A mixture of 7-bromo-5-fluoro-4-[(phenylmethyl)oxy]-1H-indole (D5) (3 g, 9.37 mmol), {3-fluoro-4-[(phenylmethyl)oxy]phenyl}boronic acid (3.46 g, 14.06 mmol), copper (II) acetate (2.55 g, 14.06 mmol) and pyridine (0.834 mL, 0.815 g, 10.31 mmol) in dichloromethane (50 mL) were stirred together vigorously under an air atmosphere with powdered 4A molecular sieves (˜10 g). After stirring for 20 hours, another 0.5 g of boronic acid were added and the mixture was stirred for a further 24 hours. Then another 1.73 g boronic acid (0.75 eq), copper acetate (1.28 g, 0.75 eq) and pyridine (1.52 mL, 2 eq) were added and stirring was continued at room temperature. After a further 24 hours, the reaction was diluted with ethyl acetate and filtered through celite. The celite was washed with ethyl acetate and the combined filtrates were washed with water (2×), dried (Na2SO4) and concentrated. Chromatography SP4 (0-30% ethyl acetate in hexane) gave the title compound as a white solid (D6), (1.463 g).
