DE850747C - Process for the production of lactams containing nitrile groups - Google Patents

Description

Process for the preparation of lactams containing nitrile groups It was found that nitrile groups can be obtained in a simple manner and with very good yields containing lactams is obtained if such aliphatic primary aminocarboxylic acids, which in themselves are capable of forming lactams, with a, ('-unsaturated nitriles heated to higher temperatures until lacta formation has ended.

Suitable starting materials are on the one hand z. B. y-aminobutyric acid, y- and 8-aminovaleric acid and 'y-, 8- or e-aminoca.pronic acid, on the other hand acrylic, methacrylic or crotonic acid nitrile.

The implementation of the aminocarboxylic acids with the unsaturated nitriles takes place at moderately elevated temperatures, e.g. B. at 8o to 15o °. You can also use The presence of solvents or diluents, such as water or alcohol, work.

The reaction products obtained are, if appropriate after distilling off of the diluent, heated to higher temperatures until the formation of the lactam ring is completed with elimination of water or alcohol, ammonia or amine. The cheapest Temperatures can easily be determined by preliminary experiments. In many cases it is enough that Easy to distill products at normal, reduced or increased pressure, to achieve the formation of the lactams. The nitrile groups containing Lactams are valuable intermediate products for the plastics industry.

The parts used in the following examples are parts by weight.

Example i 927 Teiley-Am.inobutters-acid are made with 477 parts acrylonitrile Heated to 100 ° in an autoclave for 12 hours. Then you distill the first with water and, after a slight intermediate run, at 12 to 14 mm pressure and i8o to 181 ' the a-pyrrolidomyl-N-ß'propionitril in an amount of 96o parts, accordingly a yield of 90% o of theory, passes over.

Example 2 185: f parts of a 500% aqueous solution of γ-aminobutyric acid are with 477 parts of acrylonitrile for 15 hours in a closed vessel at 100 ° heated. When the reaction mixture is distilled, goo parts of a-pyrrolidonyl-N-ß'-propionitrile are obtained, corresponding to a yield of 85% of theory.

Example 3 103 parts of γ-aminobutyric acid are heated to 100 ° in an autoclave with 67 parts of crotononitrile for 15 hours. During the distillation of the reaction mixture, the water formed passes over first and then, after an intermediate fraction in an amount of 51 parts, the desired α-pyrrolidonyl-N-y'-butyromitrile.

EXAMPLE 4 131 parts of e-aminocaproic acid @ i-earths with 60 parts of acrylonitrile and 20 parts of water were heated to 10 ° in an autoclave. The crude product, which is a homogeneous clear liquid, is subjected to distillation, first water and then under 2 mm pressure at 150 to 16o ° the e-caprolactam-N-β'-propionitrile in a yield of about 5o% Theory passes over as a colorless liquid.

Claims (1)

PATENT CLAIM: Process for the production of nitrile groups. hold Lactams, characterized in that such aliphatic primary aminocarboxylic acids, which are capable of lactam formation, with α, ß-unsaturated nitriles to higher Temperatures heated until lactam formation is over.