Under argon, suspend 482 mg (11.37 mmol) of lithium chloride and 90 mg (7.84×10-5 mol) of tetrakis(triphenylphosphine)palladium in 10 ml of anhydrous toluene. Add to that suspension a solution of 1 g (3.92 mmol) of 1,3-dihydro-1,3,3-trimethyl-5-bromo-2H-pyrrolo[2,3-b]pyridin-2-one and 1.46 mg (4.04 mmol) of (1-ethoxyvinyl)tributyltin in 20 ml of anhydrous toluene. After 5 hours at reflux, evaporate off the solvent and take up the residue in a 1:1 mixture (30 ml) of dioxane and 10% hydrochloric acid. After 30 minutes' stirring at room temperature, evaporate off the dioxane. Filter off the resulting tin salts over Celite. Extract the filtrate with dichloromethane and dry over magnesium sulfate. After purification on a silica column, 780 mg of the title product are obtained in a yield of 90% ##STR59##
