Ethyl Acetate → Methyl 3,4-dihydro-2,2-dimethyl-3-oxo-2H-1,4-benzoxazine-7-carboxylate

HRID 234888Notes

Reaction equation

HRID 234888 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([O:10][CH3:11])=[O:9])=[CH:4][C:3]=1[OH:12].C(OCC)(=O)C.C(=O)([O-])O.[Na+].Br[C:25]([CH3:30])([CH3:29])[C:26](Br)=[O:27]>O>[CH3:29][C:25]1([CH3:30])[C:26](=[O:27])[NH:1][C:2]2[CH:7]=[CH:6][C:5]([C:8]([O:10][CH3:11])=[O:9])=[CH:4][C:3]=2[O:12]1

Participants

6

Reactant 4

HCID 8857Ethyl AcetateHCID 886852-Bromo-2-methylpropionyl bromideHCID 516892Sodium BicarbonateHCID 7020619Benzoic acid, 4-amino-3-hydroxy-, methyl ester

Product 1

HCID 10585820Methyl 3,4-dihydro-2,2-dimethyl-3-oxo-2H-1,4-benzoxazine-7-carboxylateYield 78.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a solution of 2-amino-5-methoxycarbonylphenol [Tetrahedron, 46(15), 5177-5186 (1990)] (9.8 g) in a mixed solvent of ethyl acetate (200 ml) and water (200 ml) were added sodium hydrogen carbonate (7.3 g) and 2-bromoisobutyryl bromide (13.7 g) and the mixture was stirred at room temperature for 10 minutes. The organic layer was separated and the solvent was distilled off under reduced pressure. The resulting residue was dissolved in dimethylformamide (500 ml), to the solution was added potassium carbonate (8.9 g) and the mixture was stirred at room temperature for a day. The reaction solution was poured into water to give precipitates, which were taken by filtration and dried to give 2,2-dimethyl-7-methoxycarbonyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (10.8 g).

Workup

  1. customThe organic layer was separated
  2. distillationthe solvent was distilled off under reduced pressure
  3. dissolutionThe resulting residue was dissolved in dimethylformamide (500 ml), to the solution
  4. additionwas added potassium carbonate (8.9 g)
  5. stirringthe mixture was stirred at room temperature for a day
  6. additionThe reaction solution was poured into water
  7. customto give
  8. customprecipitates
  9. filtrationwhich were taken by filtration
  10. customdried

Sources & evidence

ORD record
ord-78780060dd4243b1a4b2f825c06e229a
Source dataset
uspto-grants-1997_01
Patent number
US05597820

Reaction notes

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