DE1130815B - Process for the preparation of N-cyanoalkylcarboxamides - Google Patents

Description

Process for the preparation of N-cyanoalkylcarboxamides It is known to produce N N-bis-cyanoethyl-amides of carboxylic acids by the fact that Carboxamides in the presence of basic catalysts, e.g. B. potassium hydroxide Reacts at elevated temperature with acrylonitrile. This method has the disadvantage that the catalyst during the reaction by saponification of the carboxamide or of the nitrile is consumed very quickly. Hence, it is necessary to constantly add new amounts Give in to the catalyst. Another disadvantage is that through in the reaction mixture the just mentioned saponification the salt from the carboxylic acids and the relevant Cation is formed from the catalyst, which contaminates the end product. In the end it is a disadvantage of the process mentioned that the cyanoethylation of carboxamides takes place at a temperature which already favors the polymerization of the acrylonitrile.

It has been found that the same cyanoalkylcarboxamides can be obtained is of high purity when cyanoalkylamines with carboxylic acids escape with water condensed. One proceeds in such a way that one I equivalent of the amine in question mixed with about 1 equivalent of the carboxylic acid in question and with the usual, increased or reduced pressure between 50 to 300 ° C, preferably between 100 and 200 ° C, condensed and the water of reaction removed in a suitable manner. That new method avoids all the disadvantages of the initially described. Surprised and it was unexpected that during the condensation the saponification of the nitrile groups takes place to such an extent that the desired N-cyanoalkylcarboxamides are obtained are obtained in good purity.

Suitable carboxylic acids are, for. B. aliphatic mono- and dicarboxylic acids, aromatic, hydroaromatic and araliphatic carboxylic acids. Instead of the carboxylic acids the corresponding anhydrides can also be used.

As amines z. B. such primary and secondary amines in question, those involved in the reaction of ammonia or low molecular weight primary amines with acrylonitrile, Methacrylonitrile, crotonic acid nitrile and maleic acid dinitrile are formed. It can be continuous or batchwise, with or without a solvent.

The products obtained by the process described are without further cleaning z. B. used as an aid for textile printing.

The parts given in the examples are parts by weight.

Example 1 150 parts of bis-cyanoethyl-amine are combined with 65 parts of 900! Formic acid mixed and at ordinary pressure on the descending cooler at slow increasing temperature up to 130 "C condenses.

When the water of reaction no longer distills off, a weak one is passed through Nitrogen flows through the product and the temperature is maintained for an additional 2 hours 130 "C. If a sample of the product is boiled with xylene on the water separator no If more water separates, the reaction is over. Yield: 180 parts of N N-bis-cyanoethyl-formamide, that is 98.40 / 0 of theory based on the amine.

Example 2 150 parts of bis-cyanoethyl-amine are combined with 103 parts of 900% Adipic acid mixed and at ordinary pressure on the descending cooler at slow increasing temperature up to 140 "C condenses.

When the water of reaction no longer distills off, a weak one is passed through Nitrogen flows through the product and the temperature is maintained for an additional 3 hours 1400 C. If a sample of the product when boiling with xylene on the water separator no more water separates out, the reaction has ended. Yield: 215 parts of N N N ' N'-tetra-cyanoethyladipic acid diamide, that is 99% of theory. based on the amine used.

Example 3 150 parts of bis-cyanoethyl-amine are mixed with 64 parts of acetic anhydride mixed and as in example 1 implemented. Yield 191 parts of N N-bis-cyanäthylacetamid, that is 95010 of theory, based on the amine.

Claims (1)

PATENT CLAIM: Process for the production of N-cyanoalkylcarboxamides, the one or more nitrile groups bonded to the amide nitrogen atom via alkyl groups wear, characterized that one carboxylic acids or their anhydrides with such primary or secondary amines, which have at least one via an alkyl group to the Contain nitrogen atom bonded cyano group, in equivalent amounts between 50 to 3000 C, preferably between 100 and 200 ° C, at ordinary, elevated or under reduced pressure and the water of reaction removed in a suitable manner.