Br?nsted acidic ionic liquid-catalyzed one-pot synthesis of 3,4-dihydropyrimidin-2(1h)-ones and thiones under solvent-free conditions

摘要

An efficient and convenient procedure for the synthesis of 3,4-dihydropyrimidin- 2(1H)-ones and thiones by condensation of ethylacetoacetate, aldehydes, and urea or thiourea in the presence of methylimidazolium hydrogensulfate is described. Aromatic and aliphatic aldehydes reacted easily to afford the corresponding 3,4-dihydropyrimidin- 2(1H)-ones and thiones under solvent-free conditions. The use of nontoxic and inexpensive materials, straightforward and clean workup, short reaction times, and good yields are the advantages of this method.