Oxalic acid - a new catalyst for the syntheses of dihydropyrimidinones in solvent-free condition

Department of Chemistry, University of Calcutta, Kolkata-700 09, India E-mail : akmitra@cucc.ernet.in; a_k_mitra@hotmail.com Fax: 91-33-23519755 Manuscript received 17 November 2003 High yielding and fast one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones from β-ketoesters, urea and various aldehydes using oxalic acid as a catalyst in solvent-free condition under microwave irradiation is reported