To a suspension of NaH (60%, 202 mg) in THF (dry) (10 mL) was added 2-chloroethanesulfonyl chloride (0.319 mL) at 0° C. and the mixture was stirred for 5 min at the same temperature. A solution of 3-(4-(3-chlorophenoxy)phenyl)pyridin-2-amine (300 mg) in THF (dry) (10 mL) was added at 0° C. and the mixture was stirred at room temperature under nitrogen overnight. The mixture was quenched with water at 0° C. carefully. Water was added to form precipitates which were washed with water, hexane and collected. The precipitate was sonicated in EtOAc and the insoluble material was collected to give the title compound (248 mg) as an off-white solid. This was crystallized from THF-MeOH/IPE to give colorless crystals.
