JP2001316348A - New method for producing cyano group-containing cyan coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for easily producing a cyano group- containing cyan coupler in high yield and productivity. SOLUTION: This method for producing a cyan coupler of general formula 1 (R1 is H or a halogen; R2 and R3 are such that one of them is cyano, the other being H or Cl; and R4 is a lipophilic group) comprises the following process: a nitro compound as starting material is put to catalytically hydrogenating reduction to derive the corresponding amino compound of general formula 2 (R1 to R3 are each the same as that mentioned above) in an advantageous way, the amino compound is then amidated without being taken out of the system followed by separating the metal catalyst off the system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel process for producing a cyan coupler for forming a cyan dye image on a silver halide color photographic light-sensitive material.

[0002]

2. Description of the Related Art An amino compound (Chemical Formula 2) which is a precursor of a cyan coupler can be obtained by reducing a corresponding nitro compound. As a specific method, a chemical reduction method using a sulfur compound such as hydrosulfite or sodium sulfide, or a simple metal such as iron or copper has been known for a long time. However, the reduction using these compounds requires remarkable foaming during the reaction and must be produced on a scale much smaller than the capacity of the reactor used. Complicated treatments such as separation from the agent, alkali treatment, water washing, and purification are required, and many by-products are not industrial.

On the other hand, there are many cases in which a nitro compound is subjected to catalytic hydrogen reduction to lead to an amino compound. In this case, generally, there are few by-products and the reaction rate is relatively high. However, the amino compound (Chemical Formula 2) in the present invention has a cyano group, which is also reduced at the same time, and a diamino compound, which is not originally intended, is produced as a by-product and the yield decreases. In addition, the amino compound (Chemical Formula 2) of the present invention has a very low solubility in an organic solvent, and a large amount of a solvent having a high solubility such as DMF, THF, and 1,4-dioxane must be used. Therefore, the batch efficiency is poor, and a large amount of water or alcoholic solvent must be added to the reaction solution to remove the dissolved amino compound. As a result, a large amount of industrial waste is generated as in the case of chemical reduction. Resulting in.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. Sho 56-65134, there is an example in which the cyan coupler of the present invention, which is the final product, is derived without removing the produced amino compound after catalytic hydrogen reduction. This method is industrially useful from the viewpoint of reducing industrial waste. However, the yield of the target cyan coupler taken out was as low as 63%. Both catalytic hydrogen reduction and amidation reactions inherently show high reaction rates. Nevertheless, it can be judged that the reason why the yield is kept at this level is that not only the nitro group but also the coexisting cyano group is partially reduced.

[0005]

In the prior art, when the amino compound is obtained, there are various problems such as complicated post-treatment, low yield, and large amount of waste in the chemical reduction. In addition, since chemical reduction involves the risk of foaming and bumping during the reaction, it must be manufactured on a much smaller scale of the reactor used, and the production efficiency is low.

In the conventional catalytic hydrogen reduction, many organic solvents must be used due to the poor solubility of the amino compound, and the production efficiency is low. Further, the selectivity of the reduction is poor, and an undesired diamino compound is generated by the reduction of the cyano group, causing a decrease in the yield.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a method for industrially easily producing a desired cyan coupler with high yield and high productivity.

[0008]

Means for Solving the Problems The present inventor has made various studies to achieve the above object, and as a result, the general formula (Formula 1)
[In the formula (1), R1 represents a hydrogen atom or a halogen atom, R4 represents a lipophilic group, one of R2 and R3 is a cyano group, and the other is a hydrogen atom or a chlorine atom. In the method for producing a cyan coupler represented by formula (I), catalytic hydrogen reduction is carried out in an organic solvent in the presence of a metal catalyst and a nitrogen-containing organic compound in which one or a combination of two or more selected from melamine, cyanamide and dicyandiamide is used. General formula (Chemical formula 2) [In formula (2), it has the same meaning as R1, R2 and R3 (Chemical formula 1). ], Followed by the reaction with an acid halide or an acid anhydride, and then separating the metal catalyst, to find that the desired cyan coupler can be easily produced with high yield and high productivity.

