Sulfuric Acid → 3-[(3-Carboxyphenyl)sulfinyl]benzenecarboxylic acid

Participants

Reaction Steps

To a stirred ice cooled solution of 3-[(carboxyphenyl)sulfanyl]benzenecarboxylic acid (GM71/7, VIB-006) (1.0 g, 3.65 mmol) in aqueous pyridine ((1/1) 5.84 mL), phenyl trimethylammonium tribromide (1.43 g, 3.8 mmol) was gradually added in portions to keep the temperature between 0 and 10° C. When addition was complete, the reaction mixture was stirred at room temperature for 24 hours. Then the unreacted PTAB was decomposed with 40% NaHSO3 (3.65 mL). Ice water (14.6 mL) was then added and the reaction mixture was acidified with 2N H2SO4. A solid precipitated to afford (833.0 mg, 78.7%) of the desired 3-[(3-Carboxyphenyl)sulfinyl]benzenecarboxylic acid (GM71/21, VIB-032) as a white powder. M.S. m/z 288.70 (M−1)+. 1H NMR (300.13, d6-DMSO) 7.67 (2H, t, 2×ArH, J=7.8 Hz), 7.99 (4H, m, 4×ArH), 8.23 (2H, m, 2×ArH). 1H NMR (300.13, d6-DMSO) 38.8, 132.2, 133.1, 133.4, 139.5. Found C, 53.97, H, 3.22%, C14H10O5S.1.0 H2O requires C, 54.49, H, 3.24%.

Provenance & Evidence