Water → N-(1,1,3-trioxo-1,2,3,4-tetrahydro-1lambda6-benzo[1,2,4]thiadiazin-7-yl)-methanesulfonamide

Participants

Reaction Conditions

Reaction Steps

A solution of N-(4-amino-phenyl)-methanesulfonamide (Example 3b′, 90.7 g, 0.49 mol) in nitroethane (900 mL) was added dropwise over 1.5 h to a mechanically stirred solution of chlorosulfonylisocyanate (50.6 mL, 0.54 mol) in nitroethane (150 mL) at −20° C. The resulting suspension was stirred at −20° C. for 30 min, then aluminum chloride (77.9 g, 0.58 mol) was added in one portion over 1 min. The resulting brown solution was warmed to 25° C., and then was heated at 110° C. for 1 h (considerable gas evolution was noted during this time). After cooling to −5° C., water (300 mL) was added dropwise via addition funnel over 15 min, followed by the rapid addition of more water (700 mL). The resulting suspension was allowed to warm to 25° C. and vigorously stirred for 30 min, and then was filtered through medium paper using a Büchner funnel. The collected solid was washed with water (1×300 mL) and was air-dried to afford the desired product, N-(1,1,3-trioxo-1,2,3,4-tetrahydro-1λ6-benzo[1,2,4]thiadiazin-7-yl)-methanesulfonamide (115.2 g, 0.40 mmol, 81% yield) as a beige solid. 1H NMR (400 MHz, DMSO-d6) δ 3.00 (3H, s), 7.22 (1H, d, J=8.5 Hz), 7.46 (1H, dd, J1=8.8 Hz, J2=2.7 Hz), 7.51 (1H, d, J=2.4 Hz), 9.92 (1H, s), 11.20 (1H, s).

Provenance & Evidence