Water → 6-bromo-3,4-dihydro-1H-2lambda6,1-benzothiazine-2,2-dione

HRID 58861Notes

Reaction equation

HRID 58861 reaction equation
C1C(=O)N([Br:8])C(=O)C1.[NH:9]1[C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][C:13]=2[CH2:12][CH2:11][S:10]1(=[O:20])=[O:19].O.CCOC(C)=O>CN(C=O)C>[Br:8][C:17]1[CH:16]=[CH:15][C:14]2[NH:9][S:10](=[O:19])(=[O:20])[CH2:11][CH2:12][C:13]=2[CH:18]=1

Participants

6

Reactant 4

HCID 962WaterHCID 8857Ethyl AcetateHCID 67184N-bromobutanimideHCID 122033353192-06-1

Product 1

HCID 691080756-bromo-3,4-dihydro-1H-2lambda6,1-benzothiazine-2,2-dioneYield 79.1%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

NBS (1.5 g, 8.2 mmol) was added to a solution of 3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.5 g, 8.2 mmol) in DMF (15 mL). The reaction mixture was stirred overnight at ambient temperature followed by addition of water (200 mL) and EtOAc (100 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (100 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3) to afford 6-bromo-3,4-dihydro-1H-benzo[c][1,2]thiazine 2,2-dioxide (1.7 g, 79% yield).

Workup

  1. customThe two layers were separated
  2. extractionthe aqueous phase was extracted with EtOAc (100 mL×3)
  3. washThe combined organic phases were washed with brine (200 mL×3)
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated
  6. customThe residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:3)

Sources & evidence

ORD record
ord-c88953e3d60947be945fb965a6c5a488
Source dataset
uspto-grants-2016_09
Patent number
US09434761B2

Reaction notes

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