Fe3O4 Bonded Pyridinium-3-carboxylic acid-N-sulfonic Acid Chloride as an Efficient Catalyst for the Synthesis of 3,4-dihydropyrimidin-2(1H)-ones

Fe3O4bonded pyridinium-3-carboxylic acid-N-sulfonic acid chloride, as a magnetic and reusable catalyst, was reported for the one-pot multi-component synthesis of some 3,4-dihydropyrimidin-2(1H)-ones by the reaction of urea, ethyl acetoacetateand various aldehyde under solvent-free conditions. The products were identified by FT-IR, 1H NMR and 13C NMR spectra and the catalyst was reused successfully for three times.