JPH0826236B2 - Method for producing azomethine or indoaniline dye - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an azomethine or indoaniline dye which is a compound useful for a photographic light-sensitive material or a thermal transfer material.

(Prior Art) A method for oxidative condensation of a compound having active methylene or active methine and p-phenylenediamines in the presence of an oxidant and a base in the presence of an appropriate solvent for the synthesis of azomethine or indoaniline dyes. Is the most widely used.
The most widely used system in the past is, for example, J. Am. Chem. So.
c., 79 , 2919, (1957), JP-A-61-31292, and JP-A-61-2299.
As described in No. 3, etc., it comprises alcohol-water as a solvent, an inorganic oxidizing agent (potassium ferricyanide, silver nitrate, etc.) as an oxidizing agent, and an inorganic base (sodium carbonate, ammonium, etc.) as a base. However, in these systems, since water and a base coexist, a hydroxide ion is generated, which has an undesired side effect of hydrolyzing quinonediimine generated from p-phenylenediamines and hydrolyzing a produced dye. Further, since the compound having active methylene or active methine, which is a raw material of the dye for the thermal transfer material, is insoluble in water, the solubility in alcohol-water is low, and since a large amount of solvent is required, the productivity is remarkably lowered and the production cost is greatly increased. Had been raised to.

In the methods described in JP-A-60-32851 and 64-51991, a two-layer system of ethyl acetate or chloroform and water is used as a solvent. Compared with the above method, this method tends to reduce the adverse effects of hydroxyl groups, but is still insufficient. Moreover, productivity cannot be said to be sufficient.

JP-A-64-48863 describes that an organic oxidizing agent can be used as the oxidizing agent. However, the solvent used is a two-layer system of ethyl acetate-water, and the above-mentioned inconvenience has not been solved at all.

In the method described in JP-A-63-172771, methanol is used as a solvent and iodine is used as an oxidizing agent. However, since iodine has a weak oxidizing power, a large excess is required as described in the examples. For this reason,
Originally, it has a large molecular weight, which reduces productivity.
Also, since the mode is a relatively expensive oxidizer, the manufacturing cost was raised.

(Problems to be Solved by the Invention) The present invention is to provide a novel method for producing an azomethine or indoaniline dye that overcomes the above-mentioned deficiencies.

(Means for Solving the Problems) The object of the present invention was achieved by the following method.

That is, in the present invention, a compound having active methylene or active methine and p-phenylenediamines are oxidatively condensed with an organic oxidizing agent in a solvent substantially free of water in the presence of a base. Or a method for producing an azomethine or indoaniline dye, characterized in that the compound having active methylene or active methine and p-phenylenediamines are oxidatively condensed in the presence of bromine. This is a method for producing an aniline dye.

The present invention is characterized in that a solvent containing substantially no water and an organic oxidizing agent having an appropriate oxidizing power are used, or bromine is used as the oxidizing agent. It was found that the reaction proceeds without side effects and the productivity is increased as compared with the conventional method.

The p-phenylenediamines used in the present invention are not particularly limited, but those represented by the following general formula (I) are preferably used.

General formula (I) In the formula, R ^{1 to} R ⁴ are hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, cyano groups, acylamino groups, sulfonylamino groups, ureido groups, alkoxycarbonylamino groups, alkylthio groups, arylthio. Group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group, R ⁵ represents an alkyl group or an aryl group, and R ⁶
Represents a hydrogen atom, an alkyl group or an aryl group. R ⁵ and
R ⁶ may be bonded to each other to form a ring, or may be R ⁵ and R ⁵ or / and R ³ and R ⁶ combine to form a ring. The above R ^{1 to} R ⁶ groups include those which are substituted.

Preferred compounds among the compounds represented by formula (I) are described below.

R ¹ is a hydrogen atom, a C _{1 to} C ₄ alkyl group, a halogen atom (especially a fluorine atom or a chlorine atom), a C _{1 to} C ₄ alkoxy group, a C _{2 to} C ₅ acylamino group, or a C _{1 to} C ₄ A sulfonyl group,
Alkoxycarbonylamino group having C ₂ -C ₅ are preferred.

