JPS61106554A - Method for producing N-arylimide - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the invention, industrial field of application] The present invention relates to a method for efficiently producing N-arylimide with high purity and high yield. N-arylimides are useful as modifiers for dyes, medicines, agricultural chemicals, and polymer compounds.

[Conventional technology]

Conventionally, methods for producing N-arylimides have been described, for example, in Japanese Patent Publication No. 47-24024, i'
c゛=“″″′″′″u-toms″′″raa,
It is known that a dehydration ring-closing reaction is carried out in the presence of a trace amount of a basic catalyst by mixing amines and an organic solvent such as xylene.

However, as a result of repeating the above method, the N-arylimide obtained was markedly colored, and the yield (hereinafter simply referred to as yield) based on the aromatic amine as a raw material was as low as 70 to 80%, making it unsuitable for industrial use. As a manufacturing method, it is not practical.

According to the method described in Japanese Patent Publication No. 55-46394, dicarboxylic acid monoamide is obtained by reacting acid anhydride 51 with amines in a nonpolar solvent such as toluene, and then this monoamide is A method has been proposed in which an aprotic polar solvent and an acid catalyst are added to carry out the dehydration ring closure reaction without separation.

However, although the above method has a relatively high yield of about 90%, when performing the addition reaction between acid anhydride and aromatic amine, the aromatic amine is dissolved in the nonpolar solvent, so the temperature of 40 to 80 °C is required. Let the reaction ζ occur. For this reason, by-products are unlikely to be generated. In addition, during the dehydration ring closure reaction, the residual aromatic amine generated N-
However, it reacts with limide to produce a high molecular weight product, making it impossible to obtain highly pure N-arylimide.

[Problem that the invention seeks to solve]

The invention provides a method for producing highly pure N-arylimide.

[Means for solving problems]

In order to obtain highly pure N-arylimide, the formation of an unsaturated dicarboxylic anhydride and an aromatic monoamine is performed in a mixed solvent of an aromatic hydrocarbon solvent and an aprotic polar solvent to obtain N-arylamide. The N-arylamic acid is dehydrated and ring-closed in the above mixed solvent in the presence of an acid catalyst without isolating the N-arylamic acid.
-Obtaining an arylimide [Structure of the Invention] The present invention is based on the general formula (+) [wherein represents a divalent organic group containing a carbon-carbon double bond]. ] An unsaturated dicarboxylic acid anhydride represented by the general formula (n) [in the formula, x1 is a hydrogen atom, a halogen atom, an alkyl group,
Indicates an alkoxy group, nitro group, hydroxyl group, carboxyl group, phenyl group, alkenyl group, or sulfone group. Xt
i-1 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a nitro group, or a hydroxyl group. ) with the aromatic monoamines shown in the aromatic hydrocarbon solvent 50 to 98
After reaction in a mixed solvent of 50 to 2 gk% by weight of an aprotic and other polar solvent to obtain an N-arylamic acid, the acid catalyst was added without isolating this N-arylamic acid. A dehydration ring-closing reaction is carried out in the presence of the general formula (m) [wherein D, Xi and X2 have the same meanings as above. ] The present invention provides a method for producing an N-arylimide represented by the following.

(Unsaturated dicarboxylic anhydride) As the unsaturated dicarboxylic anhydride represented by the general formula (1), in the formula (1), D is the following group having 2 to 30 carbon atoms [in the formula, R1-R111 is a hydrogen atom, a Cl-C11 alkyl group, a haloalkyl group, or a halogen atom, and may be the same or different.

Specific compound names include maleic anhydride, itaconic anhydride, pyrosiconic anhydride, citraconic anhydride, dichloromaleic anhydride, and Diels-Alder reaction products of these unsaturated carboxylic anhydrides and dienes.
Examples include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, maleated allocimene, maleated myrcene, and the like.

(Aromatic monoamine) Aromatic monoamines represented by the general formula ([l) and 1-7 include aniline, toluidine, ethylaniline, xylidine, 2-methyl-6ethylaniline, anisidine, phenetidine, chloraniline, bromo Examples include aniline, iothiniline, dichloroaniline, dibromoaniline, short aniline, nitroaniline, aminophenol, and aminebenzoic acid.

(Mixed Solvent) Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, ethylbenzene, diethylbenzene, butylbenzene, cumene, mesitylene, and the like.

In addition, examples of the aprotic polar solvent include N,
Those that are liquid at room temperature, such as N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, and hexamethylphosphoramide, can be used. This aprotic solvent improves the solubility of acid anhydrides such as maleic anhydride.

The ratio of the aromatic hydrocarbon solvent and the aprotic polar solvent used is 2 to 50% of the aprotic polar solvent in the mixed solvent.
The aromatic hydrocarbon solvent is used in an amount of 98 to 50 times, preferably 2 to 30 times.

(Acid Catalyst) In the present invention, the acid catalysts used include sulfuric acid, sulfuric anhydride, para-toluenesulfonic acid phosphoric acid, polyphosphoric acid, metaphosphoric acid, condensed phosphoric acid, trichloro/I'acetic acid,
Examples include lifluoroacetic acid, trifluoromethanesulfonic acid, and benzenesulfonic acid.

