Under a nitrogen atmosphere, 15 ml of tetrahydrofuran, 1.50 g of the 2-phenyl-4-bromothiazole obtained in the above described stage, and 3.8 ml of triethylamine were added to 221 mg of dichlorobis(triphenylphosphine)palladium, 60 mg of copper iodide, and 1.24 g of N-(3-butynyl)phthalimide. The obtained mixture was stirred under reflux for 4 hours. After completion of the stirring, the reaction solution was cooled to a room temperature, and a solid was then filtrated. The filtrate was concentrated, and the residue was then purified by column chromatography (Wako Gel C-200; toluene:ethyl acetate=9:1), so as to obtain 1.24 g of a phthalimide compound.
