Ethyl Acetate → 6,7-dimethyl-2H-benzo[b][1,4]oxazin-3(4H)-one

HRID 2114325Notes

Reaction equation

HRID 2114325 reaction equation
[CH3:1][C:2]1[C:7]([CH3:8])=[CH:6][C:5]([OH:9])=[C:4]([NH2:10])[CH:3]=1.C(=O)(O)[O-].[Na+].Br[CH2:17][C:18](Br)=[O:19].CCOC(C)=O>C(Cl)(Cl)Cl.CN(C=O)C>[CH3:1][C:2]1[C:7]([CH3:8])=[CH:6][C:5]2[O:9][CH2:17][C:18](=[O:19])[NH:10][C:4]=2[CH:3]=1

Participants

7

Reactant 4

HCID 8857Ethyl AcetateHCID 61147Bromoacetyl bromideHCID 810992-Amino-4,5-dimethylphenolHCID 516892Sodium Bicarbonate

Product 1

HCID 216236736,7-dimethyl-2H-benzo[b][1,4]oxazin-3(4H)-oneYield 80%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolvent2×HCID 6228DimethylformamideSolvent

Procedure

A solution of 4,5-dimethyl-2-aminophenol (1.73 g, 12.6 mmol) in chloroform (50 mL) was added to a rapidly stirred saturated solution of sodium bicarbonate. Bromoacetyl bromide (1.1 mL, 2.54 g, 12.6 mmol) in chloroform (15 mL) was added dropwise to the rapidly stirring mixture. Stirring continued for 2 h. EtOAc was added. Layers separated and the EtOAc solution washed with H2O (1×), brine (1×), dried (MgSO4) and concentrated to give a brown solid, which was dissolved in DMF (85 mL). CsCO3 (4.1 g, 12.6 mmol) was added and the mixture heated at 80 deg. C. for 1 h, then poured into ice-H2O (200 mL). The crystallized product was collected, washed with H2O, and dried to give a tan solid (1.78 g, 80%). MS (ES) m/e 178[M+H]+.

Workup

  1. stirringStirring
  2. customLayers separated
  3. washthe EtOAc solution washed with H2O (1×), brine (1×)
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated
  6. customto give a brown solid, which
  7. temperaturethe mixture heated at 80 deg. C
  8. waitfor 1 h
  9. customThe crystallized product was collected
  10. washwashed with H2O
  11. customdried

Sources & evidence

ORD record
ord-85a9290b920f4ae2a3d3e1f31ddf2229
Source dataset
uspto-grants-2008_10
Patent number
US07432258B2

Reaction notes

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