NZ734908B2 - fi-D-2'-DEOXY-2'fi-FLUORO-2'-fi-C-SUBSTITUTED-2-MODIFIED-N6-SUBSTITUTED PURINE NUCLEOTIDES FOR HCV TREATMENT - Google Patents

Abstract

compound of the structure (A), or a pharmaceutically acceptable salt or composition thereof for the treatment of a host infected with or exposed to an HCV virus or other disorders more fully described herein.

Description

B-D-Z'-DEOXY-2'-a-FLUORO-2'-B-C-SUBSTITUTED-Z-MODIFIED-NG-SUBSTITUTED PURINE TIDES FOR HCV TREATMENT PRIORITY This application claims priority to U.S.S.N. 62/129,319 filed on March 6, 2015, U.S.S.N. 62/253,958 filed on November 11, 2015, and N 62/276,597 filed on January 8, 2016, each of which is incorporated herewith in their entirety.

FIELD OF THE INVENTION The present invention is directed to nucleotide nds and compositions and uses thereof to treat the Hepatitis C virus (“HCV”).

BACKGROUND OF THE INVENTION Hepatitis C (HCV) is an RNA single stranded virus and member of the Hepacivirus genus. It is estimated that 75% of all cases of liver disease are caused by HCV, HCV infection can lead to sis and liver cancer, and if left to progress, liver failure which may require a liver transplant. Approximately 170-200 million people worldwide are infected, with an estimated 3-4 million ions in the United States.

RNA polymerase is a key component in the ing of RNA single stranded viruses.

The HCV non—structural protein NSSB RNA-dependent RNA polymerase is a key enzyme responsible for initiating and catalyzing viral RNA synthesis. As a result, HCV NSSB is an attractive target for the current drug discovery and development of anti-HCV agents. There are two major subclasses of NSSB inhibitors: nucleoside analogs, which are anabolized to their active triphosphates i which act as alternative substrates for the rase , and non- nucleoside inhibitors (NNIs), which bind to allosteric regions on the protein. Nucleoside or nucleotide inhibitors mimic l polymerase substrate and act as chain terminators. They inhibit the initiation of RNA ription and elongation ofa nascent RNA chain.

In addition to targeting RNA polymerase, other RNA viral proteins may also be targeted in combination therapies. For example, HCV proteins that are additional targets for therapeutic approaches are NS3/4A (a serine protease) and NSSA (a non—structural protein that is an essential ent of HCV ase and exerts a range of effects on cellular pathways).

PCT/U52016/021276 In December 2013, the first nucleoside NSSB polymerase inhibitor sofosbuvir di‘fi, Gilead Sciences) was approved. Sovaldi‘I3 is a e phosphoramidate prodrug that is taken up by hepatocytes and undergoes intracellular activation to afford the active metabolite; xy— 2’-0t-fluoro-B-C-methyluridine—5’-triphosphate; see structures below: O 0 O E: I! H [f r-aowgwour§~o~r?~o N 0 0H 0H 6H --------me He? ”F 2’ -Deoxy-2’-0t-fluoro-B-C-methyluridine—5 ’ —triphosphate Sovaldi’r‘l is the first drug that has demonstrated safety and efficacy to treat certain types of HCV infection without the need for co-administration of eron. Sovaldi‘f‘ is the third drug with breakthrough therapy designation to receive FDA approval.

In 2014, the US, FDA approved Harvonif“ (ledispasvir, a NSSA tor, and sofosbuvir) to treat chronic hepatitis C virus genotype 1 infection, HarvoniR‘ is the first combination pill approved to treat chronic HCV genotype 1 infection. It is also the first approved regimen that does not require administration with interferon or ribavirin. In addition, the FDA ed simeprevir ol‘M) in combination with sofosbuvir (Sovaldi‘K) as a once—daily, all oral, interferon and ribavirin-free treatment for adults with genotype 1 HCV ion.

The US. FDA also approved Abeie’s VIEKIRA PakTM in 2014, a multipill pack containing dasabuvir (a non-nucleoside NSSB polymerase inhibitor), ombitasvir (a NSSA 2016/021276 inhibitor), paritaprevir (a NS3/4A inhibitor), and ritonavir. The VIEKIRA PakTM can be used with or without the ribavirin to treat genotype 1 HCV infected patients including patients with compensated cirrhosis. A PakTM does not e interferon co—therapy.

In July 2015, the US. FDA approved TechnivieTM and DaklinzaTM for the treatment of HCV genotype 4 and HCV genotype 3 respectively. TechnivieTM (Ombitasvir/paritaprevir/ritonavir) was approved for use in combination with ribavirin for the treatment of HCV genotype 4 in patients without scarring and cirrhosis and is the first option for HCV-4 infected patients who do not require co-administration with interferon. DaklinzaTM was approved for use with Sovaldi‘g to treat HCV genotype 3 infections. DaklinzaTM is the first drug that has demonstrated safety and efficacy in ng HCV pe 3 without the need for co- administration of interferon or ribavirin.

In October 2015, the US. FDA wamed that HCV treatments a Pak and Technivie can cause serious liver injury ily in patients with underlying ed liver disease, and required that additional information about safety be added to the label.

Other current approved therapies for HCV include interferon alpha-2b or pegylated interferon alpha—2b (Pegintronf‘), which can be administered with ribavirin (Rebetolfi), NS3/4A telaprevir (lncivekR, Vertex and Johnson & n), boceprevir (VictrelisTM, Merck), simeprevir (Olysiov'VM, Johnson & Johnson), previr (Abeie), Ombitasvir (Abeie), (NNI) Dasabuvir (ABT-333) and s ZepatierTM (a -tablet combination of the two drugs grazoprevir and elbasvir).

Additional NSSB polymerase inhibitors are currently under development. Merck is developing the uridine nucleotide prodrug MK-3682 (formerly IdeniX 1DX2143 7). The drug is tly in Phase II combination trials United States patents and WO applications which describe nucleoside polymerase inhibitors for the ent of Flaviviridae, including HCV, include those filed by Idenix Pharmaceuticals (6,812,219, 6,914,054; 7,105,493, 7,138,376; 7,148,206, 7,157,441, 7,163,929; 7,169,766, 7,192,936; 7,365,057, 7,384,924; 7,456,155, 7,547,704, 7,582,618, 7,608,597, 7,608,600, 7,625,875; 7,635,689, 7,662,798; 7,824,851; 7,902,202, 7,932,240, 7,951,789, 372; 8,299,038; 8,343,937; 068; 8,507,460; 8,637,475; 8,674,085, 8,680,071; 8,691,788, 8,742,101, 985; 9,109,001; 9,243,025; U82016/0002281; US2013/0064794; WO/2015/095305; WO/2015/081133; WO/2015/061683; WO/2013/177219; WO/2013/039920; PCT/USZOl6/021276 WO/2014/137930; WO/2014/052638; WO/2012/154321); Merck (6,777,395; 7,105,499; 7,125,855; 7,202,224; 449; 7,339,054; 7,534,767; 7,632,821; 7,879,815; 8,071,568; 8,148,349; 8,470,834; 8,481,712; 434; 8,697,694; 8,715,638, 9,061,041; 9,156,872 and WO/2013/009737); Emory University ,587; 6,911,424; 7,307,065; 7,495,006; 7,662,938; 7,772,208; 8,114,994; 8,168,583; 8,609,627; US 2014/0212382; and WO2014/1244430); Gilead Sciences/ Pharmasset Inc, (7,842,672; 7,973,013; 8,008,264; 8,012,941; 8,012,942; 8,318,682; 8,324,179; 8,415,308; 8,455,451; 8,563,530; 8,841,275; 8,853,171; 785; 8,877,733; 159; 8,906,880; 8,912,321; 8,957,045; 8,957,046; 9,045,520; 9,085,573; 9,090,642; and 9,139,604) and (6,908,924; 6,949,522; 770, 7,211,570, 572, 7,601,820; 7,638,502; 7,718,790; 7,772,208; RE42,015; 7,919,247; 7,964,580; 8,093,380; 8,114,997; 8,173,621; 8,334,270; 8,415,322; 8,481,713; 8,492,539; 8,551,973; 8,580,765; 8,618,076; 8,629,263; 8,633,309; 8,642,756; 8,716,262; 8,716,263; 8,735,345; 8,735,372; 8,735,569; 8,759,510 and 8,765,710); Hoffman La—Roche (6,660,721), Roche (6,784,166; 599, 601 and 8,071,567); Alios BioPharma Inc. (8,895,723; 8,877,731; 8,871,737, 8,846,896, 8,772,474; 8,980,865; 9,012,427; US 2015/0105341; US 2015/0011497; US 2010/0249068; US2012/007041 1; WO 54465; ; ; ; ; ; ; WO 88155; ), Enanta Pharmaceuticals (US 8,575,119; 8,846,638; 9,085,599; WO 2013/044030; WO 2012/125900), Biota (7,268,119; 7,285,658; 7,713,941; 8,119,607; 8,415,309; 8,501,699 and 8,802,840), st Pharmaceuticals (7,388,002; 7,429,571; 7,514,410; 7,560,434; 139; 8,133,870; 8,163,703; 8,242,085 and 8,440,813), Alla Chem, LLC (8,889,701 and WO 2015/053662), teX ,318 and WO/2012/092484), Janssen Products ,429; 8,431,588, 8,481,510, 8,552,021, 8,933,052; 9,006,29 and 9,012,428) the University of Georgia Foundation (6,348,587; 7,307,065; 7,662,938; 8,168,583; 8,673,926, 074; 8,921,384 and 8,946,244), RFS Pharma, LLC (8,895,531; 8,859,595; 8,815,829; 8,609,627; 7,560,550; US 2014/0066395; US 2014/0235566; US 2010/0279969; WO/2010/091386 and WO 58811) University College Cardiff Consultants Limited (WO/2014/076490, WO 2010/081082; WO/2008/062206), Achillion ceuticals, Inc. (WO/2014/169278 and ), Cocrystal Pharma, Inc. (US 9,173,893), Katholieke Universiteit Leuven (), Catabasis (WO 2013/090420) and the Regents of the University of Minnesota (WO 2006/004637).

PCT/U52016/021276 Nonetheless, there remains a strong medical need to develop anti-HCV ies that are safe, effective and well-tolerated. The need is uated by the expectation that drug resistance. More potent direct—acting antivirals could significantly shorten treatment duration and improve compliance and SVR rates for patients infected with all HCV genotypes.

It is therefore an object of the present invention to e compounds, pharmaceutical compositions, and methods and uses to treat and/or prevent infections of HCV.

Y OF THE INVENTION It has been discovered that the compounds of Formula 1, Formula II, Formula [11, lO Formula IV, Formula V, Formula VI, Formula VII and including B-D-2'—deoxy-2'-d-fluoro-2'—B- C—substituted-NO—(mono— or di—methyl) purine nucleotides, are highly active against the HCV virus when stered in an ive amount to a host in need thereof. The host can be a human or any animal that carries the Viral infection.

Disclosed nucleotides include those with nanomolar activity against HCV in Vitro and [5 therapeutic indices that range to 25,000 or more.

Surprisingly, the parent NG-(methyl) purine nucleosides of disclosed compounds had not been developed or specifically disclosed as drug candidates prior to this invention. For example, it was reported in 20l0 that 3’-azido-N"—dimethyl-2,6-diaminopurine is not substantially deaminated by adenosine deaminase over a long period (120 minutes), and for that reason it had been considered an inappropriate compound to tize as a drug (see for example, WO 2010/091386, page 86 and corresponding US Patent 8,609,627).

However, it has now been discovered that compounds of the t invention are anabolized to a 5-monophosphate of the No-substituted-purine without substantial N6- deamination and then subsequently anabolized at the 6-position to generate active e triphosphate compounds, in a manner that provides exceptional activity and therapeutic index.

In particular, it has been discovered that a 5’-stabilized phosphate prodrug or derivative ofB-D-2’-deoxy-2’-0t-fluoro-2’-B-methyl-N"-methyl-2,6-diaminopurine nucleotide, as well as B- D-2’-deoxy-2’-0t-fluoro-2’-B-methyl-N"-dimethyl-2,6—diaminopurine nucleotide, and other [3-D- 2‘—D—2'—0t—fluoro—2'—B—C—substituted—2—modif1ed—NG—substituted purine tides as bed below, are highly active against HCV. This is surprising because the activity of the parent nucleoside —deoxy-2’—0t-fluoro—2’—B—methyl—N6-methyl—2,6-diaminopurine in a replicon assay (ECso : 15.7 olar) indicates that it is not suitable for use as a human drug due to insufficient ty (in combination with the reference WO 91386, page 86 and corresponding US Patent 8,609,627 that suggests that hyl—2,6—diaminopurines are not deaminated in vivo) however, the ized racemic phosphate prodrug (phosphoramidate) exhibits an ECso : 26 nanomolar (nM), in a replicon assay, which is at least an 600 fold increase in ty. The corresponding (Sfphosphoramidate exhibits an EC50 : 4 nM, which is at least a 3,900 fold increase in activity; see the structure below and compound 5-2 in Table 7. With a TCso greater than one hundred micromolar, the compound thus has a therapeutic index of greater than 25,000. For comparison, Sofosbuvir has an ECso : 53 anl, a TC50 greater than one hundred micromolar and a therapeutic index greater than 1,920.

H3C‘NH N its ‘ 105 m0 .. <’N / \Nw O N NH2 Compound 5-2 (Table 7) se, the activity of the parent nucleoside B—D—2’—deoxy—2’—0L—fluoro—2’-[3—methyl—N6— dimethyl-2,6-diaminopurine in a replicon assay (ECso : 10,7 micromolar, “uM”) indicates that it is also not suitable for use as a human drug due to insufficient activity, however, the stabilized racemic phosphate prodrug (phosphoramidate) exhibits an ECsn : 12 nM, in a replicon assay, which is more than a 890 fold increase in activity. The corresponding (S)—phosphoramidate und 25, Table 7) also exhibits an EC50 : 4 nM, which is at least a 2,600 fold increase in activity; see the structure below. In addition, compound 25 also has a therapeutic index of greater than 25,000.

PCT/U52016/021276 9 CE (AN “as,“ \T/OWAH-‘W‘Ewowo N N NHZ O o HO ‘liF; x)/[ In another e, the compound isopropyl ((((R,b)-(2R,3[3,418,5R)—5-(2-amino(N- methyl—N—cyclopropyl—amino)—9H—purin-9—yl)—4—fluoro—3 —hydroxy—4—methyltetrahydrofuran—Z— hoxy)-phenoxy-phosphoryl)—L-alaninate exhibited an ECso : 7 nM and the corresponding (S)—phosphoramidate exhibited an ECso : 5 nM in a replicon assay; see compound 27 in Table 7 and the structure below.

H Cc A3 N “is 9 5” j ‘ /‘ ‘: \T {\HOx “WP“O N NANHZ 0 O W92 ‘ , As stated above, the metabolism of the B-D-Z’-deoxy-2’-d-fluoro-2’-|3-methyl-N6- methyl-2,6-diaminopurine nucleoside as a phosphoramidate involves the production of a 5’- monophosphate and the subsequent anabolism of the NO—methyl-2,6—diaminopurine base to te the B—D—2’—deoxy—2’—0t—fluoro—2’—B—methyl—guanine nucleoside as the 5’— monophosphate. The monophosphate is then further ized to the active species; the 5’— triphosphate The B—D-Z’-deoxy-2’-0t-fluoro-2’-B-methyl-guanine triphosphate has an leo : 0‘ 15 MW against the HCV genotype lb NSSB polymerase Thus, in one embodiment, the invention is: PCT/USZOl6/021276 (N \ N A N NH2 R O4 OR3 F Formula I wherein: Y is NR'RZ; R1 is Ci-Csalkyl (including methyl, ethyl, yl, iso—propyl, n—butyl, iso-butyl, sec— butyl, tert—butyl and pentyl), aloalkyl (including CHzF, CHFz, CF3, CH2CF3, CF2CH3 and CF2CF3), C2-C6 alkenyl, C2-C6 alkynyl, 7(C0—C2alkyl)(C3—Cocycloalkyl), *(Co— C2all<yl)(heterocycle), 7(Co-C2alkyl)(aryl), 7(Co-C2alkyl)(heteroaryl), 70R”, -C(O)R3C (including 7C(O)CH;, 7C(O)CH2CH3—C(O)CH(CH3)2, —C(O)OCH3. —C(O)OC2H5‘ —C(O)OC3H7. — 4H9. and -C(O)OCSHII), -C(S)R3D, or -SOzR28 each of which can be optionally substituted; R2 is hydrogen, Ci-Csalkyl ding methyl, ethyl, n-propyl, iso-propyl, l, iso- butyl, sec—butyl, utyl and pentyl), Ci—C5haloalkyl (including CHFz, CHF2, C133, CH2CF3 and CFzCFs), —(C0—C2alkyl)(C3—Cccycloalkyl), —C(O)R3C (including H3, —C(O)CH2CH3— C(O)CH(CH3)2, —C(O)OCH3. —C(O)OC2H5. C3H". —C(O)OC4H9. and —C(O)OC5Hii), *(Co— C2all<yl)(aryl), *(Co—Czalkyl)(heterocycle), *(Co-Czalkyl)(heteroaryl); and wherein at least one ole and R2 is methyl, CHzF, CHFz or CF3; Rsawigmgu l $ . 3A R” is hydrogen, R diphosphate, triphosphate, an optionally substituted carbonyl linked amino acid, or -C(O)R3C; R3A can be selected from O', OH, an iO-optionally substituted aryl, an iO-optionally substituted heteroaryl, or an optionally substituted heterocyclyl; PCT/U52016/021276 R3B can be selected from O', OH, an optionally substituted ed amino acid or an optionally substituted N—linked amino acid ester; R3C is alkyl, alkenyl, alkynyl, —(Co—C2)(cycloalkyl), —(Co—C2)(heterocyclo), —(Co—C2)(aryl), —(Co—C2)(heteroaryl), -O-alkyl, -O-alkenyl, -O-alkynyl, -O—(Co—C2)(cycloalkyl), -O—(C0— C2)(heterocyclo), —O-(Co-C2)(aryl), or -O—(Co—C2)(heteroaryl), each of which can be optionally substituted; R4 is a monophosphate, phate, triphosphate, or a stabilized phosphate prodrug, including but not limited to a phosphoramidate, a thiophosphoramidate, or any other moiety that is metabolized to a monophosphate, diphosphate or triphosphate in viva in the host human or lO ; or R3 and RJ' together with the oxygens that they are bonded to can form a 3’,5’—cyclic prodrug, including but not limited to, a 3’,5’—cyclic phosphate prodrug; R12 is CH3, CH2F, CHFz, CF3, or ethynyl.

In one embodiment, the invention is: N \ f N N ,.

N R42 [5 0R3 F Formula 11 wherein: Yis NRIRZ; R1 is C1-C5alkyl (including methyl, ethyl, n-propyl, iso—propyl, n-butyl, tyl, sec- butyl, tert-butyl and pentyl), C1-C5haloalkyl (including CHgF, CHFg, C173; , CF2CH3 and CFzCFs), C2-C6 alkenyl, C2-C6 alkynyl, 7(Cn—C2alkyl)(C3-C6cycloalkyl), 7(Co- C2alkyl)(heterocycle), —(Co-C2alkyl)(aryl), zalkyl)(heteroaryl), —OR25, -C(O)R3C (including —C(O)CH3, —C(O)CH2CHs-C(O)CH(CH3)2, CH3. -C(O)OC2H5, -C(O)OC3H7. - C(O)OC4H9. and —C(O)OC5H11); —C(S)R3D, or £02sz each of which can be optionally substituted; PCT/U52016/021276 R2 is hydrogen, optionally substituted C1-C5alkyl (including methyl, ethyl, n-propyl, iso- propyl, n-butyl, iso—butyl, tyl, tert-butyl and pentyl), Ci-C5haloalkyl (including CHFg, CHFz, CF3, CH2CF3 and CF2CF3), optionally substituted *(Co-Czalkyl)(C3—Cocycloalkyl), optionally substituted *(Co-Czalkyl)(heterocycle), optionally substituted *(Co—C2alkyl)(aryl), optionally substituted *(Co—C2alkyl)(heteroaryl), 3C (including *C(O)CH3, , 2CH3—C(O)CH(CH2)2, —C(O)OCH3. —C(O)OC2H5, —C(O)OC3H7, —C(O)OC4H9. and —C(O)OC5H11), -C(S)R3D, or —SOzR28; and n at least one of R1 and R2 is , CHzF, CHFz or CF3; Raw?” 1 E R3 is hydrogen, REA triphosphate, an , diphosphate, optionally substituted carbonyl linked amino acid, or -C(O)R3C; R3A can be selected from O', OH, an —O-optionally substituted aryl, an —O-optionally substituted aryl, or an optionally substituted cyclyl; R313 can be selected from O', OH, an optionally substituted N—linked amino acid or an optionally substituted N—linked amino acid ester; R3C is alkyl, alkenyl, l, -(Co-C2)(cycloalkyl), -(C0—C2)(heterocyclo), -(Co-C2)(aryl), 2)(heteroaryl), -O-alkyl, -O-alkenyl, -O-all<ynyl, -O-(Co-C2)(cycloall<yl), -O-(Co- C2)(heterocyclo), -O-(Co-C2)(aryl), -O-(Co-C2)(heteroaryl), -S-alkyl, enyl, -S—alkynyl, —S- (Co-C2)(cycloall<yl), -S-(Co-C2)(heterocyclo), -S-(Co-C2)(aryl), or -S-(Cn-C2)(heteroaryl) each of which can be optionally substituted; R3D is alkyl, alkenyl, alkynyl, -(C0-C2)(cycloalkyl), —(Co—C2)(heterocyclo), 2)(aryl), —(Co—C2)(heteroaryl), -O-alkyl, —O-alkenyl, —O—alkynyl, —O—(Co—C2)(cycloalkyl), —O—(C0- C2)(heterocyclo), —O-(Co-C2)(aryl), or -O—(C0—C2)(heteroaryl), each of which can be optionally substituted; R4 is a monophosphate, diphosphate, sphate, or a stabilized phosphate prodrug, including but not limited to a phosphoramidate, a thiophosphoramidate, or any other moiety that is metabolized to a monophosphate, diphosphate or triphosphate in vivo in the host human or animal; or PCT/U52016/021276 R3 and R4 together with the oxygens that they are bonded to can form a cyclic prodrug, including but not limited to, a cyclic phosphate prodrug; R5 is C1-C5alkyl (including methyl, ethyl, n-propyl, iso-propyl, l, iso-butyl, sec- butyl, tert-butyl and pentyl), C1-Cshaloalkyl (including CHFz, CHF2, CF3, CH2CF3 and CF2CF3), C2-C6 alkenyl, C2-C0 alkynyl, -(Co-C2alkyl)(C3-Cocycloalkyl), -(Co-C2alkyl)(heterocycle), -(Co- C2all<yl)(aryl), -(Co-C2all<yl)(heteroaryl), -OR25, -C(O)R3C (including -C(O)CH3, - C(O)CH2CH3—C(O)CH(CH3)2, —C(O)OCH3. —C(O)OC2H5, -C(O)OC3H7, -C(O)OC4H9. and -C(O)OC5H11), -C(S)R3D, or -SO2R28 each of which can be optionally substituted; R6 is hydrogen, optionally tuted C1-C5alkyl (including methyl, ethyl, yl, iso- propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl and pentyl), Ci-Cshaloalkyl (including CHF2, CHFz, CF3, CH2CF3 and CF2CF3), optionally substituted —(Co-C2all<yl)(C3-C6cycloalkyl), optionally substituted -(Co-C2alkyl)(heterocycle), optionally substituted -(Co-C2alkyl)(aryl), optionally substituted -(Co-C2alkyl)(heteroaryl), -C(O)R3C (including -C(O)CH3, - C(O)CH2CH3-C(O)CH(CH3)2, -C(O)OCH3. -C(O)OC2H5, C3H7, -C(O)OC4H9. and — 5H11), -C(S)R3D, or 8; or R5 and R6 together with the nitrogen that they are bonded to can form a heterocyclic ring; R12 is CH3, CH2F, CHF2, CF3, or l; R2 [\J is Cl, Br, F, CN, N3, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, —(C1-C2alkyl)(C3- oalkyl), —(Co.C2alkyl)(C3-Coheterocycle), -(Co-C2alkyl)(aryl), -(Co-C2alkyl)(heteroaryl); :O)OR23, -NH0R24, -0R25, -SR25, —NH(CH2)1.4N(R2")2, —NHNHR26, —N:NRZ7, -NHC(O)NHNHR27, -NHC(S)NHNHR27, -C(O)NHNHR27, —NRZ7SO2R28, —SO2NRZ7R29, —C(O)NRZ'"R29, £02112", —SO2R2", ‘ , -P(O)H(OR”), ORZ°)(OR3”), —P(O)(OR29)(NR29R3“) or -NR5R"; for example including but not limited to the following embodiments, chloro, bromo, fluoro, cyano, azido, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl and n- pentyl, 1,1—dimethylpropyl, 2,2—dimtheylpropyl, 3—methylbutyl, l—methylbutyl, l—ethylpropyl, vinyl, ally], nyl, 2-butynyl, acetylenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, -(CH2)-cyclopropyl, -(CH2)-cyclobutyl, -(CH2)-cyclopentyl, -(CH2)-cyclohexyl, aziridine, oxirane, thiirane, azetidine, oxetane, thietane, idine, tetrahydrofuran, thiolane, PCT/U52016/021276 pyrazolidine, piperidine, oxane, thiane, -(CH2)-aziridine, -(CH2)-oxirane, -(CH2)-thiirane, - (CH2)-azetidine, -(CH2)-oxetane, -(CH2)-thietane, -(CH2)-pyrrolidine, - tetrahydrofuran, - (CH2)—thiolane, —pyrazolidine, —(CHz)—piperidine, —(CH2)—oxane, —(CH2)-thiane, phenyl, pyridyl, -ONHC(:O)OCH3, —ONHC(:O)OCH2CH3, —NHOH, NHOCH3, —OCH3, OC2H5, —OPh, OCHzPh, —SCH3, —SC2H5, -SPh, SCHzPh, -NH(CH2)2NH2, -NH(CH2)2N(CH3)2, , -NHNHCH2, -N:NH, -N:NCH3, 2CH3. —NHC(O)NHNH2, -NHC(S)NHNH2, -C(O)NHNH2, -NHSOzCH3, CH2CH1-SO2NHCH3, -SOzN(CH3)2, -C(O)NH2, -C(O)NHCH3, -C(O)N(CH3)2, -CO2CH3, -C02CH2CH3, -COzPh, -CO2CH2Ph, -SOzCH3, G C5 2CH3, , -SOgCH2Ph, éHéi‘kH %%N-CH3, -P(O)H(OH), — , IO P(O)H(OCH3), -P(O)(OH)(OH), -P(O)(OH)(OCH3), -P(O)(OCH3)(OCH3), -P(O)(OH)(NH2), -P(O)(OH)(NHCH3), -P(O)(OH)N(CH3)2, -NHC(O)CH3, -NHC(O)CH2CH3, -NHC(O)CH(CH3)2‘ )OCH3, -NHC(O)OCH2CH3, -NHC(O)OCH(CH3)2‘ -NHC(O)OCH2CH2CH3‘ -NHC(O)OCH2CH2CH2CH3 and -NHC(O)OCH2CH2CH2CH2CH3; R23 is Ci-Csalkyl, —(Co—C2all<yl)(C3—C6cycloalkyl), 2alkyl)(heterocycle)—(Co. 2alkyl)(aryl) or -(Co—C2alkyl)(heteroaryl) each of which can be optionally substituted; R“ is hydrogen, C1-C6 alkyl, -(Ci-C2alkyl)(C3-C6cycloalkyl), -(Ci-C2all<yl)(C3-C6heterocycle) -(Co-C2all<yl)(aryl) or -(Co-C2all<yl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; R25 is hydrogen, 0-0, alkyl, C2-C6 alkenyl, C2—C6 alkynyl, -(Co-C2alkyl)(C3- C6cycloalkyl), —(Co-Cgalkyl)(C3-C6heterocycle), -(Co-C2alkyl)(aryl) or -(Co-C2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; R26 is independently selected from hydrogen, Ci-C6alkyl, —(Ci,)-C2all<yl)(C3- C6cycloalkyl), -(C0-C2alkyl)(heterocycle), zalkyl)(aryl), or 2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally tuted; R27 hydrogen or optionally substituted C1-C6 alkyl; R28 is Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, -(Co-C2alkyl)(Cz-C6cycloalkyl), -(C0.C2alkyl)(C3-C6heterocycle), -(C0-C2alkyl)(aryl) or -(Co-C2alkyl)(heteroaryl) each of which can be optionally substituted; PCT/U52016/021276 R29 is hydrogen, Ci-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, —(Co-C2alkyl)(C3- oalkyl), —(Co.C2alky1)(C3-C6heterocycle), -(Co-C2alkyl)(ary1) or -(Co-C2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally tuted; or R27 and R2” together with the nitrogen that they are bonded to can form a heterocyclic ring; R30 is hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, 2alkyl)(C3C6cycloalkyl), -(Co.C2alkyl)(C3-C6heterocycle), -(C0-C2alkyl)(aryl) or 2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; or R2” and R30 can be bonded together to form a heterocyclic ring; xis 1,20r3.

The metabolism of the B-D-2’-deoxy-2’-0t-fluoro-2’-B-methyl-N"-dimethyl-2,6- diaminopurine nucleotide involves both the formation of the B—D-Z’—deoxy—2’—a—fiuoro—2’—B— methyl—N6—dimethyl-2,o—diaminopurine nucleoside triphosphate as well as the generation of the corresponding guanine nucleoside triphosphate. See Scheme 2 and 3‘ 2’-Deoxy-2’-0L-fiuoro-2’-B-C-substituted-NG-substituted-2,6-diaminopurine nucleotides can be further substituted at the NZ-position by tion or acylated which can modify the ilicity, pharmacokinetics and/or targeting of the nucleotide to the liver. It has been discovered that xy—2’—0i—fiuoro—2’—B—C—substituted—N"—substituted—2,6—diaminopurine nucleotides modified at the tion of the diaminopurine can be dealkylated or deacylated by hepatic enzymes to further increase the specificity of the nucleotide derivatives both in vitro and in vivo, unless the NZ-amino group is completely replaced by a different , as described herein, such as fiuoroi For example, the nucleoside oramidate 2’-deoxy-2’-0i-fluoro-2’-B- methyl—NZ—methyl—N(’-methyl—2,o—diaminopurine nucleoside phosphoramidate is dealkylated to 2’-deoxy-2’-0t-fluoro-2’-B-methyl-N(’-methyl-2,6-diaminopurine nucleoside phosphoramidate when incubated with a human liver 89 fraction in vitro, up to 60 minutes, these conditions mimics in vivo conditions. In one embodiment, N2 modifications will increase cell permeability and hepatitic targeting.

Despite the volume of antiviral nucleoside literature and patent filings, the 5’—stabilized phosphate derivative of 2’—deoxy—2’-0t—fluoro—2’—B-methyl-N6-methyl—2,6—diaminopurine 2016/021276 nucleoside, xy-2’-0t-fluoro-2’-B-methy1-N"-dimethyl-2,6-diaminopurine nucleoside, and other B-D-2'-D-2'-d—fluoro-2'-B-C-substituted-Z-modified-N"—substituted purine nucleoside derivatives as described herein have not been specifically disclosed, nor have their advantageous activities been described.

Unless otherwise specified, the compounds described herein are provided in the [3-D— configuration. Likewise, when in phosphoramide or osphoramidate form, the amino acid portion can be in the L- or D-configuration. In an alternative embodiment, the compounds can be provided in a B—L-configuration. Likewise, any substituent group that exhibits ity can be provided in racemic, enantiomeric, diastereomeric form or any mixture f. Where a IO phosphoramidate, thiophosphoramidate or other stabilized phosphorus prodrug in which the phosphorus exhibits chirality is used as the R4 stabilized phosphate prodrug, it can be provided as an R or S chiral phosphorus derivative or a mixture thereof, including a racemic mixture All of the combinations of these stereoconfigurations are included in the ion described herein.

Accordingly, the present invention includes a compound of Formula I—VII, or a pharmaceutically acceptable ition, salt, or prodrug f, as described : {N I“ N N’yLWH2 OR3 F Formula] In one specific embodiment, the parent nucleoside, i.e., the nucleoside wherein R“1 is hydrogen and the 5’-position thus has a hydroxyl group, is not substantially deaminated by adenosine deaminase under conditions that mimic the in viva environment (ev ambient temperature and aqueous physiological pH), for a period of 7 minutes, 10 minutes, 30 minutes, 60 minutes or 120 minutes. Unless otherwise stated, the time period is 30 minutes. In this embodiment, the term “not substantially ated” means that the parent compound is not PCT/U52016/021276 converted to the ponding guanine derivative, or 6-oxo derivative, in an amount sufficient to provide a therapeutic effect in viva.

Compounds, methods, and compositions are provided for the ent of a host infected with a HCV virus via administration of an effective amount of the compound or its pharmaceutically acceptable salt.

The compounds and compositions can also be used to treat related conditions such as anti-HCV antibody ve and antigen positive conditions, viral—based chronic liver inflammation, liver cancer ing from advanced tis C, cirrhosis, chronic or acute hepatitis C, fulminant hepatitis C, chronic persistent hepatitis C and anti-HCV-based fatigue.

The compound or formulations that include the compounds can also be used prophylactically to t or ct the progression of clinical illness in individuals who are anti—HCV antibody or antigen positive or who have been exposed to hepatitis C.

In another embodiment, nds of Formula Ia are disclosed: N ‘N. </ N N NH2 CH 3 OR3 F Formula Ia wherein: Y, R3 and R4 are as defined above.

In one embodiment of Formula la, R3 is hydrogen.

In one embodiment of Formula la, when Y is NRIRZ, R1 is methyl and R2 is hydrogen.

In one embodiment of Formula la, when Y is NRIRZ, both RI and R2 are methyl.

In one embodiment of Formula Ia, when Y is NRIRZ, R' is methyl and R2 is cyclopropyl.

PCT/U52016/021276 In another embodiment, compounds of Formula Ib are disclosed: N \ < N N NH2 OR3 F Formula Ib wherein: Y, R3 and R4 are as defined above In one embodiment of Formula lb, R3 is hydrogen.

In one embodiment of Formula lb, when Y is NRIRZ, R1 is methyl and R2 is hydrogen.

In one embodiment of a lb, when Y is NRIRZ, both R1 and R2 are methyl.

In one embodiment, nds ofFormula II are disclosed: N \ < N N R12 QR“ F Formula [I wherein: Y, R3, R4, R12 and R22 are as defined above. 2016/021276 In another embodiment, compounds of Formula Ila are disclosed: {N \N N NARzz CH 3 0R3 F Formula Ha wherein: Y, R3, R"1 and R22 are as defined above.

In another embodiment, compounds of Formula 11b are disclosed: Formula llb wherein: Y, R3, R4, and R22 are as defined above.

In one embodiment, compounds ofFormula III are disclosed: N \ AlfPEN \ll N N/ r122 P O C02???“ 09:7 0R3 F Formula III n the variables Y R‘ R ,R8 R9“, Rgb, R“), R12 and R22 are described herein.

In one embodiment, compounds of Formula IV are disclosed: a IV wherein the variables Y R3, R ,,R8 R9“, R9b, R10 and R22 are described herein.

In one embodiment, compounds of Formula V are disclosed: Formula V wherein the variables Y, R3, R7, R8, Roa, R91”, R10 and R22 are described herein.

PCT/U52016/021276 In one embodiment, compounds ofFormula VI are disclosed: N \ < N N NH2 0R3 R41 Formula VI wherein: R41 is halogen (in particular F or Cl), 0R3, N3, NH2 or CN; and the variables Y, R3, R4, and R12 are described herein.

In one embodiment, compounds ula VII are sed: N \ N N N/ R22 0R3 R41 Formula VII Wherein the variables Y, R3, R4, R12 and R41 are described .

The phosphorus in any of the Formulas above may be chiral and thus can be provided as an R or S enantiomer or mixture f, including a racemic mixture, Compound 5 was separated into the enantiomer compounds 5-1 and 5-2. Compound 5—2 was also prepared by chiral synthesis and assigned compound 24.

In one embodiment, compounds, methods, and compositions are provided for the treatment of a host infected with or exposed to hepatitis C described herein. The compounds of the invention can be administered in an effective amount alone or in combination with another anti-HCV drug, to treat the infected host. In certain embodiments, it is useful to administer a combination of drugs that tes the same or a different pathway or inhibits a different target in the virus. As the disclosed B—D—2'—D—2'—0t—fluoro—2'—B—C—substituted—2—modif1ed—N6-substituted purine nucleotides are NSSB polymerase inhibitors, it may be useful to administer the compound to a host in combination with a se inhibitor, such as an NS3/4A protease inhibitor (for example, telaprevir (Incivel<®) boceprevir (VictrelisTM) simeprevir (OlysioTM), or paritaprevir, or an NSSA inhibitor (for example, Ombitasvir). The compounds of the invention can also be administered in combination with a structurally different NSSB polymerase inhibitor such as another compound described herein or below, including Gilead’s SovaldiRC The compounds of the invention can also be stered in combination with interferon alfa-2a, which may be pegylated or otherwise modified, and/or rin.

The [3-D-2‘-D-2'—0t—fluoro-2'-B—C—substituted—2—modif1ed—N6—substituted purine nucleotides of the invention are typically administered orally, for e in pill or tablet form, but may be administered via an other route which the attending physician considers appropriate, I5 including via intravenous, transdermal, subcutaneous, topical, parenteral, or other le route, BRIEF DESCRIPTION OF THE FIGURES Figure l is a sample chromatogram of a rep run rating the separation of the stereoisomers of Compound 5 using a Phenominex Luna column as disclosed in Example 9. The y axis is shown in mAU and the x axis is measured in minutes.

Figure 2 is a graph of the HCV replication inhibition curves for Compound 5—2 (Table 7) and Sofosbuvir. Compound 5—2 has an ECso : 4 nM, a TCso greater than one hundred micromolar and a therapeutic index of greater than 25,000, Sofosbuvir has an EC50 : 53 nM, a TCso greater than one hundred micromolar and a eutic index greater than 1,920. The y- axis is the percent of virus control and the x-axis is the concentration of drug in ulVI.

Figure 3 is a graph of the HCV replication inhibition curves for Compound 25 (Table 7) and Sofosbuvir. As described in Example 27, Compound 25 has an EC50 : 4 nM, a TCso of greater than 100 uM, and a eutic index of greater than 25,000. Sofosbuvir has an ECso : 53 nM, a TCso greater than one d olar and a therapeutic index greater than 1,920.

The y-axis is the t of virus control and the x-axis is the concentration of drug in uM.

Figure 4 is an intra-assay comparison of the CV activity for Compounds 5-2. 25, 27 (Table 7) and Sofosbuvir. The y-axis is the t of virus control and the x-axis is the concentration of drug in uM. See, Example 27.

