1,1-Dibromoethane → 2H-1,4-Benzoxazine, 3,4-dihydro-4-methyl-

HRID 2261078Notes

Reaction equation

HRID 2261078 reaction equation
[CH3:1][NH:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[OH:9].C([O-])([O-])=O.[K+].[K+].Br[CH:17](Br)[CH3:18]>CC(C)=O.O>[CH3:1][N:2]1[C:3]2[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=2[O:9][CH2:18][CH2:17]1

Participants

6

Reactant 3

HCID 112011,1-DibromoethaneHCID 11430Potassium CarbonateHCID 69138o-(Methylamino)phenol

Product 1

HCID 37550242H-1,4-Benzoxazine, 3,4-dihydro-4-methyl-Yield 85.1%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolvent2×HCID 962WaterSolvent

Procedure

0.97 g of 2-(N-methylamino)-phenol were dissolved in 50 ml acetone, followed by the addition of 2 g of K2CO3 dissolved in water. To this suspension was added slowly a solution of 2.66 g of dibromoethane in acetone. The reaction mixture was stirred for 22 hours under reflux. Acetone was evaporated and 200 ml of EtOAc were added and the organic layer was washed 3× with 0.1N HCl and 3× with brine. The remaining organic layer was dried over MgSO4 and filtrated. EtOAc was removed under reduced pressure affording 1 g of pure 4-methyl-3,4-dihydro-2H-benzo[1,4]oxazine.

Workup

  1. temperatureunder reflux
  2. customAcetone was evaporated
  3. addition200 ml of EtOAc were added
  4. washthe organic layer was washed 3× with 0.1N HCl and 3× with brine
  5. dry with materialThe remaining organic layer was dried over MgSO4
  6. filtrationfiltrated
  7. customEtOAc was removed under reduced pressure

Sources & evidence

ORD record
ord-cb15cdde662c4fb381a278cc2db1e0a6
Source dataset
uspto-grants-2010_12
Patent number
US07846925B2

Reaction notes

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