DE2455212C2 - Process for the monoacylation of an aromatic diamine - Google Patents

Description

The invention relates to a process for the monoacylation of an aromatic primary meta- or para-diamine which does not contain sulfonic acid groups.

It is known that monoacylated derivatives of aromatic primary diamines can be obtained by direct acylation only obtained when the presence of sulfonic acid groups in the aromatic diamine has certain steric properties Effects are given. If such sulfonic acid groups are not present, the corresponding ones are prepared Monoacyl derivatives in another way. Thus, m-aminoacetanilide is made by acetylation of m-nitroaniline and subsequent reduction produced while the production of p-aminoacetaniline by nitration of acetanilide and subsequent reduction takes place.

It has now been found that the monoacylation can also take place without the presence of sulfonic acid groups is possible if the process conditions specified in the preceding claim 1 are met will.

Diamines which can be acylated by the process according to the invention do not contain any Sulphonic acid groups, but they can have other substituents on the aromatic nucleus, such as. B. lower alkyl and lower alkoxy groups and halogen atoms. The method according to the invention is suitable especially for the acylation of m-phenylenediamine and p-phenylenediamine.

In the process according to the invention, the reaction temperature ^{is preferably kept below 20 ° C.}

The monoacylation occurs particularly smoothly when the reaction is carried out in the presence of 0.5 to 10% by weight of one surfactant based on the weight of the diamine. The surface-active Agent can be anionic, cationic or nonionic in nature. Examples of useful surface-active agents Means are alkyl sulfates and sulfonates, alkyl aryl sulfonates, Polyethoxy compounds, polyglyceryl esters of fatty acids and long chain quaternaries Links.

The reaction product can be isolated in a customary manner, for example by salting out the monoacylated Diamine hydrochloride.

The invention is described in more detail in the following examples. The parts and percentages relate focus on the weight.

example 1
108 parts of 1,3-phenylenediamine (1 mol) are added to a mixture of 203 parts of 36% strength hydrochloric acid (2 mol) and 800 parts of water, and the liquid is cooled to below 15 ° C. 204 parts of acetic anhydride (2 mol) are added in Added over a period of 4 to 6 hours, the temperature being kept below 15 ° C. by cooling. The mixture is then stirred for 1 hour after which time common salt is added to precipitate the hydrochloride, which is filtered off.

The yield is 92% of theory for the monoacylated diamine, which is less than 2% of the diacylated Compound and 0.5% unconverted dianene

A similar result is obtained when the m-phenylenediamine is replaced by p-phenylenediamine.

Example 2

108 parts of 1,4-phenylenediamine (1 mol) are added to a stirred mixture of 205 parts of 36% strength hydrochloric acid (2 mol) and 800 parts of water, and the liquid is cooled ^{to below 10 ° C.} 127.5 parts of acetic anhydride (1.25 mol) are added in the course of 4 to 6 hours, the temperature being kept at 5 to 10 ^° C. by cooling. The mixture is then stirred for 1 hour after which time common salt is added to precipitate the hydrochloride, which is filtered off.

The yield is 92% of theory for the monoacylated diamine which contains less than 1% of the diacylated compound and 0.5% of unconverted diamine .

Example 3

108 parts of 1,2-phenylenediamine (1 mole) become one stirred mixture of 205 parts of 36% hydrochloric acid (2 mol) and 800 parts of water added, and the liquid is cooled to below 15 ° C. 150 parts of acetic anhydride (1.47 moles) are added over the course of 4 to Added for 6 hours, the temperature being maintained at 5-15 ° C by cooling. The mixture is then 1 h stirred for a long time, after which common salt is added to precipitate the hydrochloride, which is filtered off.

The yield is 39.5% of theory for the monoacylated diamine.

Example 4

122 parts of 2,4-tolylenediamine (1 mol) are stirred Mixture of 205 parts of 36% hydrochloric acid

so (2 mol) and 800 parts of water are added, and the liquid is cooled to below 15 ° C. 204 parts of acetic anhydride (2MoI) become in the course of 4–6 h added, keeping the temperature at 5-15 ° C by cooling. The mixture is stirred for 1 hour, whereupon common salt is added to precipitate the hydrochloride, which is filtered off.

The yield is 75% of theory for the monoacylated diamine, which is a mixture of the 2-amino and of 4-amino compounds, with the 2-amino compound predominating.

Example 5

108 parts of 1,3-phenylenediamine (1 mol) are added to a stirred mixture of 250 parts of 36% hydrochloric acid (2.5 moles) and 800 parts of water are added and the liquid is cooled to below 5 ° C. 252 parts of propionic anhydride (1.94 moles) become in the course of 4

h added to S, wherein the temperature is maintained by cooling between -5 and +5 ^0C. The mixture is then stirred for 1 hour after which time common salt is added to precipitate the hydrochloride, which is filtered off.

The yield is 82% of theory for the monoacylated diamine.

Example 6

138 parts of 2,4-diaminoanisole (1 mole) to a stirred mixture of 205 parts of 36 ° / cent hydrochloric acid (2 mol) and 800 parts of water was added and the liquid is cooled to below 10 ⁰ C. 250 parts of acetic anhydride (2.45 mol) are added to h in the course of 4 to 6, wherein the temperature is maintained by cooling at 0-10 ⁰ C. The mixture is then stirred for 1 hour after which time common salt is added to precipitate the hydrochloride, which is filtered off.