Figure 5 is a graph that shows the stability of compounds 5—2; the N2—acetate of compound 5—2. the NZ—butyrate of compound 5—2; the NZ—methyl derivative of compound 5—2; and the entylcarbamate of compound 5-2 in human blood The x axis is incubation time measured in minutes and the y axis is the measurement of the percent of the parent compound remaining.

Figure 6 is a graph showing the in vitro time course dealkylation of2’-deoxy-2’-d-1‘luoro- 2’-B-methyl-NZ-methyl-N"-methyl-2.6-diaminopurine nucleoside phosphoramidate to 2’-deoxy- fluoro-2’-B-methyl-N"-methyl-2.6-diaminopurine nucleoside phosphoramidate in the presence of a human liver S9 on. The x axis is measured in minutes and the y axis is the measurement of the concentration of the compound remaining in nM.

Figure 7 is a graph showing the stability of compounds 5—2; the NZ—acetate of compound I5 5-2, the NZ-butyrate of compound 5-2; the NZ-methyl derivative of compound 5-2; and the NZ-n- pentylcarbamate of compound 5-2 in the presence of a human liver 89 fraction. The x axis is measured in minutes and the y axis is the measurement ofpercent compound remaining.

Figure 8 shows the predominant Compound 25 metabolites generated in human hepatocytes. The x axis is tion time in hours The y axis is intracellular concentration in pmol/lO" cells, See Example 33.

Figure 9 shows the predominant Compound 27 metabolites generated in human hepatocytes. The x axis is incubation time in hours. The y axis is intracellular concentration in O6 cells. See Example 33.

Figure 10 shows the predominant Compound 5-2 metabolites generated in human cytes. The x axis is tion time in hours. The y axis is intracellular concentration in pmol/lO6 cells. See Example 33, Figure ll is a graph showing the activation pathways for Compounds 25, 27 and 5-2. As can be seen, Compounds 25, 27 and 5—2 are converted to their corresponding monophosphate s which are subsequently metabolized to a common MP analou; B-D—2’—deoxy—2’-0t— fluoro-2’-B-methyl-guanine osphate. The monophosphate is then stepwise PCT/U52016/021276 phosphorylated to the active triphosphate: B-D-2’-deoxy-2’-0t-fluoro-2’-B-methyl-guanine triphosphate. See Example 33.

DETAILED DESCRIPTION OF THE INVENTION The invention disclosed herein is a compound, method, and composition for the treatment of infections in or exposure to humans and other host animals of the HCV virus that includes the administration of an effective amount of a compound of Formula I-VII as described herein or a pharmaceutically acceptable salt or prodrug thereof, optionally in a pharmaceutically acceptable carrier. The compounds of this invention either possess antiviral activity, or are metabolized to a compound that exhibits such activity.

The nds and itions can also be used to treat conditions related to or occurring as a result of a HCV viral exposure. For example, the active compound can be used to treat HCV antibody positive and HCV n positive conditions, viral-based chronic liver inflammation, liver cancer resulting from ed hepatitis C, cirrhosis, acute hepatitis C, fulminant tis C, chronic tent hepatitis C, and anti-HCV—based e, In one embodiment, the compounds or formulations that include the compounds can also be used prophylactically to prevent or retard the progression of clinical illness in individuals who are HCV antibody or HCV antigen positive or who have been exposed to tis C.

In particular, it has been discovered that a 5’-stabilized phosphate prodrug or derivative of B-D-2’-deoxy-Z’-0t-fluoro-2’-B-methyl-N"-methyl—2,6—diamino purine nucleotide, as well as B— D-2’-deoxy-2’-0t-fluoro-2’-B-methyl-NG-dimethyl-2,6-diamino purine tide, and other [3—D— 2‘—D—2‘—0t—fluoro—2'—[3—C—substituted—Z—modified—NG—substituted purine tides as described below, are highly active against HCV. This is surprising because the activity of the parent nucleoside B-D—27-deoxy-2’-0L-fluoro-2’-B-methyl—N°—methyl—2,o—diamino purine in a replicon assay (ECso : 15.7 micromolar) indicates that it is not suitable for use as a human drug due to insufficient activity, however, the ized phosphate prodrug (phosphoramidate) ts an ECso : 26 nanomolar, in a replicon assay, which is at least an 870 fold increase in activity.

Likewise, the activity of the parent nucleoside B—D—2’-deoxy—2’—d—fluoro—2’-[3—methyl—N"— dimethyl-Z,6-diaminopurine in a on assay (ECso : 10.7 micromolar, “uM”) indicates that it is also not suitable for use as a human drug due to insufficient activity, however, the stabilized PCT/U52016/021276 phosphate prodrug (phosphoramidate) exhibits an EC50 : 12 nanomolar, (“nM”), in a replicon assay, which is more than a 1,300 fold increase in activity.

Despite the volume of antiviral side literature and patent filings, the 5’—stabilized phosphate derivative of 2’—deoxy-2’-0t—fluoro-2’-B-methyl-N"-methyl-2,6-diamino purine nucleotide, xy—2’—0L—fluoro—2’—B—methyl-N6—dimethyl—2,6—diamino purine nucleotide, and other B-D-2'-D—2‘-0L-fluoro-2'-B-C-substitutedmodified-NG-substituted purine nucleotides have not been specifically disclosed, Unless otherwise specified, the compounds described herein are provided in the [3-D- uration. In an alternative embodiment, the compounds can be provided in a B-L- configuration. Likewise, any substituent group that ts chirality can be provided in racemic, enantiomeric, diastereomeric form or any e thereof. Where a oramidate, thiophosphoramidate or other stabilized phosphorus g in which the phosphorus exhibits chirality is used as the R4 stabilized phosphate prodrug, it can be provided as an R or S chiral phosphorus derivative or a mixture thereof, including a c mixture. The amino acid of the phosphoramidate or osphoramidate can be in the D- or L-configuration, or a mixture thereof, including a racemic mixture. All of the combinations of these stereo urations are included in the invention described herein.

The present invention es the following features: (a) a compound of Formula I-VH as described , and pharmaceutically acceptable salts and prodrugs thereof; (b) Formulas I—VH as described herein, and pharmaceutically acceptable salts and prodrugs thereof for use in the treatment or prophylaxis of a hepatitis C virus infection; (c) use of Formulas I-VH, and pharmaceutically acceptable salts and prodrugs thereof in the manufacture of a medicament for treatment of a hepatitis C virus infection; (d) a method for manufacturing a medicament intended for the therapeutic use for ng a hepatitis C virus infection, characterized in that a as I-VII as described herein is used in the manufacture, (e) a pharmaceutical formulation comprising an effective host—treating amount of the Formulas I—VH or a pharmaceutically acceptable salt or prodrug thereof together with a pharmaceutically acceptable carrier or diluent; WO 44918 PCT/U52016/021276 (f) Formulas l-VII as described herein substantially in the absence of stereoisomers of the described compound, or substantially isolated from other chemical entities; and, (g) processes for the preparation of therapeutic products that contain an effective amount of a Formulas I—VII, as described herein. l. 2’-De0xy-2’-a-Flu0r0—2’-[5—C-Substituted-Z-Modified-N“-Substituted Purine tides 0f the ion The active compounds of the invention are those depicted, for example, in Formula I, which can be provided in a pharmaceutically acceptable composition, salt or g thereof: N \ {ilkN/N N NH2 Formula I wherein: YisNR'RZ; R1 is C1-C5alkyl (including methyl, ethyl, n—propyl, iso—propyl, n—butyl, iso-butyl, sec— butyl, tert—butyl and pentyl), C1-C5haloalkyl (including CHzF, CH2F, CF3, CH2CF3, CF2CH3 and CF2CF3), C2-C6 alkenyl, C2-C0 alkynyl, 2alkyl)(Cz—Cscycloalkyl), *(Co— C2all<yl)(heterocycle), 2alkyl)(aryl), 7(Co-C2alkyl)(heteroaryl), 70R”, -C(O)R3C (including 7C(O)CH2, 7C(O)CH2CH3—C(O)CH(CH3)2, —C(O)OCH3. C2H5, —C(O)OC3H7, - C(O)OC4H9. and -C(O)OCSHII), -C(S)R3D, or -SOzR28 each of which can be optionally substituted; R2 is hydrogen, optionally substituted Ci-Csalkyl (including methyl, ethyl, n-propyl, iso- propyl, n—butyl, tyl, sec—butyl, tert—butyl and pentyl), C1—Cshaloalkyl (including CHFz, CHzF, CF3, CH2CF3 and CF2CF3), optionally tuted *(Co-Czalkyl)(C3—Cocycloalkyl), optionally substituted *(Co-Czalkyl)(heterocycle), optionally substituted *(Co-Czalkyl)(aryl), PCT/U52016/021276 optionally substituted —(Co-C2alkyl)(heteroaryl), -C(O)R3C (including —C(O)CH3, — C(O)CH2CH3-C(O)CH(CH3)2, -C(O)OCH3. -C(O)OC2H5, C3H7, -C(O)OC4H9. and —C(O)OC5H11), -C(S)R3D, or —SOzR28; and wherein at least one of R1 and R2 is methyl, CHzF, CHFz or CF3; Rsswfiéwgm R3 is hydrogen, RgA , diphosphate, sphate, an optionally substituted carbonyl linked amino acid, or —C(O)R3C; R3A can be ed from O', OH, an iO-optionally substituted aryl, an iO-optionally substituted heteroaryl, or an optionally substituted heterocyclyl; R313 can be ed from O', OH, an optionally substituted N-linked amino acid or an optionally substituted N-linked amino acid ester; R3C is alkyl, alkenyl, l, 2)(cycloalkyl), -(Co-C2)(heterocyclo), -(Co-C2)(aryl), -(Co-C2)(heteroaryl), -O-all<yl, -O-all<enyl, -O-alkynyl, -O-(Co-C2)(cycloall<yl), -O-(Co- C2)(heterocyclo), —O-(Co-C2)(aryl), or -O—(Co-C2)(heteroaryl), each of which can be optionally substituted; R4 is a monophosphate, diphosphate, triphosphate, or a stabilized phosphate prodrug, including but not d to a phosphoramidate, a thiophosphoramidate, or any other moiety that is metabolized to a monophosphate, diphosphate or triphosphate in viva in the host human or animal; or R3 and R4 together with the oxygens that they are bonded to can form a 3’,5’-cyclic prodrug, including but not limited to, a 3’,5’-cyclic phosphate g; R[2 is CH3, CH2F, CHFg, CF3, or ethynyl.

A stabilized phosphate prodrug is any moiety that can deliver a mono, di, or triphosphate.

In r embodiment, compounds of Formula Ia are disclosed: PCT/U52016/021276 <” \N N NANHZ 0R3 F a Ia wherein: Y, R3 and R“1 are as defined above.

In another embodiment, compounds of Formula 1b are disclosed: N \ N NH2 0R3 F Formula Ib wherein: Y, R3 and R“l are as defined above PCT/U52016/021276 In another embodiment, the compound is according to Formula lc: Formula [C wherein: R7 is hydrogen, Cmalkyl; C3.7cycloall<yl; heteroaryl, cyclic, or aryl, which includes, but is not limited to, phenyl or naphthyl, where phenyl or naphthyl are optionally substituted with Ci-calkyl, kenyl, Cz-c alkynyl, Cmalkoxy, F, Cl, Br, 1, nitro, cyano, Ci- ahaloalkyl, -N(R—')2, Cmacylamino, alkyl, —SOzN(Rw)2, COR7", and -SOZC1-6all(yl, (R7, is independently hydrogen or C1.(,alkyl; R7" is iORH or—N(R7)2); R8 is hydrogen, C1.(,alkyl, or R921 or Rt)b and R8 together are (CH2)n so as to form a cyclic ring that includes the adjoining N and C atoms; where n is 2 to 4; R9H and R9b are (i) independently selected from hydrogen, Cmalkyl, cycloalkyl, -(CH2)C(NR°')2 , Ci.ohydroxyall<yl, --CHzSH, —(CH2)2S(O)(Me, 3NHC(:NH)NH2, (1H- indol—3—yl)methyl, (lH—imidazol—4—yl)methyl, —(CHz)cCOR9", aryl and aryl(C1.3all<yl)—, the aryl groups can be optionally substituted with a group selected from hydroxyl, C1-oalkyl, Ci-calkoxy, halogen, nitro and cyano; (ii) R9“ and R9b both are Cmalkyl; (iii) R9‘1 and R0b together are (CH2)- so as to form a spiro ring; (iv) R9a is hydrogen and R9b and R8 together are (CH2)n so as to form a cyclic ring that includes the adjoining N and C atoms (v) Rob is hydrogen and R9“ and R8 together are (CH2)n so as to form a cyclic ring that includes the adjoining N and C atoms, where c is l to 6, n is 2 to 4, r is 2 to 5 and where R9' is independently hydrogen or CH) alkyl and R9" is —OR11 or )2 ); (vi) R9“ is hydrogen and R9b is hydrogen, CH3, CH2CH3, )2, CH2CH(CH3)2, CH(CH3)CH2CH3, CHzPh, CH2—indol—3—yl, -CH2CH2SCH3, CH2C02H, CH2C(O)NH2, CH2CH2COOH, CH2CH2C(O)NH2, CH2CH2NH2, —CH2CH2CH2NHC(NH)NH2, CH2— imidazolyl, CHzOH, CH(OH)CH3, '—OH)-Ph), CstH, or lower cycloalkyl; or (Vii) R”3 is CH3, CH2CH3, CH(CH3)2, CH3)2, CH(CH3)CH2CH:, CHzPh, CHz-indolyl, WO 44918 PCT/U52016/021276 -CH2CH28CH3, CH2C02H, CH2C(O)NH2, CH2CH2COOH, CH2CH2C(O)NH2, CH2CH2CH2CH2NH2, -CH2CH2CH2NHC(NH)NH2, CH2-imidazol—4-yl, CH2OH, CH(OH)CH3, CH2((4'—OH)-Ph), CstH, or lower cycloalkyl and R9b is hydrogen; R10 is hydrogen, yl optionally tuted with an alkoxy, di(lower alkyl)-amino, or halogen, Crchaloalkyl, C3.7cycloalkyl, heterocycloalkyl, aminoacyl, aryl, such as phenyl, heteroaryl, such as, pyridinyl, substituted aryl, or substituted heteroaryl; R11 is an optionally substituted C1.6alkyl, an optionally substituted cycloalkyl; an optionally substituted C2.(,alkynyl, an optionally substituted Czaalkenyl, or ally substituted acyl, which includes but is not limited to C(O)(Cl-6 ; and Y, R3 and R12 are as defined herein.

In one embodiment, compounds of Formula II are disclosed: N \ N M N R-- 07° 5" Formula [I wherein: Y is NR'RZ; R1 is Ci-Csalkyl (including methyl, ethyl, n—propyl, iso—propyl, n—butyl, iso-butyl, sec— butyl, tert—butyl and pentyl), C1—C5haloalkyl (including CHzF, CHFz, CF3, CH2CF3, CF2CH3 and CF2CF3), C2-C6 alkenyl, C2-C6 l, 2alkyl)(C3—C6cycloalkyl), *(Co— C2all<yl)(heterocycle), 7(Co-C2alkyl)(aryl), 7(Co-C2alkyl)(heteroaryl), 70R”, 3C (including 7C(O)CH2, 7C(O)CH2CH3—C(O)CH(CH3)2, —C(O)OCH3. —C(O)OC2H5, —C(O)OC3H7. - C(O)OC4H9. and -C(O)OCSHII), -C(S)R7‘D, or -SOzR28 each of which can be optionally substituted; R2 is hydrogen, optionally substituted Ci-Csalkyl (including methyl, ethyl, n-propyl, iso- propyl, n—butyl, tyl, sec—butyl, tert—butyl and pentyl), aloalkyl (including CHF2, PCT/U52016/021276 CHFz; C133,; CH2CF3 and CF2CF3); optionally substituted —(Co-C2alkyl)(C3-Cocycloalkyl); optionally substituted —(Cu-C2alkyl)(heterocycle); optionally substituted —(Co-C2alkyl)(aryl); optionally substituted *(Co—C2alkyl)(heteroaryl), -C(O)R3C (including *C(O)CH3, , C(O)CH2CH3—C(O)CH(CH3)2, —C(O)OCH3. —C(O)OC2H5. —C(O)OC3H7; —C(O)OC4H9. and —C(O)OC5H11), -C(S)R3D, or —SOzR28; and wherein at least one of R1 and R2 is , CH2F; CHFz or C133; R3BMEW§M l a R3 is hydrogen; RM an optionally substituted ; diphosphate, triphosphate; carbonyl linked amino acid; or —C(O)R3C; R3A can be selected from O'; OH; an —O-optionally substituted aryl, an —O-optionally tuted heteroaryl; or an optionally substituted heterocyclyl; R3B can be selected from O'; OH, an optionally substituted N—linked amino acid or an optionally substituted N—linked amino acid ester; R3C is alkyl, alkenyl, alkynyl, —(Co—C2)(cycloalkyl), —(Co—C2)(heterocyclo), —(Co—C2)(aryl), 2)(heteroaryl), -O-alkyl, -O-all<enyl; <ynyl, -O—(C0—C2)(cycloall<yl), —O—(Co— C2)(heterocyclo), -O-(Co-C2)(aryl); -O-(Co-C2)(heteroaryl); -S-all<yl; -S—alkenyl, -S-alkynyl; -S- (Co-C2)(cycloalkyl); -S-(Co-C2)(heterocyclo); -S-(Co-C2)(aryl); or —C2)(heteroaryl) each of which can be optionally substituted; R3D is alkyl; alkenyl; alkynyl; -(Co-Cz)(cycloalkyl); -(Co-C2)(heterocyclo); -(Co-Cz)(aryl); -(C(,)-C2)(heteroaryl); yl; -O-alkenyl; -O-alkynyl; -O-(Co-C2)(cycloalkyl); -O-(Co— C2)(heterocyclo), -O-(Co-C2)(aryl); or -O-(Co-C2)(heteroaryl), each of which can be optionally substituted; R4 is a monophosphate, phate, triphosphate, or a stabilized phosphate prodrug, including but not d to a phosphoramidate; a thiophosphoramidate, or any other moiety that is metabolized to a monophosphate; diphosphate or triphosphate in vivo in the host human or ; or R3 and R4 er with the oxygens that they are bonded to can form a 3’;5’-cyclic prodrug; including but not limited to; a 3’;5’-cyclic phosphate prodrug; WO 44918 PCT/USZOl6/021276 R5 is lkyl (including methyl, ethyl, n-propyl, iso—propyl, n-butyl, iso-butyl, sec- butyl, tert-butyl and pentyl), Ci-Cshaloalkyl (including CHF2, CHFz, CF3, CH2CF3 and CF2CF3), C2-C6 alkenyl, C2-C6 alkynyl, 2alkyl)(C3-Cocycloalkyl), *(Co—C2alkyl)(heterocycle), *(Co— C2alkyl)(aryl), *(Co—Czalkyl)(heteroaryl), 70R”, —C(O)R3C (including H3, , C(O)CH2CH3—C(O)CH(CH3)2, —C(O)OCH3. —C(O)OC2H5, —C(O)OC3H7, C4H9. and -C(O)OC5HH), 3D, or -SOzR28 each of which can be ally substituted; R6 is hydrogen, optionally substituted Ci-Csalkyl (including methyl, ethyl, n-propyl, iso- propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl and pentyl), Ci-Cshaloalkyl (including CHFg, CH2F, CF3, CH2CF3 and CF2CF3), optionally substituted —(Co-C2alkyl)(C3-Cscycloalkyl), lO optionally substituted —(Co-C2all<yl)(heterocycle), optionally substituted —(Co-Czalkyl)(aryl), optionally substituted —(C0—C2alkyl)(heteroaryl), —C(O)R3C (including —C(O)CH3, — C(O)CH2CH3—C(O)CH(CH3)2, —C(O)OCH3, —C(O)OC2H5. C3H,'. —C(O)OC4H9. and — C(O)OC5H11), -C(S)R3D, or —SOzR28; or R5 and R6 together with the nitrogen that they are bonded to can form a heterocyclic ring; [5 RI2 is CH3, CHzF, CHFg, CF3, or ethynyl; R22 is Cl, Br, F, CN, N3, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 l, 7(Ci-C2alkyl)(C3- Cecycloalkyl), 2alkyl)(C3-C6heterocycle), -(Co-C2alkyl)(aryl), -(Co-C2alkyl)(heteroaryl); :O)OR33, -NHOR24, -OR25, -SR25, -NH(CH2)1.4N(R3")2, -NHNHR2", —N:NR27, -NHC(O)NHNHR27, -NHC(S)NHNHR27, HNHR27, -NR27802R28, -SOzNR27R29, N—R25 R3'"R29, $02112", $02112", 'X , -P(O)H(OR29), —P(0)(0R2")(0R‘”), -P(O)(OR29)(NR2°R3”) or —NR5R", for example including but not limited to the following embodiments, chloro, bromo, fluoro, cyano, azido, ethyl, n—propyl, opyl, n—butyl, iso—butyl, sec—butyl, tert—butyl and n— , 1,1—dimethylpropyl, 2,2-dimtheylpropyl, 3—methylbutyl, l—methylbutyl, l—ethylpropyl, Vinyl, allyl, l-butynyl, 2-butynyl, acetylenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, -(CH2)—cyclopropyl, -(CH2)-cyclobutyl, -(CH2)—cyclopentyl, -(CH2)-cyclohexyl, aziridine, oxirane, thiirane, azetidine, oxetane, thietane, pyrrolidine, tetrahydrofuran, thiolane, pyrazolidine, piperidine, oxane, thiane, -(CH2)-aziridine, -(CH2)-oxirane, -(CH2)-thiirane, - (CH2)—azetidine, -(CH2)—oxetane, -(CH2)—thietane, -(CH2)-pyrrolidine, -(CH2)- tetrahydrofuran, - PCT/U52016/021276 thiolane, -(CH2)-pyrazolidine, -(CH2)-piperidine, -(CH2)-oxane, -(CH2)-thiane, phenyl, l, -ONHC(:O)OCH3, -ONHC(:O)OCH2CH3, -NHOH, NHOCH3, -OCH3, OC2H5, -OPh, OCH2Ph, -SCH3, -SC2H5, —SPh, SCH2Ph, —NH(CH2)2NH2, —NH(CH2)2N(CH3)2, , —NHNHCH3, —N:NH, —N:NCH3, 2CH3. —NHC(O)NHNH2, -NHC(S)NHNH2, —C(O)NHNH2, —NHSO2CH3, -NHSO2CH2CH3‘ —SO2NHCH3, —SO2N(CH3)2, —C(O)NH2, —C(O)NHCH3, —C(O)N(CH3)2, -CO2CH3, —CO2CH2CH3, —CO2Ph, —CO2CH2Ph, -SO2CH3, G O E <:N H § $54 CH3 —SO2CH2CH3, —SOzPh, —SO2CH2Ph, -P(O)H(OH), — , , P(O)H(OCH3), —P(O)(OH)(OH),—P(O)(OH)(OCH1),—P(O)(OCH3)(OCH3), -P(O)(OH)(NH2), —P(O)(OH)(NHCH3), —P(O)(OH)N(CH3)2, —NHC(O)CH3, )CH2CH3, —NHC(O)CH(CH3)2‘ IO —NHC(O)OCH3, -NHC(O)OCH2CH3, -NHC(O)OCH(CH3)2‘ —NHC(O)OCH2CH2CH1 -NHC(O)OCH2CH2CH2CH3 and -NHC(O)OCH2CH2CH2CH2CH3; R23 is C1-C5alkyl, —(Cu-C2alkyl)(C3-C6cycloalkyl), -(Co-C2alkyl)(heterocycle)-(Co- 2all<yl)(aryl) or -(Co-C2all<yl)(heteroaryl) each of which can be ally substituted; R24 is hydrogen, C1-C6 alkyl, —(C1—C2all<yl)(C3—C6cycloalkyl), —(C1—C2alkyl)(C3—C6heterocycle) -(Co-C2alkyl)(aryl) or -(Co—C2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; R25 is hydrogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, -(Co-C2all<yl)(Cz- C6cycloalkyl), —(Co-C2alkyl)(Cs-C6heterocycle), -(Cn-C2alkyl)(aryl) or -(Co-C2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; R26 is independently selected from hydrogen, C1-C6alkyl, —(Co-C2alkyl)(C3- oalkyl), -(Co-C2alkyl)(heterocycle), -(Co-C2alkyl)(aryl), or -(Co-C2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; R27 hydrogen or optionally substituted C1—C6 alkyl; R28 is C1—C6 alkyl, C2—C6 alkenyl, C2—C6 alkynyl, -(Co-C2alkyl)(C3—C6cycloalkyl), -(C0.C2alkyl)(C3-C6heterocycle), -(Co-C2alkyl)(aryl) or —(Co-C2alkyl)(heteroaryl) each of which can be optionally substituted; R29 is en, C1-C6 alkyl, C2—C6 alkenyl, C2—C6 l, —(Co-C2alkyl)(C3— C6cycloalkyl), -(Co.C2alkyl)(C3-C6heterocycle), -(Co-C2alkyl)(aryl) or -(Co-C2alkyl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; or PCT/U52016/021276 R27 and R29 together with the nitrogen that they are bonded to can form a heterocyclic ring; R30 is hydrogen, C1—C6 alkyl, C2—C6 alkenyl, C2—C6 alkynyl, —(Co—C2alkyl)(C3C6cycloalkyl), —(C0.C2alkyl)(C3—C6heterocycle), —(Co—C2all<yl)(aryl) or —(Co—C2all<yl)(heteroaryl) wherein except for the hydrogen each of which can be optionally substituted; or R29 and R30 can be bonded together to form a heterocyclic ring; x is l, 2 or 3.

In another embodiment, nds of Formula Ila are disclosed: R O4 CH 3 OR3 F Formula IIa wherein: Y, R3, R"1 and R22 are as defined above.

In r embodiment, compounds of a IIb are disclosed: Formula IIb wherein: PCT/U52016/021276 Y, R3, R4 and R22 are as defined above, In a typical embodiment, the compound is a [3-D isomer with reference to the corresponding nucleoside (i.e., in the naturally occurring configuration). In an alternative configuration, the compound is provided as a B—L isomer. The nd is typically at least 90% free of the opposite enantiomer, and can be at least 989/6, 9996 or even 10096 free of the te enantiomer, Unless described otherwise, the compound is at least 9096 free of the opposite enantiomer.

In another embodiment, the compound is according to Formula 111: Rab, 3 O “N 3: ? O (SC-2R” 0R7 0R3 F Formula 111 wherein: R7 is en, Croalkyl; C3.7cycloalkyl; heteroaryl, heterocyclic, or aryl, which includes, but is not limited to, phenyl or naphthyl, where phenyl or naphthyl are optionally substituted with Ci-oalkyl, C2.oalkenyl, Cz-o alkynyl, Crealkoxy, F, Cl, Br, I, nitro, cyano, Cl- ohaloalkyl, -N(R'—')2, Creacylamino, NHSO2C1-oalkyl, -SOzN(R7V)2, COR7", and —SOzCi-oalkyl; (R7 is independently hydrogen or Croalkyl; R7" is iORH or—N(R7)2); R8 is hydrogen, Cmalkyl, or R9a or R9b and R8 together are (CH2)n so as to form a cyclic ring that es the adjoining N and C atoms; where n is 2 to 4; RE”l and R9b are (i) independently selected from hydrogen, Cmalkyl, cycloalkyl, -(CH2)C(NR9')2 , Crohydroxyalkyl, --CH28H, -(CH2)28(O)(Me, -(CH2)3NHC(:NH)NH2, (1H- indolyl)methyl, (lH—imidazolyl)methyl, -(CH2)CCOR9", aryl and aryl(C1.3alkyl)-, the aryl groups can be optionally substituted with a group selected from yl, Croalkyl, Crealkoxy, halogen, nitro and cyano; (ii) R”8 and R9b both are Croalkyl; (iii) R9a and R0b together are ‘ so as to form a spiro ring; (iv) R9a is en and R9b and R8 together are (CH2)n so as to form a cyclic ring that includes the adjoining N and C atoms (v) R9b is hydrogen and R9” and R8 together PCT/U52016/021276 are (CH2)11 so as to form a cyclic ring that includes the ing N and C atoms, where c is l to 6, n is 2 to 4, r is 2 to 5 and where R9 is independently hydrogen or CH) alkyl and R9" is —OR11 or -N(RH')2 ); (vi) R9a is hydrogen and R9b is hydrogen, CH3, CH2CH3, CH(CH3)2, CH2CH(CH3)2, CH(CH3)CH2CH3, CHzPh, dol—3—yl, —CH2CH2SCH3, CH2C02H, CH2C(O)NH2, CH2CH2COOH, C(O)NH2, CH2CH2CH2CH2NH2, 2CH2NHC(NH)NH2, CH2— imidazolyl, CH20H, CH(OH)CH3, CH2((4'—OH)-Ph), CHgSH, or lower cycloalkyl; or (vii) R’0a is CH3, CH2CH3, CH(CH3)2, CH2CH(CH3)2, CH(CH3)CH2CH3, CH2Ph, CH2—indol—3—yl, —CH2CHzSCH3, CH2CO2H, CH2C(O)NH2, COOH, CH2CH2C(O)NH2, CH2CH2CH2CH2NH2, -CH2CH2CH2NHC(NH)NH2, CHg-imidazolyl, CH20H, CH(OH)CH3, CH2((4'-OH)-Ph), CH2SH, or lower cycloalkyl and R9b is hydrogen; R“) is hydrogen, Croalkyl optionally substituted with an alkoxy, di(lower alkyl)-amino, or halogen, thaloalkyl, C3.7cycloalkyl, heterocycloalkyl, aminoacyl, aryl, such as phenyl, heteroaryl, such as, pyridinyl, tuted aryl, or substituted heteroaryl; R11 is an optionally substituted Cmalkyl, an optionally substituted cycloalkyl; an optionally substituted Cmalkynyl, an optionally substituted Cmalkenyl, or optionally substituted acyl, which includes but is not limited to C(O)(Cl-6 alkyl); and Y, R3 R12 and R22 are as defined above.

In one ment, compounds ofFormula IV are disclosed: N \ <‘ N Rab O N N/ R22 \P O (:0ng c927 “ CHA OR“ f“ FormulalV wherein the variables Y, R3, R7, R8, R9“, Rgb, R[0 and R22 are described herein.

In one embodiment, compounds ofFormula V are disclosed: Formula V wherein the variables Y, R3, R7, R8, R9“, Rgb, R10 and R22 are described herein.

In an ative ment, compounds, methods, and compositions are provided for the treatment of a host infected with or exposed to hepatitis C.

In one ment, compounds of Formula VI are disclosed: N \ N NH2 ORB R41 Formula VI wherein: R41 is halogen (in particular F or Cl), OR3 (including OH), N3, NHz or CN; and the variables Y, R3, R4, and R12 are described herein, PCT/U52016/021276 In one embodiment, compounds ula VII are disclosed: N \ <1 N N N/ R22 0R3 R41 Formula VII Wherein the variables Y, R3, R4, R12 and R"ll are described herein. lism of [5-D-2’-deoxy-Z’-a-flu0r0-2’-[i-C-substituted-N“—substituted—2,6- diaminopurine nucleotides The metabolism of the B-D-2’-deoxy-2’-d-fluoro-2’-B-methyl-N(’-methyl-2,()- diaminopurine nucleoside phosphoramidate involves the production of a 5’-monophosphate and the subsequent anabolism of the N"-methyl-2,6-diaminopurine base to generate the B—D-2’- deoxy—Z’—0L—fluoro—2’—B—methyl—guanine nucleoside as the ophosphate. The monophosphate is then further ized to the active species; the 5’—triphosphate. The B—D—2’— deoxy—2’-0L—fluoro—2’—B—methyl—guanine triphosphate has an ICso : 0.15 uM against the HCV genotype lb NSSB polymerase The metabolic pathway for the B-D-Z’-deoxy-2’-d-fluoro-2’-B- methyl—N6—methyl—2,6—diaminopurine nucleoside phosphoramidate is illustrated in Scheme 1 below‘ PCT/U52016/021276 mi“?EMONQ N N NH: ,, N N“ \NH2 i 2 ansQ—PMONpOH 7 xi f , HO F Pd ’5: Q a My“)? $3, (a) ... ... _., ... (Nijii-i HG“P”OHO Q<NAN HO 5” O F: CNN/C? N A /\\ NH2 N Nq: OH QH \ HQ P H5 1’: 0 (a? O «Nj:“WP was» HOPQP—QP(fix/(3wN«x ¢9L N \NHZ cm OH OH ¥______; Ho‘ ’P Schemel The metabolism of the B-D-2’-deoxy-2’-0i-fluoro-2’-B-methyl-N6-dimethyl-2,6- opurine nucleotide involves both the formation of the B-D-Z’-deoxy-2’-d-fluoro-2’-B- methyl—NG—dimethyl-2,6—diaminopurine nucleoside triphosphate as well as the generation of the corresponding guanine side triphosphate. These metabolic pathways are illustrated in Schemes 2 and 3 below. 2016/021276 X; N “L "\z N W 0PM _ ' LL HG“ ”F Hi3 ’F \‘NH 0 N~ ”*5 Nu 34:3“ng {3 § «j: "“““”“" 9 I - <5 r EH M O N : N NHZ }‘1Q‘”E‘"Q O N N/ \NH? OH OH HOT ’F HO; ”’F E.“ LL" 9 ‘7? $2 <2?“ ‘I 32*“ H04?"Emil-"O"-FlL-O-m NIQNNHZ CH OYN OH {3H HQ: ’3': Scheme 2 WO 44918 PCT/USZOlo/021276 Ho? 1% H5? 2'F {I /NN \NEL/ , 9 9 HO“?“O"?“O"‘\KO\,N r1 ‘NHZ OH OH kmghm Ho r N is 999 <21? Ho~E—o~$~oue~o o, N ~ / Scheme 3 Stabilized Phosphate Prodrugs Stabilized phosphate prodrugs are moieties that can deliver a mono, di, or triphosphate in viva. For example, McGuigan has disclosed oramidates in US Patent Nos: 8,933,053; 8,759,318; 8,658,616; 8,263,575, 8,119,779; 787 and 7,115,590, Alios has disclosed thiophosphoramidates in US 8,895,723 and 8,871,737 orated by reference herein. Alios has also disclosed cyclic nucleotides in US Patent No. 8,772,474 incorporated by reference herein. Idenix has disclosed cyclic phosphoramidates and phosphoramidate/SATE derivatives in incorporated by reference . Idenix has also disclosed substituted carbonyloxymethylphosphoramidate compounds in incorporated by reference herein, Hostetler has disclosed lipid phosphate prodrugs, see, for example, US 858.

Hostetler has also disclosed lipid conjugates of phosphonate prodrugs, see, for example, US 8,889,658; 8,846,643; 8,710,030, 8,309,565; 8,008,308; and 7,790,703. Emory University has PCT/USZOl6/021276 disclosed nucleotide sphingoid and lipid derivatives in . RFS Pharma has disclosed purine nucleoside monophosphate prodrugs in . Cocrystal Pharma Inc. has also disclosed purine nucleoside monophosphate prodrugs in US Patent No.: 9,173,893 incorporated by reference herein. ectTM technology is disclosed in the article "Design, sis, and Characterization of a Series of Cytochrome P(450) 3A-Activated Prodrugs (HepDirect Prodrugs) Useful for Targeting Phosph(on)ate—Based Drugs to the Liver,” (J , Am.

Chem. Soc. 126, 5154-5163 (2004). Additional phosphate prodrugs include, but are not limited to phosphate , 3’,5’-cyclic phosphates ing CycloSAL, SATE derivatives (S-acyl- 2thioesters) and DTE odiethyl) prodrugs. For literature reviews that disclose non-limiting es see: A. Ray and K. Hostetler, “Application of kinase bypass strategies to nucleoside antivirals,” Antiviral Research (2011) 277-291; M. Sofia, “Nucleotide prodrugs for HCV therapy,” Antiviral Chemistry and herapy 2011; 22—23—49; and S. Peyrottes et al., “SATE Pronucleotide Approaches: An Overview,” Mini Reviews in Medicinal Chemistry 2004, 4, 395.

In one embodiment, a 5’—prodrug described in any of these patent filings or literature can be used in the R4 position of the presented nds.

In one alternative embodiment, the stabilized phosphate prodrugs, e, but are not limited to those described in US. Patent No. 9,173,893 and US. Patent No, 8,609,627, incorporated by reference herein, including for processes of preparation. For example, 5’- prodrugs of Formula I-V can be represented by the group: Réme,. ’15ka :0 m In an alternate embodiment, 3’,5’—prodrugs of Formula I-V can be represented by the group: H "g R‘)“ if)“ wherein: when chirality exists at the orous center it may be wholly or partially Rp or Sp or any e thereof.

ZisOorS; PCT/U52016/021276 R33 is ed from OR“, Rob ‘5’; or ‘3’; and fatty alcohol derived (for example but not limited to: Emoieyhfl}. i s , oieybflmg—m (l > ) wherein R34, R35, and R36 are as defined below; R31 and R32, when administered in vivo, are capable of providing the nucleoside monophosphate or thiomonophosphate, which may or may not be partially or fully resistant to 6-NH2 deamination in a biological system, Representative R31 and R32 are independently selected from: (a) 0R3“l where R34 is selected from H, Li, Na, K, phenyl and pyridinyl; phenyl and pyridinyl are substituted with one to three substituents independently selected from the group consisting of (CH2)0-0CO2R37 and (CH2)0-6CON(R37)2, R37 is independently H, Ci.2n alkyl, the carbon chain d from a fatty alcohol (such as oleyl l, octacosanol, triacontanol, linoleyl alcohol, and etc) or Cl-20 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C340 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, such as phenyl, heteroaryl, such as, pyridinyl, substituted aryl, or tuted heteroaryl, wherein the substituents are C1.5 alkyl, or Ci.5 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)—amino, , C340 cycloalkyl, or lkyl; (3"? Hi? (b)ELM 5‘ (c) the ester of a D-amino acid or L-amino acid $235?)ka i39‘5 R35 where R36 is restricted to those sidechains occurring in natural L-amino acids, and R35 is H, Ci-zo alkyl, the carbon chain derived from a fatty alcohol (such as oleyl alcohol, octacosanol, triacontanol, linoleyl l, and etc) or Ci-2o alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)—amino, fluoro, C340 lkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, such as phenyl, heteroaryl, such as, pyridinyl, substituted aryl, or substituted heteroaryl; wherein the substituents are C1-5 alkyl, or C1.5 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C340 cycloalkyl, or lkyl; (d) R31 and R32 can come together to form a ring QR38 O33- Kara where R"8 is H, Cl-ZU alkyl, Ci.2o alkenyl, the carbon chain derived from a fatty l (such as oleyl alcohol, octacosanol, triacontanol, linoleyl alcohol, etc) or Cl-Zt) alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C340 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, such as , heteroaryl, such as, pyridinyl, substituted aryl, or substituted heteroaryl; wherein the substituents are C1-5 alkyl, or C1.5 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, Cmo cycloalkyl, or cycloalkyl; (e) R31 and R32 can come together to form a ring selected from RorS R431 Q"\ FEE? N \ RESME \l m 5 0 i R2}; , / R3913? Q < (H = WV 4 C3:56 and 9 R”I‘D/“E Ni (3 R40 Q ow‘g» xx: NR39___‘?§W ... whereR'wisOorNHand 2016/021276 R40 is selected from H, Cl-ZU alkyl, C 1.20 alkenyl, the carbon chain derived from a fatty acid (such as oleic acid, ic acid, and the like), and C 1.20 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C340 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, such as phenyl, heteroaryl, such as pyridinyl, substituted aryl, or substituted heteroaryl; wherein the substituents are C1-5 alkyl, or C1-5 alkyl substituted with a lower alkyl, alkoxy, di(lower all<yl)- amino, fluoro, Cmo cycloalkyl, or cycloalkyl.

