To a solution of 6-bromo-1-cyclobutyl-1H-indole-3-carbonitrile (1.38 g, 5.0 mmol), and triisopropylborate (1.37 mL, 6.0 mmol) in THF (15.0 mL) at −78° C. was added LDA (1.5M mono THF in cyclohexane, 3.83 mL, 5.75 mmol) with stirring. The mixture was stirred at −78° C. for 10 min and at room temperature for 30 min followed by addition of (4-iodophenyl)-carbamic acid tert-butyl ester (1.75 g, 5.5 mmol) and PdCl2(dppf) (0.37 g, 0.5 mmol). The reaction mixture was cooled to −78° C., flushed with nitrogen and DMF (30 mL) and aq. K2CO3 (2.0M, 7.5 mL, 15.0 mmol) added. The mixture was stirred at −78° C. for 20 min, room temperature overnight and poured into ice water (200 mL). The precipitate was filtered, washed with water and purified on silica gel (hexanes/EtOAc, 9:1 to 8:2) to give [4-(6-bromo-3-cyano-1-cyclobutyl-1H-indol-2-yl)-phenyl]-carbamic acid tert-butyl ester as a solid (1.23 g, 53%).
