In this study, a new, effective and environmentally benign procedure for the synthesis of dihydropyrimidinone and thione derivatives with various benzaldehydes, urea or thiourea, and ethyl acetoacetate in the presence of 1,4-diazabicyclo[2.2.2]octanium diacetate as a novel acidic ionic liquid, in high yield and short reaction time is reported. This method provides several advantages such as easy work-up, green, environmental friendliness and fast reaction condition along with high yields.
Keywords: Biginelli reaction, ethyl acetoacetate, ionic liquid, solvent free, thiourea, urea.