In 30 ml of tetrahydrofuran were suspended 1.8 g of zinc chloride at room temperature unclear a nitrogen gas stream. A 1.4M tetrahydrofuran solution of methyl lithium (9.5 ml) was added dropwise to the resulting suspension and the resulting mixture was stirred for one hour. The reaction mixture was added dropwise to a solution of 1 g of methyl 4-trifluoromethanesulfonyloxy-8-isopropylquinoline-2-carboxylate and 153 mg of tetrakis(triphenylphosphine)palladium in 20 ml of tetrahydrofuran, followed by stirring at room temperature for 65 hours. Dilute hydrochloric acid was added to the reaction mixture and the resulting mixture was extracted with ethyl acetate. The organic layer was successively washed with water and saturated saline, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue so obtained was subjected to chromatography on a silica gel column (developing solvent: 2% ethyl acetate/n-hexane), whereby 125 mg of the title compound were obtained in the form of a colorless solid.
