Sodium Hydroxide → 4-[[(1S,4S)-5-[[4-(2,2,3,3-tetrafluoropropoxy)phenyl]methyl]-2,5-diazabicyclo[2.2.1]hept-2-yl]methyl]benzoic acid

Methyl 4-[[(1S,4S)-5-[[4-(2,2,3,3-tetrafluoropropoxy)phenyl]methyl]-2,5-diazabicyclo[2.2.1]hept-2-yl]methyl]benzoate (177 mg, 0.38 mmol) was stirred with 1.9 mL aqueous sodium hydroxide solution (2 M) in 3.9 mL methanol overnight at room temperature, and then concentrated under reduced pressure. The residue was diluted with water, adjusted to pH 8 with 1 M aqueous hydrochloric acid, and extracted with butanol. The combined organic layers were concentrated under reduced pressure. Flash chromatography gave 91 mg of 4-[[(1S,4S)-5-[[4-(2,2,3,3-tetrafluoropropoxy)phenyl]methyl]-2,5-diazabicyclo[2.2.1]hept-2-yl]methyl]benzoic acid; 1H NMR (300 MHz, CD3OD) δ 7.92 (d, 2H), 7.41 (d, 2H), 7.40 (d, 2H), 7.02 (d, 2H), 6.32 (tt, 1H), 4.45 (tt, 2H), 3.98 (d, 2H), 3.88 (d, 2H), 3.69 (br s, 1H), 3.64 (br s, 1H), 3.17 (d, 1H), 3.12 (d, 1H), 2.90 (dd, 1H), 2.85 (dd, 1H), 2.02 (s, 2H) ppm.