0.52 g (0.013 mol) of sodium hydride was added to a solution of 4.00 g (0.0117 mol) of 2-formyl-4-(3,4-methylenedioxybenzyl)amino-6-chloroquinazoline in 250 ml of tetrahydrofuran. 2.8 ml (0.013 mol) of triethyl 2-phosphonopropionate was dropped into the mixture prepared above under stirring and cooling with ice. The mixture thus prepared was stirred under cooling with ice for a while, heated to room temperature and stirred for additional one hour, followed by the addition of 1.5 ml of 8M hydrochloric acid/ethanol. The obtained mixture was passed through a small amount of silica gel and distilled under a reduced pressure to remove the solvent. The residue was purified by silica gel column chromatography (ethyl acetate/n-hexane) and recrystallized from chloroform/n-hexane to give 2.00 g of the title compound.
