Synthesis and characterization of selected fused isoxazole and pyrazole derivatives and their antimicrobial activity

Abstract

New potent antibacterials, fused isoxazole and pyrazole derivatives, were synthesized using 5,5-dimethylcyclohexane-1,3-dione (1) and 3-[(4-chlorobenzylidene) amino]-2-thioxoimidazolidin-4-one (2) as synthons. Aromatic aldehydes on condensation with 1 and 2 gave 2-arylidene-5,5-dimethylcyclohexane- 1,3-dione (3) and 5-arylidene-3-[(4-chlorobenzylidene)amino]-2-thioxoimidazolidin-4-one (4), respectively. Compounds 3 and 4 were forced to undergo heterocyclization reaction with nucleophilic reagents to give the title compounds. The newly synthesized heterocyles (5-8) were characterized based on their chemical properties and spectroscopic data, and were found to inhibit Staphylococcus aureus and Corynebacterium diphtheriae.

Keywords

• isoxazole
• pyrazole
• thiohydantoin
• dimedone
• antibacterial activity