A mixture of 5-chloro-3-(4-(2-(trifluoromethyl)pyridin-4-yloxy)phenyl)pyridin-2-amine (220 mg) in THF (dry) (10 mL) was added to a mixture of NaH (60%, 120 mg) and 2-chloroethanesulfonyl chloride (294 mg) in THF (dry) (10 mL) at room temperature. The mixture was stirred at 70° C. for 1 hr. MeOH and NH silica gel were added and the mixture was concentrated in vacuo. The residue was purified by column chromatography (NH silica gel, eluted with MeOH in EtOAc) to give the titled compound (253 mg) as a white solid. The solid was crystallized from CH3CN-IPE to give a white solid.
