rate accelerations in trichloroisocyanuric acid and trichlorotriazine promoted synthesis of 3,4-dihydropyrimidinones/thiones under vilsmeier-haack and solvent free conditions

In the present study, we have accomplished n,n’-dimethyl formamide (dmf)/trichloroisocyanuric acid and dmf/trichlorotriazine as efficient catalysts for the synthesis of 3,4-dihydropyrimidinones/thiones from one-pot multi-component reaction of β-ketoester, aromatic aldehydes, and urea under reflux condition. the reaction operates also under solvent free microwave condition. the results obtained from this study were compared with those obtained from classical vilsmeier-haack adducts (dmf/pocl3 and dmf/socl2) as catalysts. reaction times and product yields observed in this study indicated shorter reaction times and better product yields with modified vh reagents (tcca/dmf and tcta/dmf) over classical vh reagents (pocl3/dmf and socl2/dmf). the catalytic activity of (tcta/dmf)>(tcca/dmf)>(pocl3/dmf>socl2/dmf).