To a 0° C. solution of {2-[(2,4-dimethoxybenzyl)amino]-5-methoxyphenyl}(3-fluorophenyl)methanone (190 mg, 0.480 mmol) in 5 mL of dichloromethane was added triethylamine (0.335 mL, 2.40 mmol), followed by chloroacetyl chloride (0.115 mL, 1.44 mmol). After 30 minutes, another portion of chloroacetyl chloride (0.115 mL, 1.44 mmol) was added, and the mixture was stirred overnight. The reaction was partitioned between EtOAc and saturated NaHCO3 solution, and the organic layer was washed with saturated NH4Cl solution and brine, dried over Na2SO4, filtered, and concentrated in vacuo. The titled product was isolated as a brown foam (229 mg, 100% yield) which was used in the next step without further purification ESI+MS: 472.1 [M+H]+.