The solvent used for the reduction reaction and the amidation reaction in the present invention is required to be not reduced itself and be inert to acid halides and acid anhydrides in the production process. Therefore, any one of ethyl acetate, diethyl ether, THF, 1,4-dioxane, and dimethyl carbonate, or a mixed solvent of two or more thereof is preferable. The amount used is preferably 1 to 15 parts by weight, more preferably 2 to 8 parts by weight, per 1 part by weight of the nitro compound corresponding to the amino compound.

Examples of the nitrogen-containing organic compound to be added for the purpose of suppressing the diamino compound by-produced by the reduction of the cyano group include melamine, cyanamide and dicyandiamide each alone or a mixture of two or more thereof. The amount used is 1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the nitro compound. Examples of the metal catalyst for catalytic reduction include a Raney nickel catalyst, a palladium catalyst, and a platinum catalyst. In the present invention, a combination of melamine and a Raney nickel catalyst has provided particularly good results.

The hydrogen pressure during the catalytic hydrogen reduction is carried out at normal pressure or under pressure, and the reaction temperature is carried out between normal temperature and 100 ° C., but the present invention is not limited to these pressures and temperatures. After the completion of the catalytic hydrogen reduction, the amino compound is precipitated and is in a suspended state including the metal catalyst and the nitrogen-containing organic compound. An acid halide or an acid anhydride having a lipophilic group is added thereto to derive a cyano group-containing cyan coupler as a final product. This amidation reaction can be performed by a conventional method. The reaction can also be carried out using an organic base such as pyridine, dimethylaniline, triethylamine or the like, or an aqueous solution such as caustic soda, caustic potash, potassium carbonate, sodium carbonate or sodium acetate. The amidation reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen, helium, or argon in order to prevent oxidation of the amino compound and to prevent ignition by a metal catalyst.

The cyan coupler in the present invention obtained after the completion of the amidation reaction is ethyl acetate, diethyl ether, TH
It has high solubility in one or a mixture of two or more of F, 1,4-dioxane, and dimethyl carbonate. At this time, only the metal catalyst and the nitrogen-containing organic compound are precipitated. Therefore, after the end of the amidation reaction, the cyan coupler can be separated from the metal catalyst and the nitrogen-containing compound. Separation of the metal catalyst can be performed by a conventional method using a filter such as a filter press.

After separating the metal catalyst and the nitrogen-containing organic compound, the solvent used is diethyl ether, THF, 1,
In the case of 4-dioxane or dimethyl carbonate or a mixture thereof, the solvent can be distilled off and replaced with a non-water-soluble solvent such as ethyl acetate or toluene, and the remaining water-soluble impurities can be removed by washing with water. When the solvent used is ethyl acetate, it is possible to wash with water without replacing the solvent.

After water-soluble impurities have been removed by washing with water, the mixed solution containing the cyan coupler is cooled to crystallize the desired product, which can be taken out by a solid-liquid separation method.
It is also possible to remove the solvent such as ethyl acetate and toluene and recrystallize with an organic solvent such as methanol, ethanol and acetonitrile to take out the desired cyan coupler. The present invention is not limited to the presence or absence of these recrystallizations, the type of solid-liquid separation solvent, the apparatus used for solid-liquid separation, and the like.

[00015]

According to the present invention, the desired cyan coupler can be obtained in a high yield without a complicated post-treatment as in the case of chemical reduction, and with higher selectivity as compared with conventional catalytic hydrogen reduction. In addition, there is no need to dissolve the amino compound after the reduction reaction, and the production can be performed with a small amount of an organic solvent, thereby improving the production efficiency.

