Potassium Carbonate → 8-Bromo-2,2-dimethyl-2H-1,4-benzoxazin-3(4H)-one

HRID 1270099Notes

Reaction equation

HRID 1270099 reaction equation
Br[C:2]([CH3:15])([CH3:14])[C:3]([NH:5][C:6]1[CH:11]=[CH:10][CH:9]=[C:8]([Br:12])[C:7]=1[OH:13])=[O:4].C([O-])([O-])=O.[K+].[K+].O.C(OCC)(=O)C>CN(C=O)C>[Br:12][C:8]1[C:7]2[O:13][C:2]([CH3:15])([CH3:14])[C:3](=[O:4])[NH:5][C:6]=2[CH:11]=[CH:10][CH:9]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 218735182-bromo-N-(3-bromo-2-hydroxy-phenyl)-2-methyl-propionamideHCID 22728543Water ethylacetate

Product 1

HCID 218735118-Bromo-2,2-dimethyl-2H-1,4-benzoxazin-3(4H)-oneYield 84.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
150 °C

Procedure

The 2-bromo-N-(3-bromo-2-hydroxy-phenyl)-2-methyl-propionamide of step 1 was dissolved in DMF (200 ml), and to the DMF solution was added to K2CO3 (6.3 g, 45.58 mmol). The mixture was heated overnight at 150° C., then cooled and poured into a mixture of water/ethyl acetate. The organic fraction was washed with brine. After drying over MgSO4, the organic fraction was concentrated in vacuo and resulting brown residue was purified by flash chromatography to give 8-bromo-2,2-dimethyl-4H-benzo[1,4]oxazin-3-one as a white solid (84.6%). MS: (M−H)− 256.

Workup

  1. temperaturecooled
  2. washThe organic fraction was washed with brine
  3. dry with materialAfter drying over MgSO4
  4. concentrationthe organic fraction was concentrated in vacuo
  5. customresulting brown residue
  6. customwas purified by flash chromatography

Sources & evidence

ORD record
ord-89a2c7c3c4004b8e8d01f4948e3b7480
Source dataset
uspto-grants-2007_04
Patent number
US07202241B2

Reaction notes

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