A mixture of 1-benzenesulfonyl-5-bromo-2-methyl-1H-indole (810 mg, 2.31 mmol), phenylboronic acid (850 mg, 6.97 mmol) and tetrakis(triphenylphosphine)palladium(0) (55 mg, 0.029 mmol) in 20 mL of toluene, 10 mL of ethanol, and 5 mL of 2 M sodium carbonate was warmed at reflux for 4 hours. The reaction was monitored by TLC (ethyl acetate-hexanes (5:95), 2× developed; and toluene-hexanes (1:1)) indicating a slightly more polar product. The mixture was cooled and diluted with 12% aqueous ammonium hydroxide solution and extracted with three 15 mL portions of ethyl acetate. The combined organic layers were washed with three 15 mL portions of brine, dried over magnesium sulfate, filtered, and concentrated in vacuo. The crude mixture was adsorbed onto silica gel and chromatographed on silica gel using ethyl acetate-hexanes (1:99, then 2:98, then 3:97) to afford 731 mg (91% yield) of 1-benzenesulfonyl-2-methyl-5-phenyl-1H-indole.
