One-pot synthesis of tri- and tetra-substituted imidazoles using sodium dihydrogen phosphate under solvent-free conditions

Sodium dihydrogen phosphate（NaH;PO;） efficiently catalyzes the condensation reaction of benzil,aldehydes,amines and ammonium acetate in a four-component reaction under solvent-free conditions.The reaction proceeds rapidly and affords the corresponding tetra-substituted imidazoles in high yields.Also an efficient route was developed for the synthesis of tri-substituted imidazoles from condensation of benzil,aldehydes and ammonium acetate using NaH;PO;.