PEG-SO3H as catalyst for 3,4-dihydropyrimidones via Biginelli reaction under microwave and solvent-free conditions

An efficient and environmentally friendly process for the synthesis of 3,4-dihydropyrimidones via the Biginelli-type condensation reaction using poly(ethylene glycol)-bound sulfonic acid as catalyst irradiated by microwave has been developed. The functionalized poly(ethylene glycol) acted simultaneously as catalyst and as solvent in the condensation. The workup was easy, and the products were obtained in good to excellent yields and high purities.