To a solution of tert-butyl 4-bromo-3-(bromomethyl)phenyl(5-cyano-6-methoxypyridin-2-yl)carbamate (4.46 g, 8.98 mmol) in N,N-dimethylformamide (60 mL) was added sodium acetate (3.68 g, 44.9 mmol). The reaction was stirred at 50° C. for two hours. The mixture was cooled to room temperature and extracted with ethyl acetate and water in portions. The organic layer of each portion was washed three times with water and brine, and dried over sodium sulfate, and filtered. The portions were combined and the solvent was removed under reduced pressure. The residue was purified by Combiflash to give 2-bromo-5-(tert-butoxycarbonyl(5-cyano-6-methoxypyridin-2-yl)amino)benzyl acetate (1.99 g, 2 steps 46%).
