium bicarbonate (1.14 M; 250 mL, 285 mmol) was added {CAUTION: gas evolution} and stirring was continued at 20° C. for 10 min. The resulting mixture was heated to 40° C., stirred for 30 minutes and again treated with aqueous sodium bicarbonate (1.14 M; 125 mL, 142 mmol). After stirring the mixture for 80 minutes, water (75 mL) was added and stirring continued for 10 minutes. The organic layer was subjected to distillation at 60° C. and 500 mbar until the mixture was reduced to 5 volumes. 2-Methyltetrahydrofuran (125 mL) was added, the temperature was adjusted to 45° C. to 50° C. and the mixture was filtered through diatomaceous earth. Additional 2-methyltetrahydrofuran (50 mL) was used to rinse the filter pad and the combined filtrate was distilled at 60° C. and 500 mbar to approximately 3 volumes. Heating was increased to 80° C. until the solids in the bottom of the reactor were released and then reduced to 50° C. The resulting material was treated with heptane (250 mL) at 50° C. over 15 minutes and stirred at 50° C. for 90 minutes. It was then cooled to 20° C. at a rate of 1° C./min and stirred for 3 days whereupon it was diluted to a volume of 600 mL by adding 10 mol % 2-methyltetrahydrofuran in heptane. Filtration provided a filter cake which was rinsed with heptane (75 mL) and dried overnight in vacuum at 50° C. to give (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]propan-1-one (14) as a solid. Yield: 29.63 g, 64.06 mmol, 73%. HPLC purity: 100%. LCMS m/z 463.3 [M+H] ⁺ . ¹ H NMR (600 MHz, DMSO-d ₆ )
δ [8.81 (d, J = 4.8 Hz) and 8.80 (d, J = 4.7 Hz), total 2H], [8.12 (s) and 8.10 (s), total 1H],
[7.90 (s) and 7.87 (s), total 1H], [7.33 (s) and 7.23 (s), total 1H],
7.30 - 7.26 (m, 1H), [6.75 (d, J = 4.8 Hz) and 6.69 (d, J = 4.8 Hz), sum 1H], [4.15 (q, J = 6.9 Hz) and 4.10 (q, J = 6.9 Hz), sum 1H], [3.83 (s) and 3.82
(s), total 3H], [3.78 - 3.71 (m),
3.61 - 3.49 (m), 3.47 - 3.41 (m), 3.42 (d, J = 11.2 Hz), 3.32 - 3.28 (m, estimated; partially obscured by water peak), and 3.25 (d, J =
10.4 Hz), total 4H], [2.80 - 2.65
(m) and 2.5 - 2.43 (m, estimated; partially obscured by solvent peak), total 2H], [2.59 (s) and 2.57 (s), total 3H], [2.03 - 1.94 (m) and 1.87 - 1.72 (m), total 3H],
1.67 - 1.60 (m, 1H), 1.36 - 1.30 (m, 3H).

Acquisition of Powder X-ray Diffraction (PXRD) Data for Crystalline Example 14 A sample of Example 14 (prepared essentially as described in this alternative synthetic method, except that in Step 4, the filtration portion through diatomaceous earth was replaced by treatment of the mixture with SiliaMetS® thiol, followed by filtration. SiliaMetS® thiol: Silicycle Inc., product number R51030B) was ground and sent for powder X-ray diffraction (PXRD) analysis and found to be a crystalline material (designated as Form I).

Powder X-ray diffraction analysis was performed using a Bruker AXS D8 Endeavor diffractometer equipped with a copper (Cu) radiation source. The divergence slit was set to 15 mm continuous illumination. Diffracted radiation was detected by a PSD-LynxEye detector with the detector PSD aperture set to 4.123 degrees. The X-ray tube voltage and amperage were set to 40 kV and 40 mA, respectively. In addition, an energy dispersive detector, nickel filter was used. Data were collected on a theta-theta goniometer at Cu wavelengths from 3.0 to 40.0 degrees 2 theta using a step width of 0.0100 degrees and a step time of 1.0 seconds. The anti-scatter screen was set at a fixed distance of 1.5 mm. Samples were prepared by placing them in a silicon low background sample holder and rotating at 15 revolutions per minute during collection. Data was collected using Bruker DIFFRAC Plus software and analysis was performed with EVA diffract plus software. PXRD data files were not processed prior to peak searching. Preliminary peak assignments were made using the peak search algorithm in the EVA software, with peaks selected as thresholded at 1. Adjustments were made manually to ensure validity; the output of the automatic assignment was visually verified and peak positions were adjusted to the peak maximum. Peaks with a relative intensity of 3% or greater were generally selected. Peaks that were not resolved or consistent with noise were typically not selected. Typical errors associated with peak positions from PXRD as stated in the USP are a maximum of +/- 0.2° 2-theta (USP-941).

One representative diffraction pattern was observed for Form I of Example 14 and is provided in Figure 1. A list of PXRD diffraction peaks, expressed in degrees 2θ and relative intensities, with a relative intensity of 3.0% or greater from a sample of crystalline Example 14 is provided in Table X1 below.

In some embodiments, the present invention provides a crystalline form of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one. In some further embodiments, the present invention provides a crystalline form of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one designated as Form I.

In some embodiments, Form I (of Example 14) exhibits a powder X-ray diffraction pattern comprising at least one characteristic peak at 2θ selected from those at 8.7±0.2°; 11.1±0.2°; and 13.3±0.2°. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least one characteristic peak at 2θ at 8.7±0.2°. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least one characteristic peak at 2θ at 11.1±0.2°. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least one characteristic peak at 2θ at 13.3±0.2°. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks at 2θ selected from those at 8.7±0.2°; 11.1±0.2°; and 13.3±0.2°. In some embodiments, Form I exhibits an X-ray powder diffraction pattern that includes two characteristic peaks at 2θ selected from those at 8.7±0.2°; and those at 11.1±0.2°. In some embodiments, Form I exhibits an X-ray powder diffraction pattern that includes at least three characteristic peaks at 2θ selected from those at 8.7±0.2°; 11.1±0.2°; and those at 13.3±0.2°.

In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks at 2θ selected from those at 8.7±0.2°; 11.1±0.2°; and 26.0±0.2°. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks at 2θ selected from those at 8.7±0.2°; and 26.0±0.2°. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least two characteristic peaks at 2θ selected from those at 11.1±0.2°; and 26.0±0.2°. In some embodiments, Form I exhibits a powder X-ray diffraction pattern comprising at least three characteristic peaks at 2θ selected from those at 8.7±0.2°; 11.1±0.2°; and 26.0±0.2°.

In some embodiments, Form I exhibits a powder X-ray diffraction pattern with at least two characteristic peaks in 2θ, such as those listed in Table X1. In some embodiments, Form I exhibits a powder X-ray diffraction pattern with at least three characteristic peaks in 2θ, such as those listed in Table X1. In some embodiments, Form I exhibits a powder X-ray diffraction pattern with at least four (e.g., 4, 5, 6, 7, 8, 9, or 10) characteristic peaks in 2θ, such as those listed in Table X1.

In some embodiments, Form I exhibits a powder X-ray diffraction pattern substantially as shown in FIG. 1.

