ZnO Nanocatalyst Mediated Convergent Synthesis of Highly Substituted Imidazole and Imidazole-derived Bi-heterocyclic Scaffolds as Potential Antibacterial Agents

A new series of novel highly substituted imidazole and imidazole bi-heterocycles have been synthesized via atom economic, one-pot condensation reaction using benzil, substituted benzaldehydes, various amine scaffolds, and ammonium acetate using ZnO nanoparticles as effective catalyst. Simple operation, cheap catalyst, good to excellent yield, etc, are some of the advantages of this protocol. The characterization of the synthesized imidazole analogues was performed by Fourier transform infrared, nuclear magnetic resonance (¹H and ¹³C), mass analysis, and elemental analysis. The structures were unequivocally confirmed by single-crystal X-ray diffraction analysis. Synthesized compounds were tested for antibacterial activities by resazurin reduction assay. All compounds tested showed significant activity against bacteria. Among the 24 compounds tested, compounds 1c, 1i, 2c, 2g, and 3a proved to be more active against the bacterial strain tested.