Study of catalytic activity of ammonium dihydrogen orthophosphate in the synthesis of 3,4-dihydropyrimidin-2-(1<i style="">H</i>)-one

865-867Application of ammonium dihydrogen orthophosphate as a catalyst in the one pot synthesis of 5-ethoxycarbonyl-6-methyl-4-phenyl-3,4-dihydropyrimidin-2-(1H)-one by Biginelli condensation is reported. The effect of temperature and the presence of solvents such as ethanol, acetonitrile, toluene, chloroform, acetic acid, n-hexane, etc. on the activity of the catalyst are studied