Design and Optimization of Eco-Benign One-Pot Synthesis of 2,4,5-triaryl-1<i>H</i>-imidazoles by Three Component Condensation Using Response Surface Methodology

Phase-transfer catalyzed, highly versatile and high-yielding protocol for the synthesis of 2,4,5-triaryl-1H-imidazoles was developed through response surface methodology (RSM). The <b>effects</b> of different solvents, reaction path and phase-transfer catalysts (PTCs) in different concentration were envisioned. Three independent variables (catalyst, catalyst loading and solvent volume) identified by OFAT study were screened through full factorial design at two levels. The ANOVA results suggested the significance of catalyst PEG400 and solvent glacial acetic acid at 5 h reaction. <b>The optimum reaction conditions suggested by the RSM were the use of PEG400 (10.61 mol%) and glacial acetic acid (10.71 mL) for 5 h cycloocondensation.</b> The experimental yield of 4,5-diphenyl-2-nitrophenyl-1H-imidazole (97%) was in agreement with predicted yield (97.5%).