P-Anisidine → 7-Methoxy-2H-benzo[e][1,2,4]thiadiazin-3(4H)-one 1,1-dioxide
Reaction equation
[CH3:1][O:2][C:3]1[CH:9]=[CH:8][C:6]([NH2:7])=[CH:5][CH:4]=1.Cl[S:11]([N:14]=[C:15]=[O:16])(=[O:13])=[O:12].[Cl-].[Al+3].[Cl-].[Cl-]>>[CH3:1][O:2][C:3]1[CH:9]=[CH:8][C:6]2[NH:7][C:15](=[O:16])[NH:14][S:11](=[O:13])(=[O:12])[C:5]=2[CH:4]=1Participants
4
Procedure
Commercially available 4-methoxyaniline can be treated with chlorosulfonyl isocyanate followed by aluminum chloride to give the corresponding 7-methoxy-1,1-dioxo-1,4-dihydro-2H-1λ6-benzo[1,2,4]thiadiazin-3-one. Opening of the cyclic urea with a strong acid (e.g., sulfuric acid) gives the desired 2-amino-5-methoxy-benzenesulfonamide intermediate.
Sources & evidence
- ORD record
- ord-14242063a8b344cfa36e3d4609ca696b
- Source dataset
- uspto-grants-2009_09
- Patent number
- US07582754B2
Reaction notes
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