To a degassed mixture of 1-(4-methylphenylsulfonyl)-5-bromoindole-3-carboxaldehyde (36.9 g), 1-decyne (16.8 g), in dry triethylamine (200 ml) and dry tetrahydrofuran (150 ml) was added, 1 mole percent of copper (II) iodide and 2 mole percent of bis(triphenylphosphine)palladium (II) chloride. The reaction mixture was stirred at 65° C. for 7 days. The solution was evaporated, and the residue was flash chromatographed (silica gel:4:1, dichloromethane:heptane). The appropriate fractions were collected and evaporated. The residue was recrystallized from hexane to give 23.1 g (50.8%) of product, mp 84°-86° C.
