Synthesis and antibacterial activity of a series of 2‐trifluoromethylbenzimidazole‐thiazolidinone derivatives

A series of 2‐phenyl‐3‐(2‐(trifluoromethyl)‐1H‐benzoimidazol‐6‐yl)thiazolidin‐4‐one derivatives were synthesized from p‐nitro‐o‐phenylenediamine in a three‐step reaction. Their structures were elucidated by NMR and mass spectral data. The synthesized compounds showed excellent antibacterial activity ranging from 3‐fold, to greater than 100‐fold higher than the standard antibiotics, ciprofloxacin and levofloxacin. Compounds 3d (2′‐Br), 3j (4′‐Br), and 3l (4′‐NO2) displayed a broad spectrum of activity against the strains tested (0.14–38.33 μM). The brominated derivatives 3d and 3j showed excellent activity against the Gram‐positive bacterial strains (MBC between 0.12 and 35.46 μM), while the nitro derivative 3l showed excellent activity against all four Gram‐negative strains tested (MBC between 0.15 and 9.58 μM).