Synthesis
mixture of (4-(N-acetamidosulfonyl)phenyl)methylene diacetate intermediate compound 61 (4.55 mmol, 1.5 g), H₂SO₄ (0.3 mL), H₂O (1.5 mL), and EtOH (4.8 mL) was stirred in a sealed tube at 90°C for 3 hours. The brown solution was then cooled and the solvent was removed under reduced pressure. The residue was partitioned between EtOAc and water (3 x 10 mL). The organic layer was washed with 5% K₂CO₃ aqueous solution and water. The solution was then dried with anhydrous MgSO₄, filtered, and the solvent was reduced under reduced pressure to give the title compound 4-Benzenesulfonamide, 4-formyl- (9CI). Yield: 677 mg, 80%. ¹H NMR (400 MHz, DMSO-d⁶) δ 10.1 (¹H, s) 8.18 (²H, d, J = 8.4 Hz), 7.99 (²H, d, J + 8.8 Hz), 4.96 (¹H, s), 4.91 (¹H). Figure 4. Synthetic route of Benzenesulfonamide, 4-formyl- (9CI).