Kourosh Motevalli - Department of Applied Chemistry, Islamic Azad University, South Tehran Branch, Tehran, Iran,
Zahra Yaghoubi - Faculty of Industrial Engineering, Islamic Azad University, South Tehran Branch, Tehran, Iran

Lanthanum chloride was found to be an excellent catalyst for the synthesis of 2,4,5-trisubstituted imidazoles via microwave-promoted, one-pot reaction of an aldehyde, a 1,2-diketone and guanidine (or urea, thiourea) under solvent-free condition. This method elucidates guanidine, urea or thiourea as an environmentally benign source of ammonia for the synthesis of 2,4,5-trisubstituted imidazoles.

Imidazole; Aldehyde; 1,2-Diketone; Solvent-free conditions; Lanthanum chloride; Microwave-assisted