Environmentally benign approach to imidazole 2-thiones

1549-1553An ecofriendly synthesis of some novel 1,4,5-triarylimidazole-2-thiones/1,3,4,5-tetraarylimidazole-2-thiones is described. The reaction involves condensation of benzoin with various readily accessible N-substituted thioureas/N,N'-disubstituted thioureas under microwave over recyclable inorganic solid support. This methodology eliminates the usage of solvent and external catalyst in the reaction step and reduces the reaction time from hours to minutes along with remarkable yield enhancement. In addition versatility of various solid supports as catalyst is also studied