JPH07100705B2 - Method for synthesizing 1H-pyrazolo [1,5-b-1,2,4-triazole derivative - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is useful as a silver salt color photographic coupler and the like.
-Pyrazolo [1,5- b ] -1,2,4-triazole derivative production method.

(Prior Art) The inventors of the present invention disclosed in Japanese Patent Application Laid-Open No. 59-171956, European Patent Application Publication No. 0,119,860, and U.S. Pat. No. 4,540,654 that pyrazolo [1,5- b ] -1,2,4-triazole was used. Report that it can be a new and excellent magenta coupler in silver salt color photography. This new coupler has the shortcomings of previous pyrazolone centered couplers:
A pyrazolo [1,5- c ] -1,2,4-triazole coupler, which has been used relatively recently, has solved the problem that the formed dye has a color turbidity due to side absorption near 430 nm, and has been used relatively recently. Japanese Patent Publication No.
48-30895, U.S. Pat. No. 3,725,067, etc.), which is a drawback of the formed dye, which is low in light fastness. As a result, the development of a high-yield and simple synthetic method for pyrazolo [1,5- b ] -1,2,4-triazole has become a very important issue.

Examples of the method for synthesizing the pyrazolo [1,5- b ] -1,2,4-triazole include those disclosed in JP-A-60-197688 and 60-19779.
No. 60-215687, and related ones are JP-A No. 61-145163, which relates to an intermediate synthesis method.

(Problems to be Solved by the Invention) Among these synthetic methods, JP-A-60-197688 discloses a synthetic method by a dehydration cyclization reaction of an amido oxime represented by the following reaction formula (1). However, this method had the following problems.

(In the formula, R ₁₁ and R ₁₂ represent a hydrogen atom or a substituent, and Ts represents a tosyl group.) That is, as shown in the above reaction formula (1), in the ring-closing reaction, the main formation of the target compound In addition to the product (B), a by-product (C) is produced to reduce the yield of the compound (B). The by-product (C) is a compound in which the 4-position and the 7-position of the compound (A) are bonded.

(Means for Solving Problems) The inventors of the present invention have conducted extensive studies in order to solve the problems of the above-mentioned conventional methods, and as a result, have found that the compound (A) of the formula (1) has a certain kind at the 4-position. It was found that the introduction of such a substituent can suppress the formation of the by-product part (C) due to the ring closure reaction, and the present invention has been completed based on this finding.

That is, the present invention has the general formula (I) (In the formula, R ₁ is a hydrogen atom, an alkyl group, an aryl group, an aryloxy group or an alkoxy group, R ₂ is a chlorine atom,
R ₃ represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ) An N-pyrazolylamide oxime compound represented by (Wherein R ₁ , R ₂ and R ₃ have the same meanings as described above) and a method for synthesizing a 1H-pyrazolo [1,5- b ] -1,2,4-triazole derivative represented by Is.

In the general formula the present invention (I), the in the compounds represented by (II), when described in detail R _1, R ₂ and R _3, R ₁
Is a hydrogen atom, an alkyl group, an aryl group, an alkoxy group,
It represents an aryloxy group, and R ₁ may be a divalent group to form a bis form.

More specifically, each R ₁ is a hydrogen atom, an alkyl group (a linear or branched alkyl group having 1 to 32 carbon atoms, an aralkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group or a cycloalkenyl group, each of which is an oxygen atom). , A nitrogen atom, a sulfur atom, a substituent linked by a carbonyl group, a hydroxy group,
It may be substituted with an amino group, a nitro group, a carboxy group, a cyano group or a halogen atom, and examples thereof include a methyl group, a propyl group, a t-butyl group, a tridecyl group, a 2-methanesulfonylethyl group and a 3- (3-penta group. Decylphenoxy) propyl group, 3- {4- {2- [4- (4-hydroxyphenylsulfonyl) phenoxy] dodecanamido} phenyl} propyl group, 2-ethoxytridecyl group, trifluoromethyl group, cyclopentyl group, 3 −
(2,4-di-t-amylphenoxy) propyl group, etc.),
Aryl group (for example, phenyl group, 4-t-butylphenyl group, 2,4-di-t-amylphenyl group, 4-tetradecanamidophenyl group, etc.), alkoxy group (for example,
Methoxy group, ethoxy group, 2-methoxyethoxy group, 2
-Dodecylethoxy group, 2-methanesulfonylethoxy group, etc.), aryloxy group (eg, phenoxy group, 2
-Methylphenoxy group, 4-t-butylphenoxy group and the like).