The compounds can be prepared, for example, by preparing the 5'-OH analogs, then converting these to the monophosphate analogs Embodiments In particular embodiments: (i) in Formula Ia, Y is NRLRZ, R1 is methyl, R2 is hydrogen, R3 is en, R“l is a stabilized ate prodrug; (ii) in Formula Ia, Y is \IR1R2, R1 is methyl, R2 is hydrogen, R3 is hydrogen, and R“1 is a stabilized thiophosphate prodrug, (iii) in Formula la, Y is \lRle R1 is methyl, R2 is en, R3 is hydrogen, and R4 is a phosphoramidate, (iv) in Formula la, Y is \JRIR2 R1 is , R2 is hydrogen, R3 is hydrogen, and R4 is a thiophosphoramidate: (v) in Formula Ia, Y is \lRlR2 R1 is methyl, R2 is hydrogen, R3 is hydrogen, and R"1 is a monophosphate; (vi) in Formula Ia, Y is \IRIR2 R1 is , R2 is hydrogen, R3 is hydrogen, and R4 is a diphosphate; (vii) in Formula la, Y is \lRlR2 R1 is methyl, R2 is hydrogen, R3 is hydrogen, and R“1 is a triphosphate, (viii) in Formula Ia, Y is NR‘R2, R1 is methyl, R2 is methyl, R3 is en, R“1 is a stabilized phosphate prodrug; (ix) in Formula Ia, Y is NRIRZ, Rl is methyl, R2 is methyl, R3 is hydrogen, and R4 is a stabilized thiophosphate prodrug; (X) in Formula Ia, Y is NRIRZ, R1 is methyl, R2 is methyl, R3 is hydrogen, and R4 is a phosphoramidate, PCT/USZOl6/021276 (X0 in Formula Ia, Y is V'RlRZ, R' is methyl, R2 is methyl, R3 is hydrogen, and R4 is a thiophosphoramidate: (xii) in Formula Ia, Y is \lR1R2, R1 is methyl, R2 is methyl, R3 is en, and RJ' is a monophosphate; (xiii) in Formula Ia, Y is \IRIRZ, R1 is methyl, R2 is methyl, R3 is hydrogen, and R“l is a diphosphate; (xiv) in a Ia, Y is \lRlRZ, R1 is , R2 is , R3 is hydrogen, and R4 is a triphosphate; (XV) in Formula la, Y is NRlRZ, R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, R4 is a lO stabilized phosphate prodrug; (xvi) in Formula Ia, Y is \IRIRZ, RI is methyl, R2 is ropyl, R3 is hydrogen, and RJ' is a ized thiophosphate prodrug; (xvii) in Formula Ia, Y is \lR1R2, R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a phosphoramidate; [5 (xviii) in Formula Ia, Y is \IRIRZ, R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a thiophosphoramidate: (xix) in Formula Ia, Y is \JRIRZ, R1 is methyl, R2 is cyclopropyl, R3 is en, and R4 is a monophosphate‘ (XX) in Formula la, Y is l\R1R2, R1 is methyl, R2 is cyclopropyl, R3 is methyl, and R4 is a diphosphate; (xxi) in Formula Ia, Y is NRIRZ, R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a triphosphate; (xxii) in Formula Ia, Y is NRIRZ, R1 is methyl, R2 is propyl, R3 is hydrogen, R4 is a stabilized phosphate prodrug; (xxiii) in Formula Ia, Y is NRle, R1 is methyl, R2 is propyl, R3 is hydrogen, and R4 is a stabilized thiophosphate prodrug; (xxiv) in Formula Ia, Y is NRIRZ, Rl is methyl, R2 is , R3 is hydrogen, and R4 is a phosphoramidate; (xxv) in Formula Ia, Y is NRIRZ, R1 is methyl, R2 is propyl, R3 is hydrogen, and RJ' is a thiophosphoramidate: PCT/USZOl6/021276 (xxvi) in Formula Ia, Y is NRIRZ, R1 is methyl, R2 is , R3 is hydrogen, and R4 is a monophosphate; (xxvii) in Formula Ia, Y is NRIRZ, RI is methyl, R2 is propyl, R3 is hydrogen, and RJ' is a diphosphate; (XXViii)in Formula Ia, Y is NR1R2, Y is NRIRZ, R1 is methyl, R2 is propyl, R3 is hydrogen, and R“1 is a triphosphate; (xxix) in Formula Ia, Y is NR1R2, R1 is methyl, R2 is ethyl, R3 is hydrogen, R“1 is a stabilized phosphate prodrug; (xxx) in Formula Ia, Y is NR1R2, R1 is methyl, R2 is ethyl, R3 is hydrogen, and R“1 is a lO stabilized thiophosphate g; (xxxi) in Formula Ia, Y is , R1 is methyl, R2 is ethyl, R3 is hydrogen, and R“l is a phosphoramidate; (XXXii) in Formula Ia, Y is , R1 is methyl, R2 is ethyl, R3 is hydrogen, and R“l is a thiophosphoramidate: [5 (xxxiii)in Formula Ia, Y is \IR1R2, R1 is methyl, R2 is ethyl, R3 is hydrogen, and R‘1 is a monophosphate; (xxxiv)in Formula Ia, Y is \IR1R2, R1 is , R2 is ethyl, R3 is hydrogen, and R“1 is a diphosphate, (xxxv) in Formula Ia, Y is \TRIRZ, R1 is methyl, R’2 is ethyl, R3 is hydrogen, and R“l is a triphosphate; (xxxvi)in a Ib, Y is NRLRZ, R1 is methyl, R2 is methyl, R3 is hydrogen, R“1 is a stabilized ate prodrug; (XXXVii) in Formula 1b, Y is NRIRZ, R1 is methyl, R2 is methyl, R3 is hydrogen, and R4 is a stabilized thiophosphate prodrug; (xxxviii) in Formula 1b, Y is NRlRZ, R1 is , R2 is methyl, R3 is hydrogen, and R4 is a phosphoramidate; (xxxix)in a lb, Y is NR‘RZ, R[ is methyl, R2 is methyl, R3 is hydrogen, and R4 is a thiophosphoramidate: (x1) in Formula Ib, Y is NRIRZ, RI is methyl, R2 is methyl, R3 is hydrogen, and R4 is a monophosphate; PCT/USZOl6/021276 (xli) in Formula lb, Y is NR1R2,R[ is methyl, R2 is , R3 is hydrogen, and R4 is a diphosphate; (xlii) in Formula Ib, Y is NRIRZ, R1 is , R2 is methyl, R3 is hydrogen, and RJ' is a triphosphate; (xliii) in Formula Ib, Y is NR1R2, R1 is methyl, R2 is hydrogen, R3 is hydrogen, R“l is a stabilized phosphate g; (xliv) in Formula Ib, Y is NRle, R1 is , R2 is en, R3 is hydrogen, and R4 is a stabilized osphate prodrug; (le) in Formula Ib, Y is NR1R2, R1 is methyl, RN is hydrogen, R3 is hydrogen, and R4 lO is a phosphoramidate, (xlvi) in Formula Ib, Y is \lRLRZ, R1 is methyl, R2 is hydrogen, R3 is hydrogen, and R4 is a thiophosphoramidate: (leii) in Formula Ib, Y is \lRlRZ, R1 is , R2 is hydrogen, R3 is hydrogen, and R4 is a monophosphate; [5 (leiii) in Formula Ib, Y is \lR1R2, R1 is methyl, R2 is hydrogen, R3 is hydrogen, and RJ' is a diphosphate; (XliX) in Formula Ib, Y is \JRIRZ, R1 is methyl, R2 is hydrogen, R3 is hydrogen, and R4 is a triphosphate, (1) in Formula lb, Y is NR'R2, R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, R4 is a ized phosphate prodrug, (li) in Formula Ib, Y is \lRlRZ, R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a stabilized thiophosphate prodrug; (lii) in Formula Ib, Y is VRIRZ, R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a phosphoramidate, (liii) in Formula lb, Y is , R1 is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a thiophosphoramidate: (liv) in Formula 1b, Y is \lRlRZ, Rl is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a monophosphate; (1V) in Formula Ib, Y is NRLRZ, R1 is methyl, R2 is cyclopropyl, R3 is methyl, and R4 is a diphosphate; PCT/U52016/021276 (lvi) in Formula Ia, Y is NRIRZ, R[ is methyl, R2 is cyclopropyl, R3 is hydrogen, and R4 is a triphosphate.

In alternative embodiments of any of the above, the compound has an R22 substituent. In some of these specific ments, the R22 is F, amide or carbamate, In other specific aspects of the embodiments above, R22 is chloro, bromo, cyano, azido, ethyl, n—propyl, iso-propyl, n— butyl, iso-butyl, sec-butyl, tert-butyl and n-pentyl, l,l-dimethylpropyl, 2,2—dimtheylpropyl, 3- methylbutyl, l-methylbutyl, l-ethylpropyl, vinyl, allyl, l—butynyl, 2-butynyl, acetylenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, -(CH2)—cyclopropyl, -cyclobutyl, - (CH2)-cyclopentyl, -(CH2)-cyclohexyl, aziridine, e, thiirane, azetidine, oxetane, thietane, pyrrolidine, tetrahydrofuran, thiolane, pyrazolidine, piperidine, oxane, thiane, -(CH2)-aziridine, - (CH2)-oxirane, -(CH2)-thiirane, -(CH2)—azetidine, -(CH2)—oxetane, —(CH2)—thietane, —(CH2)— pyrrolidine, — tetrahydrofuran, —(CH2)—thiolane, —(CH2)—pyrazolidine, -(CH2)-piperidine, — (CH2)—Oxane, —(CH2)—thiane, phenyl, pyridyl, —ONHC(:O)OCH3, :O)OCH2CH3, — NHOH, NHOCH3, —OCH3, OCsz, -OPh, , -SCH3, , -SPh, SCH2Ph, - NH(CH2)2NH2, 2)2N(CH2)2, -NHNH2, -NHNHCH3, —N:NH, —N:NCH3, -N:NCH2CH2. - NHC(O)NHNH2, )NHNH2, -C(O)NHNH2, -NHSOzCH3, -NHSOzCH2CH3. -SOgNHCH3, -SOzN(CH3)2, -C(O)NH2, -C(O)NHCH3, -C(O)N(CH3)2, -CO2CH3, -C02CH2CH3, -CO2Ph, O O COzCHzPh, —SOZCH3, —SOZCH2CH3, —SOzPh, -SOzCH2Ph, H %%N-CH3 - , , P(O)H(OH), —P(O)H(OCH3), —P(O)(OH)(OH), —P(O)(OH)(OCH3), -P(O)(OCH3)(OCH3), — P(O)(OH)(NH2), -P(O)(OH)(NHCH3), -P(O)(OH)N(CH3)2, -NHC(O)CH3, -NHC(O)CH2CH3, — NHC(O)CH(CH3)2, -NHC(O)OCH3, -NHC(O)OCH2CH3, )OCH(CH3)2, — NHC(O)OCH2CH2CH3, -NHC(O)OCH2CH2CH2CH3 and -NHC(O)OCH2CH2CH2CH2CH3; In alternative embodiments of compounds (i) through (lvi), an L-nucleoside is used in Formula I-VII.

In an alternate embodiment, the Formula I R12 variable is CH2F, In an alternate embodiment, the a I R12 variable is CHFz, In an alternate embodiment, the Formula I R12 variable is CF3.

In one embodiment, a compound ofFormula Ia is provided. Non-limiting examples of nds of Formula Ia include: HgtéfiNH HngH mmN x.

N x 0 O u HOPON <N HOPOPONO N‘ 3i ZFcHgN N” ‘ 2 OH OH . J HO“ ”P , , HN"CH3 NH O ix 9 PWO éfiNN\ is N N O NA 0 O O </ ExN N/E N NH2 HO--P--O-~P--O---P-—O- N 5 H o [\K/PNH2 O 9 H63 :,FCH3 OH OH OH UCHs /i H6 ”F ‘\ , , HN‘CH3 HN’CH3 x N o </ o ’ i j: , I f r 5:“, <7f2ii“"x N N42 UWNP’E 3%;ng M \ CJxN/ESMONJZN NH. i/ H 0 (3 H WCH; i ,CHB \r 0 (3 H? ’P ‘ HO‘ ’P “” / i i k2}, \ HN”CH3 HN”CH3 N.. AN N AisN 9 “5” T! - = ‘ Q N’KNPK ‘ " 61N / HH‘EHCP‘ HgfrCi"; N. x N x YCANWEMOY‘ZE2% «fj ~ 9 <’ ,i if N N42 ,«OYAN/EhO—KVOYN .NANHP O H O H . .CHa 3 0 WC“, WO 44918 HN’Wz HN“CH3 1 _ 3 éfi‘f/fiN o 6N \N \\x0\rj\NW§wOww\f07;% N’Q fik ? “ N’Li 4* N%; \N/Ofiffix N Hax§“O“‘\(OZ: am .M3 so .x......9cm, EH3 F HO F 0 /. x”is \ \fx‘ HN”CH3 HN”CH3 ('5: "r H& F HO F x/ x,: // \ x: ;%T] HN"CH3 HN’L”3 P(rr/Us2016/021276 HN’LHS H§“CH3 O /N‘ \N __ O {NVQN fi—o N’i 4k " ' 0 fi~o N’i {l C5J :1“ ,5 ‘3‘_____£¢aiCl*“o o H o \m CH3 Hé‘ ‘ \u \\ and N vk In one ment, a thiophosphoramidate of Formula la is provided. Non-limiting examples of thiophosphoramidates of Formula Ia include, but are not limited to: HN”CH3 HN’CHS N in N x I § €L:E: :fi § : P~o Pwo fin:fijllz N/§ ”xii: ll ’4 NW \YOmJRN/é ”K<Q¢ NW 6 +4 o E +1 . }CH3 0 0 fwugCHg HO F HO F /,1 \f’i/”71 12/ HN,CHQ 6N,CH3 N x N <3 i‘” S <5 .5 1: Hm NA" ’f “I“ M’k‘ if:/ ONT/Amway"? CY: M O N Y NH? NH: 11 \v/Ofig‘l‘lfpi O H \ O 5 .5 ;CH3 E} IQHA? HO F HO 1 /" ,/ ‘x \“l WO 44918 WO 44918 .. N .. o A x: 0&0? NH2 O\ N T: N N”I; ou‘voy x \ H O K}______.4§::1CH3 H O O O \ \L_____ijH3 = HO F HO F K/V x / i l RN \ \ \ Wan-E3 ”NM-s Nu . N . =3 / 2:? S 6“ l1 E: “m \N / H... NA“ 9’“ /o.\n/:\Wl: 0%“ N NH o Lg; OW N NH; ~z _ \ C“ Y a ". (,3 ,3 (3% "/7\ Q O ’~ / ‘~ HF “F ”? (fly? i is» ' HN»CH3 HN“CH3 In one embodiment, a stabilized phosphate prodrug of Formula la is provided. Non- limiting examples of stabilized phosphate prodrugs of Formula la are illustrated below: HN“CH3 HN“CH3 IN New 0 IN AN _ (3 < l A — ‘5 < i A '2- ,..\ N‘ / '3- I ». r\ N OWN/P @ng N NH; 0 N NH2 : N/P 0pr 0‘ ”F o” ”N «Cir, mkH,M \ ,\ luCGuCW (EN/“(3 Hlf t (NI/1W if [N o ‘N o / = o v’ x, o l ‘ w l f \ U s: N’i‘ ”A 3 \P—c (\ N ~ 62k “VJ N rho O “\i NH~ . w / O A 1 2 OH N Z (EH: {/Hz . ‘ . ....‘ Ho‘ ”F Ho" "F H2{;(H/C)MVQ{Oxxwm“ii <N/K’L‘sN JP / ""Y N In another embodiment, a nd of Formula la is provided. Non-limiting examples of compounds of Formula Ia include: P130NCH3 '. ‘ ., 33”,Ci‘ig [N /j\ {\L HO" P.—0 1&1\NANHZHOmgwomfi-wf‘ NAN’VK.

N233%AN - WWW ! :- . O ! i “ KEHE 2 OH O“ \m“ CH3 u N N NH2 (1 n Cs) {Ml/QM ROWAN/g ONO HOPoPoP~o N 5 Q NAN“ H O 9 ; uCH3 {IDH WK '2 ,3 HO F OH OH ______ @513 v _ 40 ’P ’\E WO 44918 H3C\NJCH3 HBCxNIZHg N ”3% N\ \ N 9 <1 I ,N I? (y F \roW/iN/g—OWN No NH2 \rngfifE:_O.K/Q\fmm\fq¢k\NHz H O CH2 H ~I j,CH3 O C) O V: HO F HO F / x" Lax 1 E WO 44918 #gc\ N4CH3 chmN’CHg = 3 N. k N O / WWW} O _ (1’ $5] /O\{AN\\: Oin NA 5:1“ 2 H... N . {I NH2 WOYxN/l; ONO N NH2 é £37k, r4 O x.....afiCHs +4 0 0 CH3 Hd‘ ’% Hd‘ % x’ / t g x \ H-C\‘3 ‘_ H-C\ ngHg 3. ,CH3 0 o “- emf/’1‘: ' r” ’ 3 ‘u $ng \k/O\(§\Nx§ O"‘xif2:‘ N’*\ % N NH2 \\/o\K/mfimwf U“‘\/U7y N 0 6) {CH3 H . _ E?) ‘}_.____1¢CH3 Hd’ ‘% a+d‘ '% V” ”" l E R \ Hr’xNILHg,r ‘ a 4RL“N*CH: N \\_ \5 x o </ I N <9 <’ E N IH3}{3 - \Ef’CPB chanCHg N ”x N 0 <2“ *5“? o </ \N H“. i N fig : / _ {Ax u N HO F HO F 2/ fr E 3 x ifx x H C\3 HQC‘K N”CH3 (j, H5, CH3 chx N A N 9 «If? : o 6;“ _\ 3" _ N A li“fi‘ V N N N \ o \NNVF: OWN/03;» NH2 \ (if f V : N E CK}; H {VH3p o o {Fm-ifCH3 0 H 0 .

I} HO F HO F UN)/ {ya/y \ NJ fingJ‘Fg HBC\N”CH3 O s— o H3 o , LgéaCHs HO F 71\ HO F 2 53/ \ L‘x E HSC‘NNWCH3 HBCN. ,CH3 N \ «Nf'ixN N \ N C? «N § 4 z 9 OJ‘N’IEWONO N NH2 onNwfiflwo N *5 H o \mNmH3 i o H 5 ”CH3 H6 ’F / H6 ’F x” x" rf / \ a Cb XEJAVHZ .—£"-J\E?EWCH3Ar «IiiN x N A o = O 3L0 N 6’1”? ‘~‘ o N“ Q ‘Jzto N- NA (”*7 ““sz\ “Y 2: ““2 WNN “YO “H?- O <3 CH3 0 H _ , Q CH3 K .

Ho‘ ”F HO‘ ”F g// / \ and HSCEJFUHJt n o 61‘“ O E NWOWC’N NAN/ Y NF N“ E 2 O H C“ N O a x ', In one embodiment, a thiophosphoramidate of Formula la is provided. Non-limiting es of thiophosphoramidates of Formula Ia include, but are not limited to: "lgCNNJCHE HscxN CH3 N N \l‘, S <’ j s m <, f'?‘ {Kl/M“: ONO::3 M {‘4 Hm N P O Y N4 ~ 0 H O ______ C1 ‘iz C) . .

NJCH?’ H‘CN ,CH N A Z 2,.4. c (5’ “if “N 03 n» «"<~ E $3 >~ 0’ >Z\ 53 1).." Z {3 0.E‘E‘QZ 2‘ “A Z I M [C3OIJQ“Jim "k 2?; ii La: O!!!“ 3‘ 12 ii Olin-‘13: :jiCM("x )3 55, .T‘x U} ‘\ {I‘lCKEIEwCl‘g H C‘k-(JHQ i N : 8 <, " .F'LO 6f?N 0 N 3:11 3 N” N \f WNW WY i - Z M \VO til-5%.? o N/ N; “V “75’ NH; " H o * o H . .CHa o WCHS No‘ F No‘ F /’ W x R l N»CH3 chxon3 N, <> N AN : ’8 (N i 7’? § 6N”; 6': ~VO‘ «x £an ,0‘ N N ‘4” M, \VOe NH2 N s 7:.“ Nxgflwoy9 \ O D 1"“). :3 H .3 O O CH3 {I _ HO F 0. f5O n7:NME“N/L‘NH O 1 ”WWN é-VV‘Phi“) O fx NH}; O 0 _______ms LH 0 H O fumes; u H 3 HO F E Ht)“ F / r” I g:-l \ \. 3 H30\N«CH3 N\ if: N s (I g s (i i g \N E. N / ‘N {’4‘ YO‘WN/E O NO NH2 I \l/OYiN/E OW b H O a(”CH3 H O O M. \ [CH3 HO F HO F E/ / / / 1 E HSCNNVCHg H3Cxfid,CH3 N”. N\ 8 <2 “Kg“; S; { ‘5 ”a“ / . NA [aw MJ\{ix/E/ N d N \rOWN??? ONCE: NH2 WO%N¢? 0‘: MHZ (E) éni E) (3342 3 CE-iz E-i 5 x j, EC} u. I fl HO F HO F ./ / \ O \ i C3 \fvaHfzi H C3 \N«CH3 N. \ Nx \. N : s (I Tim? S <” f 7 ’ o {55—0 150 N \q/x w5 o N N E ”WY a;0 NAN“I MHZ \/ x. \x NH2 ijatE-h E N i WOW? 3 H 0 O H O MCI—13 HS ”F H6 ’F / 1’" / E i \ ‘\ \ H}3C\N’(’H’o‘ H3C‘~N»CH3 N N N A m <’ i ‘i/ 1 : ”w N r’ ”Six/NM”): CV03? ‘ng OVENN/P ONO?”, N 7K 5:» H O H Q______glfwg 41 5 o ......{aCHs PCT/U82016/021276 \ET‘YWHOr Has: A u \N’MHOA N \ N N x _ § </ At t; may?: 'uww (3]: A N‘ (I 0 kw «;~\ 'v' N NH; OW); vi; Own/Ow M rfax {ZCHS NH; \______Ac:- 7\‘ I W 5* i :.PEGT 3" (NT/g 1 5 1 I‘m/ARK Wit»!N5 \N‘C! 3 H3C\M~CH3 L a”! L) C} / x. «1 l’O F HO F ”If / / 1" E, i \ V and x Q In one embodiment, a stabilized phosphate prodrug of Formula Ia is provided. Non— limiting examples of stabilized phosphate prodrugs of Formula Ia are illustrated below: hiSC‘N CH: i'lfjcxmflngg N N ”‘3’” \N “N ,1 _ £3 <3: , o ‘ K/OvmN Nd; o M/P'CN/O “4' Win F o r , , A o HQC H~£L “ m \ A ~ ~ N 444) ‘OJL‘RCHzlm‘vHs ‘ l a 3‘mes-i3 ngmzcm 0‘ N Y N \N VN 0‘s? < 5 O \ J <f l O 9 ,J ; dpnowxo N MAW“ ”0 N O i‘v'A‘NH ” \’ é 6»! U CH3 orig ‘ ‘ ’ PCT/U52016/021276 N /‘~L\~ H!“ ,7 N «CHI A ,, N\ L \ p—N o g (EN E [N ....1:8.

YSWVUE‘UNO 3“ W2 l m) ‘\______ can J O f o x73 5 HQ E“ \fj ‘N«CH3 "' N. A a <» 1w “ ”\ Nm wP 0 N" ”A H l HQ “\‘x/O}? NH2 \ O 0 you. My~ CH3 H3C(H2‘3}14~\¢,Q Ofliimzlmiigs. N J A H6 F \N 0 p (a: .; ‘-~_ 2 HQ? ”F ‘N,CH3 E O N f§N \f VHO ‘ a: /‘ ,,.. a” ____ __ O {N 1K Fe) Ox? N 0 0 CH3 >\‘ H6 IF H3CO i: and W In one embodiment, a compound of Formula II is provided, Non—limiting examples of compounds of Formula 11 include: H3C\N”H cherH N’H N \N No x ‘EN < «i </ WAN <é' A R04 ON R04 Nv’itr’ R04 N‘Efi’ix NNH U0 N NH U0 N NH Ni 7? a E ------ CH3 (3sz R30 ’F N ,CH3 c yCHB’ RO3 F RO3 F W wo 2016/144918 PCT/USZOl6/021276 Hi:3 ”2‘3: HBCR \NoH EH NH Nj/L. \N N\ N x <2 :' \.N </ fiN 4 <N-"i A ,E A R0 -- :1 0 a: R40 N R4O~X N \N’A‘ ‘7‘? W' 0 N . o \WéfiCi ix k CH3 i ‘ . R36 ”/F \\ R35 "F R36 ”F A L/ H3CxN’H H c3 er-H N N x 6 f“ <’ N l R4O'NX/OXPN \NANH N NH \kwéflcn—q3 L WOW!” ~:::;\ CH3 ~“:;- ; 2, R36 ”F \ F ‘\ x N / LN , , H C3 H c3 \N"H \N“H <[NE/\N (Nfiw 4 , r 4 «k A R o N o N R OWN NH N NH 2. ZCH3 CH3 ~ fl 'u. to \\ R30 1 V». r‘ ‘: F L‘fi MN R30 F L‘fo , , H3C\NgH H c3 \NH HSC‘N.—H (IA/EN\ N x N\ . \ <¥ ’d‘ 4o ”if: j 4 </N 4: X: R X: N N N N N NW N CH3 ‘LWACHg _ ,, «I :(‘CH3 / R35 ”i: / R30 F I L 5 R30 ”F \ \N H , 7 H30 HC EH 3 N. . <, I Ti <9E “‘N RC4 r’ . N xix 0 N NH RAOYZN, Ngjfiw A ~ \1T ‘JHE. CH3 g : _ H3O F (3 ”SH: R35 ”F <3 PCT/USZOl6/021276 H3C\ H30x ch\ NaH NLH3 N—CHg {/N \N (,IN \N (;:N : \N £61 A \ E R40 / 03; N R40 ”Pk HN‘ 0. o\N N R40 NH N NH Y ‘ . 07;“ ‘ . 1 i a : MCI-‘3 C5H11 CH3 CH3 CH3 J ’ \ g C2H5 R30 F O R30 F R30 F , , 3 ch- H3C «RN—Cf“? \N'CHB i '\N R40“ o<N’EN’ (£de {/Njf/{u'>1 ”A“. r 3 H i 4 ‘« CH = CH R30 F 3 /\‘7 3 N, a! x. i; A R30 F R30 F V by Has an “ \Nams ° ‘NCHg M L N <1 {‘E <3 R49 J‘ N? RON") 3‘ V)“: 0 N?‘ N, 1 W NH ”23‘: 4" F \E‘Kj F0 Rx)q’h F km!)\ H3C HC RN‘CHs 3 \N.CH3 N AN 6'1 N X N ." <? 5 N NA HC ch H3C\ ‘N«CH3 \N’CHS N»CH3 N \ ‘ er/ix N~ / l NN {l f N ‘4 ‘5 KN 4 <N“E Fix R40 N” o N/ R40 \N’ N NH 0 NRL ROflK/OV NH NH N \ 5 CH3 CH3 . \ or //A """ FFCHS L ”MW R36 ”F i/ R30 F Rso“ O a [5 Ly a ‘Kx/V \N\ ZUl6/021276 H C3 ‘N«CH3 <’JNjg/EN ng H36x Nut;”H 3 N’K’"H ~ H R (5 ’F CH3 F230 ’F (EACHg Hap H c “ 3 \NacHn, N CH3 {N‘ : gN <fN \N 4i 'E 4 N 4 f}; R "-" 07" N R O HN\ O\ N HN o\ WCHZ 1 CH3 7T CSHH F236 "F ‘3' R36 ’F O 7 , H30\ m HSCx fig \N : N <E’N ‘N N N if \‘N xN ' <I’M/Ti A \i N“KN“Kf I R40 4 4 éNji {JR R0 Rio}: N R O “NCO? NH N NH NLWYCH‘0 i E \mm 3 4 ”ENE CH3 ¢ pCHs <3sz, R30 F R30 F R30 F N \ f E N <’ R40 NA / .~:"/i\ 4, A / "Kr/O N R ONO)?4 n. NH N R 3 N NH OWN NH \m CH3 3 MCHs A Wes—a3 A Fri Rgd‘ , F \ / [2.30“ ’F Rd ”F , 3 H C H30 3 \N‘4 \N/4 N\ N \~ N N N / CH3 NL\/\ “LAWS f? F R o F 'Jl \I‘Cl- / ‘L‘NZ/ WO 44918 <3 ;“ R4Oon N N/ H c3 has ‘NrCH3 '“ ‘Nflcm «”7311 0 £er 0 4 Np“ .r’ R 0W6: N N/LE‘DCH3 4 N R 3&0 l“ N’k‘oegfii ’ H CH3 ZCH3 H . ‘3 R36 ’F WC; ”F , 7 H c3 H4: \N"CH3 4’ Kali-3H: KL“ N“ V}: r) W) ”F R"? ’F , , qu HC V \Nst 3 \N"<\- i. k A \ \ . i P4m N r’ E/JL‘O VAV R 0%0 ,A 4 N a Q N N NAOCHg) Lycra H _ “CH3 3‘30“ ”F ‘ R30 ’F H30\N/[jjx H53\NA </ ji /N”AN l 0 <_ l: 0 R40— N :3 N” JA,‘ . F240- 0 N’AN/uxOC3H7 L4;CH»; l'i R35 ’F R30 F 7 7 Ho H39. .

N [:1 i N. N 6/ 0 <5 fl 0 R 0v4 N :33r“ N NkOC4H3 R O4 N 6k O»; N N/fixom/V 3 H _____ACHE, . ‘CH3 .

R36 ”F and R36 ”F In one embodiment, a compound of a I is provided. Non—limiting examples of compounds of Formula I include: WO 44918 PCT/USZOl6/021276 HSC‘NA \NW «N1/ R40 N 0 NANH2 R40 R30 ”F R30 ”F WO 44918 PCT/USZOl6/021276 T/fl\\ N N \i/\ _ </ A \N m G <’ T :2: : ”n N / : ‘{_, Mark / \ 0V N/E’ OWOV N 5“ NH2 \, “pH/E «O? N NH T H o WCHs H O o 'CHn HO F H3 F 0/} 61 0%,} \ xN/“x HC3 X‘NAOA—m’f N x o " _ l 'E‘ '_ N”:\ ”A " ? m Nfim o 6 \m—zfiCHs (fix! HO F G? H :2ng ‘J ; , R353 ”F c x A.

In one embodiment, a compound of Formula II is ed. Non—limiting examples of compounds of Formula 11 include: Her3 Hicc NH ~ {fir-l R4o.\/Q N N ”‘0 N N GOSH M Z Q H ‘ , x? H R51 ’F RY): 3? I_|3’C‘NH \DIH NN1/EN NVAux O O d H Hd ’5 HQ‘ ’5 LEj.

\DJ”, \lyl/ NN/J‘Q Nay/k _ <2 (3‘ '3 E“ m -.“- " ’ _ N'“ N/ W;’ ‘_ ‘48:?’ GYM/go ”go“? OWN”: ONO? 3‘ N E/ H H o 0 ,CH3 \V ,3 0 MC“) HO F no“ F z ”a \ \ N «i - </ a : ”- NW /jj / . 14/ng 07’ E (5 H 5 ' \ m’LHg ,1 HQ r and O\ o 9 \wr WANmpméh H ; O O. / “i In one embodiment, and R“l is \V.

In one embodiment, a compound of Formula II is provided. Non—limiting examples of nds of Formula 11 include: PCT/USZOl6/021276 H3C\ HSCX NH NH HAN5 «NW-AN ”NV/KO J ‘ R40 N VtN 0 R40 0 Blr R40 UCHS UH MU0 {NANA R36 ’F R36 ”F NSC? "F 7 7 7 H3C\ H3C\ HsC NH NH NH N N N </ 5 :2 </ TEA/”L <“ E / / / R O NO?4 N N R O N :0»;4 NMJ‘H R O4 NA l“: N NOCH CY N N3 NQCHZCH3 MCHS CH3 H “ , WOW H R36 F R36 ’F W5 "F , , , HJC\ H C\ N34 NH MOHs H H x , $80 F [€30 F , , H30 V \ \NH NH {N‘ lN‘N 0 <5’ T ”‘3 R40 {NI ’“K O N’ ,’L A~ Pat-\Néf/KFE “N o-_. N o \\ R4”)x O J x]? H W "i WCHS I M, H / ff H R36 "F R36 ”F , , ng H30x H <3 NH NH NH N».%X N N#\ N r’\ <’ i <’ E iE“ <’ i N N" N"i NAN” N BF HaOHx/O \E/ R40 F R4QWO 0 N; AVH “H I \\ raw” ‘ “fly/"h '4/ fl/ / .. . ..

R36 ’F R307 ’F 2213 ’: wo 2016/144918 PCT/USZOl6/021276 N231; H3C\ NH NH /N INN N < // j/L‘N I \ E A N “fix N”x33” W‘OWO N . ..i N NOCH WOW/o 3‘1””. i i‘éCJChZCJHg . Vin \______ H \_______W" H R35 is R35 ”F 7 , H30 H c: \INH 3 \r' N <1; x, 9 <3 f? E g: — ‘ WOW N POW N R 0%,0 NANO/NWof“ H \ ,a/H ! 7:5” H \ 1/ H _ , , RSCT ”F R33 ’F “3be fit‘ NH {NI/i;N ' x .

. N O N it <5 N R40 N 0 o——-N’ o \ R40 N 0 Ndkfl W g g u? ‘EWW/ H r” ------ CH— . .

R36 ’F R36 ”F , , CH2 H3C\E>£/CH H3C\N/CH3 <,N a“N \N \N A <)3 ,N“: 3 < (Q R40 N q W0 N / N ”/K Q N 3 N” R40 0 N ,5“ N- R30‘ ”F R36 7? R36 ”F 7 7 V H2>C:?:,CH3 HJ’\N,.CH3 N~~ \ N A : N - N R ONO N R {EN/0;: N NOCH3 INOCHZCHE CH3 H CH3 H , 4 u , R36 ”F 5230‘ ’F , , H33x ,Cng H3 \ ,CHB N E2: <5“;- ‘N [N ‘N WONG N N"? NO’A‘V/ R40 0 l‘4MixNAN{afi‘Nv/NN \ \ \f I h (LN-{3 H théaC/Hz H R30 ”F R30 ’F WO 44918 R 0%04 4) N 7 R ON'I} Ci OWN O \5 \______ CH3 I \______M' 7 7/? R36 ’F R36 ’F 7 7 Wk ,CH3 Rik 7,12}: RsCx 713% N 3?: N N x . e :“N <54 :‘N «NW/R4 N’RN’P’RM N 7 «K NAN/PK We Br ' a Fm F O J o 0 N3 :7?ij f/XH H +213 ’F R36 ’F R36 ’F 7 7 7 Hack/77Hn "‘ a“ HAG a “N” H;F ‘93:th N F a“ ‘sx x’x HANK RO---‘77/Q77y/ N NCCH~ r240- Qf you-:ZCF-ag /H i H W H V” H i?»‘0 F R35? ”F 7 7 H7:J\N ,CHg 3113077 ”gm ft/kN 6;:fia‘i= R4uW”1;; NOW RONO :fi: NANQM H7. ”,H 1/ EI \“----v ------ R35 “F R30 F 7 7 H3C\N/CH3 H3O“ de IF 946‘ (E hue» ('- 7 7 V mg A H?“ A N N N x. N‘ [lug <’ N E (’y 5 571 R wNOY- 4,-\ N .‘7K ' 4 \N 6‘5“ N R ONO N NQCHS wowsH3 -:3 H CH3 H R35 ”F R35 IF qu A, H253x A N N N 1% «I N eNj/g-E l I CH3 H CH3 H . Q ‘ {unuéiflcHg H // \Luéoéagx/ R30 F R30 H3,C\ H q A H ‘6‘“ A N N H </N \N I“ - \‘H ,NV’AM < I ' < i N 'Ji A N/ N ”A“ N-f/L" N .__ N!) R40 Br 0 R40 0 ?- N H *i R4ONU Mi :La: .4" ii,» :C’rjfjfl‘r ----- Ln" \‘fl-n R36 ’F R3<§ "F RJC? ’F PCT/USZOl6/021276 H,C\ [A My; {E’N N A i A <’ 7/? KM :A ,z N "4 w N/ N . .. q R wax/0 New R 0%04 idCéCh2<JH;g H "‘ W21?” H «g: H R35 ’F R30“ ”F 7 , H3C\ A H3CK N N N. A = <’ 1 Xi <91"? WONOVXN a / a N No/‘x/ a: NANQW\ / H , ,; EM?” H \___ :13 H R36 ’F R3“? 9‘ 7 , <1 5‘“ 9 N 4 R40 N OMNAO ”\(‘j, 07}:65”, H H \V/ and R36 ”F ‘Jl In some embodiments, R3 is H and R4 is N“ \YO «\Nw,,f:5m§ o 9 In some embodiments, R3 is H and R41 is YO NH In some ments, R3 is H and R“l is O In one embodiment a compound of Formula II is provided. Non limitinO examples of compounds of Formula 11 include: R’\ ,R2 RL ,9? R; .,R‘ N N R <N A N A N <NI N TN \ <, N R40"%OYN N’RN R40iv N"MKNN/‘> Wonk”; N‘ N‘kN/"R Mom \3 Jerri L.“ CH3 ‘ ’ K) R36 ”F we? F Peso? ”F 7 , 7 R: 2R2 Pk /R2 R: rRZ N N N j: x N \ Nix N \ < a ‘4 <*‘ E E1“ 30AC)d;Z N NRLR: 0 «3“ ,. j:G, A" (1.7 0/ .fi..\ de \ F R3 R30 l: ’ , R\ /P/ Q1 .19? P /R2 fl 2““ is N N N\ w ‘3’ I \N <’ f” (3* fax Rift NOVN l‘k‘cu» R40"'% 0 :NJ‘NW/ R4o--‘\{O\;§‘i “N” \ R35 ”F R36 ”F R30? 1. , , wo 44918 PCT/USZOl6/021276 R»: ,R2 R1: ,,.R3 R1 ,R2 N E N ,3i. N\ :3: <, 73“” <» e :3 3: R ONO.4 ”’J‘K f F"“:3 ‘3:F” x . N i” N T” R (RX/0:3?”4 N A‘CgCgatkenyi RCJNOZ:;3 NW _ 30H; ELWRCR F335 ”F R36 ’F R30 F 3 3 R; R2 R1 F: N” R” {/N “N g “‘N E «N E 4F N‘ 4 N 4L3 fr“: \ VI 0 N{k V R ONO N ~ 2- 685?:in CH~ : ZCH3 3 , R30‘ ”F R40 ’F 3 3 R1 R7- RL R N” R” M {x Fix/i» R ORR/Ox? R\ R O ”V0 N“(Ca-CRR:F>:cs--cacycaoaikyi) M03423 H CF53 3 3 R36 “F R36 ’F 3 3 R’\ R R1: R2 N i!“ 3/ \ Nx/i‘ RIOHWOYN N R4OWWN N @6333 ‘j i _, R36 ”F R32? ”F 3 3 RR ,R3 RR ,R2 E N . 4 <33R}: RN R 0W“!3 333/:kaLOCzaikymf...~3Cahetemcycie) R0&03/ if? NjfiNH (2:33 \ 3 3 iii-3 WC} ”F R30 ”F WO 44918 R\ R2 R1 R2 if av N N. AN N N , Q m (Cc'“Czaikvbfarw RAON‘OZ N \f/tj N: N R: ,R2 2: 2: «N70: NONQ4 . N <1:jg N .» NHOCH “INC:ZN N ‘2xNHOCHgPh . “CH: CH; N35 ”F 230‘ 7 7 R; zRZ R: ,R2 F21: ”/94 N N 2;: {/N i '\ <3“ 2 j? K (Iii/NM 2 X(32+ CH3, \. XCH3 ‘ , RN? ”F N30“ "F R365 ”F , , , R; ff'iZ Rik jg? R: ,R‘ 3i N NN N i PL ”24 <9 {N <2 TEN-Nl 6’ f“: M RR N‘“ A m N” f 1 , . ,CNQ N35 “F R36 1" R35 (F , , N1 R R1 «R2 jg N N , \ N A 1 /N 4 {1’s} ,4? R }?! N R 01W“ $3024; N, \SC} JPN @0243 CH: . .