R ^{2 to} R ⁴ are preferably hydrogen atoms.

Among R ⁵ and R ⁶ , preferred are C _{1 to} C ₆ unsubstituted alkyl groups, substituents (cyano group, alkoxy group, aryloxy group, acylamino group, sulfonylamino group, halogen atom, alkoxycarbonyl group, alkoxy A C ₂ -C ₁₀ alkyl group including a carbonyloxy group, an alkoxycarbonylamino group, an aminocarbonylamino group, a carbamoyl group, an acyloxy group, an acyl group, or a hydroxyl group).

Specific examples of the compound represented by the general formula (I) are shown below.

The compound having active methylene or active methine used in the present invention may be any compound as long as it forms an azomethine or indoaniline dye by oxidative condensation with p-phenylenediamines in the presence of a base.

Particularly preferred are the following general formulas (II) to (X). Among them, particularly preferable are those represented by the general formula (V) -a and (V
I) or (VII).

General formula (II) R ⁷ represents an alkyl group (preferably C _{1 to} C ₁₀ ) or an optionally substituted phenyl group (preferably an alkyl group or an alkoxy group as the substituent), and R ⁸ represents an aryl group (preferably substituted). A good phenyl group, the substituent includes a halogen atom, an alkyl group, an alkoxy group, an acyl group, an acylamino group, a sulfonylamino group, a sulfamoyl group,
(Carbamoyl group and alkoxycarbonyl group are preferable)
X ¹ is a hydrogen atom or a leaving group (any group capable of leaving at the time of oxidative condensation may be used. Preferred is a halogen atom, a group bonded to the active site through a nitrogen atom, an oxygen atom or a sulfur atom). Represents).

 A specific example is shown below.

General formula (III) R ⁹ represents an alkyl group (preferably C _{1 to} C ₁₀ ), an aryl group (preferably a phenyl group which may be substituted) or a heteryl group (preferably oxygen-containing, sulfur-containing or nitrogen-containing 5- or 6-membered ring) X ² represents a hydrogen atom or a leaving group.

 A specific example is shown below.

General formula (IV) R ¹⁰ is an alkyl group (preferably C _{1 to} C ₁₀ ), an aryl group (preferably phenyl), an amino group, an alkylamino group (preferably C _{1 to} C ₁₀ ), an arylamino group (preferably substituted) Anilino group, the substituent is preferably a halogen atom, an alkoxy group, an alkyl group, an acyl group, an acylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group or an alkoxycarbonyl group, an acylamino group (preferably C _{2 to} C ₁₅ ). Represents a carbamoyl group (preferably C _{2 to} C ₁₅ ) or an alkoxycarbonyl group (preferably C _{2 to} C ₁₅ ) and R ¹¹ is an alkyl group (preferably C _{1 to} C ₁₀ ) or an aryl group (preferably substituted). a phenyl group which may, halogen atom as a substituent, an alkoxy group, an alkyl group is preferred), X ³ is a hydrogen atom or a leaving group Wath.

 A specific example is shown below.

General formula (V) R ¹² is a hydrogen atom, a halogen atom, an alkyl group (preferably C _{1 to} C ₁₀ ), an alkoxy group (preferably C _{1 to} C ₁₀ ),
Aryl group (preferably unsubstituted or substituted with halogen atom, alkoxy group, acylamino group, alkyl group), aryloxy group (preferably phenoxy group), cyano group, acylamino group (preferably C ₂ ~
C _15), sulfonylamino groups (preferably C ₂ ~C _15), a ureido group (preferably a C ₂ ~C _15), an alkoxycarbonylamino group (preferably a C ₂ ~C _15), an alkylthio group (preferably C ₁ To C ₁₀ ), arylthio group (preferably phenylthio group), alkoxycarbonyl group (preferably C _{2 to} C ₁₅ ), carbamoyl group (preferably C _{2 to} C ₁₅ ),
Sulfamoyl groups (preferably _{C 1 ~C 15), (C} 1 ~C 15 preferably) sulfonyl group, an acyl group (preferably C ₂ -C
₁₅ ) or an amino group, and X ⁴ represents a hydrogen atom or a leaving group. X, Y and Z are Or represents a nitrogen atom (R ¹³ is a hydrogen atom, an alkyl group,
Represents an aryl group, an alkoxy group, an aryloxy group, an amino group, a cyano group, a sulfonyl group, a sulfamoyl group, an acyl group, a carbamoyl group, an alkoxycarbonyl group and an acylamino group). Both X and Y When represented, two R ^13's may combine to form a ring.

