Synthesis and Antimicrobial Evaluation of Novel Carbazole Based β-diketones and its Pyrazole Derivatives

Novel 9-ethyl-9H-carbazole-3-carboxylic acid derivatives including ester, β-diketone and pyrazole were prepared and characterized by FT-IR, 1H NMR, 13C NMR and mass spectroscopic techniques. All synthesized compounds evaluated for their in vitro antimicrobial activities against four bacteria (Escherichia coli, Pseudomonas putide, Bacillus subtilis, and Streptococcus lactis) and three fungi (Aspergillus niger, Penicillium sp and Candida albicans). Among the compounds tested, 3a, 3b, 3c, 4a, 4b, 4c, 5a and 5b exhibited pronounced antibacterial activity as compared with standard drug ampicillin. Notably, carbazole based pyrazole derivatives 5a and 5b showed potent antifungal activity against C. albicans comparable to reference drug greseofulvin. This work is licensed under a Creative Commons Attribution 4.0 International License