Benzenesulfonamide, N-chloro-N-(phenylsulfonyl)- synthesis

Yield: 98%

Reaction Conditions:

Stage #1:dibenzenesulfonamide with sodium hydrogencarbonate in water at 15 - 20; for 0.25 h;
Stage #2: with chlorine in water

Steps:

Gram scale preparation of N-chloro-N-(phenylsulfonyl)benzenesulfonamide
In a 5 liter 4 necked round-bottomed flask fitted with an overhead stirrer, gas sparger, double surface condenser with an outlet connected to the caustic scrubber was charged with demineralized water (3.0 L, 10.0 vol) followed by sodium bicarbonate (84.0 g, 1.0 mol) under stirring. After complete dissolution, N-(phenylsulfonyl)benzenesulfonamide (297.0 g, 1.0 mol) was charged in the above reaction mass slowly in portions. During the addition, the evolution of CO₂ gas was observed. The reaction mass was stirred for 15 minutes while maintaining the reaction temperature at 15-20 °C. Chlorine gas was sparged slowly till a thick white slurry was observed. The progress of the reaction was monitored by HPLC. After completion of the reaction, the thick white slurry was filtered and washed with 2 x 300 mL DM water. The wet cake was dried under a vacuum oven on a glass tray at 45 °C for 5 hours to afford 325.0 g of N-chloro-N-(phenylsulfonyl)benzenesulfonamide (98.0% yield, 99.58% HPLC Purity and 10.5% chlorine content by Titration). IR (neat) (cm^-1): 1580, 1476, 1448, 1383, 1370, 1181, 1082, 1022, 998, 933, 876, 811, 748, 723, 682, 616. ¹H NMR (CDCl₃, 400 MHz) δ 8.03 (d, J = 7.6 Hz, 4H), 7.71 (t, J = 7.5 Hz, 2H), 7.58 (t, J = 7.8 Hz, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 136.61 (s), 134.95 (s), 129.17 (d, J = 8.8 Hz), 77.29 (s), 76.97 (s), 76.65 (s); LCMS elemental calculated for C₁₂H₁₀ClNO₄S₂: 330.97; found: negative mode (M-1) 330.05 m/z.

References:

Badani, Purav;Chaturbhuj, Ganesh;Ganwir, Prerna;Misal, Balu;Palav, Amey [Tetrahedron Letters,2021,vol. 73] Location in patent:supporting information