 A specific example is shown below.

General formula (VI) Q represents an atomic group necessary for forming a 5-membered or higher carbon ring or a 5-membered or higher heterocycle containing at least one nitrogen atom.

As for the atomic group represented by Q which is composed of carbon atoms, those forming a 6-membered ring represented by the general formula (VI) -A are preferable.

In formula (VI) -A, those represented by R ^{21 to} R ²⁴ are synonymous with R ^{1 to} R ^{4 in} formula (I), but particularly preferred are hydrogen atoms.

The atomic group represented by Q containing at least one nitrogen atom can be represented by the general formula (VI) -B or the general formula (V
Those represented by I) -C are preferred.

In formula (VI) -C, Q ¹ is a divalent amino group, an ether bond, a thioether bond, an alkylene group, an ethylene bond,
It represents an imino bond, a sulfonyl bond, a carbonyl group, an arylene group, a divalent heterocyclic group, or a group combining two or more of these. Preferred of these are: Wherein R ^{25 to} R ³¹ are a hydrogen atom or a group capable of substituting for the carbon atom or the nitrogen atom (specifically,
C ₁ -C ₆ alkyl group, an aryl group having a carbon number of C ₆ -C _10, a halogen atom).

R ²⁰ is synonymous with R ^{1 to} R ² of the general formula (I).

Preferred among R ²⁰ is when Q is of formula (VI) -A or (V
I) -B represents a C _{2 to} C ₈ carbamoyl group (eg, methylcarbamoyl, ethylcarbamoyl, butylcarbamoyl, isopropylcarbamoyl,
t-butylcarbamoyl, cyclopentylcarbamoyl, cyclohexylcarbamoyl, methoxyethylcarbamoyl, chloroethylcarbamoyl, cyanoethylcarbamoyl, benzylcarbamoyl, furfurylcarbamoyl, tetrahydrofurfurylcarbamoyl, phenoxymethylcarbamoyl, allylcarbamoyl, phenylcarbamoyl, 2-pyridylcarbamoyl); Q
Is represented by the formula (VI) -C, a C _{2 to} C ₁₁ acylamino group (for example, acetylamino, propionylamino, isobutyroylamino, hexahydrobenzoylamino, pivaloylamino, trifluoroacetylamino, heptafluorobuty). Loylamino, chloropropionylamino, cyanoacetylamino, phenoxyacetylamino, acryloylamino, benzoylamino, p-trifluoromethylbenzoylamino, picolinoylamino, nicotinoylamino, thenoylamino,
Furoylamino).

X ⁵ represents a hydrogen atom or a leaving group.

Specific examples of the compound represented by formula (VI) are shown below.

General formula (VII) R ^{32 to} R ³⁵ are synonymous with R ^{1 to} R ^{4 in} formula (I).

Preferred among R ³² is a C _{2 to} C ₁₁ acylamino group (for example, acetylamino, propionylamino, isobutyroylamino, hexahydrobenzoylamino, pivaloylamino, trifluoroacetylamino, heptafluorobutyroylamino, chloropropionylamino. , Cyanoacetylamino, phenoxyacetylamino, acryloylamino, benzoylamino, p-trifluoromethylbenzoylamino, picolinoylamino, nicotinoylamino, isonicotinoylamino, thenoylamino, furoylamino).

