Synthesis and characterization of novel series of the imidazoles under solvent free conditions by using sodium dihydrogen phosphate.

2,4,5-triphenylimidazoles/1-(2-Methyl)-3-(2-hydroxyphenyl)imidazo[1,5- a]pyridine could be obtained in excellent yields by the one-pot three-component condensation of benzil/2-acetyl pyridine, aldehyde and ammonium acetate in the presence of catalytic amount of the inexpensive, readily available NaH2PO4 under solvent-free condition. The mixture was ground together in a mortar with a pestle at room temperature for short reaction time and easy operation under solvent free condition.

A novel method for the synthesis of meso substituted dipyyromethanes.

Meso-substituted dipyrromethanes have been synthesized in the presence of SnCl2.2H2O as a catalyst. The reaction is carried out in water, a very green solvent, under stirring at room temperature. The reaction work-up is simple and the catalyst is easily separated from the products by filtration.