A solution of 7-bromo-5-fluoro-1-{3-fluoro-4-[(phenylmethyl)oxy]phenyl}-4-[(phenylmethyl)oxy]-1H-indole (D6) (400 mg, 0.769 mmol) in toluene (10 mL) was degassed by bubbling Argon through for a few minutes and tributylstannane (0.248 mL, 0.922 mmol) was added. The mixture was heated to reflux under argon and AIBN (˜5 mg) was added and refluxing was continued. After 6 hours, another 0.124 mL of Bu3SnH and a few crystals of AIBN were added and the mixture refluxed overnight—only a small amount of further reaction occurred therefore another 0.124 mL of Bu3SnH and a few crystals of AIBN added and refluxing continued, again further reaction occurred but then stopped. Further quantities of Bu3SnH (4×0.124 mL) together with a few crystals of AIBN were added at approx 2 hourly intervals. It was noticed that the reaction proceeded much more with thorough degassing with argon prior to addition of Bu3SnH. After completion of the reaction (˜48 hours total reaction), the toluene was evaporated and ether/20% aqueous ammonia were added. The product was extracted into ether and the extracts were washed with 20% aqueous ammonia (3×). The ether layer was dried over Na2SO4 and concentrated and the product was triturated with hexane to remove high Rf impurities. Chromatography on silica gel (elution with 0-15% diethyl ether in hexane) gave the title compound as a clear gum (D7), (143 mg).
