1,3,5-Trioxane → 6-Nitro-3,4(1H)-dihydro-2,3-benzothiazine 2,2-dioxide

Participants

Reaction Conditions

Reaction Steps

To a mixture of (4-nitrophenyl)methanesulfonamide (864 mg, 4.0 mmol) and s-trioxane (120 mg, 4.0 mmol) in 1,2-dichoroethane (10 mL) was added trifluoromethanesulfonic acid (1.5 mL), followed by the addition of trifluoromethanesulfonic anhydride (1.5 mL, 4.0 mmol). The reaction mixture was stirred at 35° C. for 2 hours and refluxed overnight. The mixture was then diluted with dichloromethane (100 mL) and washed with water (100 mL) and brine (50 mL). The solvents were evaporated and the residue was purified by Prep-HPLC to give 6-nitro-3,4-dihydro-1H-benzo[d][1,2]thiazine 2,2-dioxide (210 mg, 23%) as a gray solid. MS (ES+) C8H8N2O4S requires: 228, found: 229 [M+H]+.

Provenance & Evidence