JPH0566386B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to pyrazolo[1,5-b][1,2,4] which is useful as a silver salt color photographic coupler, etc.
The present invention relates to a method for producing an N-pyrazolylamidoxime compound, which is a synthetic intermediate for triazole. (Prior art) The present inventors have disclosed in Japanese Patent Application Laid-Open No. 59-171956 and European Patent Application No. 0119860 that pyrazolo [1,
It has been reported that 5-b][1,2,4]triazole can serve as a new and excellent magenta coupler for silver salt color photography. This new coupler overcomes the drawbacks of previous pyrazolone magenta couplers, namely that the dye formed is
The pyrazolo[1,5-c][1,2,4]triazole coupler, which has been used relatively recently, solves the problem of color turbidity due to side absorption near 430 nm (a patent for its use in photosensitive materials). (Japanese Patent Publication No. 48-30895, U.S. Pat. No. 3,725,067, etc.) also solves the problem of low light fastness of the formed dye. As a result, the development of a simple synthetic method for pyrazolo[1,5-b][1,2,4]triazole has become extremely important. The method for synthesizing this pyrazolo[1,5-b][1,2,4]triazole is described in European Patent Application Publication No.
Five synthetic methods are reported in No. 0119860. They can be roughly divided into methods using an aminating agent (method 1 in the aforementioned European Patent Application Publication No. 0119860), methods using a dehydration cyclization reaction of amidoxime (methods 2, 4, and 5 in the same); , and a method using an oxidative cyclization reaction of amidine (the third method). (Problems to be Solved by the Invention) Among these conventional methods, the method based on the cyclized dehydration reaction of amidoxime is the most efficient, and in particular, the second method represented by the following reaction scheme 1 is the most efficient. suitable. Reaction equation 1 (R ₅ and R ₆ represent substituted and unsubstituted alkyl groups, aryl groups, or heterocyclic groups.) However, in the method of reaction scheme 1 above, the key compound, the amidoxime compound (), There were some difficulties with the synthesis method. That is, in this method, it is necessary to first synthesize orthoester ( ) from imidoester hydrochloride in step (1), and this synthesis reaction requires a long reaction time (6 hours to several days), and Due to the low yield, there is a demand for the development of a method that does not use orthoester (). In addition, the reaction solvent, temperature conditions, etc. of steps (1) and (2) are different, and it cannot necessarily be said that this is a method that can be easily implemented as a method for synthesizing an amidoxime compound. (Means for Solving the Problems) The present inventors have conducted extensive research in order to overcome the difficulties in the above method for synthesizing amidoxime compounds. The inventors have discovered that N-pyrazolylamidoxime compounds can be synthesized in high yield by obtaining a salt of an N-pyrazolylamidine compound and reacting this salt with hydroxylamines, and based on this knowledge, the present invention has been made. It came to this. That is, the present invention is based on the general formula (In the formula, R ₁ and R ₂ represent a hydrogen atom or a substituent other than an amino group.) Aminopyrazole represented by the general formula (In the formula, R ₃ is a substituted or unsubstituted alkyl group,
It represents an aryl group or a heterocyclic group, and R ₄ represents an alkyl group or an aryl group. ) by reacting the imidoester represented by the general formula in the presence of an acid. (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as above.) Obtaining a salt of N-pyrazolylamidine represented by
By reacting this with hydroxylamine or its salt, the general formula (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as above.) It is. The general formula (), (), () in the present invention
