Synthesis and biological evaluation of coumarin based isoxazoles, pyrimidinthiones and pyrimidin-2-ones

The titled compounds (6′a–k) , (7′a–k) and (8′a–k) were synthesized from chalcones (5a–k) having coumarin moiety. Cyclization of chalcones (5a–k) with hydroxyl amine hydrochloride, thiourea and urea resulted in corresponding isoxazoles (6′a–k) , pyrimidinthiones (7′a–k) and pyrimidin-2-ones (8′a–k) . Structures of newly synthesized compounds were established on the basis of their elemental analysis, IR, 1 H NMR, 13 C NMR, and mass spectral data. The synthesized analogs were evaluated for their antimycobacterial activity and antimicrobial activity against eight bacteria ( Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi, Proteus vulgaris, and Shigella flexneri ) and four fungi ( Aspergillus niger, Candida albicans, Aspergillus fumigatus, and Aspergillus clavatus ).