First application of hexaaquaaluminium(III) tetrafluoroborate as a mild, recyclable, non-hygroscopic acid catalyst in organic synthesis: a simple and efficient protocol for the multigram scale synthesis of 3,4-dihydropyrimidinones by Biginelli reaction
used as a mild acid catalyst in organic synthesis. A simple method of its preparation based on the reaction of aluminium triisopropoxide and tetrafluoroboric acid in isopropanol afforded catalyst of high purity and activity. The three-component Biginelli condensation of acetoacetate esters, urea and aldehydes catalyzed by 10 mol % of [Al(H2O)6](BF4)3 in refluxing acetonitrile afforded 3,4-dihydropyrimidonones
Vanadatesulfuric Acid: A Novel, Recyclable, and Heterogeneous Catalyst for the One-Pot Synthesis of Dihydropyrimidinones and Dihydropyrimidinthiones Under Solvent-Free Conditions
作者:Masoud Nasr-Esfahani、Tooba Abdizadeh
DOI:10.1080/10426507.2012.694001
日期:2013.5.1
Abstract Vanadatesulfuric acid (VSA), as a novel and heterogeneous catalyst, was used for an efficientsynthesis of 3,4-dihydropyrimidin-2(1H)-ones (thiones) using an aldehyde, urea, or thiourea and an acyclic β-dicarbonyl compound undersolvent-freeconditions. VSA is prepared via the reaction of sodium metavanadate and chlorosulfonic acid in high purity. The catalyst was characterized by FTIR, X-ray