Synthesis of some New Thiosemicarbazide and 1,3,4-Thiadiazole Heterocycles Bearing Benzo[b]Thiophene Nucleus as a Potent Antitubercular and Antimicrobial Agents.

Reaction of 2-hydrazinocarbonyl-3-chloro-5-phenoxy-benzo[b] thiophene with different substituted phenyl isothiocyanate gave n-substituted arylthiosemi-carbazide derivatives (1a-h). 1,3,4-thiadiazole derivatives (2a-h) were prepared by the cyclization of arylthiosemicarbazides (1a-h) with concentrated sulphuric acid. all the compounds were screened for their antitubercular activity against mycobacterium tuberculosis (h37rv) and antimicrobial activity against various microorganisms.