Methyl 3-amino-4-hydroxybenzoate → methyl 3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

HRID 551809Notes

Reaction equation

HRID 551809 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][C:11]=1[OH:12])[C:5]([O:7][CH3:8])=[O:6].C(=O)([O-])[O-].[K+].[K+].Br[CH:20](Br)[CH3:21]>CN(C)C=O>[O:12]1[C:11]2[CH:10]=[CH:9][C:4]([C:5]([O:7][CH3:8])=[O:6])=[CH:3][C:2]=2[NH:1][CH2:21][CH2:20]1

Participants

5

Reactant 3

HCID 10815Methyl 3-amino-4-hydroxybenzoateHCID 112011,1-DibromoethaneHCID 11430Potassium Carbonate

Product 1

HCID 16244461methyl 3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
110 °C

Procedure

5.16 g of methyl 3-amino-4-hydroxybenzoate are dissolved in 100 ml of dimethylformamide in a 500 ml round-bottomed flask. 17.06 g of potassium carbonate and then 7.98 ml of dibromoethane are subsequently added. The reaction medium is heated at 110° C. with stirring for five hours. After evaporating the solvent, water and ethyl acetate are added. The aqueous phase is extracted three times with ethyl acetate. The organic phases are combined and then dried over magnesium sulfate and the solvent is evaporated under reduced pressure. The residue is chromatographed on silica gel with a heptane/ethyl acetate 6/4 mixture. 3.61 g of methyl 3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate are obtained.

Workup

  1. customAfter evaporating the solvent, water and ethyl acetate
  2. additionare added
  3. extractionThe aqueous phase is extracted three times with ethyl acetate
  4. dry with materialdried over magnesium sulfate
  5. customthe solvent is evaporated under reduced pressure
  6. customThe residue is chromatographed on silica gel with a heptane/ethyl acetate 6/4 mixture

Sources & evidence

ORD record
ord-1b5cdb75d3d14604ac5d296ed2596db0
Source dataset
uspto-grants-2011_05
Patent number
US07947834B2

Reaction notes

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