2-[4-(4-hydroxybenzoyl)benzylthio]-3,5-dimethyl-4(3H)-quinazolinone (268 mg), diethyl phosphorochloridate (0.16 mg), and triethylamine (0.28 ml) were dissolved in tetrahydrofuran (8 ml) and the solution was stirred at room temperature for 14 hours. This reaction mixture was concentrated and the residue was dissolved in ethyl acetate. The solution was then washed with water, dried, and concentrated, and the residue was crystallized from hexane to provide the title compound as colorless solid (270 mg).
