Soluble polymer-supported synthesis of Biginelli compounds

An efficient and general liquid-phase synthesis of Biginelli compounds has been developed. Polyethylene glycol (PEG) bound acetoacetate reacted with urea and aldehydes under reflux or solvent-free microwave irradiation conditions to afford PEG-supported 3,4-dihydropyrimidin-2(1H)-ones. The desired 3,4-dihydropyrimidin-2(1H)-ones were cleaved from the polymer support under mild conditions in high yields and high purity.