To a solution of 2-amino-4,6-dichloro-benzamide (1.54 g, 7.50 mmol) and 4-(2-hydroxy-ethoxy)-3,5-dimethyl-benzaldehyde (1.46 g, 7.50 mmol) in N,N-dimethylacetamide (15 mL) were added sodium hydrogen sulfite (58.5 wt %, 1.51 g, 8.25 mmol) and p-toluenesulfonic acid monohydrate (0.28 g, 1.50 mmol). The reaction mixture was stirred at 120° C. for 16 hours under nitrogen, and then cooled to room temperature. Solvent was evaporated under reduced pressure. Water (100 mL) was added. The separated solid was filtered, washed with water (50 mL), and dried under vacuum. Crude compound was further washed with ether and dried under vacuum to give 5,7-dichloro-2-[4-(2-hydroxy-ethoxy)-3,5-dimethylphenyl]-3H-quinazolin-4-one as a white solid. Yield: 2.42 g (85%).
