Synthesis of Schiff bases of 2-amino-5-aryl-1,3,4-oxadiazoles and their evaluation for antimicrobial activities.

Twenty Schiff bases of 2-amino-5-aryl-1,3,4-oxadiazoles have been synthesized with different aromatic aldehydes. The structures of the compounds were confirmed by nitrogen analysis, IR and 13C-NMR spectral data. The antibacterial properties of the compounds were investigated against Proteus mirabilis (MTCC-425), Pseudomonas aeruginosa (MTCC-424), Bacillus subtilis (MTCC-619) and Staphylococcus aureus (MTCC-96) using the broth dilution method. The most active compounds were 4c (64 microg/ml), 4f (68 microg/ml), 4m (64 microg/ml) and 4q (62 microg/ml). The antifungal screening of the compounds were carried out using Aspergillus niger (MTCC-1344) and Candida albicans (MTCC-227) using the broth dilution method. Active compounds were 4g (52 microg/ml), 4h (56 microg/ml), 4l (60 microg/ml), 4m (58 microg/ml).