Pharmaceutics and therapeutics industries enforced chemists to seek/discover antibacterial novel heterocycles owing specific bioactivity and innate characteristics significance. This chapter summarized potent antibacterial profile of 5-oxo-imidazolines in the new millennium as an antibacterial against Gram-positive and Gram-negative bacteria viz. B. thuringiensis, S. aureus, E. coli, and E. aerogenes is presented in this chapter. 5-(H/Br benzofuran-2-yl)-1-phenyl 1H-pyrazole-3-carbohydrazides are condensed with 4-(arylidene)-2 phenyloxazol-5(4H)-one in acetic acid at elevated temperature to yield product 5-(H/Br benzofuran-2-yl)-N-(4-arylidene-5-oxo-2-phenyl-4,5-dihydroimidazol-1-yl)-1-phenyl-1H-pyrazole-3-carboxamides. Different substrates like 4-(arylidene)-2-phenyloxazol-5(4H)-one allowed to react with benzaldehyde hippuric acid to yield 5-oxo-imidazolines/5-oxo-4,5-dihydroimidazole. All synthesized 5-oxo-imidazolines were characterized via elemental analysis and FT-IR, 1H-NMR and mass spectra techniques. All 5-oxo-imidazolines assayed in vitro for inherent antimicrobial activity at different concentration against stated bacterial strains and compared with standard chloramphenicol. 5-Oxo-imidazolines (3a and 3c) with 125 μg/mL concentration showed excellent antibacterial profile against Gram-positive bacteria, B. thuringiensis, while other derivatives at different concentrations showed moderate antibacterial activity against Gram-positive bacteria, S. aureus and B. thuringiensis. Gram-negative bacteria like E. coli and E. aerogenes are tested at higher concentration (1000, 500, and 125 μg/mL) and found good-to-moderate antibacterial activity. Tested products found non-active against E. aerogenes for 125, 61, and 31 μg/mL concentration also inactive at conc. 31 μg/mL against E. coli.
Part of the book: Heterocycles