Bronsted acidic ionic liquid catalyzed an eco-friendly and efficient procedure for synthesis of 2,4,5-trisubstituted imidazole derivatives under ultrasound irradiation and optimal conditions

Abstract

2-[(1H-imidazol-3-ium-3-yl)methyl]-4-{bis[3-((1H-imidazol-3-ium-3-yl) methyl-(4-hydroxyphenyl]methylene}cyclohexa-2,5-dienone trihydrogen sulfate ([2-(imm)-4-{b(immh)m}c][HSO4]3), as the new Bronsted acidic ionic liquid, is effectively prepared and revealed by using FTIR, 1H NMR, SEM, EDS, XRD and mass data. Afterward, its catalytic activity was investigated for the synthesis of 2,4,5-trisubstituted imidazole derivatives via the simple reaction between different aldehydes, ammonium acetate and benzil/benzoin under ultrasound irradiation at ambient temperature and optimal conditions. The novel procedure has the advantages of high yields, easy handling, short reaction times, and being eco-friendly and economical. Moreover, the catalyst can be easily recovered for several times without any additional treatment.