R ₂ is a chlorine atom.

R ₃ represents a hydrogen atom, an alkyl group, or an aryl group among the groups shown for R ₁ , or preferably a 5- to 7-membered heterocyclic group as a heterocyclic group (for example, 2-furyl). Group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group, etc.).

R ₃ may have a substituent similarly to R ₁ .

In the present invention, the pyrazolo [1,5- b ] -1,2,4-triazole compound represented by the general formula (II) is mainly used as a magenta coupler for photography, but its use is limited to this. is not. Therefore, R ₂ is a group capable of leaving by reacting with an oxidized product of a developing agent (hereinafter simply referred to as a leaving group)
Has a particularly important meaning, but the leaving group may be formed later, and R ₂ may not necessarily be the leaving group as far as the production method of the present invention is concerned.

The amidoxime compound represented by the general formula (I) used as a starting material in the method of the present invention is disclosed in JP-A-59-
It can be synthesized by the reaction of aminopyrazole (III) with an orthoester or imidate and the subsequent reaction with hydroxylamine as shown in 171956 or JP-A-61-145163. Next, the synthesis process of the present invention is shown in the following formula (2).

(In the formula, R ₁ , R ₂ and R ₃ have the same meanings as described above. Ts represents a tosyl group.) Represented by the general formula (II) by dehydration ring closure reaction of the compound represented by the general formula (I) The synthesis of the compound is preferably carried out using a suitable dehydrating agent in the presence of a base. The reaction with the dehydrating agent is preferably carried out by using dimethylacetamide, acetonitrile, tetrahydrofuran, dioxane or the like as a reaction solvent, and by using an amount (usually 1 equivalent) of the dehydrating agent sufficient for the reaction to proceed sufficiently. The reaction temperature is preferably 0 to 25 ° C. and the reaction time is preferably 0.5 to 2 hours. As the dehydrating agent, in addition to p-toluenesulfonic acid chloride, methanesulfonyl chloride, trifluoromethanesulfonyl chloride, phosphorus oxychloride, thionyl chloride and the like can be preferably used.
-Toluenesulfonic acid chloride. As the base, in addition to triethylamine, a tertiary amine such as diisopropylethylamine, pyridine, 4-dimethylaminopyridine and the like can be used. The amount of this base is 0.5-
The amount is 2 equivalents, preferably 1 equivalent. The ring closure reaction of the addition reaction product of the compound (I) with a dehydrating agent uses an ether solvent such as tetrahydrofuran or dioxane or an alcohol solvent such as methanol or ethanol, preferably in the presence of the above base (usually 1 equivalent), It is carried out by heating under reflux. The reaction is usually completed in 1 to 3 hours.

Conditions other than the above can be performed according to the method described in JP-A-59-171956 and the method disclosed in US Pat. No. 4,540,654.

Next, the method for synthesizing the compound represented by the general formula (III) is roughly classified, and as shown in the formula (3), R ₂ is introduced into the aminopyrazole of R ₂ = H by an electrophilic substitution reaction. A general method is to synthesize a nitrile compound (IV) into which R ₂ is introduced in advance as shown in formula (4), and react it with hydrazine. Which method depends on the kind of R ₂ Can be decided

(In the formula, X is 0 or NH ₂ (HCl), and R ₁ and R ₂ have the same meanings as described above.) 1H-pyrazolo [1,5- b ] obtained by the above formula (2)
The 1,2,4-triazole derivative can be separated and recovered from the reaction solution by a conventional method, but may be used as a raw material for the subsequent reaction without isolation if necessary. As a suitable isolation means, a recrystallization method, a solvent extraction method, a filtration method, a column chromatography, a thin layer chromatography and the like can be used alone or in an appropriate combination.

(Effect of the Invention) According to the method of the present invention, the production of by-products is remarkably suppressed, the isolation and production of reaction products are facilitated, and the desired 1H-pyrazolo [1,5- b ] -1,2, The 4-triazole derivative can be obtained in high yield. Therefore, it is possible to reduce the synthesis cost and increase the utility value of 1H-pyrazolo [1,5- b ] -1,2,4-triazole as a magenta coupler.

(Example) Next, the present invention will be described in more detail based on examples.

