Sulfuric Acid → 3-Amino-6-chloro-2-hydroxy-N-methoxy-N-methyl-benzenesulfonamide

HRID 2066020Notes

Reaction equation

HRID 2066020 reaction equation
[CH3:1][O:2][N:3]([CH3:21])[S:4]([C:7]1[C:15]2[O:14]C(C(C)(C)C)=[N:12][C:11]=2[CH:10]=[CH:9][C:8]=1[Cl:20])(=[O:6])=[O:5].S(=O)(=O)(O)O>O1CCOCC1.O>[NH2:12][C:11]1[C:15]([OH:14])=[C:7]([S:4]([N:3]([O:2][CH3:1])[CH3:21])(=[O:6])=[O:5])[C:8]([Cl:20])=[CH:9][CH:10]=1

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 717215102-tert-Butyl-6-chloro-N-methoxy-N-methyl-1,3-benzoxazole-7-sulfonamide

Product 1

HCID 183734833-Amino-6-chloro-2-hydroxy-N-methoxy-N-methyl-benzenesulfonamide

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

2-tert-Butyl-6-chloro-benzooxazole-7-sulfonic acid methoxy-methyl-amide (4.8 g, 14.42 mmol) in dioxane (55 ml) and water (20 ml) was treated with concentrated sulphuric acid (20 ml) added dropwise over 30 minutes maintaining the temperature <30° C. The reaction mixture was heated at reflux for 2.5 h and then allowed to cool to RT. Dioxane was removed in vacuo and the resulting aqueous residue was basified with sat. NaHCO3 solution (250 ml) to pH12. The reaction mixture was extracted with EtOAc (3×200 ml) and the combined organic extracts were washed with water (3×100 ml) sat. brine (100 ml), dried (MgSO4) and concentrated in vacuo to afford the title compound as a brown solid; [M+H]+ 266.

Workup

  1. additionadded dropwise over 30 minutes
  2. temperaturemaintaining the temperature <30° C
  3. temperatureThe reaction mixture was heated
  4. temperatureat reflux for 2.5 h
  5. customDioxane was removed in vacuo
  6. extractionThe reaction mixture was extracted with EtOAc (3×200 ml)
  7. washthe combined organic extracts were washed with water (3×100 ml) sat. brine (100 ml)
  8. dry with materialdried (MgSO4)
  9. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-ebd9e2df81574d0ebfaee63311a72d57
Source dataset
uspto-grants-2012_10
Patent number
US08288588B2

Reaction notes

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