Methyl 2-cyclopropyl-1-phenyl-1H-benzimidazole-5-carboxylate (194 mg, 0.664 mmol) was dissolved in THF (6 mL) and MeOH (6 mL), and aqueous 5 N sodium hydroxide solution (0.66 mL, 3.30 mmol) was added to it and stirred at 60° C. for 2 hours. This was restored to room temperature, 5 N hydrochloric acid (0.66 mL, 3.30 mmol) was added thereto, the solvent was evaporated away under reduced pressure, and the residue was azeotroped with toluene. DMF (4 mL) and water (1 mL) were added to it, and 6-(tetrazol-5-yl)spiro[chroman-2,4′-piperidin]-4-one hydrochloride (256 mg, 0.797 mmol), triethylamine (0.14 mL, 0.996 mmol), HOBT (135 mg, 0.996 mmol) and WSC hydrochloride (191 mg, 0.996 mmol) were added thereto. The reaction liquid was stirred at 90° C. for 2 hours, restored to room temperature, and water was added thereto. The precipitated solid was taken out through filtration, and dried under reduced pressure to obtain the title compound as a white solid. 1H-NMR (400 MHz, DMSO-d6) δ: 8.42 (1H, d, J=2.2 Hz), 8.23 (1H, dd, J=8.8, 2.2 Hz), 7.69-7.59 (6H, m), 7.34 (1H, d, J=8.8 Hz), 7.23 (1H, dd, J=8.4, 1.6 Hz), 7.14 (1H, d, J=8.4 Hz), 4.50-3.29 (5H, m), 2.98 (2H, s), 2.06-1.77 (4H, m), 1.15-1.11 (2H, m), 1.04-1.00 (2H, m). MS [M+H]+=546.