The yield is 80% of theory for the monoacylated Diamine, which is a mixture of the two possible isomers.

Example 7

142.5 parts of 1-chloro-2,4-diaminobenzene (1 mol) are added to a stirred mixture of 205 parts of 36% strength Hydrochloric acid (2 mol) and 800 parts of water are added and the liquid is cooled to below 15 ° C. 200 parts Acetic anhydride (1.96 moles) is added over 4 to 6 hours, the temperature being reduced by cooling is set to 5 to 15 ° C. The mixture is then stirred for 1 hour, after which table salt is added to precipitate the hydrochloride, which is then filtered off.

The yield is 69% of theory for the monoacylated diamine, which is a mixture of the two isomers represents.

Example 8

108 parts of 1,4-phenylenediamine (1 mol) are added to a stirred mixture of 255 parts of 36% strength hydrochloric acid (2.5 mol) and 800 parts of water, and the liquid is cooled ^{to below 10 ° C.} 220 parts of propionic anhydride (1.69 mol) are added to this mixture in the course of 4 to 6 hours, the temperature being kept within the range from 0 to 10 ^° C. by cooling.

The reaction mass is stirred for 1 hour at a temperature below 10 ° C, whereupon common salt up to one Concentration of 20% is added to precipitate the hydrochloride, which is filtered off.

Example 9

108 parts of 1,3-phenylenediamine (1 mol) are added to a stirred mixture of 205 parts of 36% strength hydrochloric acid (2 mol), 800 parts of water and 1.0 part of cetyltrimethylammonium bromide, and the liquid is cooled ^{to below 15 ° C.} 153 parts of acetic anhydride (1.5 mol) are added to this mixture in the course of 4 to 6 hours, the temperature being kept ^{below 15 ° C. by cooling.} The reaction mass is stirred for 1 hour at 10 to 15 ° C., common salt is added to a salt concentration of 20% and stirring is continued overnight. The 3-aminoacetanilide is isolated by filtration with a 90% yield.

Example 10

108 parts of 13-phenylenediamine (1 mol) are added to a vaunted mixture of 250 parts of 36% strength hydrochloric acid (2.5 mol), 800 parts of water and 2.0 parts of cetyltrimethylammonium bromide, and the liquid is ^{cooled to below 0 °} C. and 595 parts Propionic anhydride (1.5 moles) is added to the mixture over 4 to 6 hours, the temperature being reduced by cooling

ίο is kept at -5 to +5 ⁰ C. '

The reaction mass is stirred for 1 h at 0 ^° C. and sodium chloride is added to a salt concentration of "20%, in order to precipitate the hydrochloride, which is then filtered off. The yield is 81% of theory for the monoacylated diamine.

Example 11

108 parts of 1,3-phenylenediamine (1 mol) are added to a stirred mixture of 205 parts of 36% strength hydrochloric acid (2 moles), 800 parts of water and 2.0 parts of cetylpyridinium bromide; ugesetzt, and the liquid is under Cooled 15 ° C. 153 parts of acetic anhydride (1.5 moles) are added to the mixture over 4-6 hours, keeping the temperature below 15 ° C by cooling will.

The reaction mass is stirred for 1 hour at 10-15 ° C

and mixed with common salt up to a salt concentration of 20% in order to precipitate the hydrochloride, ds is then filtered off. The yield is 92% of theory for the monoacylated diamine.

Example 12

108 parts of 1,3-phenylenediamine (1 mol) are added to a stirred mixture of 205 parts of 36% strength hydrochloric acid (2 moles), 800 parts of water and 2.0 parts of sulfated methyl oleate are added and the liquid is added to under Cooled 15 ° C. 153 parts of acetic anhydride (1.5 moles) are added to the above mixture over the course of 4-6 hours, the temperature being reduced by cooling is kept below 15 ° C.

The reaction mixture is stirred for 1 h at 10-15 ° C, and mixed with common salt up to a salt concentration of 20% in order to precipitate the hydrochloride, the is then filtered off. The yield is 91.0% of theory for the monoacylated diamine.

Example 13

108 parts of 1,3-phenylenediamine (1 mol) are added to a stirred mixture of 205 parts of 36% hydrochloric acid (2 moles), 800 parts of water and 4.0 parts of polyglyceryl ricinoleate are added and the liquid is added to under Cooled 10 ° C. 153 parts of acetic anhydride (1.5 moles) the above mixture in the course of 4-6 hours added, the temperature being kept below 10 ° C by cooling.

The reaction mass is stirred for 1 h at 5-10 ^° C. and sodium chloride is added to a salt concentration of 20% in order to precipitate the hydrochloride, which is then filtered off. The yield is 91.0% of theory for the monoacylated diamine.

Claims (2)

Patent claims: 1. Process for the monoacylation of a no sulfonic acid group containing aromatic primary meta- or para-diamines, characterized in that that the diamine in the presence of water and 2 to 2.5 equivalents of hydrochloric acid reacts each Moi diamine with acetic anhydride or propionic anhydride 2. The method according to claim 1, characterized in that the reaction is carried out in the presence of 0.5 to 10% by weight of a surfactant based on the weight of the diamine