RN? ”F N39; ’F , , N: 33 RR ,R: N N N NM N <03” A <11: W,2“: 90W“!4 a” ’ N / N NH<CH2)-1 NW? “’; “ONO N FAWN“; g A @223 R20“ ”F Rd” ”F 7 7 R\ ,R2 R1 /R2 N N N N ~ {I jg , <2 :2: “5 R40 N N 0 N R‘Om-NVQ NflNNNHRZS JCHg NEW/N \f C * px'id IF RL“: '3‘: {a ,R2 R1 ,R2 :1 I? N N /\ 4 Ai/ 4‘ «ff ROND N N _/ N NHNH; RC‘Y? N ‘NHNHCH3 . . XDW mo“ 1 RSC ”F: 7 7 R; /94 R1“ /R2 R1 /R2 N m r? «N ,2: e” 3:l 4 N / RC F4 / 4 «NHx“ 0 N A7 "‘0 N=NR-' a;in N \NEWNH ROWN N N=NCH3 CH~ MS ‘ ‘ a ,CH3 wo‘ ”F R36 3: R36 ’F , R1 ,9? R1 ,1??- N N M k m {x </ J? 1 e g RONOQ"4 .rf 4, *“K r5: N NHQDWHNHRZ’ Roxy? N \NHQOWHNHE Wei-N CH: R36 “F WC; ”F , , PK ,R‘ Rx. “9/ j N R 0 «ck/07;“4 (”NE \N, ”N ” _ r” R 3 WM4. N ._ x NHC(S)E\§HNHR"V N NHCQS)?\§HE\3H2.

WCH3 CH3 ‘ “ R36 ”F R36 ”F 7 , R\ ,R: R: ,R2 i N «N {“9 MA?“ R 9W“'4 . affiL.‘ 4““. N “/E’N N mowHNHRZ!u. R LINK/O, N/KCQBNHNHZ \wmcm ~ ACHS m3 ”F Q35 ”r 2016/021276 R\ ,R2 R1“ ”R: N N N A“ waJx </ WAN N 4 N .«kfi 7/ m4 P”77:?x R 0ND N NRWSOQRNG,7" N O 0x)?“ N \NHSOchs CH “#6333“ WC“ 1 R35 ’F 7 , R: ,R2 R1 3": N N x. N x <1 N - 4 «ILN ‘3' R OW ’ NHSOECHZCHE N Q30 F R30 ”F 7 7 N1 ,RZ R‘x J32 N a}: “; ‘N «N N R/K‘SC‘JNHZ a WONOVP‘! ’ R40. / 3" 3‘I N NA‘SQZNHCHg Wei-+3 mea, {3 R35 “F R35 r 7 7 he 3 R1 \N’R ‘96“ ) (I‘M {\N (N‘f \N R10_ N/5 'K a“! A iMAC)"N m““3 N K Nag/07;.» N C(OUNRN'R” N C(O)NH2 Mcm (3H3 R36 1 R3“? ”F 7 7 Na ,R: R1 ,R2 N E:& N «£ N\,2§ <7, i N <3: 7‘ N R40 N (jix‘ \i W N N 3W‘":45 a" mowwm N acmmm 7 7 CH3 CH3 Rd ”F R35 ”F 7 7 R1 ,RZ H1 ,R2 R1 ,R2 N N :x: R ONO N PC» R29 CQH ' ORG cog}:3 CH3 \ CH— 7 ‘3 CH3, 7 7 Dfio‘ ”F R35 is 9‘0“ 7: R\ ,R2 R1“ ”Rh :1 3‘: «wig/“N (NW/W WONG N’J‘N’kcongHs WONQ NANIKCOzfiHzPh CH ‘ .mZCH I—eJd IF R3§ If: 7 7 RL ,94 R; ,R2 RL (fig ‘3: N N /N :”‘N < {7N ‘N </N M‘ ‘ i 5 ‘40 / ,;L\ “J Q H 502R” R OWN N 5,0 H ii” NASOACHE CH~ CH2- m3 ‘ ‘ , ~ di ,F de’ “a R‘C? ”F , , R; [R2 R1 ,R4 N *f 4 ”ix 4" ’ a If R O‘No‘fgj NI R OWN Vf‘gczHa Ex 7r) CHZPr \méaC-Hz CH‘} , ' R35 “F R36? ”F , , “K ,R‘ R“ IR/ N N N /’/L\‘ Q «N‘ ”L“ 4" 1 N 5 $1 N C} R"O"%OYN/ N/ “3'\<0 N“ R25 NAN/{l CH3 Z:H \fNH .. .

Rag“ ? red“ ”F 7 , R\ IR: R1, ,R2 i N «NE “‘3 O 3“ 5 “f P H40 N Q H“ ( WC N 0 \N’A ~ ACHs -E\E\ LW/ #1fo ”F R35 F , ’ R: ,R2 R1 ng N 5‘ 0 NW CH3 xx; . ‘ {CH3 9&0“ ”F R36 ’F R ,R2 P11 ,N2 N N N ”a N </ : \N </ g \N 9 OW4 N’J‘i‘ 7/ k x 4 N 4L N / R (JR/37y N N ‘P(Q:H(ON“°; _ ‘:x_._m{_/H~g mo“ ’1 N36 ”F 7 7 R: ,N2 :31 ,.N~ N N N P(Q)(OH}(OH) M13342 \ CN R35 (F N355" ”F 7'2. ‘. 31*N” Nix 4 «W R C xiii“,__ ”PK 0E—E)(OCH3) N P(O)(OC}~:3)(OCH3).

WCH3 . JCH R31? ”F N‘d ”F A CW; 3 ms! CH N115 ”F N35 ”F , 7 R1 F,R2 R; ,N2 N N N x N A: </ N 1’ <, I N R4f‘. N \ N ’f’L\ " P'IA‘ P4? "KYO 1 9(0on‘ 29')(NR25'~19;3F» -; ‘ J‘KCZ N HWZCH 9(O)(C}HXNH2).A V. .2 , w. / N30 F FPO F R3 2 x ,R‘ x ,R i N «WW3.133 6‘ N <NA‘35: ND.. N .

P<Q><QCH33HH3 RONDCH PjOXOCHgHHCH3 _ ‘CH3 P236 ”P P30 F 3 3 N13 3R2 R1 3N2 N i (N 31 / 4, «“133x O P(_‘OKQCH3)N(C H333 ROW”! N NRR0 3 XCH3 CH3 3 , Q3CT ”P R35 ”P , 3 Rim/R: R1N/n2 <2in \i 0‘?! 3; 3 R O4 N NR5C(O)R3 Cfofjii NHC(Q\P 3 M13343 \Q2:63-13733‘ R36 (F R3C§ ’3': 1 1 RK ,R R1 sz N N N ,zk N3 3 e 1 N </ 33 N “Va/033;“ N NHC(Q)aikyE N )Oa|ky| WCHs R4O'“\<:::N 3 {'CH3 R36 ”P R36 ’F 3 3 N13 3R3 N13 ,R2 E 5'51 «NEW “ 9‘33““ EL U NWKN’WO? 3/ 3 ACHS Lmégcm R76 ”F Q35 ’F 3 3 R1 3R2 N; 73332 N *r’ 3“ 3 «NW 3‘) Jaw; H MPH H 3 «WW i K N <’ E g R40 W0 N ”fix” /‘J\O/\~. “f0. NAN” N/ \0/ N N H 3——~7;:CH;% H R35 ”F R30“ / R: ,9.

N N v G N g o WONG N N o CH~ CH3 g ‘ , ; Q30 F R30 ”F R; ,R2 RR ,R3 N N «“1 *2: J1 «W 4 f )"s. r A {,1 i Mai-+3 CH3 ~ .

R30 “F 53:30“ ”P RKNRE RlNfi 6%” if: M“ O ‘1 R40“%O N/ N/ RAG“ N", \NkN/RLCSAMA Jew N QM ‘ H VFW H R36 ”F R35 RF RLNfiE RLN,R~ N “43¢ "‘ N ”L r“. < I N 11 6 BE 1‘1 J $24ng Nai‘xfi/ Oxm~‘/’\\ $34ng Nfikfi/ \v/‘KN \\ 1 H ~ A ~ A CH3 R30“ ”F R36 ”F R1, ,R2 NR“ 0 mew 0 NAN” N/LLO/Nw/ and 9355 RR PCT/U52016/021276 In some embodiments, R3 is H and R4 is 111/ In some embodiments, R3 is H and R4 is o KT? 1PM; \\;//O\n/’E\~EéH In some ments, R3 is H and R4 is In some embodiments, R1 is CH3, R2 is H, R3 is H and R4 is In some embodiments, R1 is CH3, R2 is H, R3 is H and R4 is WO 44918 In some embodiments, R1 is CH3, R2 is H, R3 is H and R4 is up!” In some embodiments, R1 is CH3, R2 is CH3, R3 is H and R4 is In some embodiments, R1 is CH3, R2 is CH3, R3 is H and R“1 is E o o - H \Ix N: N‘I‘meg *0 E.

In some embodiments, R1 is CH3, R2 is CH3, R3 is H and R4 is In some embodiments, R1 is cyclopropyl, R2 is CH3, R3 is H and R“1 is PCT/U52016/021276 In some embodiments, R1 is cyclopropyl, R2 is CH3, R3 is H and R4 is II. tions The following terms are used to describe the present invention. In instances where a term is not specifically defined herein, that term is given an art-recognized meaning by those of ordinary skill ng that term in context to its use in bing the present invention.

The term "alkyl" shall mean within its context, a linear, or branch-chained fully saturated hydrocarbon radical or alkyl group which can be optionally substituted (for example, with halogen, including F). For example, an alkyl group can have 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms (i.e., Cl —Cs alkyl), 1, 2, 3, 4, 5 or 6 carbon atoms (i.e., C1-C6 alkyl) or 1 to 4 carbon atoms (i,e., C1—C4 alkyl). Examples of suitable alkyl groups include, but are not d to, , ethyl, n— propyl, iso—propyl, n—butyl, isobutyl, sec—butyl, tert—butyl, pentyl, isopentyl, tert—pentyl, tyl, hexyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl and 2,3—dimethylbutyl.

The term ”alkenyl" refers to a non-aromatic hydrocarbon group which contains at least one double bond between adjacent carbon atoms and a similar structure to an alkyl group as otherwise described herein, For example, an alkenyl group can have 2 to 8 carbon atoms (i.e., C2-C8 l), or 2 to 4 carbon atoms (ie, C2-C4 alkenyl). Examples of suitable alkenyl groups include, but are not limited to, ethenyl or vinyl (-CH:CH2), allyl (-CH2CH:CH2), l-butenyl (- PCT/USZOl6/021276 C:CH-CH2CH3) and 2-butenyl (-CH2CH:CHCH2). The alkenyl group can be optionally substituted as described herein.

The term "alkynyl" refers to a non—aromatic hydrocarbon group containing at least one triple bond between adjacent carbon atoms and a similar ure to an alkyl group as otherwise described herein. For example, an alkynyl group can have 2 to 8 carbon atoms (i.e., C2-C8 all<yne,), or 2 to 4 carbon atoms (i.ei, C2-C4 alkynyl). Examples of alkynyl groups include, but are not limited to, acetylenic or ethynyl and propargyl, The l group can be ally substituted as described herein The term "acyl" refers to the moiety —C(O)R in which the carbonyl moiety is bonded to lO R, for example, ll<yl. R can be selected from alkoxy, alkyl, cycloalkyl, lower alkyl (i.e., C1-C4); alkyl, including methoxymethyl; aralkyl— including benzyl, aryloxyalkyl— such as phenoxymethyl; aryl including phenyl optionally tuted with halogen, C1 to C4 alkyl or C1 to C4 alkoxy. In one embodiment, the term “acyl" refers to a mono, di or triphosphate. [5 The term ”lower acyl" refers to an acyl group in which the carbonyl moiety is lower alkyl (i.e., C1—C4).

The term "alkoxy" refers to the group —OR’ where —OR’ is -O-alkyl, -O-alkenyl, -O- alkynyl, -O-(Co-C2)(cycloalkyl), -O-(Co-C2)(heterocyclo), -O-(Co-C2)(aryl), or -O-(Co- C2)(heteroaryl), each of which can be optionally substituted.

The term "amino" refers to the group —NH2.

The term "amino acid" or ”amino acid residue" refers to a D— or L— natural or non— naturally ing amino acid. Representative amino acids include, but are not limited to, alanine, B-alanine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamic acid, ine, glycine, phenylalanine, histidine, isoleucine, lysine, leucine, methionine, proline, serine, ine, valine, tryptophan, or tyrosine, among .

The term "azido" refers to the group —N3.

The term "aryl" or "aromatic", in context, refers to a substituted (as otherwise bed herein) or unsubstituted monovalent aromatic radical having a single ring (e.g., phenyl or benzyl) or condensed rings (e.g., naphthyl, anthracenyl, phenanthrenyl, etc.) and can be bound to the compound according to the present invention at any available stable position on the ring(s) or as PCT/U52016/021276 ise indicated in the chemical ure ted. The aryl group can be optionally substituted as described herein.

"Cycloalkyl", "carbocycle", or "carbocyclyl" refers to a saturated (i.e., cycloalkyl) or partially rated (eg, cycloakenyl, lkadienyl, etc.) ring having 3 to 7 carbon atoms as a cle. Monocyclic ycles have 3 to 7 ring atoms, still more typically 5 or o ring atoms Non-limiting examples of cycloalkyl groups include ropyl, cyclobutyl, cyclopentyl, l-cyclopent-l-enyl, l-cyclopent—Z—enyl, l-cyclopent-3—enyl, cyclohexyl, l—cyclohex-l—enyl, l—cyclohex—Z—enyl, and l—cyclo-hex—3-enyl, The term "cyano" refers to the group —CN. lO The term "halogen" or "halo" refers to chloro, bromo, fluoro or iodo.

A heteroaryl ring system is a saturated or unsaturated ring with one or more nitrogen, oxygen, or sulfur atoms in the ring (monocyclic) including but not limited to imidazole, furyl, pyrrole, furanyl, thiene, thiazole, pyridine, pyrimidine, purine, pyrazine, triazole, oxazole, or fused ring systems such as , quinoline, etc, among others, which may be optionally [5 substituted as described above. Heteroaryl groups include nitrogen-containing heteroaryl groups such as pyrrole, pyridine, pyridone, pyridazine, pyrimidine, pyrazine, pyrazole, imidazole, triazole, triazine, ole, indole, isoindole, indolizine, purine, indazole, quinoline, isoquinoline, quinolizine, phthalazine, yridine, quinoxaline, quinazoline, cinnoline, pteridine, imidazopyridine, imidazotriazine, pyrazinopyridazine, acridine, thridine, carbazole, carbazoline, perimidine, phenanthroline, phenacene, oxadiazole, benzimidazole, pyrrolopyridine, pyrrolopyrimidine and pyridopyrimidine; sulfur—containing aromatic heterocycles such as thiophene and hiophene; oxygen—containing aromatic heterocycles such as furan, pyran, cyclopentapyran, benzofuran and isobenzofuran; and aromatic heterocycles sing two or more hetero atoms selected from among nitrogen, sulfur and , such as thiazole, thiadizole, azole, benzoxazole, benzothiazole, benzothiadiazole, phenothiazine, isoxazole, furazan, phenoxazine, pyrazoloxazole, imidazothiazole, thienofuran, furopyrrole, pyridoxazine, furopyridine, furopyrimidine, thienopyrimidine and oxazole, among others, all of which may be optionally substituted.

The term "heterocycle" or "heterocyclo" refers to a cyclic group which contains at least one heteroatom, i.e., O, N, or S, and may be aromatic (heteroaryl) or non—aromatic. Exemplary non—aromatic heterocyclic groups for use in the present invention include, for example, PCT/U52016/021276 pyrrolidinyl, dinyl, piperazinyl, N-methylpiperazinyl, imidazolinyl, lidinyl, imidazolidinyl, morpholinyl, tetrahydropyranyl, azetidinyl, oxetanyl, oxathiolanyl, pyridone, 2- pyrrolidone, ethyleneurea, l,3—dioxolane, l,3—dioxane, l,4—dioxane, phthalimide, and succinimide, among others, all of which may be optionally tuted.

The term "hydroxyl" refers to the group *OH.

The term "nitro" refers to the group 7N0; The term "pharmaceutically acceptable salt" or prodrug" is used hout the specification to describe any pharmaceutically acceptable form (such as an ester, phosphoramidate, thiophosphoramidate, phosphate ester, salt of an ester, or a related group) of a B-D-2'-D-2'-0L-fluoro-2'-B-C-substituted-Z-modifled—N"-substituted purine nucleotide which, upon administration to a patient, provides the d active nd. Examples of pharmaceutically acceptable salts are organic acid addition salts formed with acids, which form a physiological acceptable anion, for example, tosylate, methanesulfonate, e, citrate, malonate, tartrate, succinate, benzoate, ascorbate, glutarate, and oc—glycerophosphate. le inorganic salts may also be formed, including sulfate, nitrate, bicarbonate, and carbonate salts. Pharmaceutically acceptable salts may be ed using standard ures well known in the art, for example by reacting a sufficiently basic compound such as an amine with a suitable acid affording a physiologically acceptable anion, Alkali metal (for example, sodium, potassium, or lithium) or alkaline earth metal (for e calcium) salts of carboxylic acids can also be made.

"Pharmaceutically acceptable prodrug" refers to a nd that is metabolized, for example hydrolyzed or oxidized, in the host to form the compound of the present invention.

Typical examples of prodrugs include compounds that have biologically labile protecting groups on a functional moiety of the active compound. Prodrugs include compounds that can be oxidized, reduced, aminated, deaminated, hydroxylated, dehydroxylated, hydrolyzed, dehydrolyzed, alkylated, dealkylated, acylated, deacylated, phosphorylated, dephosphorylated, thiophoshoramidated, dethiophoshoramidated, phoshoramidated or dephosphoramidated to produce the active compound. The compounds of this invention possess antiviral activity against HCV, or are metabolized to a compound that exhibits such activity. The B-D—2'—D-2‘-0t-fluoro-2'- B—C—substituted—2-modif1ed—NG—substituted purine side can also be administered as a 5’— phosphoether lipid, a bisphosphoramidate, a 3’,5’—cyclic phosphoramidate, a 3’,5’—cyclic PCT/U52016/021276 thiophosphoramidate, a DTE conjugate, a mixed phosphoramidate-SATE derivative or a “SATE” derivative.

The term honic acid" refers to the group *P(O)(OH)2.

In one embodiment, the term purine or pyrimidine base includes, but is not limited to, adenine, ylpurines, NG-acylpurines (wherein acyl is ll<yl, —C(O)(aryl)Co—C4all<yl, or -C(O)(Co-C4all<yl)aryl), NG-benzylpurine, NG-halopurine, NG-vinylpurine, tylenic purine, NG—acyl purine, NG—hydroxyalkyl purine, NO-thioalkyl purine, NZ-alkylpurines, Nz—alkyl—o- thiopurines, thymine, cytosine, 5-fluorocytosine, 5—methylcytosine, o—azapyrimidine, including 6-azacytosine, 2- and/or 4-mercaptopyrmidine, uracil, 5-halouracil, including 5-fluorouracil, C5- alkylpyrimidines, CS-benzylpyrimidines, CS-halopyrimidines, CS-vinylpyrimidine, CS-acetylenic dine, C‘s—acyl pyrimidine, CS—hy'droxyalky'l , CS-amidopyrimidine, C5— yrimidine, CS—nitropyrimidine, nopyrimidine, NZ—alkylpurines, N2—alkyl—6— thiopurines, 5—azacytidinyl, S—azauracilyl, triazolopyridinyl, imidazolopyridinyl, opyrimidinyl, and pyrazolo—pyrimidinyl. Purine bases include, but are not limited to, guanine, adenine, hypoxanthine, 2,6—diaminopurine, and ropurine. Functional oxygen and nitrogen groups on the base can be protected as necessary or desired. Suitable protecting groups are well known to those skilled in the art, and include benzyl, trimethylsilyl, dimethylhexylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, trityl, alkyl groups, and acyl groups such as acetyl and propionyl; methanesulfonyl, and p—toluenesulfonyl, Alternatively, the purine or pyrimidine base can optionally be tuted such that it forms a viable prodrug, which can be cleaved in vivo.

Examples of riate substituents include an acyl moiety.

The term "substituted" or "optionally substituted" indicates that the moiety can have at least one additional tuent including, but not limited to, halogen (F, Cl, Br, I), OH, phenyl, benzyl, N3, CN, acyl, alkyl, including methyl, alkenyl, alkynyl, alkoxy, haloalkyl; including CHFz, CH2]: and CF3; etc. In one embodiment, the term "substituted" or "optionally substituted" indicates that the moiety can have at least one additional substituent including, but not limited to, azido, cyano, halogen (fluoro, chloro, bromo, or iodo), alkyl, alkenyl, alkynyl, cycloalkyl, heterocycle, aryl, heteroaryl, haloalkyl, hydroxyl, alkoxy, amino, -NH(Cl-C6 unsubstituted , -NH(Cl-C6 substituted alkyl), —NH-(C0-C2alky1)(C3—C8cycloall<yl), —NH-(Co-C2alkyl)(C3— Csheterocycle),-NH-(Co—C2alkyl)(aryl), -N(C1-C6 unsubstituted alkyl)2, -N(C1-C6 unsubstituted alkyl)(C1—Co substituted , -N(C1-C6 substituted alkyl)2,—NH—(Co-C2alkyl)(C3—C8cycloalkyl), PCT/U52016/021276 -NH-(C(,)—C2all<yl)(C3-Csheterocycle),-NH-(Co-C2alkyl)(aryl), acyl, nitro, sulfonic acid, sulfate, phosphonic acid, phosphate, onate, or thiol.

The term "sulfonate esters”, represented by the formula, RHS(O)2OR15, comprise RH wherein RH is alkyl, haloalkyl, aralkyl or aryl. R15 is alkyl, aryl or aralkyl.

The term "sulfonic acid" refers to the group *SO2OH.

The term ”thiol” refers to the group 4SH.

The term "nitrogen-protecting group" as used herein refers to a moiety that is covalently attached to nitrogen and which can be removed, and typically replaced with hydrogen, when appropriate, For example, a nitrogen-protecting group may be a group that is removed in viva after administration to a host, in vii/"0 by a cell, or it may be removed during a manufacturing s. Suitable nitrogen-protecting groups useful in the present invention are described by Greene and Wuts in Protective Groups in Organic Synthesis (1991) New York, John Wiley and Sons, Inc.

The term n-protecting group" as used herein refers to a moiety that is covalently I5 attached to oxygen and which can be d, and typically replaced with hydrogen, when appropriate, For example, an oxygen-protecting group may be a group that is removed in viva after administration to a host, in vim) by a cell, or it may be removed during a manufacturing process. Suitable oxygen-protecting groups useful in the present invention are bed by Greene and Wuts in tive Groups in Organic Synthesis (1991) New York, John Wiley and Sons, Inc.

"Phosphate" refers to the group *OP(O)(OH)2. hate ester" refers to mono, di, and tri phosphates unless otherwise indicated.

The term "phosphoamidate", “phosphoramidate”, or "phosphoroamidate" is a moiety that has a phosphorus bound to three oxygen groups and an amine (which may optionally be substituted). Suitable phosphoramidates useful in the present invention are described by Madela, Karolina and McGuigan in 2012, “Progress in the pment of anti-hepatitis C virus nucleoside and nucleotide prodrugs”, Full/re A/iedic/na/ 5113; 4(5), pages 625-650 :102l/jm300074y and Dominique, McGuigan and Balzarini in 2004, “Aryloxy Phosphoramidate Triesters as Pro—Tides”, XVI/Ii Reviews in Akd/c/na/ Chennai/y 4(4), pages 371— 381. onal phosphoramidates useful in the t invention are described in US. Patent Nos. 5,233,031, 590, 7,547,704, 7,879,815, 7,888,330, 7,902,202, 7,951,789, 7,964,580, 8,071,568; 8,148,349, 8,263,575, 8,324,179, 8,334,270, 8,552,021, 8,563,530, 8,580,765, 8,735,372, 8,759,318; EP 5; EP 1143995; 6,455,513, and 8,334,270. Other phosphoramidates are described in the nucleoside s described in the Background of the Invention.

Phosphoramidate groups for use in the present invention include those of the structures: PCT/U52016/021276 Other phosphoramidates for use in the present invention include those of the structure: Wall“?l ONRM wherein: RPL is an optionally substituted linear, branched, or cyclic alkyl group, or an optionally substituted aryl, heteroaryl or heterocyclic group or a linked combination thereof; and RP2 is a —NRNIRN2 group or a B’ group; wherein: RN1 and RN2 are each independently H, l, (C3-C7cycloalkyl)Co-C4alkyl—, (aryl)Co- C4alkyl-, (Cs-Coheterocyclo)Co-C4alkyl-, or (heteroaryl)Co-C4alky-; which may be optionally tuted; or RN1 and RN2 along with the en atom to which that are attached, join to form a 3 to 7 membered cyclic ring; B’isa wherein: R16 is hydrogen, (Ci—C8)all<yl, (C2—C8)alkenyl, (C2—C8)alkynyl, (C3—C8cycloalkyl)C0— C4alkyl-, (aryl)Co—C4alkyl-, (C3-Ccheterocyclo)Co—C4alkyl-, (heteroaryl)Co—C4alky-, or the sidechain of an amino acid, for example a sidechain of an amino acid (as otherwise described herein) often selected from the group consisting of alanine, B-alanine, ne, asparagine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, phenylalanine, histidine, isoleucine, lysine, leucine, methionine, proline, serine, threonine, valine, tryptophan, or tyrosine (often R[6 is hydrogen, methyl, isopropyl, or isobutyl); R[7 is en, (Ci-Cs)all<yl, (C2-Cs)alkenyl, (C2—Cs)all<ynyl, cycloalkyl)Co- l-, (aryl)Co-C4alkyl—, heterocyclo)Co—C4alkyl—, (heteroaryl)Co—C4alky—, or the sidechain of an amino acid, for example a sidechain of an amino acid (as otherwise described herein) often selected from the group consisting of alanine, B-alanine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, phenylalanine, histidine, isoleucine, lysine, leucine, methionine, proline, serine, threonine, valine, tryptophan, or ne (often R17 is hydrogen, methyl, isopropyl, or isobutyl); R18 is hydrogen or C1—C3alkyl; or R16 and R17 can form a )cycloall<yl or (Cz-C7)heterocyclic group; or R18 and R16 or R1- can form (C3-C6)heterocyclic group; and R19 is hydrogen, (C1-C6)alkyl, (C3-C6)alkenyl, (C3-C6)alkynyl, (C3-Cxcycloalkyl)Co- C4alkyl-, (aryl)Co-C4alkyl-, (Ca-Coheterocyclo)Co-C4alkyl-, (heteroaryl)Co—C4all<y-, or REC- R21 0 94/;a R19/ B’ is a 0 R18 group; wherein: R20 is hydrogen, (C1-C3)all<yl, (C3-C2cycloalkyl)Co-C4alkyl-, C0—C4alkyl-, (C2- Ceheterocyclo)Cn-C4alkyl-, or oaryl)Co-C4alky-; R21 is hydrogen, (C1-C3)all<yl, (C3-Cxcycloalkyl)Co-C4all<yl-, (awl)Co-C4all<yl-, (C3- Coheterocyclo)Co-C4alkyl-, or (heteroaryl)Co-C4alky-, and RIx and R19 are as defined above. red RPl groups include optionally substituted phenyl, naphthyl, and monocyclic heteroaryl groups, especially those groups (particularly lipophilic ) which enhance bioavailability of the compounds in the cells of the patient and which exhibit d ty, enhanced therapeutic index and enhanced pharmacokinetics (the compounds are metabolized and ed more slowly), The term oramidate is used hout the specification to describe a group that is found at the 5’ or 3’ position of the furanose ring of the nucleoside compound and forms a prodrug form of the nucleoside compound. In one embodiment, phosphoramidates can be found at both the 5’ and 3’ position of the furanose ring of the nucleoside compound and form a prodrug form of the nucleoside compound. In another embodiment, the phosphoramidate found at the 5’ position of the furanose ring of the nucleoside can form a cyclic phosphoramidate PCT/USZOl6/021276 compound by forming a bond with the 3’-hydroxyl substituent at the 3’ position of the se ring of the side compound and form a prodrug form of the nucleoside compound.

The term "thiophosphoamidate", "thiophosphoramidate", or "thiophosphoroamidate" is a moiety that has a phosphorus bound to sulfur, two oxygen groups and an amine (which may optionally be substituted). Thiophosphoramidates useful in the present invention are described in US Patent No, 474 and , Thiophosphoramidate groups for use in the present invention include those of the structures: PCT/U52016/021276 Other thiophosphoramidates e those of the structure: pawl”? ”‘me wherein: RPl is an optionally substituted linear, branched, or cyclic alkyl group, or an optionally substituted aryl, heteroaryl or cyclic group or a linked combination thereof; and RP2 is a -NRNIRNZ group or a B’ group; wherein: RN] and RNz are each independently H, C1-C2: alkyl, (C3-C7cycloalkyl)Co-C4alkyl—, Co-C4alkyl-, (C3-Ceheterocyclo)Co-C4all<yl-, or (heteroaryl)Co-C4alky-; or RN1 and RN2 along with the nitrogen atom to which that are attached, join to form a 3 to 7 membered heterocyclic ring, ~:;:;. : a {:8 B’ is a 0 R18 group; wherein: R16 is hydrogen, (Ci—C8)all<yl, (C2—C8)all<enyl, (C2—Cs)alkynyl, (C3—C8cycloalkyl)C0— C4alkyl-, (aryl)Co—C4alkyl-, (C3-Ccheterocyclo)Co—C4alkyl-, oaryl)Co—C4alky-, or the sidechain of an amino acid, for e a sidechain of an amino acid (as otherwise described herein) often selected from the group consisting of alanine, B-alanine, arginine, gine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, phenylalanine, histidine, cine, lysine, leucine, methionine, proline, serine, threonine, valine, tryptophan, or tyrosine (often R16 is en, methyl, isopropyl, or isobutyl); R” is hydrogen, (Ci-Cs)alkyl, (C2-Cs)alkenyl, )alkynyl, (Ca-Cscycloalkyl)Co- C4all<yl-, (aryl)Co-C4alkyl—, (C3-Ceheterocyclo)Co—C4alkyl—, (heteroaryl)Co—C4alky—, or the sidechain of an amino acid, for example a sidechain of an amino acid (as otherwise described herein) often selected from the group consisting of alanine, B-alanine, arginine, asparagine, WO 44918 2016/021276 ic acid, cysteine, cystine, ic acid, glutamine, glycine, phenylalanine, histidine, isoleucine, lysine, leucine, methionine, proline, serine, threonine, valine, tryptophan, or tyrosine (often R17 is hydrogen, methyl, isopropyl, or isobutyl); R18 is hydrogen or C1—C3alkyl, or R16 and R17 can form a (C3—C7)cycloalkyl or (C3—C7)heterocyclic group; or R18 and R16 or R1” can form (C3-C6) heterocyclic group; and R19 is hydrogen, (C1-C6)alkyl, (C2-C6)alkenyl, (C3-C6)alkynyl, (Cs-Cscycloalkyl)Co— C4alkyl—, (aryl)Co—C4alkyl-, heterocyclo)Co—C4alkyl-, (heteroaryl)Co—C4alky-, or RL‘J Ril (J V R19 rat/g B” is a 0 R18 group; and R18, R19, R20 and R21 are as defined above.

Preferred RPl groups include optionally substituted phenyl, naphthyl, and monocyclic heteroaryl groups, especially those groups (particularly lipophilic groups) which enhance bioavailability of the compounds into the cells of the patient and which exhibit reduced toxicity, ed therapeutic index and ed pharmacokinetics (the compounds are metabolized and excreted more slowly).

The thiophosphoramidate can be at the 5’ or 3’ on of the furanose ring of the nucleoside compound to form a prodrug form of the nucleoside compound. In one embodiment, thiophosphoramidates can be found at both the 5’ and 3’ position of the furanose ring of the nucleoside nd and form a prodrug form of the nucleoside compound. In another embodiment, the osphoramidate found at the 5’ position of the furanose ring of the nucleoside can form a cyclic thiophosphoramidate compound by forming a bond with the 3’- hydroxyl substituent at the 3’ position of the furanose ring of the nucleoside compound and form a prodrug form of the nucleoside compound, The term "D-configuration" as used in the context of the present invention refers to the principle configuration which mimics the natural configuration of sugar moieties as opposed to the unnatural occurring nucleosides or "L” configuration. The term "[3" or "B anomer" is used PCT/USZOlo/021276 with reference to nucleoside analogs in which the nucleoside base is configured (disposed) above the plane of the furanose moiety in the nucleoside .

The terms "coadminister" and "coadministration" or combination therapy are used to describe the administration of at least one of the 27—deoxy-2’—01-fluoro—2’—B—C—nucleoside compounds according to the present invention in combination with at least one other active agent, for example where appropriate at least one additional anti-HCV agent, including other 2’- deoxy-Z’-0t-fluoro-2’-B-C-nucleoside agents which are disclosed herein. The timing of the coadministration is best determined by the medical specialist treating the patient, It is sometimes preferred that the agents be administered at the same time. Alternatively, the drugs selected for combination therapy may be administered at different times to the patient. Of course, when more than one viral or other infection or other condition is t, the present compounds may be combined with other agents to treat that other infection or condition as required.

The term , as used herein, refers to a unicellular or multicellular sm in which a HCV virus can replicate, including cell lines and animals, and typically a human. The term host specifically refers to infected cells, cells transfected with all or part of a HCV , and animals, in particular, primates ding chimpanzees) and humans, In most animal applications of the present ion, the host is a human patient. Veterinary applications, in certain indications, however, are clearly anticipated by the present invention (such as nzees). The host can be for example, bovine, equine, avian, canine, feline, etc. ic Substitution The t invention es compounds and the use of compounds with desired isotopic substitutions of atoms, at amounts above the natural abundance of the isotope, i.e,, enriched. es are atoms having the same atomic number but ent mass numbers, i.e., the same number of protons but a different number of neutrons. By way of general example and without limitation, isotopes of hydrogen, for example, deuterium (2H) and tritium (3H) may be used anywhere in bed structures, Alternatively or in on, isotopes of carbon, e.g., l3C and 1“C, may be used. A preferred isotopic substitution is deuterium for hydrogen at one or more locations on the molecule to improve the performance of the drug. The deuterium can be bound in a location of bond breakage during metabolism (an u—deuterium kinetic isotope effect) or next to or near the site of bond breakage (a B—deuterium kinetic isotope effect). Achillion Pharmaceuticals, Inc. (WO/20l4/l69278 and WO/20l4/l69280) describes deuteration of nucleotides to improve their pharmacokinetics or codynamics, including at the 5-position of the molecule.

Substitution with isotopes such as deuterium can afford certain therapeutic ages resulting from greater metabolic stability, such as, for example, increased in vivo half—life or reduced dosage requirements Substitution of deuterium for hydrogen at a site of metabolic break down can reduce the rate of or ate the metabolism at that bond. At any position of the compound that a hydrogen atom may be present, the hydrogen atom can be any isotope of hydrogen, including protium (1H), deuterium (2H) and tritium (3H), Thus, reference herein to a compound encompasses all potential isotopic forms unless the context clearly es ise The term "isotopically—labeled” analog refers to an analog that is a rated analog", a "BC—labeled analog, ' or a "deuterated/l’lC—labeled analog." The term "deuterated analog" means a compound described herein, whereby a H—isotope, i.e., hydrogen/protium (1H), is tuted by a H—isotope, i.e., ium (2H). Deuterium substitution can be partial or complete. Partial I5 deuterium tution means that at least one hydrogen is substituted by at least one deuterium.

In certain embodiments, the isotope is 90, 95 or 999/6 or more enriched in an e at any location of interest. In some embodiments it is deuterium that is 90, 95 or 9996 enriched at a desired location. Unless indicated to the contrary, the ation is at least 8096 at the selected location. Deuteration of the nucleoside can occur at any replaceable hydrogen that provides the desired s. 111. Methods of Treatment 0r laxis Treatment, as used herein, refers to the administration of an active compound to a host that is infected with a HCV virus.

The term “prophylactic” or preventative, when used, refers to the administration of an active compound to prevent or reduce the likelihood of an occurrence of the viral disorder. The present invention includes both ent and prophylactic or preventative therapies. In one embodiment, the active compound is administered to a host who has been exposed to and thus at risk of infection by a hepatitis C virus infection.