In the compound represented by and (), R ₁ , R ₂ , R ₃
and to elaborate on R ₄ , R ₁ and R ₂
is hydrogen atom, halogen atom, aliphatic group, aryl group, heterocyclic group, cyano group, alkoxy group, aryloxy group, acylamino group, anilino group, ureido group, sulfamoylamino group, alkylthio group, arylthio group, alkoxy carbonylamino group, sulfonamide group, carbamoyl group, sulfamoyl group, sulfonyl group, alkoxycarbonyl group, heterocyclic oxy group, acyloxy group,
Represents a carbamoyloxy group, silyloxy group, aryloxycarbonylamino group, imide group, heterocyclic thio group, sulfinyl group, phosphonyl group, aryloxycarbonyl group, acyl group,
R ₁ or R ₂ is a divalent group and may form a bis body. More specifically, R ₁ and R ₂ are each a hydrogen atom,
Halogen atoms (e.g. chlorine atoms, bromine atoms, etc.),
Alkyl group (straight chain, branched alkyl group, aralkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group having 1 to 32 carbon atoms,
These may be substituted with an oxygen atom, a nitrogen atom, a sulfur atom, a substituent linked with a carbonyl group, a hydroxy group, an amino group, a nitro group, a carboxy group, a cyano group, or a halogen atom, such as a methyl group or a propyl group. , t-butyl group, tridecyl group, 2-methanesulfonylethyl group, 3-(3-
pentadecylphenoxy)propyl group, 3-{4
-{2-[4-(4-hydroxyphenylsulfonyl)phenoxy]dodecaneamide}phenyl}propyl group, 2-ethoxytridecyl group, trifluoromethyl group, cyclopentyl group, 3-(2,4
-di-t-amylphenoxy)propyl group, etc.),
Aryl group (e.g., phenyl group, 4-t-butylphenyl group, 2,4-di-t-amyl phenyl group, 4-tetradecanamidophenyl group, etc.), 5
7-membered heterocyclic group (e.g., 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-
benzothiazolyl group, etc.), cyano group, alkoxy group (e.g., methoxy group, ethoxy group, 2-methoxyethoxy group, 2-dodecylethoxy group, 2-
methane sulfonylethoxy group, etc.), aryloxy group (e.g., phenoxy group, 2-methylphenoxy group, 4-t-butylphenoxy group, etc.), acylamino group (e.g., acetamide group, benzamide group, tetradecaneamide group, α-(2, 4-
di-t-amylphenoxy)butanamide group, γ
-(3-t-butyl-4-hydroxyphenoxy)
butanamide group, α-{4-(4-hydroxyphenylsulfonyl)phenoxy}decaneamide group, etc.), anilino group (e.g. phenylamino group, 2
-chloroanilino group, 2-chloro-5-tetradecanaminoanilino group, 2-chloro-5-dodecyloxycarbonylanilino group, N-acetylanilino group, 2-chloro-5-{α-(3-t- butyl-4-hydroxyphenoxy)dodecaneamide}anilino group, etc.), ureido group (e.g., phenylureido group, methylureido group, N,N-dibutylureido group, etc.), sulfamoylamino group (e.g., N,N-dibutylureido group, etc.) -dipropylsulfamoylamino group, N-methyl-N-decylsulfamoylamino group, etc.), alkylthio group (e.g., methylthio group, octylthio group, tetradecylthio group,
2-phenoxyethylthio group, 3-phenoxypropylthio group, 3-(4-t-butylphenoxy)
propylthio group), arylthio group (e.g.
phenylthio group, 2-butoxy-5-t-octylphenylthio group, 3-pentadecylphenylthio group, 2-carboxyphenylthio group, 4-tetradecanamidophenylthio group), alkoxycarbonylamino group ( For example, methoxycarbonylamino group, tetradecyloxycarbonylamino group, etc.), sulfonamide group (for example, methanesulfonamide group, hexadecanesulfonamide group, benzenesulfonamide group, p-toluenesulfonamide group, octadecanesulfonamide group, -methyloxy-5-t-butylbenzenesulfonamide group, etc.), carbamoyl group (e.g.,
N-ethylcarbamoyl group, N,N-dibutylcarbamoyl group, N-(2-dodecyloxyethyl)
carbamoyl group, N-methyl-N-dodecylcarbamoyl group, N-{3-(2,4-di-t-amylphenoxy)propyl}carbamoyl group, etc.), sulfamoyl group (e.g., N-ethylsulfamoyl group, , N-dipropylsulfamoyl group,
N-(2-dodecyloxyethyl)sulfamoyl group, N-ethyl-N-dodecylsulfamoyl group, N,N-diethylsulfamoyl group, etc.), sulfonyl group (e.g. methanesulfonyl group, octanesulfonyl group, benzene sulfonyl group, benzenesulfonyl group, toluenesulfonyl group, etc.),
