p-Toluenesulfonic acid → 6-cyano-3,4-dihydro-2,2-dimethyl-4-(6-oxo-1-cyclohexen-1-yl)-2H-1,4-benzoxazine

HRID 37116

Reaction equation

HRID 37116 reaction equation
[C:1]([C:3]1[CH:4]=[CH:5][C:6]2[O:11][C:10]([CH3:13])([CH3:12])[CH2:9][NH:8][C:7]=2[CH:14]=1)#[N:2].[C:15]1(=O)[CH2:20][CH2:19][CH2:18][CH2:17][C:16]1=[O:21].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[C:1]([C:3]1[CH:4]=[CH:5][C:6]2[O:11][C:10]([CH3:12])([CH3:13])[CH2:9][N:8]([C:15]3[C:16](=[O:21])[CH2:17][CH2:18][CH2:19][CH:20]=3)[C:7]=2[CH:14]=1)#[N:2]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 130061,2-CyclohexanedioneHCID 105356226-cyano-3,4-dihydro-2,2-dimethyl-2H-1,4-benzoxazine

Product 1

HCID 104931656-cyano-3,4-dihydro-2,2-dimethyl-4-(6-oxo-1-cyclohexen-1-yl)-2H-1,4-benzoxazineYield 66.7%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

In 15 ml of toluene were dissolved 0.5 g of 6-cyano-3,4-dihydro-2,2-dimethyl-2H-1,4-benzoxazine, 0.33 g of cyclohexane-1,2-dione and a catalytic amount of p-toluenesulfonic acid and using a Dean-Stark trap, the solution was refluxed under heating for 4 hours. After cooling, the reaction mixture was washed with saturated aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution and dried over anhydrous magnesium sulfate and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography and the resulting crude crystals were washed with ethanol to give 0.5 g of 6-cyano-3,4-dihydro-2,2-dimethyl-4-(6-oxo-1-cyclohexen-1-yl)-2H-1,4-benzoxazine.

Workup

  1. temperaturethe solution was refluxed
  2. temperatureunder heating for 4 hours
  3. temperatureAfter cooling
  4. washthe reaction mixture was washed with saturated aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution
  5. dry with materialdried over anhydrous magnesium sulfate
  6. distillationthe solvent was distilled off under reduced pressure
  7. customThe residue was purified by silica gel column chromatography
  8. washthe resulting crude crystals were washed with ethanol

Sources & evidence

ORD record
ord-543880f311e840e5a659f21d25f74264
Source dataset
uspto-grants-1995_05
Patent number
US05420126

Linked notes

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