The invention is directed to a method of ent or prophylaxis of a hepatitis C virus, including drug resistant and multidrug resistant forms of HCV and related disease states, conditions, or ZOl6/021276 cations of an HCV infection, ing cirrhosis and related hepatotoxicities, as well as other conditions that are secondary to a HCV infection, such as weakness, loss of appetite, weight loss, breast ement (especially in men), rash (especially on the palms), difficulty with clotting of blood, spider—like blood vessels on the skin, confusion, coma (encephalopathy), buildup of fluid in the abdominal cavity (ascites), esophageal varices, portal hypertension, kidney failure, enlarged , decrease in blood cells, , thrombocytopenia, jaundice, and hepatocellular cancer, among others. The method comprises administering to a host in need f an effective amount of at least one -D-2'-0L-fluoro-2'-B-C-substituted-2—modif1ed- NG-substituted purine nucleotide as described herein, optionally in combination with at least one lO additional bioactive agent, for example, an additional anti-HCV agent, further in combination with a pharmaceutically acceptable carrier additive and/or excipient.

In yet another aspect, the present invention is a method for prevention or prophylaxis of a an HCV infection or a disease state or related or follow—on disease state, condition or complication of an HCV infection, including sis and related hepatotoxicities, weakness, [5 loss of appetite, weight loss, breast enlargement (especially in men), rash (especially on the palms), difficulty with clotting of blood, spider-like blood vessels on the skin, confusion, coma (encephalopathy), buildup of fluid in the abdominal cavity (ascites), esophageal varices, portal hypertension, kidney failure, enlarged spleen, decrease in blood cells, anemia, ocytopenia, jaundice, and hepatocellular (liver) cancer, among others, said method comprising stering to a patient at risk with an effective amount of at least one compound according to the present invention as described above in ation with a pharmaceutically acceptable carrier, additive, or excipient, ally in combination with another CV agent. In another embodiment, the active compounds of the invention can be administered to a patient after a hepatitis-related liver transplantation to protect the new organ, The 5’—stabilized B—D-2'-D-2'—0i-fluoro-Z'-B-C-substitutedmodified-NG-substituted purine nucleotide can be administered if desired as any salt or prodrug that upon administration to the recipient is capable of providing directly or indirectly the parent compound, or that exhibits activity itself. iting examples are the pharmaceutically acceptable salts and a compound, which has been modified at a function group, such as a hydroxyl or amine on, to modify the biological activity, pharmacokinetics, half-life, controlled delivery, lipophilicity, absorption kinetics, ease of phosphorylation to the active 5’—triphosphate or efficiency of PCT/USZOlo/021276 delivery using a desired route of administration; of the compound, Methods to modify the properties of an active compound to achieve target properties are known to those of skill in the art or can easily be assessed by standard methods, for e, acylation, phosphorylation, thiophosphoramidation, phosphoramidation, phosphonation, alkylation, or tion.

IV. Pharmaceutical Compositions In an aspect of the invention, pharmaceutical compositions ing to the present invention comprise an anti-HCV virus effective amount of at least one of the 5’-stabilized [3-D- 2'-D-2'-u-fluoro-2'-B-C-substitutedmodified-Nfi-substituted purine nucleotide compounds IO described herein, optionally in combination with a pharmaceutically acceptable carrier, additive, or excipient, further optionally in combination or alternation with at least one other active compound.

In an aspect of the invention, pharmaceutical compositions ing to the present invention comprise an anti-HCV effective amount of at least one of the active —D—2‘—u— -2'-B-C-substitutedmodifled-NO-substituted purine tide nds described herein, optionally in ation with a pharmaceutically acceptable carrier, additive, or excipient, further optionally in combination with at least one other antiviral, such as an anti-HCV agent.

The invention includes pharmaceutical compositions that include an effective amount to treat a hepatitis C virus infection, of one of the B-D—2'—D—2'—0t—fluoro-2‘-B—C—substituted—2— modified-NO-substituted purine nucleotide compounds of the present invention or its salt or prodrug, in a pharmaceutically acceptable r or excipient. In an alternative embodiment, the invention includes pharmaceutical compositions that include an effective amount to prevent a hepatitis C virus infection, of one of the B-D-2'-D-2'-0t-fluoro-2‘-B-C-substitutedmodified-NG- substituted purine nucleotide compounds of the present invention or its salt or prodrug, in a pharmaceutically acceptable carrier or excipient.

One of ordinary skill in the an will recognize that a therapeutically effective amount will vary with the ion or condition to be treated, its severity, the treatment regimen to be employed, the pharmacokinetics of the agent used, as well as the t or t (animal or human) to be treated, and such therapeutic amount can be determined by the attending physician or specialist.

PCT/U52016/021276 The 5’-stabilized B-D-2'-D-2'-0t-fluoro-2'-B-C-substituted modified -N“-substituted purine nucleotide compounds according to the present invention can be formulated in an admixture with a pharmaceutically acceptable carrier. In general, it is preferable to administer the pharmaceutical composition in orally—administrable form, but certain formulations may be administered via a parenteral, intravenous, intramuscular, topical, ermal, buccal, aneous, suppository, or other route, including intranasal spray, Intravenous and intramuscular formulations are often administered in sterile saline. One of ry skill in the art may modify the formulations to render them more soluble in water or other e, for example, this can be easily accomplished by minor modifications (salt formulation, fication, etc) which are well within the ordinary skill in the art. It is also well within the routineers’ skill to modify the route of administration and dosage regimen of a particular compound in order to manage the pharmacokinetics of the present compounds for maximum beneficial effect in patients.

In certain pharmaceutical dosage forms, the prodrug form of the compounds, especially including acylated (acetylated or other), and ether (alkyl and d) derivatives, ate esters, thiophosphoramidates, phosphoramidates, and various salt forms of the present compounds, are preferred. One of ordinary skill in the art will recognize how to readily modify the present compounds to prodrug forms to facilitate delivery of active compounds to a ed site within the host organism or patient. The routineer also will take advantage of ble pharmacokinetic ters of the prodrug forms, where applicable, in delivering the present compounds to a targeted site within the host sm or patient to maximize the intended effect of the compound.

The amount of compound included within therapeutically active formulations according to the present invention is an effective amount for treating the HCV infection, reducing the likelihood of a HCV infection or the inhibition, reduction, and/or ion of HCV or its secondary effects, including disease states, conditions, and/or complications which occur secondary to HCV, In l, a therapeutically effective amount of the present compound in pharmaceutical dosage form y ranges from about 0.001 mg/kg to about 100 mg/kg per day or more, more often, slightly less than about 0.1 mg/kg to more than about 25 mg/kg per day of the patient or considerably more, depending upon the compound used, the condition or infection treated and the route of administration. The active nucleoside compound according to the PCT/U52016/021276 present invention is often administered in amounts g from about 0.1 mg/kg to about 15 mg/kg per day of the patient, depending upon the pharmacokinetics of the agent in the patient.

This dosage range generally produces effective blood level concentrations of active compound which may range from about 0.001 to about 100, about 0.05 to about 100 micrograms/cc of blood in the patient.

Often, to treat, prevent or delay the onset of these infections and/or to reduce the likelihood of an HCV virus infection, or a ary e state, condition or complication of HCV, the itions will be administered in oral dosage form in amounts ranging from about 250 micrograms up to about 500 mg or more at least once a day, for example, at least 25, 50, 100, 150, 250 or 500 milligrams, up to four times a day. The present compounds are often administered orally, but may be administered parenterally, topically, or in suppository form, as well as intranasally, as a nasal spray or as otherwise described herein.

In the case of the co—administration of the present compounds in combination with another anti—HCV compound as otherwise described herein, the amount of the compound according to the present invention to be administered ranges from about 0.01 mg/kg of the patient to about 500 mg/kg, or more of the patient or considerably more, depending upon the second agent to be co-administered and its potency against the virus, the condition of the patient and severity of the disease or infection to be treated and the route of administration, The other anti-HCV agent may for e be administered in amounts ranging from about 0.01 mg/kg to about 500 mg/kg. In n preferred embodiments, these compounds may be often stered in an amount ranging from about 0.5 mg/kg to about 50 mg/kg or more ly up to about 100 mg/kg), generally depending upon the cokinetics of the two agents in the patient. These dosage ranges generally produce effective blood level trations of active compound in the patient.

For purposes of the present invention, a prophylactically or preventive effective amount of the compositions ing to the present invention falls within the same concentration range as set forth above for therapeutically effective amount and is usually the same as a therapeutically effective .

Administration of the active compound may range from continuous (intravenous drip) to several oral or intranasal administrations per day (for example, Q.I.D.) or transdermal administration and may include oral, topical, parenteral, intramuscular, intravenous, PCT/U52016/021276 sub-cutaneous, transdermal (which may include a penetration ement agent), buccal, and itory administration, among other routes of administration. Enteric coated oral tablets may also be used to enhance bioavailability of the compounds for an oral route of administration.

The most effective dosage form will depend upon the bioavailability/pharmacokinetics of the particular agent chosen as well as the severity of disease in the patient Oral dosage forms are particularly preferred, because of ease of administration and prospective favorable patient ance.

To prepare the pharmaceutical itions according to the present invention, a therapeutically effective amount of one or more of the compounds according to the present lO ion is often intimately admixed with a pharmaceutically acceptable carrier according to conventional pharmaceutical compounding techniques to produce a dose. A carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.0., oral or parenteral. In preparing pharmaceutical compositions in oral dosage form, any of the usual pharmaceutical media may be used. Thus, for liquid oral preparations such as sions, [5 elixirs, and ons, suitable carriers and additives including water, glycols, oils, alcohols, flavoring agents, preservatives, coloring , and the like may be used, For solid oral ations such as powders, tablets, capsules, and for solid preparations such as suppositories, suitable rs and additives including starches, sugar carriers, such as dextrose, manifold, e, and related carriers, diluents, granulating agents, lubricants, binders, disintegrating agents, and the like may be used. If desired, the tablets or capsules may be enteric—coated or ned release by standard techniques. The use of these dosage forms may significantly enhance the bioavailability of the compounds in the patient.

For parenteral formulations, the carrier will usually comprise sterile water or aqueous sodium de solution, though other ingredients, including those which aid dispersion, also may be included, Of course, where sterile water is to be used and maintained as sterile, the compositions and carriers must also be sterilized. Injectable suspensions may also be ed, in which case appropriate liquid carriers, suspending agents, and the like may be employed.

Liposomal suspensions (including liposomes targeted to viral antigens) may also be prepared by conventional methods to produce pharmaceutically acceptable carriers. This may be appropriate for the ry of free nucleosides, acyl/alkyl nucleosides or phosphate ester pro— drug forms of the side compounds according to the t invention.

PCT/U52016/021276 In typical embodiments according to the present invention, the compounds and compositions are used to treat, prevent or delay a HCV ion or a secondary disease state, condition or complication of HCV.

V. Combination and Alternation Therapy It is well recognized that drug-resistant variants of viruses can emerge after prolonged treatment with an antiviral agent Drug resistance most typically occurs by mutation of a gene that encodes for an enzyme used in viral replication. The efficacy of a drug t an HCV infection, can be prolonged, augmented, or restored by administering the compound in lO ation or alternation with another, and perhaps even two or three other, antiviral compounds that induce a different mutation or act through a different y, from that of the principle drug, Alternatively, the cokinetics, bio distribution, half—life, or other parameter of the drug can be d by such combination therapy (which may include alternation therapy if considered concerted). Since the disclosed B—D—Z'—D—2'—0t—fluoro—2'—B-C-substituted—2— modified— [5 NG-substituted purine nucleotides are NSSB polymerase inhibitors, it may be useful to administer the compound to a host in combination with, for example a: (l) Protease inhibitor, such as an NS3/4A protease inhibitor; (2) NSSA inhibitor, (3) Another NSSB polymerase inhibitor, (4) NSSB non-substrate inhibitor; (5) Interferon alfa-2a, which may be pegylated or otherwise modified, and/or ribavirin; (6) Non-substrate-based inhibitor; (7) Helicase inhibitor, (8) Antisense oligodeoxynucleotide ); (9) Aptamer, (l 0) Nuclease-resistant me, (l l) iRNA, including NA and SiRNA; (12) Antibody, partial antibody or domain antibody to the virus, or (13) Viral antigen or partial antigen that induces a host antibody response.

PCT/U52016/021276 Non limiting examples of anti-HCV agents that can be administered in combination with the [3- D-2'—D-2'-0t-fluoro-2'-B-C-substituted modified-N"-substituted purine nucleotides of the invention are: (i) protease inhibitors such as telaprevir (Incivek‘B), boceprevir (VictrelisTM), simeprevir (OlysioTM), paritaprevir (ABT—450), ACH—2684; AZD—7295; BMS—791325; danoprevir; Filibuvir, GS-9256; GS-9451; 2; Setrobuvir; evir; Tegobuvir; VX—135; VX-222 and 0; (ii) NSSA inhibitor such as ACH—2928, ACH-3102, lDX—719, daclatasvir, ledispasvir and Ombitasvir (ABT-207); (iii) NSSB inhibitors such as ACH—3422, AZD-7295; Clemizole, ITX-506l; 13131-461; PPI—688, Sovaldi '3, 2, and mericitabine; (iv) NSSB inhibitors such as 3, MEX—700; and, (V) Antibody such as GS—6624.

If the B-D—2‘—D-2'—0L—fluoro—2'—B-C-substituted—2— modified—NO—substituted purine nucleotide is administered to treat advanced tis C virus leading to liver cancer or cirrhosis, in one embodiment, the compound can be administered in combination or ation with r drug that is typically used to treat hepatocellular carcinoma (HCC), for example, as described by Andrew Zhu in “New Agents on the Horizon in cellular Carcinoma” Therapeutic Advances in l Oncology, V 5(1), January 2013, 41-50. Examples of suitable compounds for combination therapy where the host has or is at risk of HCC include anti— angiogenic agents, sunitinib, brivanib, linifanib, ramucirumab, bevacizumab, cediranib, pazopanib, TSU—68, lenvatinib, antibodies against EGFR, mTor inhibitors, MEK inhibitors, and histone decetylace inhibitors.

Drugs that are currently approved for influenza are Amantadine, Rimantadine and Oseltamivir. Any of these drugs can be used in combination or ation with an active compound provided herein to treat a viral infection susceptible to such. Ribavirin is used to treat measles, Influenza A, influenza B, parainfluenza, severe RSV bronchiolitis and SARS as well as other viral infections, and therefore is particularly useful in combination with the present compound for treatment of the host ed with a single stranded RNA virus, Palivizumab is approved for use in infants with high risk for RSV infection.

PCT/USZOlo/021276 Currently, there are no approved drugs for West Nile virus, Physicians are recommended to provide intensive support therapy, which may involve hospitalization, intravenous fluids, use of a ventilator to assist breathing, tions to control es, brain swelling, nausea and vomiting, and the use of antibiotics to prevent bacterial infections for making the disease even worse. This highlights the ance of the present compounds for viral medical therapy.

VI. Process of Preparation of -D-2'-a-fluoro—2'-B-C-substituted-Z-modified-N“- Substituted Purine Nucleotides of the Invention General methods for providing the compounds of the present invention are known in the art or described herein. The synthesis of2’-chloro nucleotides is described in US 20150366888, WO 8801; and WO 0219.

The following abbreviations are used in the synthetic schemes.

CBr4: Carbon tetrabromide DBU: azabicyclo[5.4.0]undec—7—ene DCM: Dichloromethane THF: Tetrahydrofuran (THF), ous EtOAc: Ethyl acetate EtOH: Ethanol Li(OtBu)3AlH: Lithium tri-tert-butoxyaluminum hydride \lazSO4: Sodium sulphate (anhydrous) VIeCN: Acetonitrile VIeNszMethylamine VIeOH: Methanol -li Sodium sulfate \laHCO3: Sodium bicarbonate VH4C1: Ammonium chloride VH4OH: Ammonium hydroxide PE: Petroleum ether Ph3P: Triphenylphosphine Silica gel (230 to 400 mesh, Sorbent) t-BuMgCl: t—Butyl magnesium chloride PCT/U52016/021276 t-BuOK: Sodium tert-butoxide t-BuOH: Tert-butanol EXAMPLES General Methods 1H, 19F and 31P NMR spectra were recorded on a 300 MHz Fourier transform r spectrometer Spectra were ed from samples prepared in 5 mm diameter tubes in CDCl;, CD30D or DMSO-do. The spin multiplicities are indicated by the symbols s (singlet), d (doublet), t (triplet), m (multiplet) and, br (broad). Coupling constants (J) are reported in Hz.

MS a were obtained using electrospray tion (EST) on an Agilent Technologies 6120 quadrupole MS apparatus. The ons were generally carried out under a dry nitrogen atmosphere using Sigma—Aldrich anhydrous solvents. All common chemicals were purchased from commercial sources. 03940 n aware “I >10 MM» WW 1310 GYM“? 7"N ‘ a a, ‘ ‘ [‘20‘ ’5 13ch ”i a: f ’fF 15H? '1 2 3 N 1 ”N : fl WM: MM: \/ O r/i/ ' \E \/ \ V 3 N\N “ ‘ \ N «am—w— Hflm \ N O ~ ”ii‘OM 7’E M NI: “1-7;“ 0P1} ‘ _ 1 H’S‘ ’91: W5 ’9? \‘ .0 NH2 “Hz 4 i) LE(OtBu)3Aét-E, THE-3 -30 “Cw‘rwtifi “C; ai) PPh3, (313:4, DEM. ""C»->0 “Q; iii) laminati— chéoro ‘urme. , iBuOH/MeCN 9:1, ('35 “(3; av) MeNH; (33%)? MeOH, 85 C; v) leopropyi (PS)—(peniafiuorophenoxy)~phenoxy—phosphoryi)“L—aianinate; tBuMgCi, THF, un are ——“ rt.c Example 1. Preparation of isopropyl ((((R,S)—(2R,3R,4R,5R)—5-(2—amino(methylamin0)— 9H-purinyl)—4-flu0r0hydr0xymethyltetrahydrofuranyl)meth0xy)—phenoxy- phosphoryl)—L-alaninate PCT/USZOl6/021276 Step 1, Preparation of ((216,31€,4l€,5/€)(benzoy1oxy)bromofiuoro methyltetrahydrofuran-2—yl)methyl benzoate (2).

To a solution of (2R)-3,5—di-O-benzoylfluoroC-methyl-D-ribono-y-lactone (24.8 g, 66.6 mmol) in dry THF (333 mL), under a nitrogen atmosphere and cooled to -30 0C, was added lithium tri—ferf—butoxyaluminum hydride (1.0 M in THF, 226 mL, 226 mmol) dropwise, After completion of the addition the reaction mixture was slowly warmed up to -15 0C over 90 min then EtOAc was added (300 mL) and the mixture was quenched with a saturated aq. NH4C1 solution (200 mL). The resulting solution was filtered on Celite® and the e was extracted twice with EtOAc. The combined organics were dried (NazSOi), filtered and concentrated. The residue was taken up in dry DCM (225 mL) under a nitrogen atmosphere, cooled to —20 CC, then PPh3 (19.1 g, 72.8 mmol) was added. After 10 min of stirring at -20 0C, CBr4 (26.0 g, 78.4 mmol) was added and the reaction e was allowed to slowly warm up to 0 0C over 2 h, The ing mixture was poured onto a silica gel column and eluted with PE/EtOAc (gradient 100:0 to 80:20). The fractions ning the oc—bromofuranoside were collected and concentrated to afford the product 2 (18.1 g, 41.3 mmol, 6296 over two steps) as a thick colorless oil. 1H NMR (300 MHz, CDC13) é 8.15—8.11 (m, 2H), 8.04—8.01 (m, 2H), 7.64—7.55 (m, 2H), 7.51— 7.41 (m, 4H), 6.34 (d, J: 1.6 Hz, 1H), 5.29 (dd, J: 5.5, 3.1 Hz, 1H), .85 (m, 1H), 4.78 (dd, .1: 12.5, 3.2 Hz, 1H), 4,63 (dd, .1: 12.5, 4.5 Hz, 1H), 1.72 (d, .1: 21.6 Hz, 3H). 19F NMR (282 MHz, CDC13) 5 450.0.

Step 2. Preparation of (218,318,416,5R)—5-(2-aminoch1oro-9H—purinyl) (benzoyloxymethyl)fluoromethyltetrahydrofuran-3—y1 benzoate (3). 2—Amino—6—chloropurine (2.63 g, 15.5 mmol) was ded in l—BuOH (54 mL) under a nitrogen atmosphere. The reaction mixture was heated to 30 0C then potassium fert-butoxide (1.69 g, 15.1 mmol) was added. After 45 min a solution of bromofuranoside 2 (2.24 g, 5.12 mmol) dissolved in anhydrous MeCN (6 mL) was added, the reaction mixture was heated to 65 0C for 16 h then cooled down to room ature, A saturated aq. NH4C1 solution (70 mL) was added and the resulting solution was ted with EtOAc (3 x 60mL). The combined organics were dried (Na2804), filtered and concentrated. The residue was purified twice by column tography (gradient PE/EtOAc 80:20 to 0:100 then 60:40 to 20:80) to afford the product 3 (1.56 g, 2.96 mmol, 57%) as a white solid.

PCT/USZOl6/021276 1H NMR (300 MHZ, CDC13) 0‘ 8.05-8.02 (m, 2H), 7.95-7.92 (m, 2H), 7.88 (s, 1H), 7.63-7.57 (m, 1H), 7.53-7.41 (m, 3H), 7.35-7.30 (m, 2H), 6.43 (dd. J: 22.6.9.1Hz. 1H). 6.12 (d. J: 18.3 Hz, 1H), 5134 (br s, 2H), 5.00 (dd, J: 11.9, 4.5 Hz, 1H), 479—4173 (m, 1H), 4.60 (dd, J: 11.9, 5.3 Hz, 1H), 1.34 (d, J: 22.6 Hz, 3H). l”F NMR (282 MHz, CDC13) 6 —157.0. MS (ESI) m/z calcd. for C25H22FN505 [M+H]' 5269; found 527.0.

Step 3. Preparation of (218.3R.4R.5R)—5—(2—amino-6—(methylamino)—9H—purin-9—y1)—4—fluoro—2- (hydroxymethyl)—4—methy1tetrahydrofuran—3-ol (4).

To a solution of compound 3 (575 mg, 1.09 mmol) in MeOH (9 mL) was added methylamine (3396 in absolute EtOH. 17 mL, 1.81 mmol). The reaction mixture was heated to 85 0C in a sealed tube for 16 h. cooled down to room temperature and concentrated. The residue was d by column chromatography (gradient OH 100:0 to 85:15) then reverse phase column tography gradient H2O/MeOH 100:0 to 0:100) to afford the product 4 (286 mg, 0.91 mmol, 8496) as a white solid. 1H NMR (300 MHz. CD3OD) o‘ 8.06 (s, 1H), 6.11 (d, .1: 18.1 Hz. 1H), 4.41 (dd, .1: 24.4, 9.1 Hz, 1H), 407—401 (m, 2H), 3186 (dd, .1: 12.9. 3.3 Hz, 1H), 3,04 (br s, 3H), 1,16 (d, .1: 2213 HZ, 3H), 1"1: NMR (282 MHZ, CDsOD) (5 -1637. MS (ESI) m/Z calcd‘ for C12H19FN603 [M+H]+ 313.1;found 3132, Step 4. Preparation of isopropyl S)-(2R.3R.4R.5R)—5-(2-amino(methylamino)-9H—pun'n- 9—y1)-4—fluoro—3—hydroxy-4—methyltetrahydrofuran—2—y1)methoxy)—phenoxy—phosphoryl)—L— ate (5).

To a solution of nd 4 (114 mg. 365 umol) in dry THF (4 mL), under a nitrogen atmosphere and cooled to 0 0C was added I—butyl magnesium chloride (1.0 M in THF, 0.66 mL, 660 umol) dropwise over 10 min. The on mixture was stirred 15 min at 0 0C then another min at room temperature. The reaction mixture was cooled down to 0 °C then a solution of isopropyl ((R,S)—(pentafluorophenoxy)-phenoxy-phosphoryl)-lr-alaninate, Ross. BS. Reddy, P.G.. Zhang. H.R.. Rachakonda, S, and Sofia, Ml. J, Org. Chem, (2011), (253 mg. 558 umol) dissolved in dry THF (1 mL) was added dropwise over 10 min. The reaction mixture was stirred at 0 0C for 30 min followed by 18 h at room temperature then quenched with a saturated aq.

NH1C1 solution (4 mL) and extracted with EtOAc (3 x 5 mL). The combined organics were WO 44918 PCT/USZOl6/021276 dried, filtered (NazSO4) and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 90:10) then reverse phase column chromatography (gradient H2O/MeOH 100:0 to 0:100) to afford product 5 (a mixture of diastereomers, 101 mg, 174 umol, 48%) as a white solid. 1H NMR (300 MHz, CD3OD) 6 7.83 (s, 0.55H), 7.82 (s, 0.45H), 7.38—7.16 (m, 5H), 6.15 (d, J: 18.5 Hz, 045 H), (d, J: 18.8 Hz, 0.55 H), 4.99—4.88 (overlapped with H20, m, 1H), 4.65—4.36 (m, 3H), 4.25—4,l7(m, 1H), 3.97—3.85 (m, 1H), 3.05 (brs, 3H), 1.32—1.28 (m, 3H), 1.25—1.15 (m, 9H), 19F NMR (282 MHz, CDsOD) 0‘ —162,8 (3), —163.3 (s). 31P NMR (121 MHz, CDsOD) (5 4.10 (s), 3.99 (3). MS (ESI) m/z calcd. for C24H34FN707P [M+H]+ 5822; found 582.2.

If): ”—1N ca 1;» Nit/19;: o N,‘ /\§\/ g pvt: / “11/ 3/075. 2}: FO‘} 2"}: 1‘ng RH; / L, l ---------as» O“rt 0Ph N 3“ a» “J?” ‘2 Ho‘ ”F ‘ i) Fv‘iegNH‘HCE, DBU, MGOH, 85 0C: v) lsopropyi {(R,S)--(;:>entafiuorc-pheno:~<y)--phe=noxy— oryiyiralaminate, tBuMgCl, THF, 0 “C.

Example 2. Preparation of isopropyl ((((R,S)-(2R,3R,4R,5R)—5-(2-Amin0 (dimethylamin0)—9H-purin—9-yl)flu0r0hydr0xymethyltetrahydrofuran-Z- h0xy)—phen0xy-ph0sphoryl)—L-alaninate (7).

Step 1. Preparation of (2R,3R,4R,5R)—5-(2-amino(dimethylamino)-9H-purinyl)fiuoro- roxymethyl)methyltetrahydrofuranol (6), To a solution of compound 3, from Example 1, (500 mg, 0.95 mmol) in MeOH (6 mL) was added dimethylamine hydrochloride (783 mg, 9.6 mmol) and azabicyclo[5.4.0]undec— 7—ene (1.43 mL, 9.6 mmol). The reaction mixture was heated at 85 °C in a sealed tube for 6 h, cooled down to room temperature and concentrated. The residue was purified by column WO 44918 PCT/USZOl6/021276 chromatography (gradient DCM/MeOH 100:0 to 85:15) then by e phase column chromatography (gradient H2O/MeOH 100:0 to 0:100) to afford product 6 (200 mg, 0.61 mmol, 6496) as a white solid. 1HM (300 MHz, CD3OD) d 8.07 (s, 1H), 6.14 (d, J: 18.1 Hz, 1H), 4.41 (dd, J: 24.4, 9.2 Hz, 1H), 4.08—4.02 (m, 2H), 3.87 (dd, J: 12.8, 2.9 Hz, 1H), 3.42 (br s, 6H), 1.16 (d, J: 22.0 Hz, 3H). 19F NMR (282 MHz, CDxOD) 6 —lo3.8i MS (ESI) m/z calcd. for C13H20FN603 [M+H]+ 3272; found 3272, Step 2. Preparation of isopropyl ((((R,S)-(2R,318,418,5R)—5-(2-amino(dimethylamino)-9H— purinyl)fluorohydroxymethyltetrahydrofuranyl)methoxy)—phenoxy-phosphoryl)-];- alaninate (7).

To a solution of compound 6 (80 mg, 245 umol) in dry THF (4 mL), under a nitrogen atmosphere and cooled to 0 °C was added fel'f-butyl magnesium chloride (1.0 M in THF, 0.64 mL, 640 umol) drop-wise over 10 min. The reaction mixture was d 15 min at 0 0C then another 15 min at room temperature. The reaction mixture was cooled down to 0 0C then a solution of isopropyl ((R,S)—(pentaf1uorophenoxy)-phenoxy—phosphoryl)—li—alaninate (167 mg, 367 umol) dissolved in dry THF (4 mL) was added drop-wise over 10 min. The reaction mixture was d at 0 0C for 30 min and 18 h at room temperature. The reaction was quenched with a saturated aq. NH4C1 solution (4 mL) and extracted with EtOAc (3 x 5 mL). The ed organics were dried, filtered (Na2804) and concentrated. The residue was purified by column chromatography (gradient OH 100:0 to 90:10) and then by reverse phase column chromatography (gradient H20/MeOH 100:0 to 0:100) to afford the product 7 (mixture of diastereomers, 35 mg, 58 umol, 2496) as a white solid. 1H NMR (300 MHz, CD30D) (5 7.83 (s, 0.5H), 7.82 (s, 0.5H), 7.34—7.16 (m, 5H), 6.15 (d, J: 18.7 Hz, 0. 5 H), 6.13 (d, .1 : 18.8 Hz, 0.5 H), 4.99—4.85 (overlapped with H2O, m, 1H), 4.65— 4,26 (m, 3H), 4.27-4.12(m, 1H), 3.99-3.81 (m, 1H), 3.42, 3.41 (2br s, 6H), 136-125 (m, 3H), 11 (m, 9H). 19F NMR (282 MHz, CDsOD) 0‘ -162.7 (s), -163.2 (s). 31P NMR (121 MHz, CD3OD) (5 4.08 (s), 4.00 (5). MS (ESI) m/z calcd. for C25H30FN707P [M+H]_ 5965; found 5962.

PCT/U52016/021276 M“ \ If“ c: We L3 h‘% Ty K N a W \ PA “2 N \ l\ ______________.3,» HO \ N-tl“ \ N ~...~ ¢ ”a; \ , g 1»: \ azg r Ho .

N112 NH; i) a) Ali—Meihyicyclopropyiamine hloride. E513“; MeOH 100 ”C3; b)- NH4tZ3-H, MEOH‘ 100 “C: n) isopropyl ((R,SHpentafluorophenoxy)phenoxyphosphoryl)~L~aianinate, tauMgCE, THF, 0 “-3 Example 3. Preparation of Isopropyl ((((R,S)—(2R,3R,4R,5R)—5-(2-amino(N—methyl— cyclopropylamin0)-9H-purinyl)—4-flu0r0hydroxymethyltetrahydrofuran-Z- yl)meth0xy)-phen0xy-phosphoryl)—L-alaninate (9).

Step 11 Preparation of (2R,3R,4R,5R)—5-(2-Amino(N—methyl-cyclopropylamino)-9H—purin yl)—4-1‘1uoro—2—(hydroxymethyl)—4—methyltetrahydrofuran-3—ol (8).

To a solution of compound 3 (600 mg, 1.14 mmol) in MeOH (10 mL) was added N- methylcyclopropylamine hydrochloride (366 mg, 3.40 mmol) and ylamine (470 uL, 3.40 mmol). The reaction mixture was heated at 1000 C in a sealed tube for 15 h and cooled down to room temperature. An aqueous solution containing 30% NH40H (4 mL) was added and the reaction e was heated at 1000 C in a sealed tube for 2 h, cooled down and concentrated.

The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 90: 10) to afford product 8 (351 mg, 0.99 mmol, 87%) as a white solid. 1H NMR (300 MHz, CD3OD) d 8.13 (s, 1H), 6115 (d, .1 : 18.0 Hz, 1H), 4.40 (dd, J : 24.3, 910 Hz, 1H), 406-4102 (m, 2H), 3.89-3.83 (m, 1H), 3.32 (m, 3H), 318—311 (m, 1H). 1,16 (d, J: 22.2 H2314), 096-089(m, 2H),0,74—0.69(m,2H). ”P NMR (282 MHz, CDROD) 0‘ 4638. MS (ESI) m/z calcd. for CISHZZFN603 [M+H]_ 3532; found 3532.

PCT/U52016/021276 Step 2. Preparation of isopropyl ((((R,S)—(2R,3/{4/6,5R)(2-amino(N-methyl- cyclopropylamino)-9H—purinyl)fluorohydroxymethyltetrahydrofuranyl)methoxy)- phenoxy—phosphoryl)—L—alaninate (9).

To a solution of compound 8 (200 mg, 0.57 mmol) in dry THF (15 mL) at 0° C was added IeI‘f—butyl magnesium chloride (1.0 M in THF, 680 uL, 0.68 mmol) dropwise over 10 min.

The reaction mixture was d 15 min at 00 C then another 15 min at room temperature. The reaction mixture was cooled down to 0° C and a solution of isopropyl ((18,183- (pentafluorophenoxy)-phenoxy—phosphoryl)—li—alaninate (283 mg. 0.62 mmol) dissolved in dry THF (4 mL) was added dropwise over 10 min. The reaction mixture was d at 0 °C for 30 min and 18 h at room temperature. The on was quenched with a saturated aq. NH4C1 solution (4 mL) and extracted with EtOAc (3 x 5 mL). The ed organics were dried over Na2804 and concentrated The residue was purified by column chromatography (gradient OH 100:0 to 90:10) and then by reverse phase column chromatography (gradient H20/MeOH 100:0 to 0:100) to afford t 9 (mixture of 2 diastereoisomers, 160 mg, 026 I5 mmol, 4596) as a white solid. 1H NMR (300 MHz, CD30D) (5 7.85 (m, 1H). 7.38—716 (m, 5H), 6.18 (d, .1: 18.6 Hz) and 6.16 (d, .1 : 189 Hz. 1H). 4.95—4.90 (overlapped with H20, m. 1H). 458-447 (m, 3H), 4.22—4.19 (m, 1H), 3.95-3.87 (m. 1H), 3.36—3.34 (overlapped with MeOH, m, 3H), 3.19—3.12 (m, 1H), 1.32— 1.22 (m, 12H), 0.96-0.89 (m, 2H), 0.74-0.69 (m,2H). 3'P NMR (121 MHz, CD3OD) (5 4.11 (s), 4.02 (s), MS (ESI) m/Z calcd. for C27H38FN70~P [M+H]_ 6222; found 622.2.

PCT/USZOl6/021276 [-7 \~ C1 AB!“ 1 Nx ifif H 820 (O\ "'""""'*"" BEGN \7“ N l“ W M ‘ \ no“ ”r 320° [’9' )3 2 ‘19 i} 2x6-d1631'1EGE'ODLEE'WEB lBuQKS ZBuOH/l‘fleCN, ~35 “C: 105115311142. Mac-H. 130°C; iii)lisoprc>py1<<fl8>~ (roentafiuorophenoxy)~phenoxy-phosphoryl)-L~aianinate‘ L THF, 0 “C to RT Example 4. Preparation of isopropyl ((((R,S)—(2R,3R,4R,5R)—5-(2,6-bis-methylamin0-9H- purinyl)flu0r0hydr0xymethyltetrahydrofuran—Z-yl)methoxy)—phen0xy- ph0sph0ryl)—L-alaninate (12).

Step 1. Preparation of (2R,3R,4R,5R)—5—(2,6—dichloro—9H—purin-9—y1)—2—(benzoy1oxymethy1)—4— fluoro—4-methyltetrahydrofuran—3-y1 benzoate (10).

The nd 2,6—dichloropurine (1.30 g, 6.86 mmol) was suspended in t-BuOH (25 mL) under a nitrogen atmosphere. Potassium fert—butoxide (778 mg, 6.92 mmol) was added n-wise then the reaction mixture was stirred at room temperature After 1 h, a solution of bromofuranoside 2 (1.0 g, 2.29 mmol) dissolved in anhydrous MeCN (20 mL) was added and the reaction mixture was heated at 65 OC ght and then cooled down to room temperature. A saturated aq. NH4C1 solution was added and the resulting solution was extracted with EtOAc (3 times). The combined organics were dried over NazSO+ and concentrated. The residue was d by column chromatography (gradient PE/EtOAc 100:0 to 0:100) to afford product 10 (148 mg, 0.27 mmol, 1296) as a sticky solid. 1H NMR (300 MHz, CDC13) d 8.31 (s, 1H), 8.12—8.09 (m, 2H), 8.02—7.99 (m, 2H), 7.64—7.39 (m, 6H), 6.38 (d, J: 1712 Hz, 1H), 6102 (dd, J: 2112. 819 Hz, 1H). 4190—468 (m, 3H), 1.33 (d, J: 22.4 Hz, 3H). 19F NMR (282 MHZ. CDC13) (5 -1580. MS (ESI) m/z calcd. for C25H20C12FN405 [M+H]‘ 546.4; found 5463.

WO 44918 PCT/USZOl6/021276 Step 2. Preparation of (216,316,4R,5R)(2,6-b/s-methylamino-9H-purinyl)—4-f1uoro (hydroxymethyl)—4-methyltetrahydrofuranol (11).

A solution of compound 10 (148 mg, 0.27 mmol) in methylamine (3396 in EtOH, 30 mL) was heated at 130 °C in a sealed tube for 4 days, cooled down to room temperature and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 50:50) followed by reverse phase column chromatography (gradient H20/MeOH 100:0 to 0:100) to afford product 11 (33 mg, 0.10 mmol, 3796) as a white solid. 1H NMR (300 MHz, CD3OD) (5 8.00 (s, 1H), 6.12 (d,.]: 18.5 Hz, 1H), 45] (dd, J: 24.4, 95 HZ, 1H), 4.06-3.85 (m, 3H), 3.04 (s, 3H), 2.93 (s, 3H), 1.20 (d, .1 : 22.4 Hz, 3H). 19F NMR (282 MHZ, CD30D) (5 — 1632. MS (ESI) m/z calcd. for FN603 [M+H]‘ 3272; found 3272.

Step 3. Preparation of pyl ((((R,S)—(2R,3R,4R,5R)-5—(2,6—bi.s'—methylamino—9H—purin—9—yl)— 4—f1uoro-3—hydroxy—4—methy1tetrahydrofuran—2—y1)methoxy)—phenoxy—phosphory1)-L—alaninate (12).

To a solution of compound 11 (55 mg, 0: 17 mmol) in dry THF (2 mL) at 0 0C was added ferf—butyl magnesium chloride (1 M in THF, 304 1 L, 0.30 mmol) dropwise over 10 min. The on mixture was stirred 15 min at 0 OC and then 15 min at room temperature. The solution was cooled down to 0 OC and a solution of isopropyl ((13,183-(pentaf1uorophenoxy)—phenoxy- phosphoryl)-L-alaninate (115 mg, 0.25 mmol) dissolved in dry THF (1 mL) was dropwise added over 10 min. The mixture was warmed slowly to room temperature and stirred for 4 days. The reaction was quenched with a saturated aq. NH4C1 solution and ted with EtOAc (3 times).

