3-[2-(Benzo[b]thiophene-2-sulfonylamino)phenylsulfamoyl]-4-methoxybenzoic acid methyl ester → 3-[2-(Benzo[b]thiophene-2-sulfonylamino)-phenylsulfamoyl]-4-methoxybenzoic acid

Participants

Reaction Steps

To a solution of 3-[2-(Benzo[b]thiophene-2-sulfonylamino) -phenyl sulfamoyl]-4-methoxy-benzoic acid methyl ester (5 mmol, obtained as in Example 3) in THF (10 mL) and methanol (10 mL), 4 M aq. NaOH (5 mL) was added at RT. The reaction mixture was stirred at room temperature till the reaction was complete. The reaction mixture was then concentrated in vacuo and acidified with 10% aq. HCl to pH ˜3. A white precipitate was formed which was filtered, washed with ether and dried, affording 2.5 g of 3-[2-(benzo[b]thiophene-2-sulfonylamino) -phenylsulfamoyl]-4-methoxybenzoic acid. MS: 519.8 (M+1)+. 1H NMR (DMSO-d6, 400 MHz): δ 4.05 (s, 3H), 6.89 (d, 1H), 6.99 (dd, 1H), 7.11 (dd, 1H), 7.25 (d, 1H), 7.38 (d, 1H), 7.48 (dd, 1H), 7.53 (dd, 1H), 7.91 (s, 1H), 7.98 (d, 1H), 8.65 (d, 1H), 8.13 (dd, 1H), 8.16 (dd, 1H) ppm.

Provenance & Evidence