The title compounds (7a-f), (8a-f) and (9a-f) have been prepared from chalcones (6a-f) having s-triazine nucleus. These chalcones on cyclisation with hydroxyl amine hydrochloride in the presence of alkali and malononitrile in the presence of ammonium acetate give isoxazoles (7a-f) and cyanopyridines (8a-f) respectively. Chalcones (6a-f) on condensation with thiourea in the presence of alkali give pyrimidinthiones (9a-f). Structures of newly synthesised compounds were established on the basis of their elemental analysis, IR and 1H NMR spectral data. Antibacterial activity (minimum inhibitory concentration MIC) against Gram-positive (S. aureus MTCC 96 and S. pyogeneus MTCC 442 ) and Gram-negative (P. aeruginosa MTCC 1688 and E. coli MTCC 443) bacteria, as well as antifungal acivity (MIC) against C. albicans MTCC 227, A. niger MTCC 282 and A. clavatus MTCC 1323 were determined by broth dilution method.
