Fe+3-montmorillonite K10: As an effective and reusable catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and –thiones
In this study, a novel, clean, convenient, appropriate and environmentally benign route to dihydropyrimidinone and thione derivatives has been developed using the reaction between various benzaldehydes, urea or thiourea, and ethyl acetoacetate in the presence of Fe+3-montmorillonite K10 under grind condition. The present methodology has several advantages such as simple work-up, solvent-free conditions, environmental friendliness and shorter reaction time along with high yields. Several aromatic aldehydes carrying either electron-releasing or electron-withdrawing substituents in the ortho and para positions were tested in this reaction. Another important feature of this procedure is the survival of a variety of functional groups under the reaction conditions. All of synthesized compounds were characterized by IR, 1HNMR, 13CNMR and elemental analyses.
KEY WORDS: Grinding, K10, Urea, Thiourea, Ethyl acetoacetate, Biginelli reaction
Bull. Chem. Soc. Ethiop. 2017, 31(2), 313-321.