Synthesis and antibacterial activities of 1,3,4-thiadiazole, 1,3,4-oxadiazole and 1,2,4-triazole derivatives of 5-methylisoxazole

A series of 5-(5-methylisoxazol-3-yl)-1,3,4-thiadiazoies 3a-d, 1,2,4-triazo les 4, 5 and 1,3,4-oxodiazoles 7, 8, 9 have been synthesized from 5-methyli soxazol-3-acetic acid hydrazide 1 via N-4-aroyl-N-1-(5-methylisoxazol-3-for myl) thiosemicarbazides 2a-h and N-1-(5-methylisoxazol-3-carbonyl)-N-4-phen y semicarbazide 6. The thiosemicarbazides 2a-h and semicarbazide 6 have bee n readily obtained from 5-methylisoxazol-3-acetic acid hydrazide 1 in good yield. Structures of the compounds have been established on the basis of el emental analyses and spectral data. Some of them have been screened for ant ibacterial activities.