“…Thiadiazoles and their derivatives exhibit wide range of pharmacological activities such as antimicrobial activity (3) , antidepressant, cardiotonic (4) , antibacterial activity against Klebsiella pneumonia (5) , antitubercular (6,7) ,anticonvulsant (8) , antileshmanial , analgesic (9) ,antiinflammtory (10) , anticancer (11) , phosphodiesterase inhibitors (12) and effect on Tyrosinase enzyme (13) .This diversity of biological activity may be due to the presence of -N=C-S moity (14,15) . There are four isomers of thiadiazole , among these four isomers 1,3,4-thiadiazole is the most thermally stable; which is only isomer doesn´t contain any sulphur-nitrogen bond (16) . 1,3,4-thiadiazole relatively stable in aqueous acid solutions but the nucleus can undergo ring cleavage by aqueous base solutions (17) .…”