The combined organics were dried over Na2804 and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 50:50) to yield product 12 re of diastereomers, 13 mg, 0.02 mmol, 1396) as a white solid: 1H NMR (300 MHz, CDxOD) (5 7.78 (s, 1H), 7.35—7.12 (m, SH), 013 (d, .1: 19.1 Hz, 0.53H), 6.10 (d, .I: 19.2 Hz, 0.47H), .78 (overlapped with H20, m, 1H), 4.72—4.40 (m, 3H), 4.24—4.15 (m, 1H), 3.79—3.92 (m, 1H), 3.02 (br s, 3H), 2.92 (s+s, 3H), 1.29—1.11 (m, 12H). l9F NMR (282 MHz, CD30D) (5 -162.0 (s), - 162.3 (s). 31P NMR (121 MHZ, CD3OD) 5 3.97 (s), 3.89 (s). MS (ESI) m/Z calcd. for C25H36FN7O7P [M+H]+ 596.6; found 596.2.

PCT/USZOl6/021276 {TN -:’\i , .

NHMG fr» [AH-{Me L).. N / \\ O\ N‘ / \ i .9 \f‘l 1| —————x..Arg to ”a. “a... \«a. 6‘! N»: ¢ 9, \ "m, if} c ”/7 r HQ F “Si“O 5‘ NH“ / NH) ’ fix a N I NHMe I O 3,.

\Sifn F HV‘fi“. H5\ (I 14 ...__./ 15 E‘ \\ O / i\ , N [fr with e1 1’) I : ”r 0 NJ“ N Y \F: M N: 5/ x’ i \O \ “N \ ‘\ m” 0 l z . \7‘4 ~~{ \ H ‘3 .3 ‘5 \ .e‘ HO r- 16 \\ i) TIPDSCQ. imidamle, DMF. ii) isobutyryi chloride pyridine: iii) TBAF, THF; iv} isopropyi (WE)— (pentafiuorophenomfi—phenoxyphosphoryi)—L—aianirxate. i. THF, 0 “C.

Example 5. Preparation of isopropyl ((((R,S)-(2R,3R,4R,5R)(2-isobutyramid0 methylamino—9H-purinyl)—4-flu0r0hydr0xymethyltetrahydr0furanyl)meth0xy)- phen0xy-phosphoryl)-L-alaninate (16).

Step 1. Preparation of compound 13.

To a solution of compound 4 (286 mg, 092 mmol) and imidazole (370 mg, 5.43 mmol) in dry DMF (6 mL) at 0 0C was added 1,3—dichloro—l,1,3,3—tetraisopropyldisiloxane (300 pL, 094 mmol). The reaction e was stirred for 2 h at RT, diluted with EtOAc (50 mL) and the suspension was washed with saturated aq‘ NH4Cl solution and brine (40 mL each). The organics were dried over Na2S04 and concentrated. The residue was purified by column chromatography (gradient Ac 7:3 to 3:7) to afford product 13 (283 mg, 0.51 mmol, 56%) as a white solid.

MS (ESI) m/z calcd. for C24H44FN604Si2 [M+H]+ 555.8; found 5552.

Step 2‘ Preparation of nd 14‘ To a solution of compound 13 (200 mg, 0.36 mmol) in dry pyridine (3 mL) at 0 0C was added isobutyryl chloride (38 pL, 036 mmol). The on mixture was stirred for 2 h at RT.

PCT/U52016/021276 The reaction was quenched by the addition of water (500 uL). The mixture was concentrated and co-evaporated with toluene (3 x 10 mL). The residue was purified by column chromatography (gradient PE/EtOAc 1:0 to 1:1) to afford product 14 (99 mg, 0.16 mmol, 4496) as a white solid. MS (EST) m/z calcd. for C28H50FNGOSSlZ [M+H]+ 6259; found 625.3.

Step 3‘ Preparation of ,4R,5R)—5-(2-isobutyramidomethylamino-9H—purinyl) fluoro—2-(hydroxymethyl)-4—methyltetrahydrofuran—3—ol (15) To a solution of compound 14 (90 mg, 0.14 mmol) in dry THF (2 mL) was added tetrabutylammonium fluoride (1 M in THF, 38 uL, 0.38 mmol). The mixture was stirred for 2 h at RT and concentrated. The e was purified by column chromatography ent DCM/MeOH 10:0 to 9:1) followed by reverse phase column chromatography (gradient H2O/MeOH 100:0 to 0:100) to give product 15 (42 mg, 0.11 mmol, 7796) as a white solid. 1H NTVIR (300 MHz, CD3OD) 6 8.31 (s, 1H), 6.29 (d, J: 17.9 Hz, 1H), 4.70-4.60 (m, 1H), 4.07- 3.98 (m, 2H), 3.89 (dd, J: 125,34 Hz, 1H), 3.10 (br s, 3H), 2.87 (br s, 1H), 1.23-1.16 (m, 9H).

I5 19F NMR (282 MHz, CD20D) (5 —163.8. MS (ESI) m/z calcd for C16H24FN604 [M+H]‘ 3834; found 3832 Step 4, ation ofisopropyl ((((R,S)—(2R,3[8,416,5R)(2-isobutyramidomethylamino-9H- purinyl)fluorohydroxymethyltetrahydrofuranyl)methoxy)-phenoxy-phosphoryl)-L- alaninate (16).

To a solution of compound 15 (27 mg, 0.07 mmol) in dry THF (1 mL) at 0 0C was added f—butyl magnesium chloride (1.0 M in THE, 130 uL, 0.13 mmol) dropwise over 10 min. The reaction mixture was d 15 min at 0 0C then another 15 min at room temperature The reaction mixture was cooled down to 0 OC and a solution of isopropyl ((13,18)- (pentailuorophenoxy)-phenoxy—phosphoryl)—l:—alaninate (50 mg, 0.11 mmol) dissolved in dry THF (1 mL) was added dropwise over 10 min. The reaction mixture was d at 0 °C for 30 min followed by 18 h at room temperature then quenched with a saturated aq. NH4C1 solution (2 mL) and ted with EtOAc (3 x 5 mL). The combined organics were dried over NazSO4 and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 95:5) then reverse phase column chromatography (gradient H20/MeOH 100:0 to 0: 100) to afford t 16 (mixture of 2 diastereoisomers, 25 mg, 0.04 mmol, 5496) as a white solid.

PCT/USZOl6/021276 1H NMR (300 MHz. CD30D) a 8.05 (s. 1H). 7.33—7.13 (m. 5H). 6.27 (d. J 2 18.6 Hz) and 6.21 (d. J: 19.1 Hz. 1H). 5.10-4.95 (m. 1H). 4.93-4.78 (overlapped with H20. m. 1H). 4.60-4.42 (m. 2H). 4.26-4.18 (m. 1H). 3.90-3.80 (m. 1H). 3.09 (br s. 3H). 2.84—2.80 (m, 1H). 1.33—1.15 (m. 18H). 31P NMR (121 MHz. CD3OD) a‘ 3.69 (s). 31P NMR (121 MHz. CD3OD) 0‘ 4.11 (s). 3.99 (8). MS (ESI) m/z calcd. for C28H4OFN'OSP [M+H]‘ 6526; found 652.3. f; 3 [2’1” NW O N‘f{ {‘1 N l \ f “u 82Wm N x» t “3= mun—saw HOW» 1 - N‘<< ’ e “a 1.4% 1320 1 W, 3‘ F MHz NH; :3 17 i) N—Methylethyiamine, Meet-l. 4:00 ”C; 3%) isopropyl 4(pentafluor0phenoxy)Aphenoxy-phospheryE)-L»- alamrzate. ti—SuMgCEl. THF. (1°C Example 6. Preparation of pyl ((((R,S)—(2R,3R,4R,5R)—5-(2-amin0(N-methyl- min0)—9H—p11rinyl)flu0r0—3-hydr0xy—4-methyltetrahydr0furanyl)meth0xy)— y-ph0sph0ryl)-L-alaninate (18).

Step 1. Preparation of (2R.3R.4R.5R)—5-(2-amino(N—methyl-ethylamino)—9H—purinyl) fluoro—Z-(hydroxymethyl)-4—methyltetrahydrofuran—3—ol (17).

To a solution of compound 3 (150 mg. 0.29 mmol) in MeOH (4 mL) was added N— methylethylamine (245 11L. 2.90 mmol). The reaction mixture was heated at 100 CC in a sealed tube for 15 h. cooled down to room temperature and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 90:10) to afford product 31 (89 mg. 0.26 mmol, 89%) as a white solid. 1H NMR (300 MHz. CDsOD) (5 8.06 (s. 1H). 6.13 (d. .1 : 18.0 Hz. 1H). 4.40 (dd. .1 : 24.9. 8.7 Hz. 1H). 4.11—4.01 (m. 4H). 3.98—3.83 (m. 1H). 3.34 (br, s. 3H). 1.24—1.11 (m. 6H), ”P NMR (282 MHz, CDsOD) (5 -163,7. MS (ESI) m/z calcd. for C14H22FN603 [M+H]+ 3412; found 341.2.

Step 2. Preparation of isopropyl ((((R,S)—(2R,3R,4R,5R)—5-(2—amino—6—(N—methyl—ethylamino)— 9H—purinyl)fluorohydroxymethyltetrahydrofuranyl)methoxy)—phenoxy- phosphoryl)-L-alaninate (18).

To a solution of compound 17 (30 mg. 0.09 mmol) in dry THF (2 mL) at 0 0C was added ferf—butyl magnesium de (1.0 M in THF. 1 10 uL, 0.1 1 mmol) dropwise over 10 min. The reaction mixture was stirred 15 min at 0 0C then another 15 min at room temperature. The reaction mixture was cooled down to 0 OC and a solution of pyl ((13.13)- (pentafluorophenoxy)-phenoxy—phosphoryl)—L—alaninate (48 mg. 0.11 mmol) dissolved in dry THF (1 mL) was added dropwise over 10 min. The reaction mixture was stirred at 0 0C for 30 min and 18 h at room temperature. The reaction was quenched with a saturated aq. NH4C1 on (4 mL) and ted with EtOAc (3 x 5 mL). The combined organics were dried over NazSO4 and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 90:10) to afford the product 18 (mixture of 2 diastereoisomers, 22 mg, 0.04 mmol, 40%) as a white solid. 1H NMR (300 MHz, CD3OD) (5 7.69 (m. 1H). 7.26-7.04 (m. 5H), 6.05 (d, J : 18.6 Hz) and 6.03 (d. J: 18.9 Hz. 1H). 4.86-4.79 (overlapped with H20. m. 1H). 4.50-4.32 (m. 3H), 4.12-4.06 (m, 1H), 3.96-3.79 (m, 3H). 3.25 (br. s. 3H), .02 (m, 15H). 31P NMR (121 MHz. CD3OD) d 4.07 (s), 4.00 (s). MS (ESI) m/z calcd. for C26H38FN707P [M-rH]+ 609.3; found 6092. 2016/021276 \ r‘ g? f" 3 ’19 \...._.__ N \‘ . NMe \f .. a : ,9 eff[:5 \ \ N "3 “fife/N V “fits/NH M “X"N W oer: \ A? ’/_ i) N~1\J’1ethy1propyiaméne, MeOH, 100 1:;11) lsopropyi ({r’if,S)~(pentafiuczrophenoxyH)henoxy~phosphoryi)~i_.- alamnate, tBuMgCl, THF, 0 0C.

Example 7. Preparation of isopropyl ((((R,S)—(2R,3R,4R,5R)—5-(2-amino(N—methyl- amin0)-9H-purinyl)flu0r0hydr0xymethyltetrahydr0furanyl)meth0xy)- phen0xy-ph0sph0ryl)-L-alaninate (20).

Step 1. Preparation of (2R,3R,4R,5R)(2-amino(N-methyl-propylamino)—9H-purinyl) fluoro(hydroxymethyl)methyltetrahydrofuranol (19).

To a solution of compound 3 (150 mg, 0.29 mmol) in MeOH (4 mL) was added N— methylpropylamine (295 uL, 2.90 mmol), The reaction mixture was heated at 100 0C in a sealed tube for 15 h, cooled down to room temperature and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 90:10) then e phase column chromatography (gradient HzO/MeOH 100:0 to 0:100) to afford product 19 (80 mg, 0.23 mmol, 7896) as a white solid. 1H NMR (300 MHz. CDxOD) 0‘ 8.04 (s, 1H), 6.13 (d, ./ : 18.3, 1H), 4.40 (dd, .1: 24.2. 9.2 Hz, 1H), m, 4.06-3.84 (m, SH), 168 (sept, J: 7.5 HZ, 2H), l.l5 (d, J : 22.2 Hz, 3H), 093 (t, J: 7.5 Hz. 3H). IL’1: NMR (282 MHz, CD3OD) (5 -163.8. MS (ESI) m/Z calcd. for C15H24FN603 [M+H]‘ 3552; found 355.2.

PCT/USZOl6/021276 Step 2, Preparation ropyl ((((R,S)—(2R,3R,4R,5R)(2-amino(N—methyl-propylamino)- 9H-purinyl)fluorohydroxymethyltetrahydrofuran-Z-yl)methoxy)-phenoxy— phosphoryl)—L—alaninate (20).

To a solution of compound 19 (30 mg, 0.09 mmol) in dry THF (2 mL) at 0 0C was added utyl magnesium chloride (1.0 M in THF, 110 11L, 0.11 mmol) se over 10 min. The reaction mixture was stirred 15 min at 0 0C then another 15 min at room temperature The reaction mixture was cooled down to 0 OC and a solution of isopropyl ((18,183- (pentafluorophenoxy)-phenoxy—phosphoryl)—li—alaninate (46 mg, 0.11 mmol) dissolved in dry THF (1 mL) was added dropwise over 10 min. The reaction mixture was stirred at 0 0C for 30 min and 18 h at room temperature. The reaction was quenched with a saturated aq. NH4C1 solution (4 mL) and extracted with EtOAc (3 x 5 mL). The ed organics were dried over NazSO4 and concentrated The residue was purified by column tography (gradient DCM/MeOH 100:0 to 90:10) to afford product 20 (mixture of Z diastereoisomers, 22 mg, 0.03 mmol, 3396) as a white solid. 1H NMR (300 MHZ, CD30D) (5 7.78, 7.77 (5+5, 1H), 7.37—7.13 (m, 5H), 6.15 (d, ./ : 18.6 Hz) and o. 13 ((1.1: 18.9 Hz, 1H), 4.97—4.89 (overlapped with H20, m, 1H), 4.63—4.30 (m, 3H), 4.22— 4.14 (m, 1H), 4.02—3.84 (m, 2H), 1.74-1.63 3H, m), 1.32—1.27 (m, 3H), 1.23—1.13(m,9H),0.94 (t, ./ : 7.4 Hz) and 0.93 (1, .1 : 7.4 Hz, 311). “P NMR (121 MHZ, CD30D) (5 4.05 (s), 4.00 (s).

MS (ESI) m/z calcd. for C27H40FN707P [M+H]+ 623.3; found 623.2.

PCT/USZOl6/021276 nun: Ho F N42 Em 3 21 [Y 1:27—N\ NMQ \\( g n flwhx /\\< \ (4 \ [P‘sofi /' mg... 0 ........M rm» \5 HQ?“ IF i) a) N—W’lethyicyclobutylamine hydrochioride. Eth. MeOH, 100 ”C: b) NWOH, MeOH, 100° C; ii) Esopropyl ((133,SHp8mafluomphenoxy)~phersoxy-phosphoryl}-L.-alaninzate. [BLEMQCL THE 0 “C.

Example 8. ation of Isopropyl S)—(2R,3R,4R,5R)—5-(2-amin0(N-methyl- cyclobutylamin0)—9H—purinyl)—4-flu0r0hydr0xymethyltetrahydr0furan yl)meth0xy)-phen0xy-phosphoryl)—L—alaninate (22).

Step 1. Preparation of (2R,3R,4R.5R)(2-amino(N—methyl-cyc1obutylamino)-9H—purin fluoro(hydroxymethyl)methy1tetrahydrofuranol (21).

To a solution of compound 3 (150 mg, 0.29 mmol) in MeOH (4 mL) was added N— methylcyclobutylamine hydrochloride (105 mg, 0.90 mmol) and triethylamine (190 uL, 1.00 mmol). The reaction mixture was heated at 100 0C in a sealed tube for 15 h and cooled down to room temperature. An aqueous solution containing 3096 NH4OH (1 mL) was added and the reaction mixture was heated at 100 0C in a sealed tube for 2 h, cooled down and concentrated.

The residue was purified by column chromatography (gradient OH 100:0 to 90:10) to afford product 21 (90 mg, 0.25 mmol. 86%) as a pale yellow solid. lH NMR (300 MHZ, CD3OD) (5 8.09 (s, 1H), 6.14 (d, J : 18.0 Hz, 1H), 5.80-5.70 (m, 1H), 4.44- 4.33 (m. 1H), 4.06-4.02 (m, 2H). 3.88-3.84 (m. 1H), 3.34 (s, 3H), 2.38-2.19 (m. 4H), 1.79-1.71 (m. 2H), 1.17 (d. J : 22.2 Hz. 3H). l9F NNIR (282 MHz, CD3OD) 6 -163.8. MS (ESI) m/z calcd. for C16H24FN603 [M+H]‘ 367.2; found 367.2.

WO 44918 Step 2. Preparation of isopropyl ((((R,S)—(2R,3/{4/6,5R)(2-amino(N-methyl- cyclobutylamino)-9H—purinyl)-4—fluorohydroxymethyltetrahydrofuranyl)methoxy)- phenoxy—phosphoryl)—L—alaninate (22).

To a solution of compound 21 (50 mg, 0.14 mmol) in dry THF (2 mL) at 0 0C was added fert—butyl ium chloride (1.0 M in THF, 210 11L, 0.21 mmol) dropwise over 10 min. The reaction mixture was stirred 15 min at 0 0C then r 15 min at room ature The reaction mixture was cooled down to 0 OC and a solution of isopropyl ((18,18)- (pentafluorophenoxy)-phenoxy—phosphoryl)—li—alaninate (74 mg, 0.16 mmol) dissolved in dry THF (2 mL) was added dropwise over 10 min. The reaction mixture was stirred at 0 0C for 30 min and 18 h at room temperature. The reaction was quenched with a saturated aq. NH4C1 solution (4 mL) and extracted with EtOAc (3 x 5 mL). The combined organics were dried over Na2804 and trated The residue was purified by column chromatography ent DCM/MeOH 100:0 to 90:10) and then by reverse phase column chromatography (gradient H20/MeOH 100:0 to 0:100) to afford product 22 (mixture of 2 diastereoisomers, 24 mg, 004 I5 mmol, 28%) as a white solid. 1H NMR (300 MHz, CDsOD) (5 7.79 (s, 02H), 7.77 (s, 0811). 7.38—7.12 (m, SH). 618 (d, ./ : 17.6 Hz) and 6,16 (d, ./ : 17.5 Hz, 1H). 495-481 (m, 2H). 3 (m, 3H). 425-418 (m, 1H), 3.96-3.83 (m, 1H). 3,38 (s) and 3.36 (s, 3H). 238-221 (m, 4H), 1.75—1.63 (m. 2H), 1.32— 1.16 (m, 12H). 3'P NMR (121 MHZ, CD30D) (5 4.04 (s). 3.97 (s). MS (ESI) m/z calcd. for C28H40FN7OTP [Mi-H]+ 6363; found 636.2.

Modification of the 2-amino moiety in the active compounds One of ordinary skill in the art can add a substituent to the 2-amino purine moiety by methods well known to those skilled in the alt, One non-limiting process is provided here, and others can be easily adapted, ((216,3]€,4R,5R)—3—(benzoyloxy)—5-bromo—4—fluoro—4- methyltetrahydrofuranyl)methyl benzoate, is treated with commercially ble 2,6- dichloropurine. a base and a mixture of organic solvents at an elevated temperature to generate (2R.3R.4R.5R)—5-(2.6—dichloro—9H—purin—9-yl)—2—(benzoyloxymethyl)—4—fluoro—4— methyltetrahydrofuran—3—yl benzoate. In one embodiment, the base is potassium utoxide.

In one embodiment, the mixture of organic solvents comprises tert—butanol and acetonitrile. The compound, (2R,3R,4R, 5R)(2,6-dichloro-9H—purinyl)(benzoyloxymethyl)fluoro PCT/USZOlo/021276 methyltetrahydrofuranyl benzoate is treated with an amine, a base and an organic solvent at ambient temperature to generate 2-chloro-N"-substituted purines. In one embodiment, the amine is amine. In one embodiment, the base is triethylamine. In one ment, the organic solvent is ethanol. One skilled in the art will also recognize that upon treatment with an amine and base, the benzoate groups on the nucleoside will simultaneously be removed to te the deprotected furanose moiety. 2-Chloro-N6-substituted purines can then be treated with an amine, and an organic solvent in a sealed tube at an elevated temperature of about 100 0C to generate N2,N(’-disubstituted purine sides of the present invention. In one embodiment, the amine is amine. In one embodiment, the organic solvent is ethanol. N2,N6-Disubstituted purine nucleosides of the t invention can be treated with a base, isopropyl ((13,53- (pentafluorophenoxy)-phenoxy—phosphoryl)—L—alaninate and an organic solvent at a reduced temperature to generate compounds of Formula I—V. In one embodiment, the base is tert—butyl magnesium chloride. In one embodiment, the organic solvent is tetrahydrofuran. ation of Stereospecific Phosphorus Enantiomers Certain of the active compounds bed herein have a chiral phosphorus moiety. Any of the active compounds described herein can be provided as an isolated phosphorus enantiomeric form, for example, at least 80, 90, 95 or 9896 of the R or S omer, using methods known to those of skill in the art. For example, there are a number of publications that describe how to obtain such compounds, including but not limited to column chromatography, for example as described in Example 17 below and US. Patent No. 756; 8,642,756 and 8,333,309 to Ross, et al.

Example 9. Separation of the stereoisomers of compound 5.

The stereoisomers of Compound 5 were separated on a Phenominex Luna column using the following conditions: Column: Phenominex Luna 5 micron C18 (2) 250 x 10 mm part# OOGBO Sample tration: Approximately 50 mg/ml in acetonitrile Injection volume: 50 ul Mobile phase A: HPLC grade water Mobile phase B: HPLC grade acetonitrile.

PCT/U52016/021276 Flow: 5 ml/min UV: 283 nm Gradient: Time %B 0 2 4O 50 41 50 41:1 2 45 2 Run time: 45 minutes Column ature: 40 0C A sample chromatogram ofa semi-prep run is illustrated in Figure l.

The combined fractions were evaluated using an analytical column with the following conditions: Column: Phenominex Luna 5 micron C18 (2) 250 x 2mm part# OOG—4252—BO Injection volume: 10 ul Mobile phase A: HPLC grade water Mobile phase B: HPLC grade itrile.

Flow: 0.2 ml/min UV: 283 nm Gradient: Run time: 45 minutes Column Temperature: 40 OC The combined fractions for each stereoisomer were evaporated to dryness using a rotovap with a bath ature of 30 0C. The resulting solids were dissolved in 1 ml of acetonitrile, PCT/USZOlo/021276 transferred into 1.7 ml microcentrifuge tubes and the solvent evaporated on the vacuum centrifuge at a temperature of 30 OC.

The data on the final samples are as follows: 1. First g peak: Compound 5 #1 (5-1) (21.7 mgs , 97.8% ee). 2. Second eluding Peak: Compound 5 #2 (5-2) (13.2 mgs , 95.9% ee).

The final weights of the lSt and 211C1 peak correspond well to their percentages in the original mixture. (622% and 37.8% tively) Stereospecific Syntheses of Compounds of Formula I-VII (N Nil/2:? {fly/TN .A / \ ll (6 “ixi ixiH wa J\ 4 (\ N NH) ___________a, o\ BEGNJ6 WCl‘lfi l'lOthtHs EEC? IF HCS: 5:: 3 23 Example 10. Preparation of ,4R,5R)—5-(2-aminochloro-9H—purinyl)—2— (hydroxymethyl)—4-fluoromethyltetrahydrofuranol (23).

Step 1. Preparation of (2R,3R,4R,5R)—5—(2—amino—6—chloro—9H—purin—9-yl)—2—(hydroxymethyl)— 4—fluoro-4—methyltetrahydrofuran-3—ol (23).

The compound (2R,3R,4R,5R)—5-(2-amino-o-chloro-9H—purinyl) (benzoyloxymethyl)—4—fluoro-4—methyltetrahydrofuran—3—yl benzoate, 3, (80 g, 140 mmol) was added to a solution of hylamine in methanol (7 M, 800 mL) and stirred at RT ght.

The mixture was concentrated and then purified by column chromatography (DCM:MeOH : 100:1) to afford (2R,3R,4R,5R)(2-aminochloro-QH-purin-Q-yl)(hydroxymethyl) fluoro—4-methyl-tetrahydrofuranol (23) (40 g, 90%).

PCT/USZOlo/021276 /(:H3.

C” W F r: pkg/QM N~~ 6’ \ @1139 1:4 1 N ‘2’ i Hg“ /U /J\ T//\ : "\ ':/‘\ {x ,f-?-\< T N 3 \ ,c-Vai‘e H \in 1:; N my H o \‘ //~ ”um-fie ' NH.

/M/ \f ' J ‘ 'v— \ {P I 6H,; 0 \§(,.r U MuHsP HO WCH “ F F v “3 H 5; fl: HO“; ’r: \L/ 23 4 PPAL-S CH,‘ HN " 4147 “N : 0 Ho 0. ix “\JH2 N P .4 N/ i; \n 3/“ a) (E‘H 1/ iii KEV/Miméf‘w”' ’ fix ~41“? ”F ‘J 24 Example 11. Preparation of ((((S)—(2R,3R,4R,5R)—5-(2-amin0(methylamin0)-9H-purin yl)fluor0-3—hydroxy-4—methyltetrahydr0furan-2—yl)methoxy)-phen0xy-ph0sph0ryl)—L- alaninate.

KCH3 g HN lN~~./J\\}N N\‘ /i\. <1” ””21 f: <7 ‘ 1f”? 0 N \ 3A N A~ .{/*\ HON W NH2 -----------—% Mo‘sWN N NH2 \ /,,.¢RCH3 HO \ ,1 aCHg Hd F HO‘i ’F 23 4 Step 1. Preparation of (2R,3R,4R,5R)—5-(2-amino(methylamino)-9H—purinyl)—4-fluoro hydroxymethyltetrahydrofuranol (4).

To a solution of (218,318,418,5R)—5—(2—amino—o—chloro—QH—purin—Q-yl)—2—(hydroxymethyl)— o-4—methyl—tetrahydrofuran-3—ol (2.0 g, 1.0 eq) in dioxane (15 mL) was added MeNHz aqueous solution (5.0 eq). After stirring overnight at RT. TLC showed that the starting material was consumed. The mixture was concentrated and d by column chromatography (DCM:MeOH : 40:1— 30:1) to afford (2R,3R,4R,5R)—5—(2-amino—6-(methylamino)—9H—purin—9— y1)fluorohydroxymethy1tetrahydrofuran—3—ol as a white powder (1.6 g, 81.6%).

[M+H]' : 313.5 PCT/U52016/021276 mg m F F : N x: (313 I: \_/ 51‘ V ”W . :\ M". x l~1"93“/‘*- “‘“\ H ,1 ‘1’ T if I "'F T 9 ./-' 3 we 0. a ,r; M/O\ £N’T‘N‘”K‘kti4r' 7 - x p , 2‘ AX/0\7’Ni l‘i/\M*'~.. , Q i .1, + CH; C 1’: I \ \E/ T]; \l‘v 111.0 \\ CH».

Ho (“x F F i ,1 cm ,U 1an o .r J ' ;\ /:- '“‘ “ f=>< *0 F Ho‘ ‘F “\f \ f} 4 PWXL-S 24 Step 2. Preparation of ((((iS)-(2R,3R,4R.5R)—5—(2—amino—6—(methylamino)—9H—purin—9—yl)—4— hydroxymethyltetrahydrofuranyl)methoxy)-phenoxy-phosphoryl)-l.-alaninate, The compound (2R.3R.4R.5R)—5-(2-amino(methylamino)-9H-purinyl)fluoro ‘Jl hydroxymethyltetrahydrofuran-3 -01 (1.47 g, 1.0 eq) and PPAL-S (2.35 g, 1.1 eq) were dissolved in anhydrous THF (29 mL). After cooling the mixture to -10 0C. I-BuMgCl (5.8 mL, 1.7 M, 2.1 eq) was slowly added under a blanket of N2. After stirring at RT for 45 min, the mixture was quenched with aq. saturated NH4C1, and extracted with EtOAc (20 mL X 3). The combined organic layers were washed with water, brine (30 mL), dried over anhydrous NazSO4 and concentrated The crude product was purified by column chromatography (DCM:MeOH : 50: 1— 20:1) to afford ((((iS')—(2R,3R,4R,5R)—5—(2—amino—O-(methylamino)—9H—purin—9-yl)—4—fluoro- 3-hydroxymethy1-tetrahydrofurany1)methoxy)-phenoxy-phosphoryl)-l.-alaninate as a white powder (1.1 g, 40.3%), 1H NMR (400 MHZ. CD3OD) 6 7.81 (s. 1H). .16 (m. 5H), 6.10 (d, J: 18.4 Hz, 1H), 4.90- 4.84(m, 5H), 4.55-4.46 (m, 3H), 4.20-4.16 (m, 1H), 3.91-3.87 (m, 1H), 3.30 (m, 1H), 3.03 (s, 3H), 1.30-1.20(m, 12H). [M+H]'= 582.8.

PCT/U52016/021276 CI H3C\N,.CH3 F F {NNI’LNNN N /£§N <1 9r HO 0 CH3?!) H <51 A 3v WANM< WP N NHZW \Nf NHz O . \ M CH:3 O (l: HO fih<:_LmCHO\7fN O\/N HO/fihf. H( F F w, 3 CH <7 ~‘ ”a \LJ Ho‘ F HO ’F 23 6 PPAL-S NHsd'ECH3\.

~ “N o <. l 9H3 l H N O N; \NH2 Example 12. Preparation of isopropyl —(2R,3R,4R,5R)—5-(2-amin0(dimethylamin0)- 9H—purinyl)-4—fluoro-3—hydr0xy-4—methyltetrahydrofuran-Z-yl)methoxy)—phen0xy- phosphoryl)—L-alaninate (25). ”3 :wéfiCH3 HO ~____,ta,ac;~iz H3 % ho' 1 Step 1. Preparation of (2R,3R,4R,5R)—5—(2—amino—6—(dimethy1amino)-9H—purin—9—y1)—4—fluoro—3— hydroxy—4—methy1tetrahydrofuran—3 —ol.

To a solution of ,4R,5R)(2—amino-o-ch1oro-9H-purinyl)—2—(hydroxymethyl)- 4—fluoro-4—methyl—tetrahydrofuran-3—ol (2.8 g, 8 mmol) in dioxane (20 mL) was added dimethylamine aqueous solution (5 mL), After ng at RT for 3 h. TLC showed that the starting material was consumed, The mixture was concentrated and purified by column chromatography (DCMjMeOH : 60:1) to afford (2R,3R,4R,5R)(2-amino(dimethy1amino)- 9H—purin-9—y1)—4—fluoro—3-hydroxy—4—methy1tetrahydrofuran-3—ol (2.2 g).

IHNlVER (400 MHz, CD30D) 5 8.08 (s, 1H), 6.13 (d, J: 18.0 Hz, 1H), 4.43 (dd, J: 9.2, 9.2 Hz, 1H), 4.06 (d, J: 10.8 Hz, 2H), 3.90 (m, 1H), 3.37 (s, 3H), 3.06 (s, 3H), 1.18(d, J: 22 Hz, 3H).

“N" 3 2439...»:3-12A r" PK F Nag/R l“ /L\ CH3 )7, ‘l (1; 11 "N XV: “N H c r:- 1 is I \ .1 ,1 \ ; V / ‘N"’=7“\ 55 l ‘3 ‘ A //¥“F EH3 ‘1'; fl NA“ fix? V \\ N”"~N”\1H.- . 3 LJ -.

I H O H p O F“ O l N / - ‘3-~'\ “7/9 "Jr—l? ‘1‘ *n—k» \ r " ('H~’ C‘ J ; i- \‘T/\.?\ x 3\« \r‘ P] b A .5 ‘1 “—.:' f; (: ' F ”‘1' HO La 13 been CH O H ,0 ------ , \‘r ,_.- 2., L / m4 i-EC- F HO F (\ \, -----j FPAL-S 25 Step 2, Preparation of isopropyl ((((iS)-(2R,3R,4R,5]€)—5—(2—amino—o-(dimethylamino)-9H—purin— 9-yl)fluorohydroxymethyltetrahydrofuran-Z-yl)methoxy)-phenoxy-phosphoryl)-lj- alaninate (25).

The compound (213,3RAR,5R)—5-(2-amino(dimethylamino)-9H—pun'nyl)fluoro hydroxymethyltetrahydrofuran-3 -ol (8 g, 1.0 eq) and PPAL—S (11.1 g, 1 eq) were ved in anhydrous THF (100 mL). The mixture was cooled to —5—0 3C and r—BuMgCl (30.5 mL, 1.7 M, 2.1 eq) was slowly added under a N2 atmosphere. After stirring at RT for 2 h, the mixture was quenched with aq. saturated NH4C1 on and ted with EtOAc (70 mL X 3). The combined organic layers were washed with water, brine (30 mL), dried over anhydrous Na2SO4 and concentrated. The crude product was purified by column chromatography (DCM:MeOH : 50:1) to afford isopropyl ((((S)-(2R,318,416,5R)(2-amino(dimethylamino)-9H-purinyl) hydroxymethyltetrahydrofuran-Z-yl)methoxy)-phenoxy-phosphoryl)-L-alaninate as a white powder (9.5 g, 65%).

IH N1VIR (400 MHZ, CD3OD) 5 7.81(s, 1H), 7.35-7.19 (m, 5H), 6.15 (d, J: 18.8 Hz, 1H), 4.90 (m, 1H), 4.54—4.49 (m, 3H), 4.22—4.19(m, 1H), 3.90 (m, 1H), 3.43 (s, 3H), 1.32(d, J: 7.2 Hz, 3H). 1.24—1.17(m, 9H). 311) NMR (160 MHz. CD3OD) 5 3.89. m c. “Ct-13 {saw-3+‘ F F “L L O r‘:[ \ I TIN/QM N /\ 3'5 i “.3 H31“ XL.

.! F: ]] a </ I CHI i ‘N’T’X /\ “ .4 «VA w 1 t '9 3 E i {'12 N f \ - i“ O l": \H‘lv: ~[v— > < H-C o A h {3‘ h ------------.3. .s \ ~ / xw" V" ION/ V k') VI 3 ‘ F F if Q . a :1 1.414 1 L____I:;flk/H3 \lw/ (,r‘l ( /:::_< H f 7F m r (\i p .\ 2/ 6 PPAL-R 26 Example 13. Preparation of isopropyl ((((R)—(2R,3R,4R,5R)—5-(2-amin0(dimethylamin0)- 9H—purinyl)fluor0hydr0xymethyltetrahydr0furanyl)meth0xy)—phenoxyphosphoryl )—L-alaninate (26).

PCT/U52016/021276 The compound (218,318,418.510(2-amino(dimethylamino)-9H-purinyl)fluoro hydroxymethyltetrahydrofuranol (3 g, 1.0 eq) and PPAL-R (4.17 g, 1 eq) were dissolved in anhydrous THF (60 mL). The mixture was cooled to -5—0 0C and I-BuMgCl (11.4 mL, 1.7 M, 2.1 eq) was slowly added under a N2 atmosphere. After stirring at RT for 16 h, the mixture was ed with aq. saturated NH4C1 solution and extracted with EtOAc (50 mL X 3). The combined organic layers were washed with water, brine (30 mL), dried over anhydrous NazSO4 and concentrated The crude product was purified by column chromatography (DCM:MeOH : 50:1) to afford isopropyl ((((R)—(2R,3R,4R,510-5—(2-amino—O-(dimethylamino)—9H—purin—9-yl)—4- fluorohydroxymethyltetrahydrofuran-Z-yl)methoxy)-phenoxy-phosphoryl)-li-alaninate as a white powder (2.2 g, 41%). 1H NMR (400 MHz, CDsOD) 5 7.8(s, 1H), 7.35-7.29 (m, 5H), 6.18 (d, J: 18.8 Hz, 1H), 4.92 (m,1H), 4.60 (m, 1H), 4.51—4.23 (m, 3H), 3.90 (m, 1H), 3.44 (s, 6H), , J: 6 Hz ,3H), 1.22— , 10H). 31P NMR (160 MHZ, CD3OD) 5 3.98.

HC 2“ (El MN] F F (N\//\\ CH3 0 1’\ «Mfi/QN + .O~ >___{\ H3C /_._.3 /EE «’3 H3C\ /"\ ,P\{ / 3314 2? fl ! F fie!“ \N’L ”“2, N TNANHZ H o b H/ HO/ """"""""""""k” HOTW 3 l \l’i v]: \ F F ‘m’CH3 \\ HO F /7\ H6 ‘~~ 23 8 PPAL-S N /k. 9H3 <9, N’ 0 'NANHZ H3C\E/.O.T/\N/Pk\o/N<~ ~ CH3 0 (’0 C»-—-.;:¢CH3 !/:::::\ HO F \ *) \\ i 27 Example 14. Preparation of isopropyl ((((S)—(2R,3R,4R,5R)—5-(2-amin0 (methylcyclopr0panamin0)—9H—purinyl)flu0r0hydr0xymethyltetrahydrofuran yl)methoxy)—phenoxy-ph0sphoryl)—L—alaninate.

PCT/USZOl6/021276 ff; N NN/ QM A viN <\5/ z’L3 r7 6j\ H3C“N//_\ \ MEL N ’f£\ £3fo N NH: N .

H O NHL 40” 1‘ WM HQ’MW/ 7 _______[flap \‘i ”CH3 HO E- HG F 23 8 Step 1: Preparation of 4R,5R)—5—(2—amino—6-(methy1cyclopropanamino)—9H—purin-9—y1)— 4—fluoro-3—hydroxy—4—methyltetrahydrofuran—3—ol (8).

K2CO3 (53 g, 500 mmol) was added to N—methylcyclopropanamine hydrochloride in aqueous solution (100 mL). After stirring at RT for 10 min, a solution of (2R,3R,4R,5R)-5—(2— aminochloro-9H-purinyl)-2—(hydroxymethyl)fluoromethyl-tetrahydrofuranol (35 g, 109 mmol) in dioxane (300 mL) was added. The mixture was stirred at RT for 16 h and HPLC indicated that the reaction was complete. The mixture was concentrated and ed by column chromatography (DCMjMeOH : 60:1) to afford 3,413,5R)(2-amino (methylcyclopropanamino)—9H—puriny1)fluorohydroxymethyltetrahydrofuranol (30 g. 82%).

IHNMR (400 MHz, CD3OD) 5 8.16 (s, 1H), 6‘17(d,J: 18.0 Hz, 1H), 4.41 (dd, J: 9.2, 9.2 Hz, 1H), 4.06 (m, 2H), 3.90 (m, 1H), 3.37 (s, 3H), 3.16 (m, 1H),l.l8 (d, J: 22.4 Hz, 3H), 0.94 (m, 2H), 0.74 (m, 2H). [M+H]’ : 353.2.

