Synthesis of Schiff’s Bases of Dihydropyrimidones by Organic Red Clay as a Mild Catalyst Under Microwave Irradiation

In the present study, we have developed Schiff' bases of dihydropyrimidones (DHPMs) with aniline by using organic red clay as mild catalyst under solvent-free condition. Compounds S1a-S1f obtained in almost good yield. A simple multicomponent one pot method was developed for synthesis of DHPMs by combining substituted aromatic aldehydes, ethyl acetoacetate/ acetyl acetone with urea/thiourea in the presence of red clay as a catalyst by microwave irradiation technique under solvent-free condition. The compounds were obtained in good yield. Then these were combined with aniline to form their Schiff's bases.