Process for the preparation of N-vinyl-N-alkyl-carboxylic acid amides

摘要

N-Vinyl-N-alkyl-carboxylic acid amides are prepared, starting from N-ethyl-carboxylic acid amides, in a 3-stage process consisting of the following stages: (a) anodic alkoxylation of the N-ethyl-carboxylic acid amides to give N- alpha -alkoxyethyl-carboxylic acid amides; (b) alkylation of these N- alpha -alkoxyethyl-carboxylic acid amides with an alkyl halide or dialkyl sulfate in an alkaline medium to give N- alpha -alkoxyethyl-N-alkyl-carboxylic acid amides; and (c) splitting off of alcohol from the products of stage (b) by heating to temperatures between about 60 DEG and about 350 DEG C. Instead of stages (b) and (c), it is also possible to carry out the following stages after stage (a): (b1) splitting off of alcohol from the N- alpha -alkoxyethylcarboxylic acid amides obtained in stage (a) by heating to temperatures of about 60 DEG to about 600 DEG C., to give N-vinyl-carboxylic acid amides; and (c1) alkylation of these N-vinyl-carboxylic acid amides by reaction with an alkylating agent of the same type as in stage (b) in an alkaline medium. The N-vinyl-N-alkyl-carboxylic acid amides obtained by the process are valuable intermediate products, in particular for the manufacture of homopolymers and copolymers with interesting properties.