Heterocyclic compounds. Part 6. Synthesis of 1,3,4-thiadiazolidines from the reactions of phenyl hydrazones with phenyl isothiocyanate and carbon disulphide

Abstract

The reactions of phenyl isothiocyanate with ketonephenylhydrazones in the presence of sodium hydride in dimethylformamide afforded 4-phenyl-5-phenylimino-1,3,4-thiadiazolidines (2a–e) in good yields. Aldehyde phenylhydrazones, however, gave the thiosemicarbazone (8). Reactions using carbon disulphide instead of isothiocyanates under similar conditions yielded 4-phenyl-1,3,4-thiadiazolidine-5-thiones (3a–e). The mechanisms of formation and 13C n.m.r. spectra of the products are also described.