To 2,3-dihydro-4,5-diphenyl-1H-imidazol-2-one (4.76 g, 20 mmol) in 50 mL DMF was added to a suspension of NaH (0.8 g, 20 mmol) in 25 mL DMF. The suspension was stirred at ambient temperatures for 30 minutes, then heated to 50° C. for 30 minutes. A solution of methyl 3-bromomethylbenzoate (2.86 g, 12.5 mmol) in 20 mL DMF was then added and the reaction stirred for 10 min at 50° C. The mixture was poured into 1N HCl, filtered, washed with water and dried. Chromatography on silica gel (2% EtOH in 7:3 methylene chloride/ethyl acetate) afforded 1.2 g of 3-(3-methoxycarbonylphenyl)methyl-4,5-diphenyl-1H-imidazol-2-one as a white solid.
