To a solution of 2-amino-3-bromopyridine (44.1 mg, 0.26 mmol) in anhydrous tetrahydrofuran (7 mL) were added 1-(4-benzyloxy-benzyl)-4-tributylstannanyl-1H-pyrazole (141 mg, 0.26 mmol) described in Manufacturing Example 31-1-2, copper (I) iodide (19.4 mg, 0.10 mmol) and bis(triphenylphosphine)palladium (II) (35.8 mg, 0.05 mmol) under nitrogen atmosphere, which was stirred for 4 hours at 70° C. Water and ethyl acetate were added to the reaction mixture at room temperature, which was then filtered through a Celite pad, and the filtrate was partitioned into water and ethyl acetate. The organic layer was washed with water and saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under a reduced pressure. The residue was purified by NH silica gel column chromatography (ethyl acetate:heptane=2:1, then ethyl acetate) to obtain the title compound (1.8 mg, 2%).