Use of these acid catalysts (t is preferably o, o o 1 to 1 mol per 1 mol of aromatic monoamine; 0°01 to 0
．． It is used in a range of 5 mol.

The N-arylimide is produced by using an unsaturated dicarboxylic anhydride at a ratio of 1.0 to 1.6 mol, preferably 1.0 to 1.3 mol, per 1 mol of aromatic monoamine. The addition reaction is carried out in the mixed solvent for 0.5 to 5 hours at a temperature range of 80°C, preferably 10 to 40°C to generate N-arylamic acid, and then the amide moromi is isolated. 60-170 without adding acid catalyst.
After carrying out a dehydration ring-closing reaction in a temperature range of 0.5 to 10 hours, the product is neutralized with an alkali such as sodium carbonate, potassium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, etc., and further washed with water. Next, the reaction solution is added to a poor solvent to precipitate crystals of N-7 lylimide, or the organic solvent is removed under reduced pressure and the crystals are isolated to obtain high-purity N-
Arylimides can be produced.

EXAMPLES The present invention will be explained in more detail with reference to Examples.

[Example-1] Maleic anhydride 21.65' (0,
22 mol) and toluene 151.2? ,N,
21.61 g of N-dimethylformamide was added and dissolved with stirring. Then p-aminephenol 21.8 y (0
, 2 mol) was slowly added into the four-day flask maintained at 20 to 30°C, and stirring was continued for an additional 30 minutes after completion.

Then p-)luenesulfonic acid 1.9 y (o, o
t) mol) was added into the flask under stirring for 4 days, and after that, the mixture was
The temperature was raised to 4° C., and stirring was continued at the same temperature for 2.5 hours while removing water azeotropically produced under solvent reflux.

After the reaction was completed, toluene was removed under normal pressure, and the concentrated solution was added dropwise to 800 m/ml of a 0.1% aqueous sodium carbonate solution. Precipitation (Also, the precipitate was separated, thoroughly washed with pure water, and dried. Melting point: 180-182°C (capillary method), purity: 98
% of orange N-(4-hydroxy)phenylmaleimide powder (yield: 91%) was obtained.

[Comparative Example-1] Maleic anhydride (21.6 f (0,22
mol) and toluene (151.2 F), and 21.8 F of p-amine phenol (21.8 F) was added under stirring at 60°C.
The reaction was carried out for 1 hour. Then, N, N was added to the obtained reaction solution.
-21.6 t of dimethylformamide and 1.9 t of p-)luenesulfonic acid were added to the reflux temperature of toluene (11 t).
The reaction was continued for 2.5 hours without azeotropic removal of water.

After the reaction is completed, post-treatment is carried out in the same manner as in Example-1.
33.6 y (yield: 89 y) of reddish brown N-(4-hydroxyphenyl)maleimide powder with a melting point of 178 to 182° C. and a purity of 90 y was obtained.

[Comparative Example-2] Maleic anhydride 21.0% was placed in a 300 m/4-day flask equipped with a water separator, thermometer, and stirrer. ey (0.22 mol), p-aminophenol 21.8 F (0.2 mol) and xylene 120 m/ml were charged and reacted at 80°C for 1 hour. Next, 0.6 v (o, o O 6 mol) of triethylamine was added to the obtained reaction solution, and the reaction was continued for 4 hours while water was azeotropically removed at the reflux temperature of xylene (145° C.).

After the reaction was completed, post-treatment was carried out in the same manner as in Example-1.
A blackish brown N-(4
-Hydroxyphenyl)maleimide powder 27.2 y
(yield: 72 cm).

[Examples 2 to 10] The table shows the contents of 0.22 mol of unsaturated dicarboxylic anhydride, 0.2 mol of aromatic monoamine, mixed solvent and acid catalyst.
1 and perform the same operation as in Example-1 to obtain N
-Complete- Obtained limide. The results are shown in Table-1.

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, D represents a divalent organic group containing a carbon-carbon double bond. ] Unsaturated dicarboxylic acid anhydride and the general formula ▲ formula,
Chemical formulas, tables, etc. are available▼ [In the formula, X_1 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a nitro hydroxyl group, a carboxyl group, a phenyl group, an alkenyl group, or a sulfone group. X_2 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a nitro group, or a hydroxyl group. ] After reacting the aromatic monoamines represented by in a mixed solvent of 50 to 98% by weight of an aromatic hydrocarbon solvent and 50 to 2% by weight of an aprotic polar solvent to obtain an N-arylamic acid, There are general formulas ▲ mathematical formulas, chemical formulas, tables, etc. ▼ that are characterized in that the N-arylamic acid is subjected to a dehydration ring-closing reaction in the presence of an acid catalyst to obtain an N-arylimide without isolating the N-arylamic acid. In the formula, D, X_1 and X_2 have the same meanings as above. ] A manufacturing method of N-arylimide shown by these. 2) The method according to claim 1, wherein the aromatic hydrocarbon solvent is a solvent selected from benzene, toluene, and xylene. 3) The method according to claim 1, wherein the aprotic polar solvent is N,N-dimethylformamide, N,N-dimethylacetamide or N-methyl-2-pyrrolidone. 4. The mixed solvent contains 2 parts by weight of aromatic monoamine.
2. A method according to claim 1, characterized in that it is used in a proportion of ~40 parts by weight.