Copper Nanoparticles on Charcoal (Cu/C) as a Heterogeneous Catalyst for the one-pot Synthesis of 2,4,5-Trisubstituted Imidazoles

Imidazoles have been identified as important biologically active compounds with antibacterial, anti-inflammatory, and antihypertensive properties [1]. Among these, 2,4,5-trisubstituted imidazoles are of great interest because of their chemical and biological activity, making them common structures in numerous synthetic compounds, for example fungicides , herbicides , plant-growth regulators , and therapeutic agents [2].There are several methods reported in the literature for the synthesis of 2,4,5-triaryl-1H-imidazoles from benzil/benzoin, aldehydes and ammonium acetate using different catalyst such as ZrCl₄, NiCl₂.6H₂O [3].Nevertheless, many of these approaches suffer from a long reaction time, low yield, acidic media, difficult work-up, expensive catalysts and excessive use of reagents and catalysts. Therefore, introducing a new green catalyst having good recyclability is of prime importance . An efficient and straight forward synthesis of 2,4,5-trisubstitutedimidazoles is achieved from benzil/benzoin, aldehydes and ammonium acetate, in optimized condition that catalyzed by a novel heterogeneous Cu/C catalyst .Interestingly, the Cu/C exhibited good catalytic activity for the 2,4,5-trisubstituted imidazoles. In this study we have reacted a range of aldehydes contain electron-donating and electron-withdrawing group to give desired products.