A mixture of [4-(6-bromo-3-cyano-1-cyclobutyl-1H-indol-2-yl)-phenyl]-carbamic acid tert-butyl ester (0.17 g, 0.4 mmol), cyclopropylboronic acid (0.047 g, 0.55 mmol), (tert-butyl)3PHBF4 (0.014 g, 0.048 mmol), KF (0.093 g, 1.6 mmol), and Pd2(dba)3-CHCl3, 0.021 g, 0.02 mmol) in THF (2.0 mL) was stirred at 60° C. overnight. The mixture was concentrated, taken up in CH2Cl2 and filtered through Celite. The solid was washed with CH2Cl2 and the filtrate was purified on silica gel (CH2Cl2) to provide [4-(3-cyano-1-cyclobutyl-6-cyclopropyl-1H-indol-2-yl)-phenyl]-carbamic acid tert-butyl ester as a solid (0.10 g, 59%).
