Synthesis and antimicrobial activity of new thiazole and thiadiazole derivatives via ethyl pyruvate

摘要

Reaction of ethyl 2-(2-((methylthio)carbonothioyl)hydrazono)propanoate (2) and ethyl 2-(2-carbamothioyl-hydrazono)propanoate (3) with hydrazonoyl halides 4a-e afforded the corresponding thiadiazoles 5a-e. Also, treatment of compound 2 with alpha-ketohydrazonoyl halides 12a-f in absolute ethanol and in the presence of triethylamine gave the corresponding thiadiazoles 13a-f; while reaction of ethyl 2-(2-carbamothioyl-hydrazono)propanoate (3) with alpha-ketohydrazonoyl halide 12 gave thiazole derivatives 15. Also, the reaction of compound 3 with hydrazonoyl chloride 12f afforded thiazolone derivative 18. Antimicrobial studies are performed using two-gram positive bacteria and two-gram negative bacteria. Data revealed that thiazole derivative 17a achieved the lowest MIC values (high efficient derivative) against the sensitive bacterial strain S. aureus with MIC value 160 mu g/ml.