Synthesis and antimicrobial activity of novel substituted 4-[3-(1H-benzimidazol-2-yl)-4-hydroxybenzyl]-2-(1H-benzimidazol-2-yl)phenol derivatives

A series of novel substituted bis-benzimidazole derivatives were synthesized by reaction of 5,5′-methylenebis(2-hydroxybenzaldehyde) with various substituted o-phenylenediamines in glacial acetic acid. The structure of the newly synthesized compounds was elucidated by 1H and 13C NMR, FT-IR, and MS spectra, and their antimicrobial activity against gram positive and gram negative bacteria and antifungal activity were evaluated. The thienyl-substituted derivative showed significant activity against Bacillus licheniformis. Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumonia (bacteria), and Fusarium solani (fungi). The activities of the fluoro-substituted substituted derivative against some bacterial strains and of the thienyl-substituted derivative against fungi were found to be similar to those of standard drugs.