An efficient one-pot multicomponent synthesis of 3,4-dihydropyrimidine-2-(1H)-ones/thiones/imines via a Lewis base catalyzed Biginelli-type reaction under solvent-free conditions

3,4-Dihydropyrimidin-2(1H)-one, 3,4-dihydropyrimidin-2(1H)-thione, and 3,4-dihydropyrimidin-2(1H)-imine derivatives were synthesized by modified Biginelli cyclocondensation reaction catalyzed by triphenylphosphine as Lewis base. The structures of the synthesized compounds have been elucidated by IR, 1H NMR and elemental analysis.