Example 1 100 g (1.03 mol) of 5-amino-3-methylpyrazolol ( 1 ) was dissolved in 500 ml of acetic acid, and 139 g (1.03 mol) of sulfuryl chloride was slowly added dropwise under ice cooling. The precipitated crystals were collected by filtration and recrystallized with acetic acid to obtain 104 g of compound 2 (yield 60%). mp210 to 211 ° C (decomposition) Next, add 100 g (0.60 mol) of compound 2 to 500 m of acetonitrile.
In addition, 84 ml (0.60 mol) of triethylamine was added and the mixture was stirred.

Next, to this solution, 204 g (0.72 mol) of methyl 2-methyl-3-phthalimidopropionimidate hydrochloride ( D ) was added and reacted in acetonitrile to obtain crystals of amidine hydrochloride. The crystals are collected by filtration and methanol
It was dissolved in 800 ml, and an aqueous solution of hydroxylamine (prepared by mixing 43 g of hydroxylamine hydrochloride and 50 g of sodium acetate in 1.2 l of water) was added thereto, and the mixture was heated under reflux for about 2 hours. 4 l of water was added to obtain 174 g (yield 80%, mp 211 ° C. (dec)) of precipitated amidoxime 3 .

Next, 174 g (0.48 mol) of Compound 3 was dissolved in 160 ml of dimethylacetamide, 160 ml of acetonitrile was further added, and the mixture was stirred. 92 g of p-toluenesulfoni chloride in it
(0.48 mol) and pyridine (39 ml, 0.38 mol) were added, and the mixture was stirred under water cooling. After about 1 hour, 1.2 liters of methanol and 39 ml of pyridine (0.
38 mol) was added and the mixture was heated under reflux for about 2 hours. About 200 ml of reaction solution
After concentrating the mixture, the mixture was poured into 1.2 l of water and the precipitated crystals were collected by filtration. The crystals were heated in 240 ml of methanol, returned to room temperature and collected by filtration to obtain 175 g of compound 4 (yield 85%). mp12
3 to 126 ° C. At this time, almost no by-products were detected.

Comparative Example 1 5-Amino-3-methylpyrazole ( 1 ) 50g (0.51mo
l) and 173 g (0.61 mol) of 2-methyl-3-phthalimidopropionimidate methyl hydrochloride ( D ) were reacted in acetonitrile to obtain crystals of amidine hydrochloride. The crystals were collected by filtration, dissolved in 700 ml of methanol, and an aqueous solution of hydroxylamine (prepared by mixing 36 g of hydroxylamine hydrochloride and 42 g of sodium acetate in 1 of water) was added thereto and heated under reflux for about 2 hours. 3 l of water was added, and the precipitated crystals were collected by filtration and dried to give 125 g of amidoxime 5 .
(Yield 75%) was obtained. mp203.0-204.0 ° C. 125 g (0.38 mol) of this amide oxime 5 was dissolved in 125 ml of dimethylacetamide, and 125 ml of aratonitrile was further added and stirred. 73 g (0.38 mol) of p-toluenesulfonyl chloride and 31 ml (0.38 mol) of pyridine were added thereto,
The mixture was stirred under water cooling. After about 1 hour, methanol 1 and 31 ml (0.38 mol) of pyridine were added, and the mixture was heated under reflux for about 2 hours. The reaction solution was concentrated to about 200 ml, poured into water 1 and the precipitated crystals were collected by filtration. The crystals were heated in 200 ml of methanol, returned to room temperature, and collected by filtration to obtain almost pure compound 6 . Yield 70g (Yield 60%) mp233-235
° C.

The filtrate was concentrated and fractionated crystals were separated with methanol to separate 33 g (yield 28%) of by-product 7 . This by-product 7
The physical properties of were as follows. Mp168 ° C. Mass spectrometry (m / e) 309 (M +) 162 (bp) Nuclear magnetic resonance spectrum (in _{DMSO-d 6) δ 1.28 (} 3H, d, J = 7.0), 2.28 (3H, s), 3.0~ 3.6 (1H,
m), 3.6 to 4.1 (2H, m), 7.78 (4H, s) 11.5 (1H, brs.), 1
1.9 (1H, brs.) Reference example 1 Under ice-cooling a mixture of methyl propionate 8 890g (10.2mol) and methoxyacetonitrile 48 g (0.68 mol) in potassium t- butoxide 92 g (0.82 mol), was added dropwise with stirring. After dropping, the mixture was stirred for about 1 hour, 500 ml of water was added, the organic layer was separated, the aqueous layer was extracted once with ethyl acetate, the ethyl acetate-soluble portion was removed, and the aqueous layer was weakly acidified with 2N hydrochloric acid water ( pH ~ 6)
After extraction with ethyl acetate three times, washing with water and saturated saline, drying over magnesium sulfate, and evaporation of the solvent, 41 g (yield 47%) of almost pure compound 9 was obtained as an oil.

