PYRIDINIUM-BASED BRONSTED ACIDIC IONIC LIQUID AS A HIGHLY EFFICIENT CATALYST FOR ONE-POT SYNTHESIS OF DIHYDROPYRIMIDINONES

In this work, the synthesis and characterization of 3-carboxypyridinium hydrogensulfate ([Hcpy]HSO4) as a new Bronsted acidic ionic liquid are reported. This reusable, inexpensive, and green catalyst was employed for one-pot condensation of 1,3-dicarbonyl compounds, aromatic aldehydes and urea or thiourea for the synthesis of the corresponding 3,4-Dihydropyrimidin-2(1H)-ones. The reactions were carried out under solvent-free and green conditions. The procedure gave the products in excellent yields within very short reaction times.