Ultrasound-mediated, uranyl nitrate hexahydrate-catalyzed synthesis of 1,4-dihydropyridines under mild conditions

Synthesis of 1,4-dihydropyridines by three-component condensation reaction of aldehyde, 1,3-dicarbonyl compounds, and ammonium acetate have been found to be efficiently catalyzed by uranyl nitrate hexahydrate [UO2(NO3)(2)center dot 6H(2)O] at room temperature under ultrasound irradiation. This novel synthetic method offers the advantages of high yields, short reaction times, simplicity, and easy workup compared to the conventional methods reported in the literature.