/\ ‘JE‘C\N/L\ LA 5 . N xx. : - . 1- , \N N /1§.N Qd: (if \)_____< ’\’ j ‘ , """ /\/ 1t , l : “mm-““4” > \‘ N//A\ /i H31 v,“ ”fire/“4. N' ' EH"‘~ W2' ' N N/ \N1 ll, :4 C /7 Fl C \v/k’x4 3’) /Wk 4 [TAKN/ kxO/W L“ O l \ ,2: F 1“ ‘ 0 Cl“ HO \ ' " A 5 R CH3 0 (1)“ / --_-:\ .40 1‘ L10 F “ <\ ” 3 PEDAL-S 2? Step 2: Preparation of isopropyl ((((S)—(2R,3R,4R,5R)(2-amino(methylcyclopropanamino)- 9H—purin—9-yl)fluorohydroxymethyltetrahydrofuran-Z-yl)methoxy)—phenoxy- phosphoryl)—l.-alaninate.

The compound (2R,316,4]6,5R)—5—(2—amino—6-(methylcyclopropanamino)—9H—purin—Q—yl)— 4-fluorohydroxymethyltetrahydrofuranol (8 g, 1.0 eq) and PPAL-S (10.3 g, 1 eq) were PCT/U52016/021276 dissolved in anhydrous THF (100 mL). After cooling the mixture to 0 DC. I-BuMgCl (28 mL, 1.7 M. 2.1 eq) was slowly added under a N2 atmosphere. The mixture was d at RT for 1h, quenched with aq. ted NH4Cl solution, and extracted with EtOAc (70 mL X 3). The combined organic layers were washed with water, brine (30 mL), dried over anhydrous Na2SO4 and concentrated. The crude product was purified by column chromatography (DCM:MeOH : 100: 1 to 50:1) to afford isopropyl ((((S)-(2R,3R,4R,5R)(2-amino (methylcyclopropanamino)—9H—purin—9—yl)—4—fluoro—3—hydroxy—4—methyltetrahydrofuran—2— yl)methoxy)-phenoxy-phosphoryl)-l‘-alaninate as a white powder (9.5 g. 6596). 1H NMR (400 MHZ, CD3OD) 6 7,86 (s. 1H). 7.35—7.19(m. 5H), 6.17 (d, .1 : 19.2 Hz, 1H), 4.91 (m. 1H). 4.52 (m. 3H). 4.21 (m. 1H). 3.93 (m. 1H). 3.35 (s. 3H). 3.16 (m. 1H). 2.0 (s, 1H), 1.26- 1.16 (m. 12H), 0.93 (m. 2H). 0.73 (m. 2H). 31P N1VIR (160 MHz, CD3OD) 8 3.90 A ch‘N/u-X 1431:.N/—X L / . N42 N /J§§N CH3 9 R)...../.F (j J \h.‘ iiiii (I i \I/FF T : 9H3 9 N \N‘5”\ H3C\ /~O.\ //\N’P§t\.<\ NH2 {\ {/4\ 1 .O N N H H3O VDW ANN ,P\ ”22/ 0 NH2 o >\__4 f \, HO,M.</ j CH3 0 24:35 F \F s \ H o _____Lam-13 1: 1 CH3 0 (I, .. ______50H 3 // x Ho F HO ‘F N (k / 8 PPAL-R ------- e 15. Preparation of isopropyl ((((R)-(2R,3R,4R,5R)—5-(2-amin0 (methylcyclopropanamino)—9H—purinyl)flu0r0hydr0xymethyltetrahydr0furan yl)meth0xy)-phen0xy-phosphoryl)—L—alaninate.

The compound (2R,3R,4R,5R)—5—(2—amino—o-(methylcyclopropanamino)—9H—purin—Q—yl)— 4-fluorohydroxymethyltetrahydrofuranol (3 g, 1.0 eq) and PPAL-R (2.8 g, 1 eq) were ved in anhydrous THF (60 mL). After cooling the mixture to 0 0C. I-BuMgCl (7.6 mL, 1.7 M. 2.1 eq) was slowly added under N2. Then the mixture was stirred at RT for 1 h and ed with aq. saturated NH4C1 solution, and extracted with EtOAc (50 mL X 3). The combined organic layers were washed with water, brine (30 mL), dried over anhydrous Na2SO4 and concentrated. The crude product was d by column chromatography (DCM:MeOH : 100:1 to 50:1) to afford the product as a white powder (3 g, 550/6) 1H NMR (400 MHz, CD20D) 8 7.81 (s, 1H). 7.30—7.25 (m, 5H), 6.16 (d, .1 : 24.8 Hz, 1H), 4.84 (m. 1H).4,84—4.50(m,3H),4.22—4.19(m, 1H). 3.88 (m. 1H). 3.33 (s. 3H). 3.14 (m. 1H). 20 (s, 1H), 1.28-1.13 (m. 1211), 0.92 (m, 2H), 0.90 (m, 2H), “P NMR (160 MHz, CD30D) 6 3.99.

Example 16. Preparation of compound 32.

H';C\ ,CH’; H-CIL ,Cl'in .. N\ c ,j N. V ”N“l/LNH :Fr 0 f/N~.,.//j\lpyy\“Mi“LN 0 ~51 HO’A‘X 75‘,“- """""" 7/1113 LJ.5 a .1er3“ HO F lr7r f5 29 Step 1. Preparation of compound 29.

To a solution of 6 (3.0 0, 1.0 eq)in pyridine (30 mL) was added TIPDSC12 (435 g, 1. 5 eq) at 0 C. After stirring at RT for 4 h, TLC showed that starting material was ed. The mixture was diluted with EtOAc, washed with 1M aq. HCl solution, saturated NaHCO3 aqueous solution, brine, dried over anhydrous NazSO4 and concentrated to afford 29 as a yellow oil (6.3 g, 100%). ~ it ,w 3 we, ,c~ \i c, 3 xx‘ ‘~ 1/1,“x 0 [Pr 0 ’4L (1‘1“ ”m1’ /E [PK Cl ~/i ML; \ “NAN”/» A ’PH ‘ NH) ,Prw‘q, N \ ’ 0 N X V a e / \ my 1 /“\ H , A H» g H m 1“ \L.._VU 11 w [FPSK : an [Hr—9k, ~ 2 0 1- a c F- [P1 [Pr 29 31;} Step 2, Preparation of compound 30, To a mixture ofCompound 29 (800 mg, 1.0 eq), DMAP (16 mg, 0.1 eq), ne (1.6 mL) and DCM (10 mL) was added yryl chloride (209 mg, 1.5 eq) at 0 0C. After stirring at RT for 2 h, TLC showed that the starting al was consumed. The mixture was quenched 2016/021276 with water, washed with aq. 1M HCl solution, saturated NaHCOs aqueous solution, brine, dried over anhydrous Na2SO4 and concentrated. The crude t was purified by column chromatography to afford the product, 30, as a white oil (563 mg, 62.3%). 1H NMR (400 MHz, CDC13) 5 7.98 (s, 1H), 787 (s, 1H), 6.20 (d, J: 16.0 Hz, 1H), .07 (m, 4H), 3.50 (s, 6H), 2.3 (m, 1H), 1.29—1.05 (m, 45H).

H30, ,CH3 HBC,N,CH3 0 0 'PRP (NI‘CN N A JLVCH3 (£1le ____________”H0 N A A CH3 /Pr~’SI \i/OM; N M g 0 N \T/ CH3 CH3 gm m o , CH3 \ Ly 3 \.......

IPr-SK , , 5 v, ‘- 0 HO F 31 Step 3. Preparation of compound 31, To a mixture of30 (560 mg, 1.0 eq) in THF (10 mL) was added EtsN'3HF (706 mg, 5 eq) and EtsN (890 mg, 10 eq) at RT. After stirring at RT for 1.5 h, TLC showed that the starting material was consumed. The mixture was concentrated and purified by column chromatography to afford 31 as a white powder (288 mg, 8396). 1H NMR (400 MHz, CDC13) 5 7.72 (s, 1H), 5.96 (d, J: 44.0 Hz, 1H), 5.22 (m, 1H), 4.13—3.99 (m, 4H), 3.42 (s, 6H), 2.83-2.63 (m, 2H), 1.29—1.17 (m, 9H).

P c ,CH» i N ‘ flN‘w/QN O (N /'§AJ D '\ < 1 “3n \y"; {7L\ /L\ of ”Hy AL P“ iv,a- "53., xx” ., 4 c c A, EMA?” CH- b 1 ”Hr J 3.2%“ ~ 3 {LHg o no 1: x“ ,1 ',1\ HO F " “Ks/:1 31 32 Step 4. Preparation of compound 32.

Compound 31 (280 mg, 1.0 eq) and PPAL-S (320 mg, 1 eq) were dissolved in anhydrous THF (10 mL). After cooling the mixture to —5 0C, r—BuMgCl (0.87 mL, 1.7 M, 2.1 eq) was slowly added under a N2 atmosphere. The mixture was stirred at RT for 2 h, ed with aq. saturated NH4C1 solution, and extracted with EtOAc (10 mL X 3), The combined organic layers were washed with water, brine (20 mL), dried over anhydrous Na2SO4 and concentrated. The PCT/U52016/021276 crude product was purified by column chromatography to afford the product as a white powder (260 mg 509o) lH NMR (400 MHZ, CD3OD) 5 7.98 (s, 1H), 7.25 (m, 5H), 6.23 (d, J: 188 Hz, 1H), 4.52 (m, 3H), 4.38 (m, 1H), 3.81 (m, 1H), 3.75 (m, 1H), 3.48 (s, 6H), , 1H), 1.32 (m, 18H).

[M+H]' : 666.9.

H C\3 ,CH3 H3C‘N CH3‘ It ’ CH3 <7N Y/VN {,N‘JN o fink/[EN 0 [PR :0» \N “i NTIKNH _’Pr\ 0 K’N/‘LNxyLHAL HO \N/i [A /k 2 N OZ too» 13'to . w H ‘ \JCHB @412ng -----------a” ,"yCH3 [PPSic 5 "a I'Pr03h‘ 5 3’ [PO F F HO F r ’P0 I r 29 33 34 H C\3 ,,CH3 o F\ {F ”N\ (TN CH3 \ ‘1‘ >....< N . ”KI /(ll H30 ’0\ AN,F{(-\“ /\/"“F CH3 0 N H, ,O\/ CH3 Y ---------- 1» H -O \\ // H30 .O\ A [Pym/Ml ’yCH3 CH3 0 Ft-(i F. \F \z/ T} E O E .II CH3 0 r‘ ‘ Ho" ”F 1"; f PPAL-S 35 Example 17. Preparation of compound 35.

HBC‘NICHB H3CcN,CH3 N‘~ .I’LQ' N N ”TEN A g Q Pr {I T [Pr 0 \ = /L 0\ N N', 5L )1 IPr SI N”\NH [Pr ‘N N ‘CH /0 2 [SI “(0.x 3 o SCH3 Ma, \ \ Q ”CH3 IPI' SK 5 / iF’r Sh ‘ '2 1 O F IPI' IPr 29 33 Step 1. Preparation of compound 33.

To a mixture of 29 (2.0 g, 1.0 eq), DMAP (0.04 g, 0.1 eq), pyridine (4 mL) and DCM (20 mL) was added AcCl (0.414 g, 1.5 eq) at 0 DC. After stirring at RT for 2 h, TLC showed that the ng material was consumed. The mixture was quenched with water, washed with aq. 1M HCl solution. saturated NaHCOs aqueous on then brine, dried over anhydrous Na2804 and concentrated. The crude product was purified by column chromatography to afford the product, 33, as a white oil (173 g. 80.8%). 2016/021276 1H NMR (400 MHz. 5 7.99 (s, 1H), 7.74 (s, 1H), 6,20 (d, .1 : 20.0 Hz. 1H), 4.33—4.11 (m, 4H), 3.50 (s, 6H), 2.63 (s, 3H), 2.3 (m, 1H), 1.26-1.05 (m, 29H). [M+H]‘ : 611.9.

Hoot {ze-eo,‘~ n _. pg 1 c i/‘VHU <1]: {ngN '\\\ N L-'\ {E /,N , , .\ . ‘N O iPr\ G ’le H0 (fl/”TE ,L L \l/O\ ’ {Prw§3§ N Q We, N ‘N’ N’ "CH3 -------------D" \ H (3. (:Ha \1/0 \ma" m \ \ LE3 :19ng 5 'a ***** 5ng N , r HO F 33 34 Step 2. Preparation of compound 34.

To a mixture of 33 (1.58 g, 1.0 eq) in THF (20 mL) was added Et3N‘3HF (2.1 g, 5 eq) and EtsN (2.6 g, 10 eq) at RT. After stirring at RT for 1.5 h, TLC showed that the starting material was consumed. The mixture was concentrated and purified by column chromatography to afford 34 as a white powder (782 mg, 829/6).

[M+H]+ : 369.6.

Liecwmh 1 4C.» ,C"lq 1 " N ‘ _ a ,N' ~f/EN L . L O \/'.::::< q ll L Nx‘h/Qh ‘;:H3 H f 0 (*4 O N ’L\ ». A R: U HO {9 \{Q\ /?—l” "If i: ‘3/(1 NA‘N; J1 ”CM/07 “Kw":J; Li (”9 lX—mfii “sf-7‘, A w \QH3 J H xix: xerFg‘L MY MC? l 3 F l: H \ Lifcn f“1.1! E t g in Vim l"!—- "d ‘ \“~f 1'0: 1?, [[6«:2.II 1 — \ ,, 34 35 amass Step 3. Preparation of compound 35.

Compound 34 (130 mg, 1.0 eq) and PPAL-S (184 mg, [.1 eq) were dissolved in anhydrous THF (3 mL). After cooling the mixture to -5 0C, r-BuMgCl (0.5 mL, 17 M, 2.1 eq) was slowly added under a N2 atmosphere, The mixture was stirred at RT for 30 min, quenched with aq. saturated NH4C1 solution and extracted with EtOAc (10 mL X 3). The combined organic layers were washed with water, brine (20 mL), dried over anhydrous and concentrated.

The crude product was purified by column tography eOH : 50:1- 20:1) to afford the phosphoramidate 35 as a white powder (150 mg, 63.8%). 1H NMR (400 MHz, CD30D) 5 7.81 (s, 1H), 7.35—7.16(m, 5H), 6110(d,J: 18.4 Hz, 1H), 4.87 (m, 1H), 452—446(m, 3H). 4.21 (m, 1H), 3.91—3.87 (m, 1H), 3.03 (s, 3H), 1.30—1.13 (m, 12H). 31P NMR (160 MHz, CD30D) 6 3.84. ”1? NMR (370 MHz. CDROD) 5 46279.

Synthesis of B-D-Z’-deoxy-2’-(1-fluoro—2’-B-ethynyl-N6-substituted-2,6-diaminopurine nucleotides Y3: OH _ , \rs‘i \TS‘I . . <3?er OH @813?” O (3;er 7/ 1% 36 , 37 5 7” TMS 33 Citl Riu »R2 N AN N ”l 0 N a N x N L nun-Eur mum-Eu I H o «:10x O «:1/ SI ~— N N m TMS N N M y N NH2 t , HO H HO 39 40 Target compound Example 18. l route to [$-D-Z’-deoxy-2’-u-fluoro-2’—B-ethynyl-N“—substituted—2,6- diaminopurine nucleotides - 5 ~ :2 0' ». I Ho 90H fixchioroguanosine \l/ 7/ 36 Step 1. Preparation of compound 36.

To a solution of o-chloroguanosine (100 g, 332 mmol) in pyridine (400 mL) was added TPDSC12 (l 10 mL, 1.05 eq.) dropwise at -5N5 0C under a N2 atmosphere. After stirring at that temperature for 2 h, TLC showed the starting material was consumed. DCM (600 mL) was added, and then TMSC] (85 mL, 2 eq.) was added dropwise at 0-5 0C, After stirring at that temperature for 2 h, TLC showed the intermediate was consumed.

Isobutyryl chloride was added dropwise at 0-5 0C. After stirring at that temperature for 2 h, TLC showed the intermediate was consumed. Water was added, and the content was extracted with DCM. The organic phase was then washed with 0.5 N HCl to remove ne.

After the pH of the content was washed to 5N6,pTSA-H20 (9.2 g, 484.5 mmol) was added at 0-5 0C. After stirring at that ature for l h, TLC showed the intermediate was consumed.

PCT/USZOl6/021276 Water was then added, and the organic phase was washed with water. saturated s NaHCO3 and brine. After being dried over Na2SO4, the solvent was removed in vacuo. The residue was then purified with column chromatography (PE/EA : 100-10/1) to afford the product as a light yellow solid (82 g, 4096). 1H NMR (400 MHZ, DMSO—do) 5 10.88 (s, 1H), 8.55 (s. 1H), 5.91 (d,J: 1.6 Hz, 1H), 5.53 (d, J : 4.6 Hz, 1H), 4.72 , 4.58 (m, 2H). 4.16 (dd, J: 12.4, 4.8 Hz. 1H), 4.00 (ddd, J: 717, 4.8, 2.6 Hz, 1H), 3.93(dd,./:12.4. 2.7 Hz, 1H), 2.78 (h, J: 6.9 HZ, 1H), 1.26 , 1.12 (m, 3H), 1.10 (d, J : 6.7 Hz. 6H), 1.09 — 0,88 (m. 24H). ,4; ”1%”ngIi \1/ 7’ 36 37 Step 2. Preparation of compound 37.

To a on of 36 (10.0 g, 16.3 mmol) in DCM (100 mL) was added Dess—Martin periodinane at rt and the reaction was stirred for 12 h. TLC showed the starting material was consumed. The reaction mixture was then diluted with DCM (200 mL) and washed with saturated s NazSzOs and brine. The organic phase was then dried over NazSO4 and concentrated to afford crude 37 as a light yellow solid (12 g). The crude 53 can be used directly in the next step t purification.

”N E71 0 Q r o N N N fix' a:m it: Esra1 a“ i 33‘ 7/ $55” bill 3? 7/7 TMS 33 Step 3. Preparation of compound 38.

To a solution of ethynyltrimethylsilane (1816 mL. 1427 mmol) in THF (240 mL) was added n—BuLi (46 mL, 2.5 M, 1 15.0 mmol) dropwise at -15~—20 0C under a N2 atmosphere. After stirring for 30 min, the reaction was cooled to —70 0C, and 37 (crude. 16.3 mmol) in THF (60 PCT/U52016/021276 mL) was added at that temperature. The content was then warmed to 0 0C. TLC showed the starting material was consumed. Saturated aqueous NH4C1 was added, and the on was extracted with EA (100 mL) three times. The organic phase was combined and then washed with brine, then further dried over NazSOi. After being concentrated in vacuo, the residue was purified by column chromatography (PE/EA : lOO->lO/l) to afford a light yellow solid (6.0 g, 52%) Step 4. Preparation of compound 39.

To a solution of 38 (6.0 g, 8.4 mmol) in DCM (240 mL) was added ne (4.2 mL, 52.9 mmol) under a N2 atmosphere. The reaction was cooled to -70 0C, and DAST (12 mL, 90.4 mmol) was added. The content was then warmed to —30 0C. TLC showed that the starting material was consumed. The reaction was poured into saturated s NaHCO3, and then extracted with DCM (200 mL). The organic phase was washed with brine and dried over NazSO4. After being concentrated in vacuo, the residue was purified with column chromatography (PE/EA : O/l) to afford a light yellow solid (3.8 g. 6396).

{Nfi‘l‘d St 4W6}? m <2 :3 O Q: H O m -- N v; was N! N ¢ of W H's/EX Z H (JKSETC) F I \r’ 7/ ‘5. or HO F 3% 43 Step 5. Preparation of compound 40.

To a solution of 39 (38 g, 5.3 mmol) in THF (120 mL) was added ACOH (13 g, 22 mmol) and TBAF (4.2 g, 15.9 mmol) at it The reaction was stirred at IT for 30 min. TLC showed the PCT/U52016/021276 starting material was consumed. After being trated in vacuo, the residue was purified with column chromatography (EA) to afford the product as a white solid (2.0 g 95%).

R‘lwaP-Z (N \N .14/513 4% Target 1110112121119 General Procedure for Amino Displacement and Deprotection: To a solution of 40 (350 mg, 0.88 mmol) in dioxane (20 mL) was added the ol or water solution of the corresponding amine (free base or salt as hydrochloride plus DIEA) at It.

The content was stirred at It for 1—12 h. TLC showed the starting material was consumed. After being concentrated in vacuo, the residue was used directly in the next step without ation.

IO The above mentioned residue was dissolved in methanol (10 mL). Aqueous NaOH (2.5 N, 10 mL) was added After ng overnight at rt, TLC showed that starting material was consumed.

The pH of the content was ed to 7-8 with l N HCl. The solution was concentrated and purified with column chromatography (DCM/MeOH : lOO->20/ 1) to afford the product as an off—white solid (yield: 40—80% over two steps). Table 1 illustrates the structures of compounds 57-63 and the corresponding mass spectral and 1H NMR for the respective compounds.

Table 1.

Compound Structure 'H NMR/ MS 41 ‘11” 1H NMR 1400 M112. Methanol-c711) 5 8.05 (s. 1H). 6.27 (d. J : N 19 16.9 H2. 1H). 4.75 (dd. J: 21.7. 9.1 H2. 1H). 4.06 (dd.J: 110.2.4H2 2H) 3.8.7(dd 14131. 32H/..1H).3.42(s. _ (33/; \11“ \th 6H).3 37(s. 2H).3 .18(d .]:5.4Hx. 1H) "9”M03319? ‘5_____4434:; 1M+HJ+:336.9 1111cS 1'1: 42 my lH NMR (400 MHy. DMSO-dfi) 8 7.94 (s 1H). 7.30 (s. 1H). 6.20 4 6.09 (m. 2H). 5.98 N 44:1 (s. 2H). 5.33 (1. .:J 5.3 112. 111). <2 jg :fi 4.57(d1. J— 22.1. 80 H2 1H). 412 (q J— 5.3H2.1H).3.91 ”fix/OVNA \11" 311;“) (d.J- 9.3H2. 1H). 3.70 (1 J— 8.6H2. 1H). 3.36 (s. 1H).3.18 c4“: (d.J—5.2 H2. 2H). 2.89 (d.J4 7.0 H2. 3H). mo“ “’F [M+H]+:323.0 PCT/USZOl6/021276 43 1": lH NMR (400 MHZ. Methanol-(11)?) 8.11 (s. 1H). 6.29 (d. J: \Nr’k" 16.9 HZ. 1H). 4.76 (dd. J = 21.7. 9.0 HZ. 1H). 4.10 7 4.01 (m.

L 2H). 3.87 (dd. J: 13.1. 3.1 HZ. 11-1). 3.37 (s. 1H). 3.24 7 3.11 {/N‘f/VN (111. 2H). 1.00 7 0.87 (111. 2H). 0.74 (td. J: 4.6. 2.8 Hz. 2H).

A“ \ ,1 M+H 2 363.0 \N/ \ 1 1 ._ {M(/UYN NH2 Ho 1 HO "1: 44 If; 1H Nl\/1R(4001\/1HL, Methanol-ch) 6 8.07 (S. 1H). 6.26 (d. J: 1111/ 16.9 HZ. 1H). 4.76 (dd. J: 21.8. 9.3 Hz. 1H). 4.11 — 4,01 (111.

N J\ 2H). 3.89 (d. J: 3.0 Hz. 1H). 3.89 — 3.75 (m. 1H). 3.37 (s. <,1 "71/ "WE: 2H). 3.21 (d. J : 5.4 HZ. 1H). 2.97 7 2.86 (111. 1H). 1.00 7 ,0. 11/111”? 11. 77 (111 21110677046011.2111 HOAX E“ N ”“4 1M+H1+— 1488 1:0?“ F Example 19. Preparation of isopropyl ((((R,S)-(2R,3R,4R,5R)(2-amin0 ylamin0-9H-purinyl)flu0r0hydr0xyethynyltetrahydrofuran-Z- yl)meth0xy)-phen0xy-phosphoryl)—L-alaninate f5“; 62 7N\ 1111111: " "J""-. ”a \Niltgh 1 C1“ 0:311 ¢ a ‘2‘ 1 52' {7‘ /1‘1% no 1111: ‘ H") F 11112 41 45 1112113111917151-’o~111a*1cc-op1-1e11oxy)-mam); p111<sp 11013111.’ -:1=aninate h THF. 0 (3 Step 1. Preparation ofisopropyl ((((R.1S3-(2R,318,418,5R)—5—(2—aminodimethylamino-QH—purin— 9-yl)fluorohydroxyethynyltetrahydrofuran-Z-yl)methoxy)-phenoxy-phosphoryl)-l.- alaninate.

To a solution of compound 41 (30 m0, 009 mmol) in dry THF (2 mL) at 0 °C was added IeI'I—butyl magnesium chloride (1.0 M in THF. 125 11L. 0.13 mmol) dropwise over 10 min. The reaction mixture was stirred 15 min at O 0C then another 15 min at room temperature. The reaction mixture was cooled down to 0 CC and a solution of isopropyl ((13.53— fluorophenoxy)—phenoxy-phosphoryl)-L-alaninate (49 mg, 0.11 mmol) dissolved in dry THF (2 mL) was added dropwise over 10 min. The reaction e was stirred at 0 0C for 30 min and 18 h at room temperature. The reaction was quenched with a saturated aq. NH4C1 solution (4 mL) and extracted with EtOAc (3 x 5 mL). The combined organics were dried over NazSO4 and concentrated. The residue was d by column chromatography (gradient PCT/U52016/021276 DCM/MeOH 100:0 to 90:10) to afford the product (mixture of 2 diastereoisomers, 12 mg, 0.02 mmol, 24%) as a white solid. lH NMR (300 MHz, CD3OD) 6 7.79 (s, 0.45H), 7.77 (s, 0.55H), 7.36—7.14(m, 5H), 6.28 (d, J: 17.4 Hz) and 6.26 (d, J : 17.5 Hz, 1H), 5.00—4.44 (m, 5H), 4.23—4.16 (m, 1H), 3.69—3.81 (m, 1H), 3.42 (bs, 3H), 3.40 (bs, 3H), .26 (m, 3H), 1.20—1.15 (m, 6H). 31P NMR (121 MHz, CD3OD) 6 4.04 (s), 3198 (3) MS (ESI) m/z calcd for ConuFN-O-P [M+H]+ 6062; found (3062. e 20. Preparation of isopropyl S)-(2R,3R,4R,5R)—5-(2-ami110methylamino- 9H-purinyl)qu0r0hydr0xyethynyltetrahydr0furanyl)methoxy)-phenoxy- phosphoryl)—L-alaninate.

N N g, \ NHMe NHMe MJYN\%- IF": . o F “‘5‘,” ‘$\ MJYNW1 f” \\ i \\\\// f; , ‘7’, HO pf}: N “‘3’" "\Nx’ C‘ \ ”a” =4 I‘” (i3 \ N t: 555 ‘ ’x... e” ’9 Hi =“ HO NH; ‘0 F N 1: i) isopropyl(1R,Sl~ipentaf1morephenoxy)~phenoxy—phosphcryi)~L-alaninale, I'Bus‘v‘igCi, THF, 0 C Step 1. Preparation of isopropyl ((((R,S)-(2R,3R,4R,5R)(2-aminomethylamino-9H-purin yl)fluorohydroxyethynyltetrahydrofuran-Z-yl)methoxy)-phenoxy-phosphoryl)-L- I5 alaninate.

To a solution of compound 42 (30 mg, 0.09 mmol) in dry THF (2 mL) at 0 0C was added IeI'I-butyl ium chloride (1.0 M in THF, 125 uL, 0.13 mmol) dropwise over 10 min. The reaction mixture was stirred 15 min at 0 0C then r 15 min at room temperature. The reaction mixture was cooled down to 0 OC and a solution of isopropyl — (pentafluorophenoxy)-phenoxy-phosphoryl)-L-alaninate (49 mg, 0.11 mmol) dissolved in dry THF (2 mL) was added dropwise over 10 min. The reaction mixture was stirred at 0 0C for 30 min and 18 h at room temperature. The reaction was quenched with a saturated aq. NH4C1 solution (4 mL) and extracted with EtOAc (3 x 5 mL). The combined organics were dried over Na2804 and concentrated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 90:10) to afford the product (mixture of 2 diastereoisomers, 9 mg, 0.02 mmol, 189/6) as a white solid. 1H NMR (300 MHz, CD3OD) 0' 7,81. 7.79 (0.9s+0.1s. 1H), 7.36-7.14 (m, 5H), 6.26 (d, J : 17.4 Hz. 0.1H) and 6.24 (d, J : 17.4 Hz, 0.9H). 4.93-4.89 (overlapped with H20. m. 1H). 4.80-4.78 (m, 1H), 4.53—4.49 (m, 2H), 4.21—4.18(m, 1H), 3.95—3.84 (m, 1H), 3.23-3.20 (m, 1H), 3.04 (bs, 1H), 1.31—1.14(m, 9H). 31P NMR (121 MHz, CD3OD) 6 4.06 (s), 3.97 (3). MS (ESI) m/z calcd. for C25H32FN7O-P [M+H]’ 5922; found 592.2.

Example 21. Preparation of isopropyl ((((RS)--(2R,3R,4R,5R)—5-(-2amino--(N- methylcyclopropylamin0)-9H-purinyl)—4-fl110r0hydr0xyethynyltetrahydrofuran yl)methoxy)-phenoxy-ph0sphoryl)-L-alaninate «NE/1'6!” 2 vaie W476.

HOV/flOwi/ JF:\-’:)/a§T<04k / \/ : [I ”I; N ’ N“ V........4/ 4 .

Te? ’4 \ NH; F 0 NH; 43 4? 1) 150;):any:{eF? tafiuorcphehowl-chartoxy-phasphcsiyl)2—L—alariiiwa‘le. tBuMgCi, THF. C- C.

Step 1. Preparation of isopropyl ((((R.,S)-(2R,3[3,416,5R)(2-amino(N— methylcyclopropylamino)-9H-purinyl)—4-fluorohydroxyethynyltetrahydrofuran yl)methoxy)-phenoxy-phosphoryl)-[,-alaninate.

To a on of compound 43 (40 mg. 0.11 mmol) in dry THF (2 mL) at 0 0C was added Icri—butyl magnesium chloride (1.0 M in THF, 160 uL, 0.16 mmol) dropwise over 10 min. The reaction mixture was d 15 min at 0 CC then another 15 min at room temperature. The reaction mixture was cooled down to 0 OC and a solution of isopropyl ((R,S)— fluorophenoxy)—phenoxy—phosphoryl)—l.—alaninate (55 mg, 0.12 mmol) dissolved in dry THF (2 mL) was added dropwise over 10 min. The reaction mixture was stirred at 0 0C for 30 min and 18 h at room temperature. The reaction was quenched with a saturated aq. NH4C1 solution (4 mL) and ted with EtOAc (3 x 5 mL). The combined organics were dried over NazSO4 and trated. The residue was purified by column chromatography (gradient DCM/MeOH 100:0 to 90:10) to afford the product (mixture of 2 diastereoisomers. 18 mg, 0.03 mmol, 26915) as a white solid.

PCT/USZOl6/021276 1H NMR (300 MHz, CD30D) (5 7.84, 7.82 (s+s, 1H), 7.35-7.14 (m, 5H), 6.30 (d, J : 17.4 Hz) and 6.26 (d, J: 17.6 Hz, 1H), 4.99-4.89 (overlapped with H20, m, 1H), 4.82-4.69 (m, 1H), 4.59- 4.46 (m, 2H), 4.21 (m, 1H), 3.96-3.82 (m, 1H), 3.24—3.22 (m, 1H), 3.17-3.11 (m, 1H) 1.31—1.26 (m, 3H), 1.20—1.15 (m, 6H), 0.93—0.89 (m, 2H), 0.75—0.68 (m, 2H). 31P NMR (121 MHz, CD3OD) 6 4.06 (s), 3.98 (s). MS (EST) m/z calcd. for C28H36FNTO‘P [M+H]+ 632.2; found 6322.

Example 22. Preparation of PPAL-S \ f ‘\ / L .2: _ E F : \«V/i _, \7/‘ _. '5 2: (I? >::::: i i (1;) ? E C) l: C?‘ >12< \ /\ \ /\ —r.'r_. . 0‘ r’ANH— C" ’“N—i—i—opb ll iffmcn'x‘k. //\>""F”“”" E ii EMS.41 \h l1 ““ ll ' ' H .L O 0P1“- _/—’\_ U W“ (”Pr O k pl 1— F l V PPAL—RS PPAL~S Step 1. Preparation of racemic PPAL To a stirred solution of phenyl dichlorophosphate (250 g) in EtOAc (800 mL) was added isopropyl L-alaninate (200 g) in triethylamine (120 g) at —10 OC. The reaction was stirred at —10 0C for l h. The compound 2,3,4,5,6-pentafluorophenol (220 g) in triethylamine (120 g) and EtOAc (400 mL) was added at *5 OC and stirred at that temperature for 0.5 h. The reaction mixture was allowed to warm to 25 OC and d at that temperature for 2 h. The solution was filtrated and washed with EtOAc (2 X 200 mL), and the combined organic phases were evaporated under vacuum to afford the solid S ate).

Step 2. Preparation of PPAL-RS To a stirred solution of PPAL-RS in EtOAc (200 mL) and tane (1.4 L) was added 5,6-pentafluorophenol (10.1 g) in triethylamine (6 g), and stirring was continued for about 4—8 h. After the R—isomer of the solid was less than 0.5%, the solid was filtered. The solid was dissolved in EtOAc (4 L), washed with water (2 X 100 mL), brine (l L), dried over anhydrous NaZSO-l, and filtered The solvent was removed under vacuum to afford the PPAL-S (350 g). 1H NMR (400 MHZ, DMSO— d6) 5 : 7,42 7 7.40 (m, 2H), 7.24 H 7,22 (m, 3H), 6.87 (dd, J : 14.1, 9.9 Hz, 1H), 4.90—4.84 (m, 1H), 3.94 —3.88 (m, 1H), 1.27 (dd, .1: 7.1, 1.1 Hz,3H), 1.15 (dd, ./ : 6.2, 12 Hz, 6H) ppm. : 0.37 ppm.

, ”P NMR (160 MHz, DMSO- d6) 5 2016/021276 Example 23. Preparation of PPAL-R V K Y E 2.2": Y; [F 00 C) F\ PPM.RS PPAL-R To a three-2811311111 round 3:11.110111 3311331; {131613 11/1131 :1 .111‘312111-’ 111112111111310 111313013 313111111113 1331:,3'131'11'1'1pi10331113111312 (389.6; g. 0.911.? 11103) and 31113111131111.1151 “03121110111313. The: 80311331111 ‘WQS 13151331313 30 "'30 ‘1' under a nitrogen 21:1111183331619 3111'»1103113111331111 nare 1'338 .12. 0 91": mr': 133} 2111113 31"312331y'3ai1'13112: (3033 g 3.32.1.1) 11111112 211311130 3311-‘213111V2 8011311131 31 31111411031913{31121301211 331' K} 1'111114t11re of 2.3.51.5,6131631311193Lt111'1.)p31en133 (365 s; 3 613'} and 31'1213111'3211'113112 (90.5 g 1213} in 3313:3236 11101323. 3 111218 2113131113 to 1111'111111'1'. \1'3:1 211::111313113011 3311111113 :11 «5"C 2111131313 1118113111111. 1111231111. was 213 3112111161:11 20»-1.21.13: . 111' 3 31111111 3311': 1.1731331: {Haiphaie ("3‘337‘13—33333 1.121154 3333611213 033111113 1111181313 with E10910 The {1311819 was trated under reduced pressure 11.1. 11113313 PPAL-RS about 280 g (S/R:1/1) 218 2'1, whfie 11., 3"1131RS {230 g) ‘11-'28 3'131111331131338 SCUM 3113 01 11831331112113.3{3‘11‘ .‘-:31 2111001111 tm'pmatuu 1'31'51 111111 3319. 11113118: 31153101133011 111213 1111111111 1.1:113 1:31:- 50331311111215 11115913 11111331 11 1313811111: (13'311313111‘233113117 1’1’.) 3').T311': 3331111111 111112121 130113613 t0 8 ""33 3 3311': 5113113 was EDUECEEd 31y 333117131011. {11111313 333’313-33 1’33. 31313311111111 121 111313 1211th 95% c311r213 33-11133 . The 1317115113 31111131101 was 3.11.11'133121'3 .3'1'11331111111'31151, 11.310112. 13331. 323? (5 .33 was 1.131121111113113 in NLT 1 133131113 31111 .

IH NMR (400 MHz, DMSO— d2) 5 : 7.43 — 7.39 (m, 2H), 7.27 — 7.22 (m, 3H), 6.87 (dd, J : 14.1, 9.9 Hz, 1H), 4.89 4 4.85 (m, 1H), 3.95 4 3.90 (m, 1H), 1.27 (dd, .1: 7.1, 1.1 Hz,3H), 1.14 (dd, .1: 6.2, 1.2 Hz, 6H). ”P NMR (160 MHz, DMSO— (36) 5 : 0.35.

Example 24: Preparation of compound 52. 9‘ ’ “NH : He. ~ LH l J A ‘1; .N/ 0/ \v/\\/ .i \k / é“ .N‘\./ “EV (/ l : (/ l N~ § / \N’ kNfix‘NH / \i”l\ "k ‘5” i ' , (J Z O ‘ N' NH; ‘ N . /J~ ’1 / / \ ’ \ r \ N :’ ‘ \m/T’ _, h“ )9 _._;,. \ _.O ”Y 11/254,; ------at» ”(I NH2 ‘ /°~..~<,O\_i >2»: ' .~ \c.«*' 3-7777?“ \ x“ x 5:» / r5\ 0‘ ’1 / 1‘ o v33 L-fi” ‘ei’ ’ , \s/ / 0c 0‘ ’F 3..... \\/ \,__u c “5;; / i ,1 Y ‘)_____ ' l 4g 49 50 -—‘—‘P" ‘ 52 {:41 ‘F‘TJH N.~ /i~} J\ <9“ E r? [1‘f \if \Ei /%10\/N'«\.—”\..N/ '<‘\ MHZ J/ XNN NH: \\:\° 0 LJL‘CHB ~—%~v {)0 \ I CH /\3 ul ‘ », r”- / ’3 6 IF I/ i. x. \A j: l , o\ “,x \ f \ "V5“ 1 ------- >----- 48 ‘ ' 49 Step 1. Preparation of compound 49.

To a solution of 48 (1.81 g, 3.23 mmol) in dioxane (18 mL) was added 40% aqueous CH3NH2 solution (162 mmol). The reaction was stirred at 40 0C for 2 h. The mixture was concentrated, diluted with EtOAc (50 mL), washed with water and brine. The organic layer was dried over anhydrous NazSO4, filtered and concentrated to afford a white solid 49 (1.66 g, 92%).