Preferred among R ³³ is a hydrogen atom.

Preferred among R ³⁴ are C _{2 to} C ₈ acylamino groups, C
_{It is a 1 to} C ₄ alkyl group, and preferred among R ³⁵ are a hydrogen atom and a halogen atom.

X ⁶ represents a hydrogen atom or a leaving group.

Specific examples of the compound represented by formula (VII) are shown below.

General formula (VIII) General formula (IX) R ³⁶ , R ³⁷ and R ³⁸ are synonymous with R ¹² of the general formula (V). R
³⁷ and R ³⁸ may form a ring (preferred aromatic ring). X ⁷
Is the same as X ⁴ in the general formula (V).

Specific examples of the compounds represented by formulas (VIII) and (IX) are shown below.

General formula (X) R ³⁹ and R ⁴⁰ are synonymous with R ¹² of the general formula (V).

Specific examples of the compound represented by formula (X) are shown below.

The organic oxidizing agent used in the present invention may be any one as long as it can oxidize p-phenylenediamines, but is preferably one which is soluble in an organic solvent containing substantially no water. Specific examples of the organic oxidizing agent used in the present invention include N-halocarboxylic acid amides (for example, N-bromoacetamide, N-
Bromosuccinimide, N-chlorosuccinimide, N
-Iodosuccinimide, N-bromophthalimide, isocyanuric chloride, N-bromocaprolactam, 1,3
-Dibromo-5,5-dimethylhydantoin etc.), organic peracids (e.g. peracetic acid, perbenzoic acid, metachloroperbenzoic acid, monoperoxyphthalic acid, performic acid, trifluoroperacetic acid, etc.), organic peroxides (e.g. t-Butyl hydroperoxide, cumyl hydroperoxide, perbenzoic acid t
-Butyl, benzoyl peroxide, etc.), quinones (eg 2,
3-dichloro-5,6-dicyano-1,4-benzoquinone, tetrachloro-1,2-benzoquinone, tetrachloro-1,4-
Benzoquinone, benzoquinone, etc., hypohalous acid ester (eg t-butyl hypochlorite, hypoiodite t)
-Butyl, t-butyl hypobromite, etc.), 1-chlorobenzotriazole, chloramine T, chloramine B, iodosylbenzene, iodosylbenzene acetate, lead tetraacetate and the like. These may be used alone or in combination of two or more. Among these, N-halocarboxylic acid amides are preferable, and N-bromosuccinimide is particularly preferable.

The type of base may be any as long as it can be dissolved in an organic solvent containing substantially no water, but as a preferable one, (R ⁴¹ , R ⁴² and R ⁴³ represent a hydrogen atom, an alkyl group which may be substituted, or an aryl group which may be substituted. R ⁴¹ and R ⁴²
Alternatively, R ⁴² and R ⁴³ may form a 5- or 6-membered ring. Specific examples include ammonia, butylamine, diethylamine, dibutylamine, methoxyethylamine,
Di-2-ethylhexylamine, triethylamine, tripropylamine, triethanolamine, N, N, N ',
N'-tetramethylethylenediamine, dimethylbenzylamine, cyclohexylamine, 2,6-dimethylpiperidine, N-ethylpiperidine, N-ethylmorpholine, diisopropylethylamine, trimethoxyethylamine, hydroxyethyldimethylamine, aniline,
N-butylaniline, N-methyl-m-toluidine, N,
N-dimethyl-o-toluidine, N, N-dimethylaniline, N, N-diethylaniline, N-hydroxyethyl-
N-methyl-m-toluidine, N, N-dimethyl-m-anisidine, etc.), nitrogen-containing unsaturated heterocycle (for example, pyridine, α-picoline, 2,6-lutidine, quinoline, N-methylpyrrole, 2,4) , 6-Colidine, isoquinoline, 6-
Methylquinoline, pyridazine, N-ethylimidazole, etc.). Particularly preferred are tertiary alkylamines, and of these, triethylamine is most preferred.

