Facile synthesis of dihydropyrimidinone derivatives via Biginelli reaction using Br?nsted acidic ionic liquid [H-NMP]+[CH3SO3]- as an efficient homogeneous catalyst

摘要

In this research, a green, operationally simple, highly efficient and facile cascade Biginelli reaction using various aromatic aldehydes, ethyl acetoacetate, and urea/thiourea has been developed. First, the ionic liquid was prepared from the reaction of 1-methyl-2-pyrolidone with methane sulfonic acid. Then, this ionic liquid was applied as an acidic catalyst in the synthesis of dihydropyrimidinones as a target product under mild conditions. The ionic liquid and resulting products were characterized by physical and spectral data such as melting point, IR, sup1/supHNMR and sup13/supCNMR. The significant advantages of this protocol are short reaction time, excellent yields and easily available starting materials.