To a solution of 5-(1-methyl-1H-indol-2-yl)pyridin-3-amine (Example 100, 150 mg, 0.672 mmol) and triethylamine (272 mg, 2.69 mmol) in DCM (6 mL) is added 2-chloroethanesulfonyl chloride (274 mg, 1.68 mmol) in DCM (2 mL) dropwise at 0° C. The mixture is stirred at 0° C. for 1 h. Silica gel (5 g) is added and the mixture is concentrated. After elution, the fractions containing the product are concentrated to give a residue, which is redissolved in benzyl alcohol (20 mL). 60% NaH in mineral oil is added. The mixture is stirred at 70° C. for 1 day. The mixture is then filtered and the filtrate is purified on Xbridge C18 eluting with a 1:9 to 9:1 acetonitrile-water gradient to give 2-(benzyloxy)-N-(5-(1-methyl-1H-indol-2-yl)pyridin-3-yl)ethanesulfonamide. MS (ESI) m/z 422.1 (M+H)+.
