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

HRID 1696291Notes

Reaction equation

HRID 1696291 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+]>CC(C)=O>[O:17]1[CH:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH2:8][NH:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]1=2

Participants

5

Reactant 3

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

Product 1

HCID 31090Ethyl 3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a solution of ethyl 2,3-dibromopropionate (8.05 g, 31.0 mmol, Aldrich) in acetone (35 mL) was added o-aminophenol (3.38 g. 31.0 mmol) and potassium carbonate (5.1 g, 36.9 mmol). The reaction mixture was stirred at reflux under a water condenser for 18 h. Upon cooling to room temperature, the reaction was concentrated in vacuo, and the residue was taken up in water (50 mL) and the product was extracted using EtOAc (3×75 mL). The organic fractions were combined, washed with saturated brine (15 mL), dried over sodium sulfate, and concentrated. Purification of the product by flash column chromatography (30% EtOAc/hexane) afforded the title compound as a yellow oil. MS m/z: 208 (M+1).

Workup

  1. temperatureat reflux under a water condenser for 18 h
  2. concentrationthe reaction was concentrated in vacuo
  3. extractionthe product was extracted
  4. washwashed with saturated brine (15 mL)
  5. dry with materialdried over sodium sulfate
  6. concentrationconcentrated
  7. customPurification of the product by flash column chromatography (30% EtOAc/hexane)

Sources & evidence

ORD record
ord-257b5df202294f9c9e9e3438f24ae9a5
Source dataset
uspto-grants-2012_04
Patent number
US08163766B2

Reaction notes

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