A flask is charged with N-(5-bromo-pyridin-3-ylmethyl)-methanesulfonamide (Example 163a, 530 mg, 2 mmol), N-Boc-6-chloro-indole-2-boronic acid (525 mg, 3.0 mmol), s-Phos (41 mg, 0.10 mmol), finely crushed potassium phosphate (849 mg, 4.0 mmol) and toluene (20 mL), and the mixture is degassed for 15 min. Pd2dba3 (37 mg, 0.04 mmol) is added and the mixture is stirred at 85° C. for 1 h. The mixture is cooled to room temperature, diluted with DCM and silica gel (10 g) is added. The mixture is concentrated in vacuo and the residue is purified by silica gel flash chromatography eluting with a 0 to 90% ethyl acetate-heptane gradient to give 6-chloro-2-[5-(methanesulfonylamino-methyl)-pyridin-3-yl]-indole-1-carboxylic acid tert-butyl ester. MS (ESI) m/z 436.1 and 437.9 (M+H)+.
