2-Aminophenol → Ethyl 3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

HRID 901938Notes

Reaction equation

HRID 901938 reaction equation
Br[CH:2]([CH2:8]Br)[C:3]([O:5][CH2:6][CH3:7])=[O:4].[NH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=1[OH:17].C(=O)([O-])[O-].[K+].[K+].C(OCC)(=O)C>CC(C)=O.O>[O:17]1[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=2[NH:10][CH2:8][CH:2]1[C:3]([O:5][CH2:6][CH3:7])=[O:4]

Participants

7

Reactant 4

HCID 58012-AminophenolHCID 8857Ethyl AcetateHCID 11430Potassium CarbonateHCID 97945Ethyl 2,3-dibromopropionate

Product 1

HCID 31090Ethyl 3,4-dihydro-2H-1,4-benzoxazine-2-carboxylateYield 24%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

Ethyl 2,3-dibromopropionate (24 g, 92 mmol) was added dropwise to a refluxing solution of o-aminophenol (10 g, 92 mmol) and potassium carbonate (15 g, 110 mmol) in acetone (100 ml). After 18 h the mixture was cooled and reduced. Ethyl acetate and water were added and the mixture separated. The organic phase was washed with brine, filtered and reduced. Chromatography (30% EtOAc/70% 60-80 petroleum ether) afforded ethyl benzomorpholine-2-carboxylate (4.5 g, 24%) as a red oil.

Workup

  1. temperatureAfter 18 h the mixture was cooled
  2. customthe mixture separated
  3. washThe organic phase was washed with brine
  4. filtrationfiltered

Sources & evidence

ORD record
ord-a335bad5586e40059a8c1f507a679299
Source dataset
uspto-grants-2008_04
Patent number
US07365065B2

Reaction notes

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