[0016]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Example 1 2- [N '-(4-chloro-3-
Cyanophenyl) ureido] -5- [2- {2,4-bis
(1,1-dimethylpropyl) phenoxy} hexanamide
Synthesis of phenol 240m into 1L stainless steel autoclave
1, 2- [N '-(4-chloro-3-cyanophenyl) ureido] -5-nitrophenol 80.0 g, Raney nickel NDT-65 (manufactured by Kawaken Fine Chemical Co., Ltd.) 6.2
g and 2.0 g of melamine, and the container was sealed and the air in the container was replaced with nitrogen. Hydrogen gas was introduced up to a gauge pressure of 0.7 MPa, and reacted at 30 to 35 ° C. until hydrogen absorption disappeared. Thereafter, the remaining hydrogen was replaced with nitrogen, and the reaction mixture was transferred to a 1-L four-necked flask under nitrogen filling, and 33.0 g of dimethylaniline and 2,4-bis (1,1-dimethylpropyl) phenoxyhexanoyl were kept under nitrogen filling. 91.0 g of chloride was added and reacted at room temperature for 1 hour.
Thereafter, Raney nickel and melamine were removed by filtration under reduced pressure using a magnetic nutchet having a diameter of 7 cm, and the reaction solution after filtration was concentrated under reduced pressure using a rotary evaporator. The concentrate was dissolved in 600 ml of ethyl acetate, washed with pure water, and the organic layer was concentrated under reduced pressure using a rotary evaporator. The concentrate was dissolved in 400 ml of methanol, cooled, stirred at 5 to 10 ° C. for 5 hours, and crystallized. The crystals precipitated with a magnetic nutchet having a diameter of 11 cm were filtered and washed with 100 ml of methanol. The wet cake was taken out and dried at 40 ° C. to give 2- [N ′-(4-
Chloro-3-cyanophenyl) ureido] -5- [2-
{2,4-bis (1,1-dimethylpropyl) phenoxy}
125.6 g of white crystals of [hexanamide] phenol were obtained. Total yield from 2- [N '-(4-chloro-3-cyanophenyl) ureido] -5-nitrophenol 8
0.0%.

Example 2 Synthesis of 2- [N '-(4-cyanophenyl) ureido] -5- [2- {2,4-bis (1,1-dimethylpropyl) phenoxybutanoylamino] phenol 1 L stainless steel Acetate 240 into autoclave made of
ml, 2- [N '-(4-cyanophenyl) ureido] -5-
71.7 g of nitrophenol, Raney nickel NDT-
After charging 5.8 g of 65 (manufactured by Kawaken Fine Chemical Co., Ltd.) and 2.0 g of melamine, the container was sealed and the air in the container was replaced with nitrogen. Hydrogen gas was introduced up to a gauge pressure of 0.7 MPa and 30
The reaction was carried out in the range of -35 ° C until hydrogen absorption ceased.
Thereafter, the remaining hydrogen was replaced with nitrogen, and the reaction mixture was transferred to a 1-L four-necked flask under nitrogen charging, and 29.6 g of dimethylaniline, 2,4-bis (1,1-1-
Dimethylpropyl) phenoxybutanoyl chloride 8
4.0 g was added and reacted at room temperature for 1 hour. Then diameter 7
Raney nickel and melamine were removed by filtration under reduced pressure with a magnetic nutchet having a diameter of 10 cm, washed with pure water, and concentrated under reduced pressure using a rotary evaporator. The concentrate is methanol 380
After dissolving in 5 ml, the mixture was cooled and stirred at 5 to 10 ° C. for 5 hours for crystallization. The crystals precipitated with a magnetic nutchet having a diameter of 11 cm were filtered and washed with 100 ml of methanol. The wet cake was taken out and dried at 40 ° C., and 2- [N ′-(4-cyanophenyl) ureido] -5- [2- {2, 106.9 g of white crystals of 4-bis (1,1-dimethylpropyl) phenoxybutanoylamino] phenol were obtained. Total yield from 2- [N '-(4-cyanophenyl) ureido] -5-nitrophenol 76.0%.

Comparative Example 1 2- [N '-(4-chloro-3-
Cyanophenyl) ureido] -5- [2- {2,4-bis
(1,1-dimethylpropyl) phenoxy} hexanamide
Synthesis of phenol Synthesis was carried out in the same manner as in Example 1 except that melamine was not used in the reduction reaction of Example 1. As a result, 2- [N '
-(4-Chloro-3-cyanophenyl) ureido] -5-
76.2 g of white crystals of [2- {2,4-bis (1,1-dimethylpropyl) phenoxy} hexanamide] phenol were obtained. Total yield from 2- [N '-(4-chloro-3-cyanophenyl) ureido] -5-nitrophenol 4
8.5%.

