반응 #65394

반응 방정식

6-cyano-3,4-dihydro-2,2-dimethyl-2H-1,4-benzoxazine

cyclohexane-1,2-dione

p-toluenesulfonic acid

→

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

수율 66.7%

용매

toluene

반응 조건

후처리

1. 1
   온도the solution was refluxed
2. 2
   온도under heating for 4 hours
3. 3
   온도After cooling
4. 4
   세척the reaction mixture was washed with saturated aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution
5. 5
   건조dried over anhydrous magnesium sulfate
6. 6
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure
7. 7
   기타The residue was purified by silica gel column chromatography
8. 8
   세척the resulting crude crystals were washed with ethanol

실험 절차

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.

출처