Compound 9 40g (0.31mol) and hydrazine hydrate 15g (0.3m
ol) was heated under reflux in ethanol for about 3 hours, the solvent was removed, and the residue was column-separated to obtain 35 g (yield 81%) of compound 10 as an oily substance.

20 g (0.41 mol) of compound 10 was treated in the same manner as in Example 1 to obtain 22 g of compound 11 (yield 80%). This compound 11 was dissolved in 20 ml of dimethylacetamide, and 78 g (0.41 mol) of p-toluenesulfonyl chloride and 33 ml of pyridine were dissolved therein.
(0.41 mol) was added and the mixture was stirred under water cooling. After about 1 hour, 200 ml of methanol and 33 ml (0.41 mol) of pyridine were added, and the mixture was heated under reflux for about 2 hours. The reaction solution was concentrated to about 50 ml, poured into water, and extracted with chloroform 5 times. The extract was dried, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography to obtain 14 g of compound 12 (yield 70%). mp˜92 ° C., almost no by-product like Compound 7 in Comparative Example 1 was obtained.

Comparative example 2 5-Amino-3-ethoxypyrazole 13 50 g (0.39 mo
Compounds 14 and 15 were sequentially synthesized from l) in the same manner as in Example 1. Compound 14 yield 100 g (75% yield), mp 182.5-1
83.0 ℃ Compound 14 The yield of Compound 15 from 100g (0.29mol) is 52g.
(Yield 55%). mp219.5-220.0 ℃ Reference example 2 Dissolve 50 g (0.39 mol) of compound 13 in 250 ml of DMF and under ice cooling 2
-N-butoxy-5-octylsulfenyl chloride 81
A dichloromethane solution of g (0.39 mol) was added dropwise and stirred. The solution obtained was extracted with ethyl acetate, washed with water, dried and the solvent was distilled off to give almost pure compound.
160 g (98%) of 16 was obtained as an oil. Example 1
The amidoxime 17 was prepared by a method similar to that shown in
5 g (yield 60%) was synthesized. mp171.0-172.0 ° C.

Furthermore, from now on, this compound 17 was converted to dimethylacetamide.
After dissolving in 150 ml, p-toluenesulfonyl chloride (43 g, 0.23 mol) and pyridine (18 ml, 0.23 mol) were added, and the mixture was stirred under ice cooling. After about 1 hour 1.5 liters of methanol and pyridine
18 ml (0.23 mol) was added, and the mixture was heated under reflux for about 2 hours. The reaction solution was concentrated to 300 ml and then poured into water, and the precipitated crystals were collected by filtration. The crystals were heated with 150 ml of methanol, returned to room temperature, and collected to obtain 106 g of Compound 18 (yield 75%).
It was possible to synthesize. mp 117.5 to 118.5 ° C. From the results of the above Examples and Reference Examples, ring closure from the amide oxime (general formula (I)) body in which a chlorine atom was introduced at the 4-position (R _{2 of the} general formula) of aminopyrazole was performed, and 1H -Pyrazolo [1,
It can be seen that the method for obtaining the 5- b ] -1,2,4-triazole derivative has a smaller amount of by-products and a significantly higher synthetic yield of the target compound than the comparative example.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Furudate 210 Nakanuma, Minamiashigara-shi, Kanagawa Fuji Photo Film Co., Ltd. (56) References JP-A-60-197688 (JP, A) JP-A-60-172982 (JP, A)

Claims (2)

[Claims] 1. A general formula (I) (In the formula, R ₁ is a hydrogen atom, an alkyl group, an aryl group, an alkoxy group or an aryloxy group, and R ₂ is a chlorine atom,
R ₃ represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. ) An N-pyrazolylamide oxime compound represented by (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as described above.) A method for synthesizing a 1H-pyrazolo [1,5- b ] -1,2,4-triazole derivative represented by the formula: 2. The synthetic method according to claim 1, wherein an alcohol solvent is used as a reaction solvent.