Tetrabromomethane (3.26 g, 9.82 mmol) was added to a solution of triphenylphosphine (2.58 g, 9.82 mmol) in anhydrous DMF (20 mL) at 0° C. A solution of 2-[4-(2-hydroxy-ethoxy)-3-methyl-phenyl]-5,7-dimethoxy-3H-quinazolin-4-one (1.75 g, 4.91 mmol) in DMF (7 mL) was then added dropwise and stirred the reaction mixture at room temperature for 16 hours. The solvent was removed under reduced pressure and the residue was diluted with water (50 mL) and extracted with dichloromethane (4×25 mL). The combined organic phase was washed with brine and dried over anhydrous magnesium sulfate. The solvent was removed and the solid was triturated with ether. The resulting slurry was filtered and washed with ether several times (to remove the triphenylphosphine oxide) and finally with a solution of dichloromethane-ether (1:1) to obtain 2-[4-(2-bromo-ethoxy)-3-methyl-phenyl]-5,7-dimethoxy-3H-quinazolin-4-one as an off-white solid. Yield: 0.70 g (34%).