The solvent that does not substantially contain water used in the present invention may be any solvent having a water content (weight conversion) of 1% or less, but a chlorine-based solvent (for example, methylene chloride, chloroform, 1,2- Dichloroethane etc.), ester solvents (eg ethyl acetate, methyl acetate, butyl acetate, methyl propionate etc.), ketone solvents (eg acetone, methyl ethyl ketone etc.), alcohol solvents (eg methanol, ethanol, isopropanol etc.), amides Solvent (e.g. dimethylformamide,
Dimethylacetamide), ether solvents (eg diethyl ether, tetrahydrofuran, dioxane, 1,2
-Dimethoxyethane etc.), aromatic solvents (eg benzene, toluene, chlorobenzene etc.) sulfolane and the like are preferable. Particularly preferred is methylene chloride.

The proportion of each component used in the reaction is not particularly limited, but 1 to 2 (mol) of the p-phenylenediamines of the general formula (I) to 1 (mol) of the active methylene or active methine compound. , Oxidizing agent 1 to 4 (mol), base 3 to 10
A ratio of (mol) is preferable. The amount of solvent is also not particularly limited, but active methylene or active methine compound 1
The solvent is preferably 5 to 60 (ml) with respect to (g).

The order of addition of the reagents is also not particularly limited, but an oxidizing agent may be added to a composition comprising a solvent, active methylene or active methine compound, base and p-phenylenediamines, or solvent, active methylene or active methine compound, base, oxidation. A method in which p-phenylenediamines are added to a composition comprising an agent is usually used, but the latter method often gives a cleaner reaction.

Further, when the oxidizing agent and the p-phenylenediamines are added, each may be added at once, but they are alternately added in several times (for example, 1/3 amount of oxidizing agent → 1/3 amount of oxidizing agent). p-phenylenediamines → 1/3 amount of oxidizing agent → 1/3 amount of p-phenylenediamines → 1/3 amount of oxidizing agent → 1/3 amount of p-phenylenediamines etc.) Often clean.

The reaction temperature is 50 ° C or lower, preferably 5 to 30 ° C.

 The reaction time is preferably 5 minutes to 1 hour.

The features of this production method are that the amount of solvent is small, the reaction is clean, and the yield is high. Therefore, it was possible to eliminate the low productivity, which was a major drawback of the conventional method for obtaining an azomethine or indoaniline dye by oxidative condensation.

(Example) The method of the present invention will be described below by way of examples, but this is only one example thereof, and the present invention is not limited thereto.

Example 1 200 ml of methylene chloride, active methine compound Va-1
5.0 g (0.015 mol) 8 and triethylamine 7.4 g (0.074 mol)
Mol), N-bromosuccinimide 3.4 g (0.019 mol)
12.5 g of 2p-toluenesulfonate of p-phenylenediamines I-23 with stirring at room temperature.
(0.019 mol) was added over 5 minutes. After reacting for 30 minutes, 200 ml of water was added to the reaction solution, stirred for 2 minutes, and separated. After washing twice with water and evaporating the solvent, the residue was recrystallized from a mixed solvent of ethyl acetate-methanol 2: 3. filtration,
After washing with methanol, the yield was 6.1 g (72% yield), mp176.
The desired product at ˜177 ° C. was obtained.

Comparative Example 1-1 The procedure of Example 1 was repeated except that N-bromosuccinimide was replaced with equimolar iodine. In this case, the reaction did not proceed smoothly probably due to the weak oxidizing power of iodine, and a considerable amount of raw material remained, and there were many by-products.
Therefore, crystals were not obtained by the purification method of Example 1, and purification by silica gel column chromatography was performed.
Yield 31%, mp 176-177 ° C.

