The New Antibacterial Agents Based on the Fused Aromatic Heterocyclic Compounds: Design, Synthesis, and Antibacterial Activity

In this study, the reaction of 1-alkyl-5-nitro-1H-benzoimidazoles and 1-alkyl-5-nitro-1H-indazoles with benzofuran and benzothiophen derivatives has led to formation of some new 3H-benzobenzofuro[2,3-b]imidazo[4,5-f]quinolines, 3H-benzo[4,5]thieno[2,3-b]imidazo[4,5-f]quinolines, 3H-benzofuro[2,3-b]pyrazolo[4,3-f]quinolones, and 3H-benzo[4,5]thieno[2,3-b]pyrazolo[4,3-f]quinolines in good yields. Structures of the new compounds have been confirmed by spectral and analytical data. Antibacterial activity of the new compounds has been tested against a panel of strains of gram negative and gram positive bacteria species. According to antimicrobial tests most of the title compounds are highly efficient against gram positive and gram negative bacteria and their MIC values are comparable with those of well known antibacterial agents ampicillin, penicillin G and sulfamethoxazole. Structure-activity relationship of the title compounds has been considered revealing imidazole core as a pharmacophore in antimicrobial tests.