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

HRID 522679Notes

Reaction equation

HRID 522679 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([CH2:10][S:11]([NH2:14])(=[O:13])=[O:12])=[CH:6][CH:5]=1)([O-:3])=[O:2].[CH2:15]1OCOCO1.FC(F)(F)S(O)(=O)=O.FC(F)(F)S(OS(C(F)(F)F)(=O)=O)(=O)=O>ClCCCl.ClCCl>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[CH2:10][S:11](=[O:12])(=[O:13])[NH:14][CH2:15][C:8]=2[CH:9]=1)([O-:3])=[O:2]

Participants

7

Reactant 4

HCID 80811,3,5-TrioxaneHCID 62406Trifluoromethanesulfonic acidHCID 67749Trifluoromethanesulfonic anhydrideHCID 2755281(4-Nitrophenyl)methanesulfonamide

Product 1

HCID 5959576-Nitro-3,4(1H)-dihydro-2,3-benzothiazine 2,2-dioxideYield 23%

Reagents, catalysts & solvents 2

HCID 111,2-DichloroethaneSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
35 °C

Procedure

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]+.

Workup

  1. temperaturerefluxed overnight
  2. washwashed with water (100 mL) and brine (50 mL)
  3. customThe solvents were evaporated
  4. customthe residue was purified by Prep-HPLC

Sources & evidence

ORD record
ord-04ed11a5cc7b4f0082559b7cfe67718d
Source dataset
uspto-grants-2016_05
Patent number
US09334263B2

Reaction notes

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