Synthesis of 3,4-dihydropyrimidin-2-ones (DHPMs) using mesoporous aluminosilicate (AlKIT-5) catalyst with cage type pore structure

Here we demonstrate on the synthesis of 3.4-dihydropyrimidin-2-ones (DHPMs) and their derivatives through a three-component condensation reactions of aldehyde, beta-ketoester and urea or thiourea using mesoporous aluminosilicate (AlKIT-5) nanocage as catalyst and acetonitrile as solvent under reflux conditions. The catalyst was found to be highly active and selective, affording a high yield of DHPMs. Compared to the classical Biginelli reaction conditions, this new approach consistently has the advantage of excellent yields (80-96%) and short reaction times, 3.0-4.0 h. The effect of the acidity and the concentration of the catalyst on the above process was investigated. We also demonstrate the synthesis of various multifunctional Biginelli compounds using the highly active AlKIT-5 catalysts. (C) 2009 Elsevier Ltd. All rights reserved.