Comparative Example 1-2 N-bromosuccinimide is equimolar ammonium persulfate, triethylamine is equimolar sodium carbonate, and 200 ml of methylene chloride is 200 ml of methylene chloride.
ml, 100 ml of ethanol, and 200 ml of water, respectively, except that the procedure of Example 1 was repeated. The reaction is described in Example 1.
It wasn't as beautiful. Yield 50%, mp175-176 ° C.

Example 2 In Example 1, the active methine compound Va-18 was converted to equimolar Va-12 and p-phenylenediamines I
The procedure of Example 1 was repeated except that the 2p-toluenesulfonate salt of -23 was replaced with an equimolar amount of I-1 sulfate. Yield 89%, mp183-184 ° C.

Comparative Example 2-1 The procedure of Example 2 was repeated, except that N-bromosuccinimide was replaced with equimolar iodine. Yield 57%, mp
182-184 ° C.

Comparative Example 2-2 N-bromosuccinimide in equimolar ammonium persulfate, triethylamine in equimolar sodium carbonate, and 200 ml of methylene chloride in 200 methylene chloride.
ml, 100 ml of ethanol, and 200 ml of water, respectively, but the procedure of Example 2 was repeated. 80% yield, mp
183-184 ° C.

Example 3 6.0 g (0.020 mol) of active methine compound VII-9, 60 ml of methylene chloride, 7.3 g (0.028 mol) of sulfate of p-phenylenediamine I-1 and 12.1 g of triethylamine (0.
To a solution consisting of 12 mol), 5.0 g (0.028 mol) of N-bromosuccinimide was added over 5 minutes while stirring at room temperature. After reacting for 30 minutes, 60 ml of water was added to the reaction solution, stirred for 3 minutes, and separated. The methylene chloride layer was washed once with water, and then the methylene chloride was distilled off until the content became about 15 ml. After adding 60 ml of warm methanol and stirring at room temperature for 2 hours, the crystals were collected by filtration and washed with methanol.
The target product with mp 119 to 120 ° C was obtained with a yield of 7.4 g (87% yield).

Comparative Example 3-1 The procedure of Example 3 was repeated, except that N-bromosuccinimide was replaced with equimolar iodine. In this case, a considerable amount of raw materials remained, and there were many by-products. yield
46%, mp 174-176 ° C.

Even when 3 equivalents of VII-9 was used as iodine, or the solvent was replaced with methanol, the yield was not significantly improved.

Comparative Example 3-2 N-bromosuccinimide is used in an equimolar amount of ammonium persulfate, triethylamine is used in an equimolar amount of sodium carbonate, and 60 ml of methylene chloride is added to 60 m of methylene chloride.
The same procedure as in Example 3 was repeated, except that 1 ml of ethanol, 30 ml of ethanol and 100 ml of water were substituted. Yield 78%, mp11
9-120 ℃.

The solvent is 60 ml of ethyl acetate, 30 ml of ethanol and 100 m of water.
The yield was not improved even when replaced with l.

Example 4 5.9 g (0.020 mol) of active methine compound VII-7, 70 ml of chloroform, 12.1 g (0.12 mol) of triethylamine,
Dihydrochloride of p-phenylenediamines I-2 7.9 g (0.03
To a solution consisting of 1 mol), 5.5 g (0.031 mol) of N-bromosuccinimide was added over 5 minutes while stirring at room temperature. After reacting for 20 minutes, 70 ml of water was added to the reaction solution, followed by stirring for 5 minutes to separate the layers. After liquid separation, the chloroform layer was washed once with water. Chloroform was distilled off, and warm methanol was added to the residue.
70 ml was added and the mixture was stirred at room temperature for 1.5 hours. After filtering and washing with methanol, 7.7g (88% yield) mp 136-137 ℃
I got the object.

Comparative Example 4-1 Example 4 was repeated except that N-bromosuccinimide was replaced with equimolar iodine. Yield 49%, mp
134-136 ° C.

Even when 3 equivalents of VII-7 was used as iodine or the solvent was replaced with methanol, the yield was not significantly improved.