(Example 15)
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]propan-1-one (15)

ステップ１． ｔｅｒｔ－ブチル（２Ｓ）－７－メチル－６－（ピリミジン－２－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－カルボキシレート（Ｃ６９）の合成。
１，４－ジオキサン（１２ｍＬ）中の４，４，４’，４’，５，５，５’，５’－オクタメチル－２，２’－ビ－１，３，２－ジオキサボロラン（２４９ｍｇ、０．９８１ｍｍｏｌ）、Ｐ２３（２５０ｍｇ、０．６５４ｍｍｏｌ）、ビス（ジフェニルホスフィノ）フェロセン］ジクロロパラジウム（ＩＩ）、ジクロロメタン錯体（２６．７ｍｇ、３２．７μｍｏｌ）、およびオーブン乾燥酢酸カリウム（２５７ｍｇ、２．６２ｍｍｏｌ）の混合物を、これに窒素を５分間にわたって吹き込むことにより脱気した。反応バイアルを密封した後に、これをアルミニウムブロック内で２時間にわたって１００℃に加熱し、次いで、室温に冷却させた。次いで、２－ブロモピリミジン（１０９ｍｇ、０．６８６ｍｍｏｌ）、ジクロロビス（トリフェニルホスフィン）パラジウム（ＩＩ）（２２．９ｍｇ、３２．６μｍｏｌ）、および炭酸ナトリウム脱気水溶液（２．０Ｍ；０．８１７ｍＬ、１．６３ｍｍｏｌ）を反応混合物に添加し、これを９０℃で１８時間にわたって加熱した。室温に冷却した後に、反応混合物を酢酸エチルで希釈し、珪藻土を通して濾過した。濾液の有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、真空で濃縮し；シリカゲル上でのクロマトグラフィー（溶離液：ヘプタン中２０％、次いで、５０％、次いで、１００％酢酸エチル）は、Ｃ６９を白色の固体として提供した。収量：５５．０ｍｇ、０．１４４ｍｍｏｌ、２２％。LCMS m/z 382.3 [M+H]⁺. ¹H NMR (400 MHz, クロロホルム-d) δ 8.76 (d, J = 4.8 Hz, 2H), 7.92 (s, 1H), 7.11 (t, J = 4.9 Hz, 1H),
5.37 (br s, 1H), 3.62 - 3.26 (m, 4H), 2.88 - 2.76 (m, 2H), 2.68 (s, 3H), 2.06 -
1.77 (m, 4H), 1.46 (br s, 9H).

Step 1. Synthesis of tert-butyl (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C69).
A mixture of 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi-1,3,2-dioxaborolane (249 mg, 0.981 mmol), P23 (250 mg, 0.654 mmol), bis(diphenylphosphino)ferrocene]dichloropalladium(II), dichloromethane complex (26.7 mg, 32.7 μmol), and oven-dried potassium acetate (257 mg, 2.62 mmol) in 1,4-dioxane (12 mL) was degassed by bubbling nitrogen through it for 5 min. After sealing the reaction vial, it was heated to 100° C. in an aluminum block for 2 h and then allowed to cool to room temperature. 2-Bromopyrimidine (109 mg, 0.686 mmol), dichlorobis(triphenylphosphine)palladium(II) (22.9 mg, 32.6 μmol), and degassed aqueous sodium carbonate (2.0 M; 0.817 mL, 1.63 mmol) were then added to the reaction mixture, which was heated at 90° C. for 18 h. After cooling to room temperature, the reaction mixture was diluted with ethyl acetate and filtered through diatomaceous earth. The organic layer of the filtrate was washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated in vacuo; chromatography on silica gel (eluent: 20%, then 50%, then 100% ethyl acetate in heptane) provided C69 as a white solid. Yield: 55.0 mg, 0.144 mmol, 22%. LCMS m/z 382.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ 8.76 (d, J = 4.8 Hz, 2H), 7.92 (s, 1H), 7.11 (t, J = 4.9 Hz, 1H),
5.37 (br s, 1H), 3.62 - 3.26 (m, 4H), 2.88 - 2.76 (m, 2H), 2.68 (s, 3H), 2.06 -
1.77 (m, 4H), 1.46 (br s, 9H).

Step 2. Synthesis of (2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (P28).
A solution of hydrogen chloride in 1,4-dioxane (4.0 M; 0.144 mL, 0.576 mmol) was added to a solution of C69 (55.0 mg, 0.144 mmol) in a mixture of dichloromethane (0.5 mL) and 1,1,1,3,3,3-hexafluoropropan-2-ol (0.5 mL) and the reaction mixture was stirred at room temperature for 2 h, whereupon LCMS analysis indicated conversion to P28: LCMS m/z 282.3 [M+H] ⁺ . The reaction mixture was concentrated in vacuo to provide P28 as a yellow gum. Yield: 50 mg, 0.141 mmol, 98%.

Step 3. Synthesis of (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one (15).
Pyridinium trifluoromethanesulfonate (35.6 mg, 0.155 mmol) was added to a solution of P2 (16.7 mg, 77.4 μmol) in acetonitrile (1 mL). The resulting solution was treated with 1,1'-carbonyldiimidazole (12.6 mg, 77.7 μmol) in one portion and the reaction mixture was stirred at room temperature for 45 min. A solution of P28 (25.0 mg, 70.6 μmol) in acetonitrile (2 mL) was then added in one portion and stirring was continued at room temperature for 3 h whereupon the reaction mixture was diluted with aqueous ammonium chloride and extracted three times with ethyl acetate. The combined organic layers were dried over magnesium sulfate, filtered and concentrated in vacuo. Purification by silica gel chromatography (gradient: 20% to 100% ethyl acetate in heptane) followed by supercritical fluid chromatography (column: Chiral Technologies Chiralcel OJ-H, 21×250 mm, 5 μm; mobile phase 9:1 carbon dioxide/(methanol containing 0.2% ammonium hydroxide); flow rate: 75 mL/min; back pressure: 150 bar) gave (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]propan-1-one (15). Yield: 5.9 mg, 12 μmol, 17%. LCMS m/z 479.3 (chlorine isotope pattern observed) [M+H] ⁺ . ¹ H NMR (400 MHz, methanol-d ₄ ) δ [8.81 (d, J = 5.0 Hz) and 8.81 (d, J = 5.0 Hz), total 2H], [8.15 (s) and 8.14 (s), total 1H],
[7.85 (s) and 7.81 (s), total 1H], [7.31 (t, J = 4.9 Hz) and 7.30 (t, J = 4.9 Hz), total 1H], [6.81 (s) and 6.76 (s), total 1H],
[4.32 (q, J = 7.0 Hz) and 4.23
(q, J = 6.9 Hz), total 1H], 3.91
(br s, 3H), [3.9 - 3.83 (m) and 3.76
- 3.52 (m), total 3H], [3.49 (d, J
= 12.2 Hz) and 3.38 - 3.3 (m, estimated; partially obscured by solvent peak), total 1H], [2.93 -
2.72 (m) and 2.56 - 2.47 (m), total 2H], [2.57 (s) and 2.56 (s), total 3H],
[2.16 - 2.07 (m) and 2.05 - 1.84
(m), total 3H], 1.80 - 1.73 (m,
1H), [1.43 (d, J = 6.9 Hz) and 1.42
(d, J = 6.9 Hz), total 3H].

Alternative Step 3. Synthesis of (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidin]-1′-yl]propan-1-one (15) for X-ray crystal structure determination.
Pyridinium trifluoromethanesulfonate (112 mg, 0.487 mmol) was added to a solution of P2 (material from Preparations P2 and P3; 50.0 mg, 0.232 mmol) in acetonitrile (3 mL). The resulting solution was treated with 1,1'-carbonyldiimidazole (39.5 mg, 0.244 mmol) in one portion, and the reaction mixture was stirred at room temperature for 30 min. A solution of P28 (82.1 mg, 0.232 mmol) was then added in one portion; after 1 h, one drop of water was added to provide a solution. After stirring the reaction mixture at room temperature for 2 h, LCMS analysis indicated conversion to 15: LCMS m/z 479.3 (chlorine isotope pattern observed) [M+H] ⁺ . The reaction mixture was then partitioned between ethyl acetate and aqueous sodium bicarbonate; the organic layer was washed successively with water and saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (Gradient: 0% to 10% methanol in dichloromethane) gave (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one (15) as a solid. Yield: 102 mg, 0.213 mmol, 92%.

