Lithium hydroxide, monohydrate → {4-[1-(2-Chloro-benzenesulfonyl)-piperidin-4-yl]-6-fluoro-naphthalen-2-yl}-acetic acid

Participants

Reaction Steps

To a stirred solution of {4-[1-(2-chloro-benzenesulfonyl)-piperidin-4-yl]-6-fluoro-naphthalen-2-yl}-acetic acid methyl ester (90 mg, 0.19 mmol) in THF (4 mL) was added a solution of lithium hydroxide monohydrate (40 mg, 0.95 mmol) in water (1 mL) and the reaction mixture was stirred for 24 h at room temperature. The reaction mixture was concentrated under reduced pressure and washed with diethyl ether (3×5 mL). The washings were discarded. Water (5 mL) was added to the residue, and the mixture acidified (pH ˜2-3) with an aqueous solution of hydrochloric acid (2 N) and extracted with ethyl acetate (3×5 mL). The combined organic extracts were dried over Na2SO4 and evaporated under reduced pressure to give {4-[1-(2-chloro-benzenesulfonyl)-piperidin-4-yl]-6-fluoro-naphthalen-2-yl}-acetic acid (40 mg, 46%) as an off-white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 12.36 (br. s., 1H), 8.03 (d, J=7.8 Hz, 1H), 7.88-7.99 (m, 2H), 7.67-7.79 (m, 3H), 7.61 (t, J=8.8 Hz, 1H), 7.40 (dt, J=8.7, 1.7 Hz, 1H), 7.35 (s, 1H), 3.88 (d, J=12.2 Hz, 2H), 3.72 (s, 2H), 3.46 (t, J=11.7 Hz, 1H), 3.04 (t, J=11.7 Hz, 2H), 1.88-1.96 (m, 2H), 1.64-1.79 (m, 2H); MS cald. for C23H22ClFNO4S [(M−H)−]: 462, obsd. 462.2.

Provenance & Evidence