Water → 7-bromo-3,4-dihydro-2H-1,4-benzoxazin-3-one

HRID 44184Notes

Reaction equation

HRID 44184 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][C:9](=[O:12])[CH2:10][OH:11])=[C:4](F)[CH:3]=1.[H-].[Na+].O>CN(C=O)C>[Br:1][C:2]1[CH:7]=[CH:6][C:5]2[NH:8][C:9](=[O:12])[CH2:10][O:11][C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 962WaterHCID 24758Sodium hydrideHCID 43558768N-(4-bromo-2-fluorophenyl)-2-hydroxyacetamide

Product 1

HCID 143051127-bromo-3,4-dihydro-2H-1,4-benzoxazin-3-oneYield 31.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
140 °C

Procedure

A solution of N-(4-bromo-2-fluorophenyl)-2-hydroxyacetamide (8.0 g, 32.3 mmol) in 50 ml dry DMF was added drop wise to a suspension of sodium hydride (5.2 g, 129 mmol) in 30 ml dry DMF and the mixture was stirred for 2 h under an atmosphere of nitrogen at 140° C. After cooling to ambient temperature water was added and the mixture was extracted several times with ethyl acetate. After washing the combined organic layers with brine and drying over MgSO4 the solvent was removed under reduced pressure and the crude product was obtained as a pale yellow solid. Purification by flash chromatography on silica gel (dichloromethane/methanol, 97/3, Rf=0.35) yielded 7-bromo-2H-benzo[b][1,4]oxazin-3(4H)-one (2.3 g, 10.1 mmol, 31%) as off-white solid.

Workup

  1. additionwas added
  2. extractionthe mixture was extracted several times with ethyl acetate
  3. washAfter washing the combined organic layers with brine
  4. dry with materialdrying over MgSO4 the solvent
  5. customwas removed under reduced pressure
  6. customthe crude product was obtained as a pale yellow solid
  7. customPurification by flash chromatography on silica gel (dichloromethane/methanol, 97/3, Rf=0.35)

Sources & evidence

ORD record
ord-29ffd9d0198e49bcbae9657f662b7b04
Source dataset
uspto-grants-2013_09
Patent number
US08541404B2

Reaction notes

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