Reaktion #220832

Reaktionsgleichung

2,2,6,6-tetramethylpiperidin-4-ol

sodium carbonate

sodium sulfite

hydrogen peroxide

tetrafluoroboric acid

→

title compound

1-Cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-ol

Lösungsmittel

water

acetonitrile

cyclohexane

water

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturmaintained at 80° C
2. 2
   Temperaturthe reaction mixture is heated at 80° C. for 3 hours
3. 3
   Temperaturcooled slowly to 50° C. over 1.75 hours
4. 4
   TemperaturThe reaction mixture is heated to 50° C
5. 5
   Temperaturmaintained at 62° C
6. 6
   Temperaturat reflux for 1 hour
7. 7
   TemperaturUpon cooling
8. 8
   SonstigeWork-up with ethyl acetate and purification by flash chromatography
9. 9
   Sonstigeafford
10. 10
    Sonstige2.03 g (24% overall yield) of a white solid

Vorschrift

A mixture of 5.21 g (33.1 mmol) of 2,2,6,6-tetramethylpiperidin-4-ol, 0.015 g (0.142 mmol) of anhydrous sodium carbonate, 15 ml of water, and 15 ml of acetonitrile is heated to 56° C. A solution of 6.5 g (96 mmol) of 50% aqueous hydrogen peroxide is added to the reaction mixture over 1.5 hours while the temperature is brought to and maintained at 80° C. After the peroxide is added, the reaction mixture is heated at 80° C. for 3 hours, then cooled slowly to 50° C. over 1.75 hours. The mixture is kept at ambient temperature overnight. A solution of 0.184 g (0.662 mmol) of ferrous sulfate heptahydrate and 0.664 g (3.6 mmol) of 48% tetrafluoroboric acid in 2 ml of water is added to the reaction mixture, followed by 30 ml of cyclohexane and 24 ml of acetonitrile. The reaction mixture is heated to 50° C. A solution of 8.7 g (128 mmol) of 50% aqueous peroxide is added to the reaction mixture dropwise over 4.5 hours while the temperature is brought to and maintained at 62° C. After the peroxide is added, the reaction mixture is stirred at reflux for 1 hour. Upon cooling, residual peroxide is decomposed by the addition of aqueous sodium sulfite solution. Work-up with ethyl acetate and purification by flash chromatography afford 2.03 g (24% overall yield) of a white solid. GC analysis shows that the reaction product has a retention time identical to that of an authentic sample of the title compound.

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