Alkoxycarbonyl groups (e.g., methoxycarbonyl group, butyloxycarbonyl group, dodecyloxycarbonyl group, octadecyloxycarbonyl group, etc.), heterocyclic oxy groups (e.g., 1-phenyltetrazol-5-oxy group, 2-tetrahydropyranyl group) oxy group, etc.), acyloxy group (e.g., acetoxy group, etc.), carbamoyloxy group (e.g., N-methylcarbamoyloxy group, N-methylcarbamoyloxy group,
-phenylcarbamoyloxy group, etc.), silyloxy group (e.g., trimethylsilyloxy group, dibutylmethylsilyloxy group, etc.), aryloxycarbonylamino group (e.g., phenoxycarbonylamino group, etc.), imide group (e.g., N- succinimide group, N-phthalimide group, 3-octadecenylsulcinimide group, etc.), heterocyclic thio group (e.g., 2-benzothiazolylthio group, 2,
4-di-phenoxy-1,3,5-triazole-6-thio group, 2-pyridylthio group, etc.), sulfinyl group (e.g., dodecanesulfinyl group, 3
-Pentadecylphenylsulfinyl group, 3-phenoxypropylsulfinyl group, etc.), phosphonyl group (e.g., phenoxyphosphonyl group, octyloxyphosphonyl group, phenylphosphonyl group, etc.), aryloxy carbonyl group (e.g., phenoxycarbonyl group, etc.), acyl group (e.g.,
acetyl group, 3-phenylpropanoyl group, benzoyl group, 4-dodecylaxybenzoyl group, etc.)
represents. Next, R ₃ has the same meaning as the substituted or unsubstituted alkyl group, aryl group or heterocyclic group explained for R ₁ and R ₂ . Furthermore, R ₄ represents a substituted or unsubstituted alkyl group or aryl group as explained for R ₁ and R ₂ . In the present invention, the compound represented by the general formula () is useful as a precursor for synthesizing a pyrazolo[1,5-b][1,2,4]triazole compound that can be used as a magenta coupler. There are no restrictions. Therefore
R ₂ is not limited to a group that can react and leave as an oxidant of a developing agent, that is, a group linked by a hydrogen atom, -O-, -S-, etc., and for example, an alkyl group, an aryl group, etc. Of course, it is also possible to use a group that cannot be separated, such as. The method of the present invention can be represented by reaction scheme 2 below. Reaction equation 2 (In the formula, R ₁ to _{R 4} have the same meanings as above.) Embodiments of the present invention will be described according to the reaction scheme 2 above. The method of obtaining imidoester () by adding alcohol or phenol to nitrile () in the presence of an acid is well known as the Pinner method, and the preferred acid commonly used is hydrogen halide (HX), and more Preferred is hydrogen chloride. Ether, dioxane, etc. are preferred as the solvent, and when nitrile is poorly soluble, a mixed solvent with a haloalkane solvent such as chloroform may be used. The reaction temperature is between 0° C. and room temperature, and the product usually precipitates from the reaction solution. In the step of obtaining amidine () by the reaction of imidoester () and aminopyrazole (), the preferred solvent is alcohol such as methanol or water. However, in the case of water, imidoester () reacts with water and easily becomes an ester, so when reacting, first
Decomposition of the imidoester () can be prevented by dissolving 2 equivalents, preferably 1.2 equivalents of aminopyrazole () in water and adding the solid imidoester () to the vigorously stirred solution. The reaction between aminopyrazole () and imidoester () is usually extremely fast. When using alcohols such as methanol, the order of addition is not very important. The reaction temperature is 0 to 40°C, preferably room temperature. When a salt of imidoester () is used, a salt of amidine () is obtained, but imidoester () does not necessarily have to be a salt. In addition, in this reaction, some () (R ₁ , R ₂ , R ₃ and R ₄ have the same meanings as above.) By-products may be produced, but this is influenced by the types of aminopyrazole () and imidoester (). However, it is usually not necessary to isolate amidine () to obtain the amidoxime compound (), and the presence of () poses no problem.
Used as is in the next reaction. If the presence of () is inappropriate, heating with ammonium chloride in methanol will convert all () to amidine (). To obtain the amidoxime compound (), add 1-2 to the amidine () solution obtained by the above method.