Comparative Example 2 5-amino-2- [N '-(4-
Synthesis of chloro-3-cyanophenyl) ureido] phenol 800 ml water and 160 m ethanol in a 2 L 4-head flask
1,8-g of 2- [N '-(4-chloro-3-cyanophenyl) ureido] -5-nitrophenol and 90.0 g of 25% aqueous ammonia were added and heated to 50 ° C. 160.0 g of hydrosulfite was added little by little, and then the mixture was heated and refluxed for 1 hour. After cooling to 30 ° C., 100.0 g of acetic acid was added, and the mixture was stirred for 1 hour, and the precipitated crystals were filtered with a magnetic nutchet having a diameter of 11 cm. The cake was washed with 1 L of warm water, taken out, dispersed in 350 ml of methanol, and stirred for 1 hour. Thereafter, the crystals were filtered through a magnetic nutchet having a diameter of 11 cm, washed with 100 ml of methanol, taken out and dried at 40 ° C., and red-purple crystals of 5-amino 2- [N ′-(4-chloro-3-cyanophenyl) ureido] phenol were obtained. 57.0 g (78.3% yield) were obtained.

Synthesis of 2- [N '-(4-chloro-3-cyanophenyl) ureido] -5- [2- {2,4-bis (1,1-dimethylpropyl) phenoxy} hexanamide] phenol 400 ml of ethyl acetate into the flask, 5 previously obtained
-Amino-2- [N '-(4-chloro-3-cyanophenyl) ureido] phenol 57.0 g, dimethylaniline 27.0 g, 2,4-bis (1,1-dimethylpropyl)
76.1 g of phenoxyhexanoyl chloride was added and reacted at room temperature for 1 hour. After washing with pure water, the organic layer was concentrated under reduced pressure using a rotary evaporator. After dissolving the concentrate in 300 ml of methanol, it is cooled and cooled at 5 to 10 ° C. for 5 minutes.
After stirring for an hour, crystallization was performed. The crystals precipitated with a magnetic nutchet having a diameter of 11 ml were filtered and washed with 100 ml of methanol.
Take out the wet cake and dry at 40 ° C, 2- [N'-
(4-Chloro-3-cyanophenyl) ureido] -5- [2
84.0 g (70.5% yield) of white crystals of-{2,4-bis (1,1-dimethylpropyl) phenoxy} hexanamide] phenol were obtained. 2- [N '-(4-chloro-3-
Total yield from cyanophenyl) ureido] -5-nitrophenol: 55.2%.

[0022]

According to the present invention, the nitro compound is led to the corresponding amino compound (Chemical Formula 2) in an advantageous manner, the amidation is carried out without removing the amino compound, and thereafter the metal catalyst is separated and the final target cyanide is obtained. It was possible to provide a method for easily producing a coupler (formula 1) with high yield and high productivity.

Claims (4)

[Claims] 1. A compound of the general formula (1) wherein R1 represents a hydrogen atom or a halogen atom, R4 represents a lipophilic group, and R2 or R3 is a cyano group, The other is a hydrogen atom or a chlorine atom. In the method for producing a cyan coupler represented by the formula (I), catalytic hydrogen reduction is carried out in an organic solvent in the presence of a metal catalyst and one or a combination of two or more of melamine, cyanamide and dicyandiamide. General formula (Formula 2) [wherein R1, R2, R3 in formula (2)
It is synonymous with (Formula 1). ], Followed by the reaction with an acid halide or an acid anhydride, followed by separation of the metal catalyst. ◎ [Formula 1] ◎ [Formula 2] 2. The method according to claim 1, wherein the organic solvent used in the catalytic hydrogen reduction and the subsequent amidation reaction with an acid halide or acid anhydride is ethyl acetate,
The method for producing a cyan coupler according to claim 1, wherein the liquid is one of diethyl ether, THF, 1,4-dioxane, and dimethyl carbonate, or a mixture of two or more thereof. 3. The method for producing a cyan coupler according to claim 1, wherein the combination of the metal catalyst and the nitrogen-containing organic compound used for catalytic hydrogen reduction is Raney nickel and melamine. 4. The amount of an organic solvent used for the catalytic hydrogen reduction and the subsequent amidation reaction with an acid halide or an acid anhydride is 1 to 15 parts by weight based on the nitro compound corresponding to the formula (2). A method for producing a cyan coupler according to claim 1.