Reacción #220835

Ecuación de reacción

hydrogen peroxide

4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine

sodium bicarbonate

sodium sulfite

hydrogen peroxide

→

title compound

1-Cyclohexyloxy-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine

Disolventes

water

acetic acid

water

acetic acid

water

acetic acid

water

cyclohexane

acetonitrile

water

acetic acid

acetonitrile

cyclohexane

Ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe red mixture is cooled
2. 2
   LavadoThe mixture is washed with water
3. 3
   Extracciónthe wash is extracted with a mixture of cyclohexane and acetonitrile
4. 4
   workup.ADDITIONmore acetonitrile (13 ml) is added
5. 5
   Otrois brought to 50° C.
6. 6
   Temperaturais maintained near 60° C
7. 7
   TemperaturaThe mixture is heated
8. 8
   workup.ADDITIONis added
9. 9
   workup.WAITto stand at room temperature overnight
10. 10
    Temperaturato reflux
11. 11
    TemperaturaThe mixture is heated
12. 12
    workup.ADDITIONis added
13. 13
    TemperaturaThe mixture is cooled
14. 14
    Extracciónthe aqueous layer is extracted with ethyl acetate
15. 15
    Concentraciónconcentrated
16. 16
    OtroThe concentrate is purified by flash chromatography with 20:1 heptane-ethyl acetate
17. 17
    Otroto afford a red liquid
18. 18
    OtroA second purification by flash chromatography

Procedimiento

A solution of 2.84 g (41.7 mmol) of 50% aqueous hydrogen peroxide is added dropwise over 3 hours to a mixture of 5.98 g (14.1 mmol) of 4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine, 0.026 g (0.31 mmol, 2.2 mole percent) of sodium bicarbonate dissolved in 0.6 g of water, 4 ml of cyclohexane, and 4 ml of acetonitrile while the reaction temperature is maintained at 65-68° C. After the peroxide is added, the reaction mixture is stirred at 65° C. for 4.5 hours. The red mixture is cooled, and then diluted with cyclohexane and acetonitrile. The aqueous layer is discarded. The mixture is washed with water, and the wash is extracted with a mixture of cyclohexane and acetonitrile. A total of 25 ml each of cyclohexane and acetonitrile are used in the work up. The organic layers are combined, and more acetonitrile (13 ml) is added. The temperature is brought to 50° C., and a solution of 0.117 g (0.433 mmol) of ferric chloride hexahydrate and 0.096 g (1.60 mmol) of glacial acetic acid in 2 ml of water is added to the reaction mixture. A solution of 4.28 g (63 mmol) of 50% aqueous peroxide is added dropwise over 3 hours to the reaction mixture while the temperature is maintained near 60° C. A solution of 0.042 g of ferric chloride hexahydrate, 0.5 g of water, and 0.044 g of glacial acetic acid is added to the reaction mixture 1.5 hours after the peroxide addition is begun. The mixture is heated at reflux for 4 hours after the peroxide is added, then allowed to stand at room temperature overnight. Glacial acetic acid (0.403 g, 6.7 mmol) and a solution of 0.130 g of ferric chloride hexahydrate in 0.5 g of water are added to the red reaction mixture. The temperature is brought to reflux, and a solution of 4.56 g (67.0 mmol) of 50% aqueous hydrogen peroxide is added dropwise over 2 hours. A solution of 0.070 g of ferric chloride hexahydrate and 0.096 g of glacial acetic acid in 1 ml of water is added to the reaction mixture 1 hour after the peroxide addition is begun. The mixture is heated at reflux for 2.5 hours after the peroxide is added. The mixture is cooled and stirred with 10 ml of 10% aqueous sodium sulfite. Ethyl acetate is added, and the aqueous layer is extracted with ethyl acetate. The organic layers are combined and concentrated. The concentrate is purified by flash chromatography with 20:1 heptane-ethyl acetate to afford a red liquid. A second purification by flash chromatography affords 1.37 g (19% yield) of the title compound as a white solid, mp 42-45. The assay is % by NMR integration.

Fuente