A mixture of 4-(4-morpholin-4-yl-2-trifluoromethanesulfonyloxyphenyl)piperazine-1-carboxylic acid t-butyl ester (1.49 g, 3.01 mmol), 1,2-dimethoxyethane (15 mL), water (1 mL), 4,4,5,5-tetramethyl-2-spiro[2.5]oct-5-en-6-yl-[1,3,2]dioxaborolane (1.13 g, 4.82 mmol) produced in Example (34b), tetrakis(triphenylphosphine)palladium(0) (278 mg, 0.241 mmol) and tripotassium phosphate (1.23 g, 5.78 mmol) was stirred for 13 hours and 20 minutes at an external temperature of 80-90° C. under a nitrogen atmosphere. Ethyl acetate and brine were added to the reaction mixture and extraction was performed three times with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate, the desiccant was filtered off and the filtrate was concentrated under reduced pressure. The residue was purified by NH silica gel column chromatography (ethyl acetate/hexane) to give 1.23 g of the title compound as a colorless solid.
