A convenient and efficient synthesis of thiazolidin-4-ones via cyclization of substituted hydrazinecarbothioamides

Abstract

2-Substituted hydrazinecarbothioamides and N,2-disubstituted hydrazinecarbothioamides react in high yield with dimethyl acetylenedicarboxylate (DMAD) to give 4-oxo-Z-(thiazolidin-5-ylidene) acetate derivatives. Several mechanistic options involving interaction are presented. The structures of thiazolidin-4-ones have been unambiguously confirmed by single crystal X-ray crystallography. Keywords: Hydrazinecarbothioamides, Dimethyl acetylenedicarboxylate, Thiazolidin-4-ones, X-ray crystallography