A Facile Method for the Synthesis of Hydrazine-4-oxothiazolidine and Imino-5-oxothiadiazine Derivatives from 1,4-Disubstituted Thiosemicarbazides

摘要

1,4-Disubstituted thiosemicarbazides reacted with dimethyl acetylenedicarboxylate with formation of (2-hydrazono-4-oxothiazolidin-5-ylidene)acetates and, in one case, a (2-imino-1,3,4-thiadiazin-5-on-6- ylidene)acetate. Several mechanistic options involving nucleophilic interaction are presented. The structures of all newly synthesized compounds were identified by ~1H NMR, ~(13)C NMR, COSY, HMQC and HMBC spectral data.