Lithium Hydroxide → [4-(4-Dimethylsulfamoyl-benzoyl)-naphthalen-2-yl]-acetic acid

Participants

Reaction Steps

To a stirred solution of [4-(4-dimethylsulfamoyl-benzoyl)-naphthalen-2-yl]-acetic acid ethyl ester (180 g, 0.42 mmol) in tetrahydrofuran:water (1:1; 4 mL) was added lithium hydroxide (40 mg, 0.97 mmol) at room temperature, and the resulting mixture was heated at reflux for 6 hours. The solvents were removed under reduced pressure, and the residue was washed with diethyl ether (5×5 mL), and then acidified with 50% aqueous hydrochloric acid solution (10 mL) and extracted with ethyl acetate (3×25 mL). The collected organic layers were dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give a crude solid, which was further washed with a hexane/ethyl acetate/ether mixture and freeze dried to give pure [4-(4-dimethylsulfamoyl-benzoyl)-naphthalen-2-yl]-acetic acid (130 g, 77%) as a brown solid. 1H NMR (300 MHz, DMSO-d6) δ ppm 12.35 (br. s, 1 H), 7.96-8.11 (m, 5 H), 7.91 (d, J=8.2 Hz, 2 H), 7.52-7.68 (m, 3 H), 3.83 (s, 2 H), 2.66 (s, 6 H); HRMS cald. for C21H19NO5S (ESI+) [(M+H)+] 398.1057, obsd. 398.1056.

Provenance & Evidence