Salicylamide → 2,2-dimethyl-3,4-dihydro-2H-1,3-benzoxazin-4-one

HRID 726564

Reaction equation

HRID 726564 reaction equation
[C:1]([NH2:10])(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4].[C:11]1(C)[CH:16]=CC(S(O)(=O)=O)=C[CH:12]=1>COC(OC)(C)C>[CH3:12][C:11]1([CH3:16])[NH:10][C:1](=[O:9])[C:2]2[CH:8]=[CH:7][CH:6]=[CH:5][C:3]=2[O:4]1

Participants

4

Reactant 2

HCID 5147SalicylamideHCID 6101p-Toluenesulfonic acid

Product 1

HCID 7174282,2-dimethyl-3,4-dihydro-2H-1,3-benzoxazin-4-one

Reagents, catalysts & solvents 1

HCID 64952,2-DimethoxypropaneSolvent

Procedure

6.86 g (50 mmol) of salicylamide was suspended in 100 ml of acetone dimethylacetal. After the addition of 2.85 g (15 mmol) of p-toluenesulfonic acid, the mixture was heated to reflux for two hours. The resulting reaction mixture was evaporated under reduced pressure. After the addition of ethyl acetate, the solvent was washed twice with a saturated aqueous solution of sodium hydrogen carbonate and once with brine. The ethyl acetate layer was dried over anhydrous sodium sulfate and the solvent was removed by evaporation under reduced pressure, to obtain 8.94 g (quantitative) of the title compound as light yellow needle-like crystals.

Workup

  1. temperaturethe mixture was heated
  2. temperatureto reflux for two hours
  3. customThe resulting reaction mixture
  4. customwas evaporated under reduced pressure
  5. additionAfter the addition of ethyl acetate
  6. washthe solvent was washed twice with a saturated aqueous solution of sodium hydrogen carbonate and once with brine
  7. dry with materialThe ethyl acetate layer was dried over anhydrous sodium sulfate
  8. customthe solvent was removed by evaporation under reduced pressure

Sources & evidence

ORD record
ord-c2af07350a1146e78187960312e477d6
Source dataset
uspto-grants-1998_01
Patent number
US05710152

Linked notes

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