Synthesis, Characterization, and Biological Evaluation of Some Tri-Substituted Imidazole/thiazole Derivatives

A novel compound series of tri-substituted imidazole/thiazole derivatives (3a-i) were prepared by Radziszewski reaction. Benzil (1), ammonium acetate or ammonium thiocynate, and 1-phenyl-3-(p-substituted phenyl)-1H-pyrazole-4-carbaldehyde (2a-g) were reacted to give the desired product. Synthesized compounds were characterized by elemental analysis (CHNS) and spectral analysis (FTIR, H-1 and C-13 FT NMR, and LC-MS). All the compounds were screened for their antibacterial, antifungal, and antimycobacterial activities. Antimicrobial activity was evaluated against some bacterial strains such as Escherichia coli (MTCC 443), Pseudomonas aeruginosa (MTCC 1688), Staphylococcus aureus (MTCC 96), Streptococcus pyogenes (MTCC 442), and the H(37)Rv strain of Mycobacterium tuberculosis, and the fungal activity was observed against strains, for example, Candida albicans (MTCC 227), Aspergillus niger (MTCC 282), and Aspergillus clavatus (MTCC 1323). All the synthesized compounds were found to possess moderate to excellent activity against the above selected strains.