This material was dissolved in a mixture of 10% ethyl acetate in heptane (approximately 12 mL) by application of heat. The solution was allowed to cool and then left partially sealed at room temperature for 3 days. The resulting solid provided crystals for X-ray structure determination (see below).

Single Crystal X-Ray Structure Determination of 15 Single Crystal X-Ray Analysis Data collection was carried out at room temperature on a Bruker D8 Venture diffractometer. Data collection consisted of omega and phi scans. The crystalline materials used, of micro-size and multi-domain type, produced theta diffraction over the 0.90-0.94 Å resolution region.

The structure was solved with intrinsic phases using the SHELX software suite in the triclinic class space group P1. The structure was then refined by full-matrix least-squares fitting. All non-hydrogen atoms were located and refined using anisotropic displacement parameters. The hydrogen atoms located on the nitrogens were located from Fourier difference distributions and refined at constrained distances. The remaining hydrogen atoms were placed in calculated positions and mounted on their carrier atoms. The final refinement included isotropic displacement parameters on all hydrogen atoms.

Analysis of the absolute structure using the likelihood method (Hooft, 2008) was performed using PLATON (Spek). The results indicate that the absolute structure has been correctly assigned. The method calculates a 100.0% probability that the structure has been correctly assigned. The Hooft parameter is reported as 0.04 with an esd (estimated standard deviation) of (3) and the Parson parameter is reported as 0.05 with an esd of (3).

The final R-index was 6.9%. The final difference Fourier revealed no missing or misplaced electron density.

Relevant crystallographic, data collection, and refinement information is summarized in Table E. Atomic coordinates, bond distances, and displacement parameters are listed in Tables F-H.

Software and References See the list provided above for the determination of 14 single crystal X-ray structures.

Therefore, the absolute stereochemistry of compound Example 15 was determined by single crystal X-ray crystallography. Figure 2 is the resulting single crystal X-ray structure (ORTEP drawing) of crystalline compound Example 15: (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one.

In some embodiments, the present invention provides a crystalline form of (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one. In some further embodiments, the crystalline form of (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one is as described (or prepared) in Example 15.

(Examples 16 and 17)
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-1 (16) and (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one, DIAST-2 (17)

ステップ１． ｔｅｒｔ－ブチル７－メチル－６－（１－メチル－１Ｈ－ピラゾール－４－イル）－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－カルボキシレート（Ｃ８０）の合成。
１，４－ジオキサン（３ｍＬ）中のＰ２２（１００ｍｇ、０．２６２ｍｍｏｌ）、１－メチル－４－（４，４，５，５－テトラメチル－１，３，２－ジオキサボロラン－２－イル）－１Ｈ－ピラゾール（１０９ｍｇ、０．５２４ｍｍｏｌ）、ビス（ジフェニルホスフィノ）フェロセン］ジクロロパラジウム（ＩＩ）、ジクロロメタン錯体（１０．７ｍｇ、１３．１μｍｏｌ）、および炭酸ナトリウム水溶液（２．０Ｍ；０．３３ｍＬ、０．６６ｍｍｏｌ）の混合物を窒素でスパージした。反応バイアルを密封し、８０℃に終夜加熱し、その後すぐに、ＬＣＭＳ分析は、Ｃ８０への変換を指し示した：LCMS m/z 384.3 [M+H]⁺.反応混合物を室温に冷却した後に、これを酢酸エチルと水との間で分配し、水層を酢酸エチルで２回抽出した。合わせた有機層を飽和塩化ナトリウム水溶液で洗浄し、硫酸マグネシウム上で乾燥させ、濾過し、シリカゲルクロマトグラフィー（勾配：ヘプタン中０％から１００％酢酸エチル）により精製して、Ｃ８０を固体として得た。収量：９３ｍｇ、０．２４ｍｍｏｌ、９２％。¹H NMR (400 MHz, クロロホルム-d), 特徴的ピーク: δ 7.52 (s, 1H),
7.36 (s, 1H), 7.19 (s, 1H), 3.95 (s, 3H), 3.62 - 3.26 (m, 4H), 2.85 - 2.68 (m,
2H), 2.41 (s, 3H), [1.47 (s)および1.45
(s), 合計9H].

Step 1. Synthesis of tert-butyl 7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C80).
A mixture of P22 (100 mg, 0.262 mmol), 1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (109 mg, 0.524 mmol), bis(diphenylphosphino)ferrocene]dichloropalladium(II), dichloromethane complex (10.7 mg, 13.1 μmol), and aqueous sodium carbonate (2.0 M; 0.33 mL, 0.66 mmol) in 1,4-dioxane (3 mL) was sparged with nitrogen. The reaction vial was sealed and heated to 80° C. overnight, whereupon LCMS analysis indicated conversion to C80: LCMS m/z 384.3 [M+H] ⁺ . After the reaction mixture was cooled to room temperature, it was partitioned between ethyl acetate and water, and the aqueous layer was extracted twice with ethyl acetate. The combined organic layers were washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and purified by silica gel chromatography (gradient: 0% to 100% ethyl acetate in heptane) to give C80 as a solid. Yield: 93 mg, 0.24 mmol, 92%. ¹ H NMR (400 MHz, chloroform-d), characteristic peak: δ 7.52 (s, 1H),
7.36 (s, 1H), 7.19 (s, 1H), 3.95 (s, 3H), 3.62 - 3.26 (m, 4H), 2.85 - 2.68 (m,
2H), 2.41 (s, 3H), [1.47 (s) and 1.45
(s), 9H in total].

Step 2. Synthesis of 7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], bis(trifluoroacetate) salt (C81).
Trifluoroacetic acid (1.0 mL) was added to a solution of C80 (92 mg, 0.24 mmol) in dichloromethane (3 mL) and the reaction mixture was stirred at room temperature for 2 h. It was then concentrated in vacuo and the residue was co-evaporated twice with ethyl acetate/heptane to give C81 as a gum. Yield: 128 mg, estimated quantitative. LCMS m/z 284.2 [M+H] ⁺ .

