The product obtained using (E)-4-[2-(1H-indazol-3-yl)vinyl]benzoic acid (500 mg, 1.89 mmol) obtained in Step 6 of Example 1, 4-(tert-butoxycarbonylamino)piperidine (538 mg, 2.84 mmol), 1-hydroxybenzotriazole monohydrate (332 mg, 2.46 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (510 mg, 2.67 mmol) and N-methylmorpholine (0.420 mL, 3.82 mmol) in a similar manner to Example 5, was dissolved in methanol (10.0 mL), and the solution was added with 4 mol/L hydrogen chloride-methanol solution (5.0 mL), followed by heating under reflux at 60° C. for 90 minutes. The reaction mixture was concentrated under reduced pressure, the residue was extracted after adding with a saturated aqueous potassium carbonate solution and ethyl acetate. The crude product was crystallized from ethyl acetate to obtain Compound 64 (435 mg, 66%).
