An efficient and one-pot synthesis of 2,4,5-trisubstituted imidazole compounds catalyzed by copper nanoparticles

Abstract

Copper nanoparticles (Cu NPs) were found to be an extremely efficient and effective catalyst for synthesis of 2,4,5-trisubstituted imidazole via three-component reactions of benzil, aldehydes, and ammonium acetate at room temperature. The products obtained were followed by thin-layer chromatography. After completion of the reaction, the reaction mixture was diluted with water (20 mL). The solid imidazole product was washed with water and recrystallized from ethanol to remove nanocopper to afford the pure imidazole compounds. The method provides several advantages such as simple operation, short reaction time, clean reaction profile, lower catalyst loading and high yield. The used catalyst in the reaction could be recovered conveniently and reused for several times. The high yields of reactions are attributed to the effect of Cu NPs due to high surface-to-volume ratio. Due to simple workup procedures, very short times and excellent product yields make this method an interesting alternative to other methodologies.