A stirred mixture of 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)indole-2-carboxylic acid ethyl ester (300 mg, 0.95 mmol; see step (a)), 2-bromo-5-(trifluoromethyl)pyridine (323 mg, 1.43 mmol), sodium carbonate (2M, 1.43 mL, 2.85 mmol), Pd(PPh3)4 (54 mg, 0.05 mmol), EtOH (5 mL) and toluene (20 mL) was heated at 80° C. for 2 h. Another portion of Pd(PPh3)4 (54 mg, 0.05 mmol) was added and the heating continued for 16 h. The mixture was diluted with EtOAc, washed with brine, dried over MgSO4, concentrated and purified by chromatography to give the sub-title compound (247 mg, 77%).
