Microwave assisted, one-pot four component designing of 1-butyl-4,5-bis(4-chlorophenyl)-2-aryl-1H-imidazoles

A novel series of 1-butyl-4,5-bis(<i>p</i>-chlorophenyl)-2-phenyl-1H-imidazole derivatives <b>5–14</b> were prepared via one-pot cyclo-condensation of aryl aldehyde derivatives, butylamine, 1,2-bis(4-chlorophenyl)-1,2-ethanedione &amp; CH₃COONH₄, undergo microwave irradiation employing 4-methylbenzenesulfonic acid (PTSA) as acidic catalyst. Also, the same compounds 1,2,4,5-tetrasubstituted-1H-imidazole products <b>5–14</b> were designed under thermal reaction condition. By optimizing the two-reaction method, it was found that under conventional condition (reflux method), the identical products <b>5–14</b> were generated in good yields (68–87%) in about 10 h. While using the microwave irradiation is an effective and clean technique than the traditional thermal method and gives the same products with higher yields (71–89%) and purity in less time (7–9 min). Additionally, we find that the concentration of <i>p</i>-toluenesulfonic acid affects both the reaction time and the yield. The structures of the prepared components were approved via Infrared spectra, Nuclear Magnetic Resonance and elementals analysis.