Sulfuric Acid → 6-Nitrosaccharin

Participants

Reaction Steps

To a solution of CrO3 (20.8 g, 208 mmol) in water (150 mL) was slowly added concentrated sulfuric acid (190 mL). To the resulting mixture was added 2-methyl-5-nitrobenzenesulfonamide (10.0 g, 46.3 mmol) and the mixture was stirred at rt for about 42 h. The mixture was filtered and the filter cake was washed with water (100 mL). The solid was dissolved in 10% aqueous NaHCO3, filtered and the filtrate acidified with 2 N HCl (pH=1). The precipitate was collected by filtration and washed with water (2×50 mL) to provide 6-nitro-1,1-dioxo-1,2-dihydro-1lambda*6*-benzo[d]isothiazol-3-one (7.2 g, 68%). 1H NMR (DMSO-d6) δ: 8.42-8.53 (m, 2H), 8.00 (s, 1H), 3.70 (br s, 1H).

Provenance & Evidence