Step 3. Synthesis of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]propan-1-one, DIAST-1 (16) and (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]propan-1-one, DIAST-2 (17).
To a solution of P7 (23.9 mg, 0.120 mmol) in acetonitrile (1 mL) was added pyridinium trifluoromethanesulfonate (57.8 mg, 0.252 mmol) followed by 1,1′-carbonyldiimidazole (20.4 mg, 0.126 mmol). After the reaction mixture was stirred at room temperature for 45 min, a solution of C81 (34.0 mg, 66.5 μmol) in acetonitrile was added and stirring was continued at room temperature overnight. LCMS analysis at this point indicated the presence of the coupling product: LCMS m/z 465.3 [M+H] ⁺ .The reaction mixture was then partitioned between dichloromethane and dilute aqueous ammonium chloride; the organic layer was washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered and concentrated in vacuo. Purification by silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) was followed by supercritical fluid chromatography (column: Phenomenex Lux Cellulose-1, 21×250 mm, 5 μm; mobile phase: 4:1 carbon dioxide/(methanol containing 0.2% ammonium hydroxide); flow rate: 75 mL/min; back pressure: 120 bar). The first eluting diastereomer was identified as 16{(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1 The first eluting diastereomer was designated as 17{(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1} and the second eluting diastereomer was designated as 17{(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2}.
16 - Yield: 7.3 mg, 15.7 μmol, 24%. LCMS m/z 465.5 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol- _{d 4} ) δ [7.99 (d, J = 1.6 Hz) and 7.97 (d, J = 1.7 Hz), total 1H], [7.67 (s) and 7.67 (s), total 1H],
7.55 - 7.52 (m, 1H), [7.29 (s) and 7.27 (s), total 1H],
[6.78 (d, J = 4.9 Hz) and 6.72
(d, J = 4.9 Hz), total 1H], [4.27
(q, J = 6.9 Hz) and 4.18 (q, J =
6.9 Hz), 1H total], [3.92 (s) and 3.92 (s), 3H total], [3.88 (s) and 3.88
(s), total 3H], [3.88 - 3.83 (m),
3.75 - 3.56 (m), and 3.54 (d, component of the AB quadruplet, J = 12.1 Hz), total 3H], [3.45 (d, component of the AB quadruplet, J = 12.3 Hz) and 3.36
(d, J = 10.6 Hz), total 1H], [2.89
- 2.70 (m) and 2.59 - 2.49 (m), total 2H], [2.37 (s) and 2.34 (s), total 3H],
2.13 - 1.81 (m, 3H), 1.80 - 1.71 (m, 1H), 1.47 - 1.40 (m, 3H).Retention time: 3.71 min. [Analytical conditions: Column: Phenomenex Lux Cellulose-1, 4.6 x 100 mm, 5 μm; Mobile phase: 3:1 carbon dioxide/(methanol containing 0.2% ammonium hydroxide); Flow rate: 1.5 mL/min; Back pressure: 200 bar].
17 - Yield: 6.2 mg, 13.3 μmol, 20%. LCMS m/z 466.6 [M+H] ⁺ . Retention time: 4.64 min (same analytical conditions as used for 16).

(Example 18)
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[(4,6- ² H ₂ )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl}propan-1-one (18).

ステップ１． （４，６－^２Ｈ_２）ピリミジン－２－アミン（Ｃ８２）の合成。
メタノール－ｄ_４（１０ｍＬ）中の４，６－ジクロロピリミジン－２－アミン（５００ｍｇ、３．０５ｍｍｏｌ）の溶液に、炭素上のパラジウム（１００ｍｇ）およびトリエチルアミン（１．３ｍＬ、９．３ｍｍｏｌ）を添加した。反応混合物を重水素ガス下で６時間にわたって２０℃で撹拌し、その後すぐに、これを濾過して、触媒を除去した。収集された触媒をメタノール（２×１０ｍＬ）で洗浄した後に、合わせた濾液を真空で濃縮し、次いで、シリカゲルクロマトグラフィー（勾配：石油エーテル中０％から８０％酢酸エチル）に掛けて、Ｃ８２を白色の固体として得た。収量：２１０ｍｇ、２．１６ｍｍｏｌ、７１％。LCMS m/z 98.2 [M+H]⁺. ¹H NMR (400 MHz, DMSO-d₆)
δ 6.60 - 6.52 (br s, 2H), 6.53
(s, 1H).

Step 1. Synthesis of (4,6- ² H ₂ )pyrimidin-2-amine (C82).
To a solution of 4,6-dichloropyrimidin-2-amine (500 mg, 3.05 mmol) in methanol-d ₄ (10 mL) was added palladium on carbon (100 mg) and triethylamine (1.3 mL, 9.3 mmol). The reaction mixture was stirred under deuterium gas for 6 h at 20° C. whereupon it was filtered to remove the catalyst. After washing the collected catalyst with methanol (2×10 mL), the combined filtrate was concentrated in vacuo and then subjected to silica gel chromatography (gradient: 0% to 80% ethyl acetate in petroleum ether) to give C82 as a white solid. Yield: 210 mg, 2.16 mmol, 71%. LCMS m/z 98.2 [M+H] ⁺ . ¹ H NMR (400 MHz, DMSO-d ₆ )
δ 6.60 - 6.52 (br s, 2H), 6.53
(s, 1H).

Step 2. Synthesis of 2-chloro(4,6- ² H ₂ )pyrimidine (C83).
Intermediate C82 (210 mg, 2.16 mmol) was added in portions to concentrated hydrochloric acid (0.7 mL) at 0° C., and the resulting mixture was stirred until homogeneous. The solution was then cooled to about −15° C., whereupon a cold solution of sodium nitrite (298 mg, 4.32 mmol) in water (0.5 mL) was added dropwise over 1 h, while maintaining the reaction temperature between −15° C. and −10° C. The reaction mixture was stirred for 1 h, allowing the temperature to rise to about −5° C.; it was then carefully neutralized to a pH of 7 by adding 30% aqueous sodium hydroxide, while maintaining the reaction temperature below 0° C. The resulting mixture was extracted with diethyl ether (3×5 mL), and the combined organic layers were washed with saturated aqueous sodium chloride (10 mL), dried over sodium sulfate, filtered, and concentrated in vacuo to provide C83 as a white solid. Yield: 115 mg, 0.987 mmol, 46%. ^1H NMR (400 MHz, DMSO- _d6 ) δ 7.60 (s, 1H).

Step 3. Synthesis of tert-butyl (2S)-7-methyl-6-[(4,6- ² H ₂ )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-carboxylate (C84).
A mixture of C83 (40 mg, 0.34 mmol), P27 (119 mg, 0.34 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos; 5.6 mg, 14 μmol), chloro(2-dicyclohexylphosphino-2',6'-dimethoxy-1,1'-biphenyl)[2-(2'-amino-1,1'-biphenyl)]palladium(II) (SPhos Pd G2; 4.9 mg, 6.8 μmol), and aqueous lithium hydroxide (2 M; 0.4 mL, 0.8 mmol) in tetrahydrofuran (5 mL) was purged with nitrogen for 3 min whereupon the reaction mixture was stirred at 60° C. for 4 h. It was then concentrated in vacuo; the residue was purified using chromatography on silica gel (gradient: 0% to 50% ethyl acetate in petroleum ether) to provide C84 as a yellow solid. Yield: 116 mg, 0.302 mmol, 89%. LCMS m/z 384.3 [M+H] ⁺ . ¹ H NMR (400 MHz, chloroform-d) δ [8.04 (s) and 8.01
(s), total 1H], 7.14 (s, 1H), 3.67
- 3.30 (m, 4H), 2.92 - 2.76 (m, 2H), [2.74 (s) and 2.73 (s), total 3H],
2.12 - 1.79 (m, 4H), [1.47 (s) and 1.46 (s), total 9H].

Step 4. Synthesis of (2S)-7-methyl-6-[(4,6- ² H ₂ )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine], dihydrochloride (C85).
A solution of hydrogen chloride in 1,4-dioxane (4 M; 3 mL) was added to a solution of C84 (116 mg, 0.302 mmol) in dichloromethane (3 mL) and the reaction mixture was stirred at 20° C. for 2 h. Concentration in vacuo afforded C85 as a yellow solid. Yield: 108 mg, 0.303 mmol, quantitative. LCMS m/z 284.2 [M+H] ⁺ . ¹ H NMR (400 MHz, DMSO-d ₆ )
δ 10.09 - 9.93 (br s, 1H), 9.82
- 9.67 (br s, 1H), 9.01 (s, 1H), 8.45 (s, 1H), 7.50 (s, 1H), 3.50 - 3.34 (m,
2H), 3.34 - 3.27 (m, 2H), 3.01 - 2.84 (m, 2H), 2.82 (s, 3H), 2.26 - 2.07 (m,
3H), 1.99 - 1.87 (m, 1H).

