To a solution of 2-chloro-4-fluoro-3-[[2-fluoro-5-(3-fluorophenyl)phenyl]methylamino]phenol (144 mg, 0.40 mmol, 1.0 eq) in acetone (3 mL) was added Cs2CO3 (193.5 mg, 0.59 mmol, 1.5 eq). The reaction mixture was stirred for 30 min, then ethyl 2-bromoacetate (79.3 mg, 0.48 mmol, 1.2 eq) was added. The reaction mixture was stirred at room temperature for 1 h and the resulting mixture poured into water and extracted with EtOAc. The organic extract was washed with water and brine, dried (Na2SO4), filtered, and evaporated in vacuo. The residue obtained was purified by column chromatography (EtOAc:petroleum ether, 1:20 to 1:10) to give the title compound as an oil (155 mg, 87%).
