The compound (460 mg, 0.99 mmol) obtained in Example 4-2), 3-pyridylboronic acid (135 mg, 1.09 mmol), tris(dibenzylideneacetone)dipalladium (45 mg, 0.05 mmol), tricyclohexylphosphine (33 mg, 0.12 mmol), and tripotassium phosphate (370 mg, 1.68 mmol) were dissolved in a mixed solvent of 1,4-dioxane (2 mL) and water (1 mL), and the mixture was stirred at 140° C. for 2 h under microwave irradiation. The reaction mixture was cooled to room temperature, then diluted with methylene chloride (100 mL), and separated into organic and aqueous layers by the addition of saturated aqueous sodium hydrogencarbonate (30 mL). The organic layer was washed with saturated sodium chloride solution and then dried with anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the obtained residue was purified by silica gel column chromatography (elution solvent: methanol/ethyl acetate=0% to 30%) to obtain the title compound (455 mg, 91%) in a yellow solid form.