Comparative Example 4-2 Example 4 except that N-bromosuccinimide was replaced with equimolar ammonium persulfate, triethylamine was replaced with equimolar sodium carbonate, and chloroform 70 ml was replaced with chloroform 70 ml, isopropyl alcohol 30 ml and water 70 ml, respectively. The same was done. Yield 76%.

Example 5 200 ml of methylene chloride, active methine compound Va-1
5.0 g (0.015 mol) 8 and triethylamine 7.4 g (0.074 mol)
), 2.7 g (0.017 mol) of bromine was added to the solution consisting of 12.5 g (0.019 mol) of 2p-toluenesulfonate of p-phenylenediamines I-23 over 5 minutes while stirring under cooling with water. After reacting for 20 minutes, 200 ml of water was added to the reaction solution, and the mixture was stirred for 2 minutes and separated. The methylene chloride layer was washed twice with water, the solvent was evaporated, and the residue was recrystallized from a mixed solvent of ethyl acetate-methanol 2: 3. After filtration and washing with methanol, the yield was 4.9g (57% yield), mp175-176 ° C.
I got the object.

Comparative Example 5-1 The procedure of Example 5 was repeated, except that bromine was replaced with equimolar iodine.

In this case, clean crystals could not be obtained without purification by silica gel calm chromatography. Yield 25%, mp 176-177 ° C.

Examples 6 to 18 performed in the same manner as Example 1, Example 3 or Example 5 are shown below.

Example 19 Methylene chloride 39, active methylene compound Va-18
While stirring 1.75 kg and 2.44 kg of triethylamine at 15 ° C, 330 g of N-bromosuccinimide and p-
1.0 kg of phenylenediamines I-30 were added simultaneously over 10 minutes. After reacting for 5 minutes, 330 g of N-bromosuccinimide and p-phenylenediamines I-30 were further added.
1.0 kg of was added simultaneously over 10 minutes. After reacting for 5 minutes, 38 g of N-bromosuccinimide and p
-1.0 kg of phenylenediamines I-30 were added simultaneously over 10 minutes and reacted for 5 minutes.

After the reaction, water 15 was added to carry out liquid separation. The organic layer was washed twice with saturated brine 10 and the solvent was evaporated under reduced pressure. To the place where the distillation was completed, ethyl acetate 3.5 was added to dissolve the residue, and the temperature was raised to 55 ° C. Methanol 7.0 was added there, and it stood to cool and stir, and recrystallized.

After 6 hours, when the internal temperature is 20 ° C, filtration is performed to obtain crystals.
2.15 kg of azomethine compound a (yield 71.9%) was obtained.

Further, recrystallization was performed using hexane 2.0 and ethyl acetate 10 to obtain 2.02 kg of azomethine compound a. (Recrystallization yield 94.0%).

(Effect of the Invention) In the production method of the present invention, a solvent containing substantially no water is used, and hydrolysis of the quinonediimine and the produced dye by the hydroxide ion in the conventional production method does not occur, and the reaction is clean. It was Further, in the present invention, the amount of solvent is smaller than that in the conventional production method, and the productivity is improved.

Further, in the production method of the present invention, the organic oxidant or bromine is used as the oxidant, and the productivity is improved as compared with the conventional production method using iodine as the oxidant.

These improvements in productivity appeared as a remarkable effect that an azomethine or indoaniline dye, which is the object of the production method of the present invention, can be obtained in high yield.

Claims (4)

[Claims] 1. A compound having active methylene or active methine and p-phenylenediamines are oxidatively condensed with an organic oxidizing agent in the presence of a base in a solvent substantially free of water. A method for producing a characteristic azomethine or indoaniline dye. 2. The organic oxidant having a bond of a halogen atom and a nitrogen atom in the molecule, the first (1)
The manufacturing method according to the item. 3. The method according to claim 1, wherein the organic oxidizing agent is N-bromosuccinimide. 4. A compound having active methylene or active methine and p-phenylenediamines in the presence of bromine.
A method for producing an azomethine or indoaniline dye, which comprises oxidative condensation.