Step 5. Synthesis of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[(4,6- ² H ₂ )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidin]-1′-yl}propan-1-one (18).
A solution of C85 (80 mg, 0.22 mmol), P7 (45 mg, 0.23 mmol), fluoro-N,N,N',N'-bis(tetramethylene)formamidinium hexafluorophosphate (BTFFH; 85 mg, 0.27 mmol), and pyridine (71 mg, 0.890 mmol) in dichloromethane (10 mL) was stirred for 16 h at 25° C. After the reaction mixture was poured into aqueous sodium bicarbonate (10 mL), it was extracted with ethyl acetate (2×20 mL); the combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (Gradient: 0% to 10% methanol in dichloromethane) afforded (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[(4,6- ² H ₂ )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl}propan-1-one (18) as a white solid. Yield: 27 mg, 58 μmol, 26%. LCMS m/z 465.3 [M+H] ⁺ . ¹ H NMR (400 MHz, methanol- _{d 4} ) δ [8.00 (d, J = 1.7 Hz) and 7.98 (d, J = 1.7 Hz), total 1H], [7.85 (s) and 7.82 (s), total 1H],
[7.31 (s) and 7.30 (s), sum 1H], [6.78 (d, J = 4.9 Hz) and 6.73 (d, J = 4.9 Hz), sum 1H], [4.28 (q, J = 6.9 Hz) and 4.20 (q, J = 6.9 Hz), sum 1H], [3.93 - 3.85 (m), 3.77 - 3.67 (m),
3.67 - 3.57 (m), 3.53 (AB quartet, J _AB
= 12.2 Hz, Δν _AB = 35.5 Hz), and 3.39
(d, J = 10.6 Hz), total 4H], [3.89
(s) and 3.88 (s), total 3H], [2.95 - 2.75 (m) and 2.64 - 2.55 (m), total 2H], [2.58 (s) and 2.55
(s), total 3H], [2.16 - 2.06 (m) and 2.05 - 1.85 (m), total 3H], 1.84 - 1.75 (m, 1H), [1.45 (d, J = 6.9 Hz) and 1.44 (d, J = 6.9 Hz), total 3H].

(Examples 19 and 20)
2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]ethan-1-one, ENT-1 (19) and 2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]ethan-1-one, ENT-2 (20)

ステップ１． １－（１－ベンジル－７－メチル－３，４－ジヒドロ－１Ｈ－スピロ［１，８－ナフチリジン－２，３’－ピロリジン］－１’－イル）－２－（４－フルオロフェニル）エタン－１－オン（Ｃ８６）の合成。
トリフルオロ酢酸（３１９ｍｇ、２．８０ｍｍｏｌ）を、ジクロロメタン（４ｍＬ）中のＰ３０（１１０．０ｍｇ、０．２８０ｍｍｏｌ）の溶液に添加し、反応混合物を室温で２時間にわたって撹拌した。次いで、これを真空で濃縮し、酢酸エチルと数回共蒸発させ、ジクロロメタン（４ｍＬ）に溶解した。得られた溶液をトリエチルアミン（８４．９ｍｇ、０．８３９ｍｍｏｌ）、Ｏ－（７－アザベンゾトリアゾール－１－イル）－Ｎ，Ｎ，Ｎ’，Ｎ’－テトラメチルウロニウムヘキサフルオロホスフェート（ＨＡＴＵ；１１７ｍｇ、０．３０８ｍｍｏｌ）、および（４－フルオロフェニル）酢酸（４３．１ｍｇ、０．２８０ｍｍｏｌ）で処理し、室温で終夜撹拌した。真空での溶媒の除去後に、残渣を、シリカゲルクロマトグラフィー（勾配：ジクロロメタン中０％から１０％メタノール）を使用して精製して、Ｃ８６を薄黄褐色の固体として得た。収量：１２０ｍｇ、０．２７９ｍｍｏｌ、定量的。¹H NMR (400 MHz, クロロホルム-d) δ [7.31 - 7.13 (m), 7.13 - 7.06 (m),および7.05 - 6.91 (m), 合計10H],
6.44 - 6.38 (m, 1H), 5.11 - 4.97 (m, 1H), [4.88 (d, AB四重線の成分, J = 16.8 Hz)および4.77
(d, AB四重線の成分, J = 16.7 Hz), 合計1H], [3.71 - 3.60 (m), 3.59 - 3.37 (m),および3.33 - 3.24 (m), 合計6H], [2.83 - 2.69 (m)および2.62 - 2.51 (m), 合計2H],
2.35 - 2.17 (m, 1H), [2.24 (s)および2.23 (s), 合計3H],
2.01 - 1.68 (m, 3H).

Step 1. Synthesis of 1-(1-benzyl-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl)-2-(4-fluorophenyl)ethan-1-one (C86).
Trifluoroacetic acid (319 mg, 2.80 mmol) was added to a solution of P30 (110.0 mg, 0.280 mmol) in dichloromethane (4 mL) and the reaction mixture was stirred at room temperature for 2 hours. It was then concentrated in vacuo, coevaporated with ethyl acetate several times, and dissolved in dichloromethane (4 mL). The resulting solution was treated with triethylamine (84.9 mg, 0.839 mmol), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU; 117 mg, 0.308 mmol), and (4-fluorophenyl)acetic acid (43.1 mg, 0.280 mmol) and stirred at room temperature overnight. After removal of the solvent in vacuo, the residue was purified using silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) to give C86 as a light tan solid. Yield: 120 mg, 0.279 mmol, quantitative. ¹ H NMR (400 MHz, chloroform-d) δ [7.31 - 7.13 (m), 7.13 - 7.06 (m), and 7.05 - 6.91 (m), total 10H],
6.44 - 6.38 (m, 1H), 5.11 - 4.97 (m, 1H), [4.88 (d, component of the AB quartet, J = 16.8 Hz) and 4.77
(d, component of the AB quadruplet, J = 16.7 Hz), total 1H], [3.71 - 3.60 (m), 3.59 - 3.37 (m), and 3.33 - 3.24 (m), total 6H], [2.83 - 2.69 (m) and 2.62 - 2.51 (m), total 2H],
2.35 - 2.17 (m, 1H), [2.24 (s) and 2.23 (s), total 3H],
2.01 - 1.68 (m, 3H).

Step 2. Synthesis of 1-(1-benzyl-6-bromo-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl)-2-(4-fluorophenyl)ethan-1-one (C87).
1,3-Dibromo-5,5-dimethylimidazolidine-2,4-dione (47.9 mg, 0.168 mmol) was added in portions to a 0° C. solution of C86 (120 mg, 0.279 mmol) in dichloromethane (5 mL). The reaction mixture was allowed to warm to room temperature; after 30 min, C87 was observed by LCMS analysis: LCMS m/z 508.3 (bromine isotope pattern observed) [M+H] ^{+ .} After 1 h, the reaction mixture was concentrated in vacuo and chromatographed on silica gel (gradient: 0% to 100% ethyl acetate in heptane) to provide C87. Yield: 65.0 mg, 0.128 mmol, 46%. ^1H NMR (400 MHz, chloroform-d) δ [7.35 - 7.17 (m), 7.16 - 7.06 (m), and 7.05 - 6.91 (m), total 10H],
[4.98 (d, AB quartet component, J = 16.7
Hz) and 4.98 (d, component of the AB quartet, J = 16.8 Hz), total 1H], [4.80 (d, component of the AB quartet, J = 16.8 Hz) and 4.72
(d, component of the AB quadruplet, J = 16.7 Hz), total 1H], [3.72 - 3.62 (m), 3.58 - 3.43 (m), and 3.33 - 3.24 (m), total 6H], [2.85 - 2.69 (m) and 2.62 - 2.48 (m), total 2H],
2.38 - 2.15 (m, 1H), [2.34 (s) and 2.32 (s), total 3H],
2.01 - 1.70 (m, 3H).