H "I 3‘ N i”!“—1 h3"\N/1LNO/”\Vfl\v/uh3' i-‘ .\ I ”V \WV (x .E 5 NY \\N r [N ,4"~\ hf” ‘11“ <f ii /L ’”< ("A O\ J C43 2W m4, , ,\ _ / \ ’1?!.. 4’4 ”\v 0 XN”\\1/ '23—” w“ ‘\ p014: / O~~~ [3 “ V? '5 1., O F . o'i / 0‘ x / ‘ \m/ T >'''''' \\ D" ' T >““ 49 / so Step 2. Preparation of compound 50.

To a solution of 49 (1.34 g, 2.42 mmol) and l—methylimidazole (794 mg, 9.68 mmol) in DCM (14 mL) was slowly added pentyl chloroformate (547 m0, 363 mmol) at 0 OC. The reaction was stirred at r.t ght. The mixture was concentrated. and purified by column chromatography (PE: EtOAc : 5:1 - 2: 1) to afford 50 (1.01 g. 6296) as a white solid. lHNMR (400 MHz, DMSO) 6 7.96 (s, 1H), 6.73 (s, 1H), 6.06—6.10(d, J: 16.0 Hz, 1H), 4.09- 4.30 (m, 2H), 3.97—4.09 (m, 4H), 3.28 (s, 3H), 1.39—1.46 (m, 2H), 2 (m, 35H), 0.73—0.76 (t, J: 8.0 Hz, 3H).

Hch N/l‘ix /\\/~\/CH3 O (N i‘éN H3O N’i\o’”\/\/CHE l //L N \ 'N" ‘NH2 ,3 j ‘5‘ \ O OVN \ I CH3 N \——"Sl _________________B, \ W O \N%\NH \f” 2 ./ / / HO I I 0‘ O F CH3 Si” -----‘1” 3_____ Ho“ ’F / 50 51 Step 3, Preparation of compound 51.

To a solution of50 (1.00 g, 1.5 mmol) in THF (11 mL) was added EtsN (2.0 mL, 15 mmol) and Et3N.3HF (1.21 g, 7.5 mmol) at 0 OC. The reaction was stirred at r.t for 1.5 h. The mixture was concentrated. and purified by column chromatography (MeOH: CH2C12 : 50: 1) to afford 75 (460 mg, 72.2%) as a white powder. a F 3:} gm <3- ):{\ 0 imoE“ ’ ~ (1” H lx" Ner« rc F . ii .

‘N \k / \ /\ \'({\ ,;)- H5132 N_/\KO/\\//\,L.Hs. a H o V /L A 1 \1 13a. r.-"/M\‘r rm“. ““1 \ f: - N. /K5 q l: ,; ~ \N “I; A ‘u ) H c \‘ i K m(J \ / . ,/L Q “5/:‘H 1H2 ~- 1: - y./ . ti C _. .\ l‘e \lH pp)“ r C/flhk‘x/ \ ,0 \H//x\ rkfi mick.“ 3 X» f t J _____be" \ ,1 CH (3H m OPh "L1 1 Lme" ~10 F Step 4. Preparation of compound 52.

To a solution of 51 (460 mg, 1.08 mmol) and PPAL-S (538 mg, 1.19 mmol) in anhydrous THF (9 mL) was slowly added f—BuMgCl (2.27 mmol) at 5-10 0C under N2. The reaction was stirred at r.t for 40 min. The mixture was quenched with aq. saturated NH4C1 solution, extracted with EtOAc, washed with aq. 50/6 K2CO3 solution and brine, dried over anhydrous NazSO4. ed and concentrated. The crude product was purified by column chromatography (CH2C12: MeOH : 15:1) to afford 52 (280 mg, 37.3%) as a white solid. lHNMR (400 MHz, DMSO) 5 8.12 (s, 1H), 7.34-7.38 (m, 2H), 7.18-7.23 (m, 3H), 6.74 (s. 2H). 6.11—6.16(d,J=16.0 Hz, 1H), 5.99-6.05 (m, 1H), 5.84 (m, 1H), .81(m, 1H), 4.30—4.41 (m, 3H), 4.03—4.11 (m, 3H), 3.78—3.80 (m, 1H), 3.3 (s, 3H), 1.44—1.51 (m, 2H), 1.00—1.21 (m, 16H), 0.76—0.80(t, J: 8.0 Hz, 3H). [M+H]+: 696.6.

Example 25: Preparation of compound 56.

CI <53 a 2- N 1 /:L ”A” «3.17? T” (I 7/ \N N" 4J\ ‘N‘J‘l‘a4k i/\j/\_\/A\/\rl5 I \ A! /.: 5-3 ””4. \l—‘Z / A M‘s/XML” (9/va0 ’y’ } «YA fi/N- M, I“ r/W ”u (L.

C/ \ ’35! J ---------b i ha ”Vi PC” "l v A H \ / w /" fa“ (*‘T‘ , (: C; _ 6 ‘v I ‘J‘\.. x" ‘~n-/ PU g: :21 \ PK \\/ \,_____ >____ i ,/ ./ 23 43 53 ,CH‘ Hf}! ”a N L H5! .. /\r |\; I l <N J‘\\{'9Lmz’}‘/ Nv~ / \\/‘~. r s N 0 /\\.-/’ g I rx <1 E ’< A A .

U f 1, f\:2\ >’/\ 4J‘L (./‘\ /’\.Vz'«/i“-u ‘ N C ( :7 ‘4 M U i".'r 7777777778- /;§\ .nyf 7777777777s» ,E, _\ 96"“ "i7 ( ' I .I“ , i c '7 \JoH‘; I O F' I O\Si’ 4‘. ,9 Ho: ’9’ x \ i)- 54 an HN’CH3 N A)“ ( i .4 J c; I» , <N”-’ U PJ”JJ\-"Z~/\\//~\v_,cl-13l ‘3 fl :5 __ h ”\V KT/“xN/E O/NV‘L'V (Em F :_ CH b '1 vt‘ “if j} a) “/in 1:): ‘V/ \}N \f A; /-L z' {\- / ».

\NA AW 4 MAX/ix N NH;. .. 3 ‘ / « 3 r « g , x ___, W/ J ', ‘ I 0~.- ,0 ’* HO' F Si‘ \ {f T \ 23 43 Step 1‘ Preparation of compound 48‘ To a solution of 23 (600 mg, 1 eq) in pyridine (30 mL) was added TlPDSClz ) at 0 0C The resulting solution was allowed to stand at room temperature for 2 h. The mixture was quenched with ice water and extracted with EtOAc. The organic layer was washed with 1M aq.

HCI solution, saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, and concentrated to yield the crude residue. The residue was d by chromatography (MeOH: CH2C12 : 1:50) to afford 48 (998 m0, 944%) as a white solid foam.

PCT/USZOl6/021276 ALL ’ Li: 8%? “Li 9 \' .,JJ «k ; “H , / .. \ \r f .. 1/’\\’,/‘\, /V / N W !\ l 0‘1 N N i t, c- {éfiiy / \AIX 0% gm H \ ,7}; ___________>- ./'.'z "" ’T ‘. .3 I Q“ /U F / 1“ ,I O\r_,0 \ 5% \V/ ‘k v/ > 1' 1 /}——- 4s 53 Step 21 Preparation of compound 53‘ A mixture of 48 (800 mg, 1 eq), pyridine (3.2 mL), DMAP (34.9 mg,012 eq) in DCM (20 mL) was stirred at room temperature, N-amyl chloroformate (32 mL) was added dropwise at 0 0C, and the mixture was stirred at room temperature for 1 day. The organic layer was washed with 1M aqueous HCl solution, saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, and evaporated in vacuo. The residue was purified by chromatography on silica gel (MeOH: CH2C12 : 1:50) to afford 53 (255 ma, 26%) as a white solid foam. c: HN” ,N'~~{""\\w “KAN o < al A </ 1: a / .fi/“NN/Nv/bl‘lj fL L 1 N "N x I ;\:-”“\. ,/ 5r /’\V/\V/Ln’13 JON \E y c / N r c 0’”RN/“L ’“ \ gym“ ' CH) 7 \ \ Vic-m \fs‘: \ -------------a. yea .....f’ .....43‘“ / o\ O ’F / Ck. JO 1“ x 5? 3! \ \r-"w t V/‘xm / \T / 5‘3 Step 3. Preparation of compound 54.

To the on of 53 (270 mg, 1 eq) in 1,4-dioxane (10 mL), was dropwise added 4096 aqueous CH3NH2 solution (2257 mg, 5 eq), The mixture was stirred for 2 h at room temperature and then concentrated in vacuo. The residue was chromatographed on silica gel (methanol: romethane: 1:40) to afford 54 (220 mg, 81.7%) as a white solid foam. , _.CH3 mit- Z N X» <1 L L N it , ‘y/ 9 0 »N{ V1.4" Gr \//’\\/“ KM ’11 {A\ /U\ f\/,~\ ,kl’ ‘ H I\ 0 V ...4.» i \t o i A pt“; g \,/9a' U . ”Om I CH /’ (Lg /G ’F 5‘""" ~\;,Si\ HO r i y...— 51 55 Step 41 Preparation of compound 55‘ Triethylamine(1011,9 mg, 10 eq) and HF (806105 mg, 5 eq) were added to an ice- cooled solution of 54 (668 mg, 1 eq) in THF (10 mL), the mixture was stirred for 2 h at room WO 44918 temperature The mixture was concentrated and chromatographed on silica gel (MeOH: CH2C12 : 1:30) to afford 55 (492 mm 8496) as a white solid foam.

[CH2 HN ‘ (3%? s“ ‘N .‘2\ \‘4¢1\ H,)/"“Ni 1 ,CH»; Ho“ "F Step 51 ation ofcompound 56.

To the mixture of 55 (113 mg, 1 eq) and PPAL-S (120 mg, 1 eq) in THF (4 mL) was dropwise added 1.7 M I-BuMgCl in THF (0.327 mL, 2.1 eq) at -10 0C. The mixture was stirred at room temperature for l h, and then quenched with saturated CH]. NH4C1 solution. The aqueous phase was extracted with EtOAc and the organic phase was washed with brine, dried and concentrated to obtain crude residue. The residue was subjected to flash chromatography to afford 56 (126 mg, 68.5%) as a white solid. 1H NMR (400 MHz, DMSO) 5 8.00 (s, 1H), .45 (m, 5H), 6.15-6.20 (d, J: 20.0 Hz, 1H), .00—5.25 (s, 1H), .86 (m, 1H).4.45—4.70(m. 2H), 4.12—4.19(m, 3H). 3.80—3.85 (m. 1H), 3.04 (s, 3H), 1.60-1.75 (m, 2H), 1.10—1.40 (m, 16H), 0.76—0.80(t. J: 8.0 Hz, 3H).

“P NMR (160 MHz, DMSO) 5 3,57. [M+H]+: 696.5.

Example 26: Preparation of compound 60. hfl \ ‘ 'SL‘N” N A} 1 (j 14 N“ i/‘N 1“-“ng , 1 NH I ,: E A iiiiiiiiiiib ”J: (“N x "mm-"9" \N’ \N':/\N.J\D/\\//\V,2,H3 34‘,”quF / U H / TC“ \“TI\ ,0/ l -T r . AS: ,I cm- I r.

I O. O r ‘3" If a.~ o F x / 2" ‘Sl/ f \ .» T ‘r« E / 57 58 V r1111}\ ,(11 ,, N I21 \W/\\ N 1;} /N V/K‘ N O \ ,4 : :: CH- \Nf’I‘LN¢-‘\N/L\CW/NV/NN/lej/ \Né-xN/“xO/xcxxc/Vl 0 E : 1 OV’N _ ‘5 s q , W 1., ,0. . ______an» “(l/N H ,_________b, Hg“ ‘_ I (w p.419: 7’ H ._ a o \ , m I .. " 71/\\."U\. MAR/UV" l r: ci—ha ‘ 7, Ho‘ ’rr CHz C gym»??? 1-10 F- 59 60 PCT/U52016/021276 H C.3 ,CP 3 i“ can l}: j 43'“ /§‘N \l~~‘ ”EN \ i o ‘i\” NF, (”R ,o/k‘f rq m” / 7/ ~ #8; LJ’ l'..J \ Cg—t 1 x , -----I" z .» 01.- _,U 1 Ho“ ' \ JR :) _____ 5? Step 1. Preparation of nd 57, To a solution of6 (20 g. 1 eq) in CHsCN (100 mL) was added imidazole (16.6 g), TIPDSClz (28.9 0, 1,5 eq) in sequence at 5:5 oC. The resulting on was allowed to stand at room temperature for 4 h. The mixture was quenched with ice water and extracted with EtOAc. The c layer was washed with water, saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, and concentrated to afford the crude residue (32 g) ng LP .,=14 ’ l chwmgl N //\\. [x \l; N NNJm r ‘ \N‘A M‘J‘M ,1 CV? A {I i r” “a“ x ’ o 1‘1". w‘ 0 "h3 \ \c‘ ’4‘,ng __ ’[\ (“N at}: H ’9: X ‘ .r ._ .v‘] \ 3‘“erI “1“” / 1) OT "F "51“ ‘ 34’ / 6‘ 0" ‘F 55? Tux}""" 53 Step 2, ation of compound 58, To the solution of 57 (9.8 g, 1 eq) in THF (4 mL) was dropwise added 1.7 M l-BuMgCl in THF (50 mL, 4.8 eq) at 0-5 OC. The mixture was stirred at room temperature for 0.5 h, and n-amyl chloroformate (2.7 g, 1.05 eq) was slowly added. The mixture was stirred at 0-5 0C for 3-4 h. The mixture was quenched with saturated ac]. NH4C1 solution. The aqueous phase was extracted with EtOAc (200 mL) and the organic phase was washed with brine, dried and concentrated to obtain 58 (1017 g) as oil.

H30._N,0H3 NN J§~ H C\ N ,CH 3 3 ('\/ f j N NA N5 N‘ ‘O’AM/“V’CFI3 N~ f “IX! A‘N 0 o’ / k ¢CH3 <7 l 5 \,.— _i’ _____________”a N O N’fNN/‘l‘50/AV/A\V/CH3 {3 o‘ F Ho’ ” ‘7‘; \\S l ¢CH3 V \ a g /)--~ 53 HO' F 59 Step 3. Preparation of compound 59, Triethylamine (10.119 g) and Et3N'3HF (8.6 g. 5 eq) were added to an ice-cooled solution of58 (7.3 g, 1 eq) in THF (100 mL) and the mixture was stirred for l h at room temperature. The mixture was concentrated and tographed on silica gel (MeOH: CHzClz : 1:30) to afford 59 (4.3 g, 91%) as a white solid.

F. ‘F CH3 0 :Ifi H30, ,0.\ AN P o~<r\\ ”PF \(EH lCl; H /O F \F H3C~N CH3 3 (““1 H301 ,CH3 N L 1:;y (f T /N PPAL-S N" A EL I/N "vCH CH 0 3 """""""""""""4:0 3 {NWT 4N. N;LNAO/\,N\ ,CH3 HO ”\(0JCHS 3 \ O\ 7/ OPh/XOXSH3N\ ““ HO F 3 o 59 GOP Step 4. Preparation of nd 60.

To the mixture of 59 (2 g, 1 eq) and PPAL-S (2.3 g, 1.1 eq) in THF (40 mL) was dropwise added 1.7 M f—BuMgCl in THF (5.6 mL, 2.1 eq) at —5 OC. The mixture was stirred at —20::5 OC for l h, and then quenched with saturated aq. NHiCl solution. The aqueous phase was extracted with EtOAc and the organic phase was washed with brine. dried and concentrated to obtain crude e The residue was subjected to flash chromatography to afford 60 (l 5 g 470o) as a white solid. 1H NMR (400 lVlHZ, CD3OD) 5 7.9 (s. 1H). 7,1~7.2 (m,5H). 0,2 (d, J: 20 Hz, 1H), 5.1 (br.1H), 4.84 (m. 1H), 4.49 (m,, 2H), 4.16 (m, 1H). 4.13 (m. 2H), 3.86 (m, 1H). 3.45 (br. 6H), 1.70 (m, 2H), 1.26 (m. 4H). 1.20 (m, 6H). 1.14 (m, 6H), 0.93 (m, 3 H). [M+H]‘ :7105.

Biological Data Example 27. Assay h’lethedelegy and Atldltlnnal Binlegieal Bate, Huh—7 lire/nee E'l' cells bearing a disoistronie HCV genotype lb luciferase reporter replieen were plated at 7.5 x 103 cells/ml in duplicate 96-well plates for the parallel determination of antiviral efficacy (Efisn) and cytotoxieity ('l‘Csn) The plates were cultured for '24 hours prior to the on of compounds. Six serial one hall‘log dilutions oi‘the test, articles (high test concentration of 100.0 lllvl or high test concentration of 10 11M) and human interferon- alphaZb (high test 10.0 U/ml) were ed in cell culture medium and added to the ed cells in triplicate wells for each on. Six wells in the test plates received medium alone as an untreated control. Following 72, hours of culture in the presence of cr‘rrnpr‘rund, one of the plates was used for the determination of cytotoxicity by staining with XTT and the other for antiviral efficacy hy determination of luciferase reporter activity. Cytotoxicity and efficacy data were collected and imported into a customized Excel workbook for determination of the TCsn and ECsn values, Data for compounds of Formula L‘v’ll are illustrated in Table 7 below. In addition, Figure 2 illustrates the HCV replication inhibition curves for Compound 5-2 and Sofosbuvir. As can be seen in Figure 2, Compound 5-2 has an ECso : 4 nM, while Sofosbuvir has an ECso : 53 nM. The y-axis is the t of virus l and the X-axis is the concentration of drug in ulVl.

Figure 3 illustrates the HCV replication tion curves for Compound 25 and Sofosbuvir.

Compound 25 has an EC50 : 4 nM and Sofosbuvir has an EC50 : 53 nM. The y-axis is the percent of virus control and the x-axis is the concentration of drug in uM. Figure 4 illustrates an intra—assay comparison of the anti—HCV activity for Compounds 5—2, 25, 27 and uvir. The y—aXis is the percent of virus control and the X—aXis is the concentration of drug in uM.

Various t—derived HCV genotypes containing wild—type and resistance—associated I5 variants were used to determine their relative replication sensitivity to test compounds. Replicon resistance test vectors (RTVs) containing the NSSB genomic regions were prepared using viral RNA isolated from plasma of HCV patients Each NSSB region was amplified by reverse- transcription rase chain reaction and cloned into an HCV replicon RTV which was then transferred by electroporation into Huh-7 cells. After tion in the e and presence of serially diluted test compounds for 72—96 hr, viral replication was measured by luciferase activity and 509/6 inhibitory concentrations (ICso ) were determined.

Table 2 reports the ICso and IC95 values for compound 25, 27, 5—2 and Sofosbuvir against various clinical isolates containing wild-type and resistance-associated variants.

All compounds were significantly more ive against HCV replication than sofosbuvir and r 25, 27 nor 5-2 compound showed any evidence of cross-resistance to Ll59F, Ll 59F and S282T, and C316N mutants.

Table 2: Antiviral Activity of Test Compounds in t—derived HCV Genotypes |C50 |C95 Fold Change in Fold Change in HCV NSSB Test Value Value ICSO |C95 l pe Mutation Compound (nM) l (nM) from Sofosbuvir from Sofosbuvir l 1a none sofosbuvir 62.7 507.7 2016/021276 . 16.2 27 19.3 —2 . 8.4 sofosbuvir . . . 20.0 lb ”one 27 . 22.2 —2 . 8.9 sofosbuvir . . 8.8 2a none 27 . . 12.0 —2 . 4.3 sofosbuvir 14.9 19.9 2b “one . 14.7 20.1 6.3 32.5 7.1 9.1 24'8 3a—1 none 27.2 11.6 123.5 808.1 33.4 3a—2 none 27 34.6 —2 14.3 . 33.0 20.7 4a none 27 . 38.1 17.9 —2 9.9 74.4 7.5 9.2 23.1 4d none 26.6 12.8 sofosbuvir ' 264 1a L159F 27 29.5 —2 . 11.2 sofosbuvir 16950.9 158.5 107.0 1a Liicng 27 141.6 119.7 5282T —2 313.5 54.1 sofosbuvir 73.9 472.8 lb C316N 25 3.2 18.1 23.1 26.2 27 3.1 16.5 23.5 28.7 PCT/U52016/021276 —2 7.7 42.7 9.6 11.1 A transient ection assay was performed to ine the sensitivity of the wild type S282T mutant of HCV to test compounds. Huh—7 cells were electroporated in the presence of RNA transcribed from wild type or S282T HCV on plasmids from the T7 promoter. The transfected cells were seeded in to 96—well plates at 7.5 X 103 cells per well in Dulbecco’s Modified Eagle’s . After 24 hr of incubation, medium was removed and replaced with fresh medium containing no or various concentrations of test compounds. Following an additional 96—hr incubation, the anti-HCV activity was measured by rase endpoint with BriteliteTM Plus luminescence reporter gene kit (Perkin Elmer, Shelton, CT). Duplicate plates were d and incubated in parallel for assessment of cellular toxicity by staining with the tetrazolium dye XTT.

Table 3 reports the ICso and IC95 values for compounds 25. 27. 5—2 and Sofosbuvir t HCV wild type and S282T replicons.

All compounds were significantly more effective against HCV replication than sofosbuvir and neither 25, 27, nor 5—2 compounds showed any evidence of cross—resistance to S282T variant.

Table 3: Antiviral Activity of Test Compounds in a HCV Transient Infection Assay Compound NSSB ICso Value 105 value Fold change in Fold Mutation (nM) (nM) ICso from change in Sofosbuvir IC95 from Sofosbuvir -2 None 1.4 9.98 26 22,2 S282T 2.8 20.6 99.3 >485 None < l 27 > 36.4 80,7 S282T < l 9.4 > 278 > 106.4 27 None < l 4.1 > 36.4 53,2 S282T <l 11.8 > 278 > 84.7 Sofosbuvir None 36.4 218 S282T 278 >lOOO The stability of selected compounds in fresh human whole blood and in human liver S9 fraction was determined in incubations containing 10 MM test nd. After incubations of O, , 60 min, and up to 120 min, aliquots were removed and immediately extracted with 3 volumes PCT/USZOlo/021276 of ice-cold methanol/acetonitrile (1:1, v/v). Extracts were centrifuged and supernatants were analyzed by LC-MS/MS for concentrations of unchanged test compound and ial lites.

Figure 5 illustrates the excellent ity of compound 5-2 and all Z-amino derivatives in human blood.

Interestingly, Figure 6 illustrates the in vitro time course dealkylation of the xy-2’- d—f1uoro-2’—B-methyl—N2—methyl—N6—methyl-2,6-diaminopurine nucleoside phosphoramidate to 2’—deoxy-2’—(x-t1uoro—2’—B—methyl—N(’—methyl-2,6-diaminopurine nucleoside phosphoramidate with a human liver 89 fraction. Furthermore, unexpected, faster, and a more extensive rate of cleavage of the ate moiety by human liver 89 fraction was ed as compared to compound 5—2 and its other 2-amino derivatives (Figure 7).

Example 28. HCV (gtlb) NSSB Polymerase Assay Inhibition of HCV (gtlb) NSSB polymerase was determined in cate by measuring de novo polymerization in reaction mixtures containing serial dilutions of TA, in vitro ribed viral RNA complementary to the HCV (-) strand 3’UTR region, polymerase, radiolabeled ribonucleotide, 250 MW non-competing rNTPs, and 1 uM competing rNTP. TA concentrations that produced 5096 inhibition (1C50) were determined from resulting inhibition curves.

Example 29. Human Bone Marrow Progenitor Cell Assay Fresh human bone marrow progenitor cells (Invitrogen) suspended in either BFU—E or GM-CSF—specific culture medium were added, at 105 cells/well, to triplicate serial dilutions of TA in 6-well plates, After 14-day incubations, colony counts were used to determine CCso , BFU-E colonies were confirmed using the benzidene technique.

Compounds 25, 27 and 5-2 show no cytotoxicity against bone marrow stem cells in vitro.

Example 30. iPS Cardiomyocyte Assay iPS Cardiomyocytes (Cellular Dynamics) were seeded in microliter plates at 1.5 x 104 cells per well. After 48-hr incubation, cells were washed and maintenance medium containing serially diluted TA was added in triplicate. After ting for an additional 3 days, cell viability was measured by ng with XTT and CCso values were calculated.

Compounds 25, 27 and 5-2 show no cytotoxicity against iPS cardiomyocytes in vitro, Example 31. Human DNA Polymerase Assays Inhibition of human DNA polymerases 0t, [3 and y (CHIMERX) was determined in triplicate in on mixtures of serially diluted TA, 0.05 mM dCTP, dTTP, and dATP, 10 uCi [32P]-0t-dGTP (800 Ci/mmol), 20 ug activated calf thymus DNA and onal ts specific for each polymerase, After 30-min incubations, incorporation of [or-32P]-GTP was measured and resulting incubation curves were used to calculate leo values.

The triphosphate, B-D-2’-deoxy-2’-0t-fluoro-2’-B-methyl-guanine triphosphate, as well as the triphosphate analogs of nds 25, 27 and 5-2 do not inhibit human DNA polymerases 0t, Bory.

Example 32. Human Hepatocyte Co-Cultures Cytotoxicity and hepatocyte health were assessed in triplicate by measuring ALT I5 leakage, urea production, albumin secretion and ar ATP contents in micro-patterned human hepatocyte co-cultures (HepatoPac®, Hepregen Corporation) prepared by seeding cryopreserved female human hepatocytes (single donor) and 3T3 J2 mouse fibroblasts in microtiter plates according to procedures established by en. Culture media was replaced with fresh media containing TA, test article, (0, 1, 10 or 30 uM) every 2 or 3 days through day 16. Spent culture media was assayed for ALT and urea content on days 2, 5, 7, 9, 12, 16 and 21 and for albumin content on days 2, 5, 7 and 9. Cellular ATP levels were measured on days 9 and 21. ATP signals in stromal—only control cultures (murine 3T3 lasts) were subtracted from those of human HepatoPac co-cultures to obtain hepatocyte-specific effects See, Table 4, 5 and 6 below, Compound 5-2 at concentrations up to 30 uM, showed no signs of cytotoxicity as measured by ALT leakage, albumin ion, urea production and cellular ATP content when incubated for up to 12 days with micro-patterned co-cultured human hepatocytes. The minor indications of cytotoxicity detected with extended exposure (up to 21 days of culture) were significantly less than those observed with sofosbuvir. See, Table 4, 5 and 6 below. 9 was highly cytotoxic to human co—cultured hepatocytes, showing decreased n ion as early as day 2 and cytotoxicity by all measures. Sofosbuvir showed more xicity than AT-51l under the same conditions.

PCT/U52016/021276 Table 4. Effect of Test Article on Cellular ATP Concentrations Test Article 5096 Inhibitory Concentration (IC50) - uM Day 9 ‘ Day 21 Cmpd 5-2 >30 [28 Sofosbuvir 8.6 2.3 INK—189 8.1 ‘ 0,1 Table 5. Effect of Test Articles on Albumin Secretion Test Article 5096 tory Concentration (ICsn) - uM Cmpd 5-2 Sofosbuvir lNX-l89 Example 33. Metabolic Studies The metabolism of compounds 25, 27 and 5-2, at a concentration of 10 MW, were investigated in fresh y cultures of human, dog and mouse hepatocytes. Plated hepatocytes from humans (XenoTech, mixed gender, pooled from 10 donors), male Beagle dog (BioreclamationIVT), and male ICR/CD-l mice (BioreclamationIVT, 8 ) in 6—well plates with matrigel overlay were incubated in singlet with 10 uM TA. After 2, 4, 6, 8 or 24 hr, intracellular levels of nucleotide prodrugs and their potential metabolites (prodrugs, monophosphates, triphosphates and nucleosides) were tated by LC-MS/MS.

Concentrations below the lower limit of tation (1,5 pmol/IO6 cells for prodrugs, monophosphates and nucleosides and 12 pmol/lO“ cells for sphates) were extrapolated from the standard curves.

The compound B-D—2’—deoxy—2’—0t—fluoro—2’—B-methyl—guanine triphosphate is the predominant metabolite of compounds 25, 27 and 5—2 observed in cultured human hepatocytes and is a potent tor of the HCV(gt1b)NSSB polymerase, with an ICso of 0.15 pM.

Figure 8 shows the predominant Compound 25 metabolites in human hepatocytes.

Figure 9 shows the predominant Compound 27 metabolites in human hepatocytes.

Figure 10 shows the predominant Compound 5-2 metabolites in human hepatocytes, Figure 11 illustrates the activation pathways for Compounds 25, 27 and 5-2. As can be seen, Compounds 25, 27 and 5-2 are converted to their corresponding monophosphate analogs which are subsequently metabolized to a common MP analog; B—D-2’—deoxy—2’-a—fluoro—2’—B— —guanine monophosphate (Compound 61). The monophosphate is then stepwise phosphorylated to the active sphate: B—D—27—deoxy-2’—0L-fluoro—27-B-methyl-guanine triphosphate (Compound 62). e 34. Controls 1NX-189 (1NX-08189/BMS-986094) and sofosbuvir were used as controls in the Examples above.

The two most potent tide prodrugs, Compounds 25 and 27, demonstrated excellent ivity, with CCso values greater than 100 pM in Huh-7 cells, human bone marrow stem cells and human cardiomyocytes. No inhibition of human DNA polymerase 0t, [3 or y, no activity against other RNA or DNA viruses, and no toxicity in all host cell lines was ed at concentrations up to 100 pM, Table 7 is a table illustrating the compounds tested in a HCV on Assay along with the EC 50/1305 {i and (39%; (pity!) results, -Fit"s/i} Table 7. Replicon Assay Results for Compounds Tested.

Cmpd Structure HCV HCV Fold No, Replicon Replicon increase ECSW’EC95 CCsn in activity (g; M) (pk/i) comparad to 351mm aside NH? 6.7 >100 . «Ni A @3wa N NHQ HQ? ”F NH2 21/904 >100 157 >100 Ho~~«\<0>yN/“NJ\NH2/' i ____4m H6 ”F ,CH3 0926/0124 \100 > 600 2016/021276 —1 0.0551/0.282 >100 >280 —2 0004/0028 >100 >3,900 6 10.7 >100 7 010121/0‘071 >100 >890 .56 >100 9 /01054 >100 >600 HBQNN NAN/ ‘NH2 >100 >100 i 23’ N N /1\/ 16 ”011111 0.576/369 >100 2016/021276 17 \N,»\ 115/654 >100 MONO N’A‘N/ N112 1—10‘ ’1: 18 \N/\ 0048/0219 9010 \NAV/ 747 >100 madam/km;<5 ,, Hit? (’1: \N”\«’/ 0073/0315 >100 “2‘ <1} (1’ E " 3 ‘ /A Y H H 5 V 7? 111::- 1': 2016/021276 0004/0019 >100 >2,600 26 00351/0057 >100 27 0005/0025 >100 >1,1OO 28 076 >100 Hng A NAN/”’LNHZ 41 0508/2511 2118 42 418/204 >100 /A‘NHZ 43 # 043/247 21.6 PCT/USZOl6/021276 45 \N/ 0 .J 6m.m6 Ow NhfixxNxWV/V \N .H ....... 4,,KN A 23.x Y0 M Q N WH H2 55$ w o \\\\J\ 4,,/ H0 .y/Ci 46 /, WA 0 2.2Mwm >m ........ Mimi/A “ELW NQNA /“Drags N N NH Q H2 a 5 E: {x HQ LIE: 47 P/ 0 3. a) w n.2 1 a NhQNJ\N H g, x fll , m\ Q \N NH2 ...... NH 333 0 a g H0 3F 61 Y» N H HOOne“; ”(NKHHHA~ w Q Y NH 350 2.

(P. 9 S? Ho~e—o-$—o—E~o OH OH OH 0052/0310 >100 / H6 (IF Sofosbuvir ()/”\\ (1045Kl259 >100 N_ x <' 1 fl N N NH; gl~awg~ci 1: PSI—3 52938 The B-D—2‘—D—2‘—d—fluoro—2‘—B—C—sub stituted—Z—modified—NG—sub stituted purine nucleotides described herein exhibit significant ty against the HCV virus. nds ing to the present invention are assayed for desired relative activity using well-known and conventional assays found in the literature.

For example, anti-HCV activity and cytotoxicity of the compounds may be measured in the HCV subgenomic RNA replicon assay system in Huh7 ET cells. (See, Korba, et a1, ral Research 2008, 77, 56), The results can be summarized in comparison to a positive control, 2’— C—Me—cytosine { 2'—C—Me—C}(Pierra, et al, Journal (filled/cilia] Che/711151132 2006, 49, 6614.

PCT/USZOl6/021276 Another in-vitro assay for anti-hepatitis C virus activity is described in US. Patent No. 7,718,790 by Stuyver, et al., and ed to Pharmasset, Inc.

This specification has been described with reference to embodiments of the invention.

Given the teaching herein, one of ordinary skill in the art will be able to modify the ion for a desired purpose and such variations are considered within the scope of the invention.

Claims (58)

The Claims Defining the Invention are as follows:

1. A compound of Formula Ic: or the pharmaceutically acceptable salt thereof; wherein: Y is NR1R2; R1 is ; R2 is hydrogen; R3 is hydrogen; R7 is hydrogen, unsubstituted or substituted C1-6alkyl, unsubstituted or substituted C3- 7cycloalkyl, unsubstituted or substituted heteroaryl, tituted or substituted heterocyclic, or unsubstituted or substituted aryl; R8 is hydrogen or unsubstituted or substituted C1-6alkyl; R9a and R9b are independently selected from hydrogen, unsubstituted or substituted C1- 6alkyl, or unsubstituted or substituted cycloalkyl; and R10 is hydrogen, unsubstituted or substituted C1-6alkyl, unsubstituted or substituted C1- 6haloalkyl, unsubstituted or substituted cloalkyl, unsubstituted or tuted heterocycloalkyl, aminoacyl, tituted or substituted aryl, or unsubstituted or substituted aryl wherein the substituent is selected from halogen, OH, phenyl, benzyl, N3, CN, acyl, and alkyl.

2. The nd of claim 1, wherein: R7 is aryl; R8 is hydrogen or C1-C4alkyl; R9a is C1-C6alkyl; R9b is hydrogen; and R10 is C1-C6alkyl.

3. The compound of claim 1 or 2, wherein R7 is unsubstituted phenyl.

4. The compound of claim 1 or 2, n R7 is unsubstituted napthyl.

5. The compound of any one of claims 1-4, wherein R8 is hydrogen.

6. The compound of any one of claim 1-4, wherein R8 is methyl.

7. The compound of claim 1, wherein R9a and R9b are both unsubstituted kyl.

8. The compound of claim 7, wherein R9a and R9b are methyl.

9. The compound of claim 1, wherein R9a is methyl and R9b is en.

10. The compound of any one of claim 1-9, n R10 is methyl, ethyl, or iso-propyl.

11. The compound of claim 10, wherein R10 is isopropyl.

12. A pharmaceutical composition comprising an effective amount of a compound of any one of claims 1-11 in a pharmaceutically acceptable carrier.

13. The pharmaceutical composition of claim 12, in an oral dosage form.

14. The pharmaceutical composition of claim 13, in a tablet.

15. The pharmaceutical composition of claim 13, in a capsule.

16. The compound of claim 1 of the formula: or a pharmaceutically acceptable salt thereof.

17. The compound of claim 16 of the formula:

18. The compound of claim 16 of the formula: or a ceutically acceptable salt thereof.

19. The compound of claim 16 of the formula:

20. The compound of claim 16 of the a: or a pharmaceutically acceptable salt thereof.

21. The compound of claim 1 of the formula: or a pharmaceutically acceptable salt thereof.

22. The compound of claim 21 of the formula: or a pharmaceutically able salt thereof.

23. The compound of claim 21 of the formula: or a pharmaceutically acceptable salt thereof.

24. A compound of the formula: or a pharmaceutically acceptable salt thereof, wherein a hydrogen is tuted for a deuterium at one or more locations on the molecule.

25. The compound of claim 24 of the formula: or a pharmaceutically acceptable salt thereof, n a hydrogen is substituted for a deuterium at one or more locations on the molecule.

26. The nd of claim 24 of the formula: or a pharmaceutically acceptable salt thereof, wherein a hydrogen is substituted for a deuterium at one or more locations on the molecule.

27. A pharmaceutical composition comprising an effective amount of a compound of any one of claims 16-26 in a pharmaceutically acceptable carrier.

28. A pharmaceutical composition comprising an effective amount of a nd of claim 17 in a pharmaceutically acceptable carrier.

29. A pharmaceutical composition comprising an effective amount of a compound of claim 18 in a pharmaceutically acceptable carrier.

30. A pharmaceutical composition comprising an ive amount of a nd of claim 19 in a pharmaceutically acceptable carrier.

31. A pharmaceutical composition comprising an effective amount of a compound of claim 20 in a pharmaceutically acceptable carrier.

32. The ceutical composition of any one of claims 27-31, in an oral dosage form.

33. The pharmaceutical composition of claim 32, in a tablet.

34. The pharmaceutical composition of claim 32, in a capsule.

35. A nd of the formula: or a pharmaceutically acceptable salt thereof wherein R4 is monophosphate, diphosphate or triphosphate..

36. The nd of claim 35, n R4 is monophosphate.

37. The compound of claim 35, wherein R4 is diphosphate.

38. The compound of claim 35, wherein R4 is triphosphate.

39. The compound of claim 1 of the formula: or a pharmaceutically acceptable salt thereof.

40. The compound of claim 39 of the formula: or a pharmaceutically acceptable salt thereof.

41. The compound of claim 39 of the formula: or a pharmaceutically acceptable salt thereof.

42. The compound of claim 18, wherein the compound is at least 90% free of the opposite phosphorus R-enantiomer.

43. The nd of claim 18, wherein the nd is at least 98% free of the opposite phosphorus R-enantiomer.

44. The compound of claim 18, wherein the compound is at least 99% free of the te phosphorus R-enantiomer.

45. The compound of claim 20, wherein the compound is at least 90% free of the opposite phosphorus S-enantiomer.

46. The compound of claim 20, wherein the compound is at least 98% free of the opposite phosphorus S-enantiomer.

47. The nd of claim 20, wherein the compound is at least 99% free of the opposite phosphorus S-enantiomer.

48. A ceutical composition comprising the compound of any one of claim 35-47, in a pharmaceutically acceptable r.

49. A pharmaceutical composition comprising the compound of claim 42, in a pharmaceutically acceptable carrier.

50. A pharmaceutical composition comprising the compound of claim 45, in a pharmaceutically acceptable carrier.

51. The pharmaceutical composition of any one of claims 48-50, in an oral dosage form.

52. The pharmaceutical composition of claim 13, 32, or 51 n the oral dosage form is a solid dosage form.

53. The pharmaceutical composition of claim 51, in a tablet.

54. The ceutical composition of claim 51, in a capsule.

55. The pharmaceutical composition of claim 13, 32, or 51, wherein the oral dosage form is a liquid dosage form.

56. The pharmaceutical composition of claim 55, in a solution or suspension.

57. The pharmaceutical composition of any one of claims 12, 27-31, and 48-50, in an intravenous formulation

58. The pharmaceutical composition of any one of claims 12, 27-31, and 48-50, in a eral formulation.