An equivalent amount, preferably 1.5 equivalents, of a hydroxylamine solution may be added at 0 to 70°C, preferably at room temperature. If the solvent used in the reaction is alcohol,
The hydrochloride of hydroxylamine is freed with sodium alcoholate in alcohol, and the by-product salt is filtered and added. When the reaction solvent is water, the hydrochloride or sulfate thereof is reacted with a base such as potassium carbonate in water, and then added as is. Since the amidoxime compound (2) usually crystallizes well, it can be isolated from the reaction solution relatively easily, but if it does not crystallize, an extraction operation is required. (Effects of the Invention) According to the method of the present invention, an N-pyrazolylamidoxime compound can be produced in high yield under mild conditions. Further, according to the method of the present invention, an N-pyrazolylamidoxime compound can be synthesized easily and at low cost by reducing the number of steps. The advantages of the method of the invention have been demonstrated in the published European patent application.
A more detailed comparison with the second method (reaction scheme 1) of No. 0119860 is as follows. In the method of Scheme 1 above, an orthoester () is used, which usually needs to be specifically synthesized from the imidoester hydrochloride used in the present invention, but as described above, this synthesis is While there were problems such as long reaction time and low yield, the method of the present invention (reaction scheme 2) eliminates this step, thereby shortening the process by one step. In the method of reaction scheme 1, step (1) is carried out in a solvent such as toluene under heating conditions, and after removing the solvent, step (2) is carried out using alcohol as a solvent, whereas in the method of the present invention, () →(),
Both steps ()→() can be carried out in the same solvent (alcohol or water) at room temperature in the same reaction vessel. Advantageously, water can be used as a solvent. These advantages of the present invention simplify the synthesis of amidoximes and allow cost savings. (Examples) Next, the present invention will be described in more detail based on Examples. Example 1 Synthesis of 300 ml of methanol was added to 800 g (3.1 mol) of imidoester hydrochloride obtained from p-nitrophenylbutyronitrile, stirred, and 300 g (3.1 mol) of 3-amino-5-methylpyrazole was added dropwise ( for about 5 minutes). After stirring for about 1 hour, a methanol solution of hydroxylamine (215 g (3.1 mol) of hydroxylamine hydrochloride was dissolved in 1.8 g of methanol, 621 ml of a 28% methanol solution of sodium methoxide was added thereto, and the precipitated sodium chloride was filtered. Add (prepared except for about 20 minutes)
did. After stirring for about 2 hours, the precipitates (1 and ammonium chloride) were filtered, the filtrate was concentrated at about 40°C using an evaporator, and the precipitated crystals were filtered and combined with the first precipitate and washed with water. , the by-product ammonium chloride was removed. After sufficient drying, the yield of (1~) is 702g (yield 75%), melting point 165~166
It was warm at ℃. Example 2

Synthesis of [Formula] 3-amino-5-methylpyrazole 97g
(1.0 mol) was dissolved in 500 ml of water, and 292 g (1.2 mol) of imidoester hydrochloride obtained from lauronitrile was added all at once while stirring vigorously. After stirring for about 1 hour, a hydroxylamine aqueous solution (prepared by mixing 83.4 g (1.2 mol) of hydroxylamine hydrochloride and 83 g (0.6 mol) of potassium carbonate in an aqueous solution) was added at room temperature, and the mixture was stirred for about 2 hours.
The precipitated crystals were filtered and washed with chloroform.
Dry. Yield 230g (yield 78%), melting point 100-101
℃. Examples 3 to 12 Various N-pyrazolylamidoxime compounds were synthesized according to the methods of Examples 1 and 2. The yield and melting point of the amidoxime compound in this case are shown in the table below together with the results of Examples 1 and 2.

【table】

【table】

Claims (1)

[Claims] 1. General formula (In the formula, R ₁ and R ₂ represent a hydrogen atom or a substituent other than an amino group.) Aminopyrazole represented by the general formula (In the formula, R ₃ is a substituted or unsubstituted alkyl group,
It represents an aryl group or a heterocyclic group, and R ₄ represents an alkyl group or an aryl group. ) by reacting the imidoester represented by the general formula in the presence of an acid. (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as above.) Obtaining a salt of N-pyrazolylamidine represented by
By reacting this with hydroxylamine or its salt, the general formula (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as above.) A method for producing an N-pyrazolylamidoxime compound, which is characterized by obtaining an N-pyrazolylamidoxime compound represented by the following formula.