Synthesis of 3,4-dihydropyrimidin-2(1H)-one via one-pot Biginelli reaction under solvent-free conditions

Three novel heteropolyanion-based acidic ionic liquids, [TMAPS]H2PMo12O40, [TEAPS]H2PMo12O40, and [TBAPS]H2PMo12O40, were used as efficient catalysts for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives by modified Biginelli-type reaction in good yields and high purity. The products could simply be separated from the reaction/catalytic system, and the catalysts could be recovered and reused conveniently without noticeable influence on the catalytic results.