Step 3. Synthesis of 1-[1-benzyl-7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]-2-(4-fluorophenyl)ethan-1-one (C88).
A reaction vial was charged with C87 (65.0 mg, 0.128 mmol), 1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (33.1 mg, 0.159 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II), dichloromethane complex (5.20 mg, 6.37 μmol), aqueous sodium carbonate (2.0 M; 0.127 mL, 0.254 mmol), and 1,4-dioxane (3 mL). The vial was purged with nitrogen before being sealed and heated at 90° C. overnight, whereupon LCMS analysis indicated conversion to C88: LCMS m/z 510.4 [M+H] ⁺ . The reaction mixture was then cooled to room temperature and partitioned between ethyl acetate and aqueous ammonium chloride. The aqueous layer was extracted twice with ethyl acetate, and the combined organic layers were washed with saturated aqueous sodium chloride, dried over magnesium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient: 0% to 10% methanol in dichloromethane) provided C88 as a solid. Yield: 65.0 mg, 0.128 mmol, quantitative.

Step 4. Synthesis of 2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]ethan-1-one, ENT-1 (19) and 2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3′-pyrrolidine]-1′-yl]ethan-1-one, ENT-2 (20).
A solution of boron tribromide in dichloromethane (1.0 M; 0.765 mL, 0.765 mmol) was added to a −78° C. solution of C88 (65.0 mg, 0.128 mmol) in dichloromethane (3 mL), whereupon the reaction mixture was allowed to warm to room temperature and stirred for 15 h. It was then treated with methanol (0.5 mL) and concentrated in vacuo. Separation of the constituent enantiomers was performed using supercritical fluid chromatography [Column: Chiral Technologies Chiralpak AS-H, 21×250 mm, 5 μm; Mobile phase: 83:7 carbon dioxide/(methanol containing 0.2% ammonium hydroxide); Flow rate: 75 mL/min; Back pressure: 200 bar]. The first eluting diastereomer was designated as 19 {2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]ethan-1-one, ENT-1} and the second eluting diastereomer was designated as 20 {2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]ethan-1-one, ENT-2}.
19 - Yield: 3.8 mg, 9.1 μmol, 7%. LCMS m/z 442.5 [M+Na ⁺ ]. Retention time: 2.88 min. [Analytical conditions. Column: Chiral Technologies Chiralpak AS-H, 4.6×100 mm, 5 μm; Mobile phase: 4:1 carbon dioxide/(methanol containing 0.2% ammonium hydroxide); Flow rate: 1.5 mL/min; Back pressure: 200 bar].
20 - Yield: 2.0 mg, 4.8 μmol, 4%. LCMS m/z 442.5 [M+Na ⁺ ]. Retention time: 4.01 min (same analytical conditions as used in 19).

Example AA
In Vitro Binding Affinity Assay Using hMC4R The binding affinity of test compounds at the α-melanocyte stimulating hormone receptor (hMC4R) was assessed using a radioligand competitive binding assay. Recombinant Chinese Hamster Ovary (CHO) cells stably expressing hMC4R (PerkinElmer #ES-191-C) were used for competitive binding. hMC4R membranes were grown in Dulbecco's Modified Essential Medium and Ham's F-12 Medium (DMEM/F12), 10% heat-inactivated fetal bovine serum (FBS), 0.4 mg/mL geneticin, and 2 mM L-glutamine. Cell membranes were collected and frozen until the assay was performed.

Compounds were solubilized in 100% dimethylsulfoxide (DMSO) to a concentration of 30 mM. A 10-point intermediate dilution series using half-log dilutions was made in 100% DMSO with a top concentration of 0.03 mM. Serially diluted compounds were spotted at 1 μL/well onto a 96-well Costar 3363 plate. Final compound range in the assay was 300 nM to 0.01 nM with a final DMSO concentration of 1%. Control wells containing 1 μL of 2 mM (2 μM final) alpha-melanocyte stimulating hormone (α-MSH-Tocris #2584) were added to non-specific binding wells and 1 μL of 100% DMSO for total binding control wells. Following this, 80 μL of assay buffer [25 mM HEPES, 5 mM MgCl ₂ , 2.5 mM CaCl ₂ , 150 mM NaCl, Complete EDTA-free protease inhibitor tablets (Thermo Scientific #11873580001) and 0.25% BSA] was added. 10 μL of [ ¹²⁵ I]-(Nle4,D-Phe7)-α-MSH (PerkinElmer #NEX3520) was added to all wells at 0.5 nM, 10x the final concentration. Radioligand concentrations used were below the equilibrium dissociation constant (K _d ) of 2.59 nM. The exact concentration of radioligand used in each experiment was determined by liquid scintillation counting and adjusted if necessary.

Frozen hMC4R cell membranes were thawed and Dounce homogenized. Homogenates were resuspended in assay buffer to a concentration of 2 μg per well. Competitive binding reactions were initiated by the addition of 10 μL of MC4R membrane solution to assay-ready plates containing test compound and [ ¹²⁵ I]-(Nle4,D-Phe7)-α-MSH. Plates were incubated at room temperature for 2 hours. Assay samples were then rapidly filtered through Unifilter-96 GF/B PEI-coated filter plates using a filter plate harvester (PerkinElmer) and rinsed with ice-cold wash buffer [25 mM (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), 1 mM MgCl ₂ , 2.5 mM CaCl ₂ , and 500 mM NaCl]. The filter plates were allowed to dry at room temperature overnight. The plates were then sealed on the bottom before adding 50 μL/well of Ultima Gold XR scintillation fluid (PerkinElmer 6013111). The plates were then sealed on top and incubated at room temperature for 60 minutes, and the amount of radioactivity present was then determined using a Microbeta Trilux (PerkinElmer The antibody titers were determined by liquid scintillation counting using a 350 mAb/s 2-amino-2-propanediol (#2450-0060).

Raw data (expressed as counts per minute) were analyzed using ActivityBase (IDBS Data Management Software). The percent effect at each concentration of compound was calculated by ActivityBase based on the values in uninhibited wells (total binding control) and fully inhibited wells (non-specific binding control) on each assay plate. The concentration required for 50% inhibition (IC ₅₀ ) values were determined from these data using a four-parameter logistic model. Equilibrium dissociation constant (K _i ) values for inhibitors of ligand and receptor interactions were then calculated from the IC ₅₀ values using the Cheng-Prusoff equation: K _i = IC ₅₀ /(1 + ([L]/K _d )), where [L] is the concentration of radioligand used in the experiment and K _d is the affinity of the radioligand (determined in a separate saturation experiment).

(Example BB)
Functional in vitro MC4R antagonist potency assay Functional in vitro antagonist potency of test compounds was determined by monitoring intracellular cyclic adenosine monophosphate (cAMP) levels in Chinese hamster ovary (CHO-) cells stably expressing the human melanocortin-4 receptor (MC4R). Following agonist activation, human MC4R associates with the G protein complex, causing the Gα subunit to exchange bound GDP for GTP, followed by dissociation of the Gα-GTP complex. The activated Gα subunit can couple with downstream effectors to regulate intracellular second messenger or cAMP levels. Determination of intracellular cAMP levels thereby allows for pharmacological characterization. Intracellular cAMP levels are quantified using a homogeneous assay utilizing homogeneous time-resolved fluorescence (HTRF) technology from CisBio. The method is a competitive immunoassay between natural cAMP produced by cells and cAMP that is labeled with an acceptor dye, d2. The two entities then compete for binding to a monoclonal anti-cAMP antibody that is labeled with cryptate. The specific signal is inversely proportional to the concentration of cAMP in the cells.

