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

Participants

Reaction Steps

To a stirred solution of [4-(1-benzenesulfonyl-piperidin-4-yl)-6-fluoro-naphthalen-2-yl]-acetic acid methyl ester (90 mg, 0.2 mmol) in THF (8 mL) was added a solution of lithium hydroxide monohydrate (26 mg, 0.6 mmol) in water (2 mL) and the reaction mixture was stirred for 24 h at RT. 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-benzenesulfonyl-piperidin-4-yl)-6-fluoro-naphthalen-2-yl]-acetic acid (35 mg, 40%) as an off-white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 12.36 (br s, 1H), 7.92-7.98 (m, 1H), 7.88 (d, J=11.2 Hz, 1H), 7.81 (d, J=7.8 Hz, 2H), 7.76 (d, J=6.8 Hz, 1H), 7.65-7.73 (m, 3H), 7.33-7.42 (m, 2H), 3.82 (d, J=11.7 Hz, 2H), 3.71 (s, 2H), 1.90 (d, J=11.2 Hz, 2H), 1.69-1.82 (m, 2H); MS cald. for C23H23FNO4S [(M−H)−]: 426, obsd. 426.2.

Provenance & Evidence