A mixture of the 2-Bromo-3-cyclohexyl-N-[(dimethylamino)sulfonyl]-1H-indole-6-carboxamide (4.28 g, 0.01 mol), boronic acid (2.7 g, 0.015 mol), 2-dicyclohexylphosphino-2′,6′-dimethoxy-biphenyl (41 mg, 0.0001 mol), palladium acetate (11.2 mg), and finely ground potassium carbonate (4.24 g, 0.02 mol) in toluene (30 mL) was stirred under reflux and under nitrogen for 30 min, at which time LC/MS analysis showed the reaction to be complete. The reaction mixture was then diluted with ethyl acetate and water, and then acidified with an excess of dilute HCl. The ethyl acetate layer was then collected and washed with dilute HCl, water and brine. The organic solution was then dried (magnesium sulfate), filtered and concentrated to give a gum. The gum was diluted with hexanes (250 ml) and ethyl acetate (25 mL), and the mixture was stirred for 20 hr at 22° C. during which time the product was transformed into a bright yellow granular solid (4.8 g) which was used directly without further purification.