Test compounds were solubilized and stored to 30 mM in 100% dimethyl sulfoxide (DMSO). An 11-point dilution series using 162-fold serial dilutions in thirds was made in 100% DMSO with a top concentration of 800 μM. Serially diluted compounds were spotted into 384-well plates (Greiner, Cat No. 781280) at 40 nL/well with duplicate points at each concentration, then diluted 1 in 1000 with 40 μL of assay buffer containing HBSS, 20 mM HEPES (Invitrogen), 0.1% BSA, and 250 μM IBMX (Sigma Aldrich) to make an intermediate plate at 2× final assay concentration (FAC). Final compound concentration range in the assay was 400 nM to 4 pM with a final DMSO concentration of 0.1%.

In-house produced CHO-cells stably expressing the Gs-coupled human MC4R receptor were plated at a density of 2,500 cells per well in 384-well assay plates (Corning, Cat No. 3570) in 50 μL/well of Ham's F-12 containing 10% heat-inactivated FBS, 1× penicillin/streptomycin, 1 mM Glutamax (Invitrogen) and incubated overnight at 37°C ( ₉₅ % O : 5% CO ) with a micro-clime lid ( _Labcyte , Cat No. LLS-0310). On the day of the assay, media was removed from the assay plates by gently tapping and blotting the plates on paper towels and replaced with 5 μL of 2× antagonist compound in assay buffer (HBSS, 20 mM HEPES, 0.1% BSA, 250 μM IBMX) and 0.1% DMSO. Cells were incubated with compounds for 30 minutes at 37° C. (95% O ₂ : 5% CO ₂ ) followed by the addition of 5 μL of EC ₈₀ agonist stimulation (200 nM α-melanocyte stimulating hormone, αMSH, Bachem) and a further 30 minute incubation at 37° C. (95% O ₂ : 5% CO ₂ ). Intracellular cAMP levels were quantified according to Cisbio's protocol (5 uL D2, then 5 uL Cryptate. Incubated at room temperature for 1-2 hours). Samples were read on an Envision plate reader (PerkinElmer Life and Analytical Sciences; excitation, 320 nm; emission, 665 nm/620 nm).

Data was analyzed using the ratio of fluorescence intensity at 620 and 665 nm for each well and extrapolated from a cAMP standard curve to express data as nM cAMP for each well. Data expressed as nM cAMP were then normalized to control wells using the activity base (IDBS). Zero percent effect (ZPE) was defined as nM of cAMP generated from EC ₈₀ agonist stimulation (200 nM αMSH). One hundred percent effect (HPE) was defined as nM of cAMP generated from assay buffer/vehicle alone in the absence of antagonist control compound. Concentration and % effect values for each compound were plotted by activity base using a four-parameter logistic dose-response equation to determine the concentration required for 50% inhibition (IC ₅₀ ). Equilibrium dissociation constant (K _b ) values were then calculated according to the Leff-Dougall equation: K _b = [IC ₅₀ ]/((2+([A]/[EC ₅₀ ]) ⁿ ) ^1/n −1), where A is the concentration of challenged agonist used in the experiment (200 nM) and n = slope.

Table 2 lists the biological activities (for K _i values, see Example AA; for K _b values, see Example BB) and compound names for Examples 1-201.

Throughout this application, various publications are referenced. The disclosures of these publications are incorporated by reference in their entireties into this application for all purposes.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims (6)

