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

Abstract

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, 1H NMR, 13C 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).

Keywords

• Coumarin
• Chalcones
• Antibacterial activity
• Antifungal activity
• Antimycobacterial activity