Thiazolidine-4-carbonitriles substituted in the 2-position

摘要

Thiazolidine-4-carbonitriles substituted in the 2-position and their salts are prepared by reacting 3-thiazolines substituted in the 2-position by means of hydrogen cyanide and optionally forming the corresponding salt by addition of an acid. The thiazolidine- 4-carbonitriles substituted in the 2-position and, if appropriate, their salts are outstandingly suitable for the preparation of D,L-cysteine by reaction with a mineral acid in the presence of water. This makes possible the preparation of D,L-cysteine of outstanding purity in excellent yield on the industrial scale. D,L-cysteine prepared in this way can be employed directly for feed purposes.