(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(6-Methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-1;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-2;
1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-1;
1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[(4,6- ² H ₂ )pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]ethan-1-one, ENT-2;
(2R)-1-{(2S)-6-[5-(difluoromethyl)pyrimidin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-1-[(2S)-6-(5-bromopyrimidin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
2-(6-Methoxy-2-methylpyrimidin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-1;
2-(6-Methoxy-2-methylpyrimidin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-2;
2-(6-methoxy-2-methylpyrimidin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-3;
2-(6-Methoxy-2-methylpyrimidin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-4;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[2-methyl-1-(trifluoromethyl)-1H-imidazol-4-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2S)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2R)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-1,3-oxazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-(2,4-dichlorophenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(2,4-dichlorophenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[5-(difluoromethyl)-2-methoxypyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[5-(difluoromethyl)-2-methoxypyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[5-chloro-2-(trifluoromethyl)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[2-Methoxy-5-(trifluoromethyl)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[2-Methoxy-5-(trifluoromethyl)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(3-fluoro-4-methoxyphenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(3-fluoro-4-methoxyphenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[6-(difluoromethoxy)-2-methylpyrimidin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[6-(difluoromethoxy)-2-methylpyrimidin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-Fluoro-2-(2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-Fluoro-2-(2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethoxy)phenyl]propan-1-one, DIAST-1;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethoxy)phenyl]propan-1-one, DIAST-2;
2-(3,4-difluorophenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(3,4-difluorophenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(2,4,5-trifluorophenyl)propan-1-one, DIAST-1;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(2,4,5-trifluorophenyl)propan-1-one, DIAST-2;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(3,4,5-trifluorophenyl)ethan-1-one;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(3,4,5-trifluorophenyl)propan-1-one, DIAST-1;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(3,4,5-trifluorophenyl)propan-1-one, DIAST-2;
2-(3-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(3-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[5-chloro-2-(difluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[5-chloro-2-(difluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[3-(difluoromethoxy)-5-methoxyphenyl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[3-(difluoromethoxy)-5-methoxyphenyl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[5-chloro-2-(trifluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[5-chloro-2-(trifluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]ethan-1-one, ENT-1;
1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]ethan-1-one, ENT-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-6-(5-methoxypyrimidin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-6-[3-fluoro-5-(trifluoromethyl)pyridin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-6-[3-fluoro-6-(trifluoromethyl)pyridin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-[(2S)-6-(5-cyclopropylpyrazin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[5-(trifluoromethyl)pyrazin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[6-(trifluoromethyl)pyrimidin-4-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-[4-(trifluoromethyl)phenyl]ethan-1-one;
(2R)-2-{5-fluoro-2-[( ² H ₃ )methyloxy]pyridin-4-yl}-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-[5-fluoro-2-(trifluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[5-fluoro-2-(trifluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[2-(difluoromethoxy)-5-fluoropyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[2-(difluoromethoxy)-5-fluoropyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[5-fluoro-2-(trifluoromethyl)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[2-(dimethylamino)-5-fluoropyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[2-(dimethylamino)-5-fluoropyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(2,6-dimethoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(2,6-dimethoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(5-chloro-2-methoxypyrimidin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(4-fluorophenyl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)ethan-1-one, ENT-1;
2-(4-fluorophenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]ethan-1-one;
(2R)-2-(3,5-dimethoxyphenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
(2R)-2-(3,5-dimethoxyphenyl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{7-methyl-6-[1-methyl-5-(trifluoromethyl)-1H-1,2,4-triazol-3-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one, DIAST-1;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{7-methyl-6-[1-methyl-5-(trifluoromethyl)-1H-1,2,4-triazol-3-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one, DIAST-2;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-{7-methyl-6-[1-methyl-5-(trifluoromethyl)-1H-1,2,4-triazol-3-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one, DIAST-1;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-{7-methyl-6-[1-methyl-5-(trifluoromethyl)-1H-1,2,4-triazol-3-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one, DIAST-2;
(2R)-2-(3,5-dimethoxyphenyl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-1;
(2R)-2-(3,5-dimethoxyphenyl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-1;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-2;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-1;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-(7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl)propan-1-one, DIAST-2;
(2R)-1-(6-chloro-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl)-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one, DIAST-1;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]ethan-1-one;
2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[6-(difluoromethoxy)pyridin-3-yl]-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-1;
1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[6-(5-methoxy-1-methyl-1H-1,2,4-triazol-3-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[6-(5-methoxy-1-methyl-1H-1,2,4-triazol-3-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[6-(5-methoxy-1-methyl-1H-1,2,4-triazol-3-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[6-(5-methoxy-1-methyl-1H-1,2,4-triazol-3-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2R)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-1,2,3-triazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-{(2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
1-{(2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(3,4-difluorophenyl)ethan-1-one;
(2R)-1-{(2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
1-{(2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(6-methoxy-2-methylpyrimidin-4-yl)propan-1-one, DIAST-1;
1-{(2S)-6-[5-(difluoromethyl)-1-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(6-methoxy-2-methylpyrimidin-4-yl)propan-1-one, DIAST-2;
2-(2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[2-(difluoromethyl)-6-methoxypyrimidin-4-yl]-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[2-(difluoromethyl)-6-methoxypyrimidin-4-yl]-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[2-(difluoromethyl)-6-methoxypyrimidin-4-yl]-1-[(2S)-7-methyl-6-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[2-(difluoromethyl)-6-methoxypyrimidin-4-yl]-1-[(2S)-7-methyl-6-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(oxan-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2-(5-fluoro-2-methoxypyrimidin-4-yl)-1-[(2S)-7-methyl-6-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(5-fluoro-2-methoxypyrimidin-4-yl)-1-[(2S)-7-methyl-6-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(5-fluoro-2-methoxypyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(5-fluoro-2-methoxypyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-(2-Methoxy-5-methylpyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(2-Methoxy-5-methylpyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-1-{(2S)-6-[1-(difluoromethyl)-2-methyl-1H-imidazol-4-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-6-(5-fluoropyridin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyridazin-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrazin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[4-(trifluoromethyl)pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-[(2S)-6-(5-chloropyrimidin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[5-(trifluoromethyl)pyrimidin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-6-(5-fluoropyrimidin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-1-[(2S)-6-(7,7-difluoro-6,7-dihydro-5H-pyrrolo[1,2-b][1,2,4]triazol-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
2-Fluoro-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-Fluoro-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(1,2-thiazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methylpyrimidin-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[6-(5-methyl-1,3,4-oxadiazol-2-yl)pyridin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-1,3-thiazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrazolo[1,5-a]pyrimidin-3-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[5-(trifluoromethyl)pyridin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(6-methylpyrazin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-1-[(2S)-6-(4-tert-butyl-1,3-thiazol-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(5-methylpyrazin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-1-{(2S)-6-[6-(difluoromethoxy)pyridin-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-1-[(2S)-6-(3,5-dimethyl-1,2-benzoxazol-6-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[3-(5-methyl-1,3,4-oxadiazol-2-yl)phenyl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[3-(propan-2-yl)-1,2,4-thiadiazol-5-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-[(2S)-6-(4,5-dimethyl-1,3-thiazol-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(3-methylpyrazin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-1,3-benzothiazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(4-methylpyridin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(1,3-thiazol-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[5-(piperidin-1-yl)-1,3,4-thiadiazol-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyridin-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[2-(trifluoromethyl)pyrimidin-5-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-[(2S)-6-(2-cyclopropyl-1,3-thiazol-4-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[3-(1,3-oxazol-5-yl)phenyl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-{(2S)-6-[6-(difluoromethyl)pyridin-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[4-(5-methyl-1,2,4-oxadiazol-3-yl)phenyl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(3-methyl-1,2-thiazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-1-[(2S)-6-(6-cyclopropylpyrazin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[6-(trifluoromethyl)pyridin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-{(2S)-6-[5-(difluoromethyl)pyridin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[5-(trifluoromethoxy)pyridin-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-{(2S)-6-[6-(difluoromethyl)pyridin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[4-(trifluoromethyl)-1,3-thiazol-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[6-methyl-2-(propan-2-yl)pyrimidin-4-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-[(2S)-6-(4,6-dimethylpyrimidin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-1-{(2S)-6-[4-(dimethylamino)-6-(trifluoromethyl)pyrimidin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-1-[(2S)-6-(5-cyclopropylpyridin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[1-methyl-5-(morpholin-4-yl)-1H-1,2,4-triazol-3-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-1-{(2S)-6-[1-(difluoromethyl)-5-methyl-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-1-{(2S)-6-[1-cyclopropyl-5-(difluoromethyl)-1H-1,2,4-triazol-3-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
2-(2,4-difluorophenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-(2,4-difluorophenyl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[2-(difluoromethoxy)-6-methoxypyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[2-(difluoromethoxy)-6-methoxypyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
2-[2-(difluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1;
2-[2-(difluoromethoxy)pyridin-4-yl]-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-2;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[2-(morpholin-4-yl)pyrimidin-4-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-6-(6-methoxypyrazin-2-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-1-{(2S)-6-[6-(difluoromethoxy)pyridin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-1-[(2S)-6-(6-cyclopropylpyridazin-3-yl)-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl]-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one;
(2R)-1-{(2S)-6-[4-(difluoromethyl)pyrimidin-2-yl]-7-methyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl}-2-(5-fluoro-2-methoxypyridin-4-yl)propan-1-one; and
A pharmaceutical composition comprising a compound or a pharma- ceutical acceptable salt selected from: (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[5-(trifluoromethyl)-1,3-thiazol-2-yl]-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidine]-1'-yl}propan-1-one . (2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one, DIAST-1;
2-(6-methoxy-2-methylpyrimidin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidin]-1′-yl]propan-1-one, DIAST-1;
1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl]-2-[4-(trifluoromethyl)phenyl]propan-1-one, DIAST-1;
1-(4,7-dimethyl-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3′-pyrrolidine]-1′-yl)-2-(4-fluorophenyl)ethan-1-one, DIAST-1;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(2-methyl-2H-tetrazol-5-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
(2R)-2-(5-chloro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one;
2. The pharmaceutical composition of claim 1, comprising a compound or a pharma- ceutically acceptable salt selected from: (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[7-methyl-6-(1-methyl-1H-pyrazol-4-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl]propan-1-one, DIAST-1; and (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-{(2S)-7-methyl-6-[( ^4,6-2H2 )pyrimidin- ₂ -yl]-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl}propan-1-one. The pharmaceutical composition of claim 1, comprising a compound or a pharma- ceutical acceptable salt thereof which is (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidin]-1'-yl]propan-1-one. The pharmaceutical composition of claim 1, comprising a compound in the form of a crystal of (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridin-2,3'-pyrrolidine]-1'-yl]propan-1-one. 5. A pharmaceutical composition according to any one of claims 1 to 4 for treating a condition, disease or disorder in a human, wherein the condition, disease or disorder is selected from cachexia; anorexia, anorexia nervosa, or geriatric anorexia; nausea; vomiting; weight loss; growth retardation; sarcopenia; muscle wasting; muscle weakness; frailty; osteoporosis; bone disorders; pain ; neuropathic pain; anxiety; depression; hypertension; malnutrition; obesity; sexual dysfunction; and inflammatory diseases. for treating cachexia, anorexia, failure to thrive, sarcopenia, muscle wasting, muscle weakness, frailty or malnutrition;
A pharmaceutical composition comprising a compound which is (2R)-2-(5-fluoro-2-methoxypyridin-4-yl)-1-[(2S)-7-methyl-6-(pyrimidin-2-yl)-3,4-dihydro-1H-spiro[1,8-naphthyridine-2,3'-pyrrolidin]-1'-yl]propan-1-one or a pharma- ceutically acceptable salt thereof.

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