3-(3,4-Dichlorophenyl)glutaric anhydride (5.0 g) in CH2Cl2 (100 mL) at 0° C. was treated sequentially with N-methyl-N-(phenylmethyl)amine (3.0 mL), triethylamine (3.36 mL) and N,N-dimethylaminopyridine (0.26)). The mixture was stirred at 0° C. for two hours then allowed to warm to room temperature and stirred for 12 hours. The reaction mixture was washed with 1N HCl (100 mL) and water (2×100 mL). The organic layers were dried over MgSO4, filtered and concentrated to afford the title compound (6.9 g).
