Reaktion #51515

Reaktionsgleichung

N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninol

TEMPO

sodium bromide

sodium bicarbonate

→

N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninal

Ausbeute 100.3%

Lösungsmittel

toluene

water

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added slowly over 30 minutes
2. 2
   workup.ADDITIONThree more additions (0.4 mL each) of bleach was added
3. 3
   workup.STIRRINGby stirring for 10 minutes
4. 4
   workup.ADDITIONafter each addition
5. 5
   Sonstigeto consume all the stating material
6. 6
   Sonstigeto separate
7. 7
   ExtraktionThe aqueous layer was extracted twice with 8 mL of toluene
8. 8
   WaschenThe combined organic layer was washed with 1.25 mL of a solution
9. 9
   workup.ADDITIONcontaining 0.075 g of potassium iodide, sodium bisulfate (0.125 g) and water (1.1 mL), 1.25 mL of 10% aqueous sodium thiosulfate solution, 1.25 mL of pH 7 phosphate buffer and 1.5 mL of brine solution
10. 10
    TrocknenThe organic solution was dried over magnesium sulfate
11. 11
    Filtrationfiltered
12. 12
    Einengenconcentrated under reduced pressure

Vorschrift

To a solution of 0.32 g (0.94 mmoles) of N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninol from Example 17 in 2.8 mL of toluene was added 2.4 mg (0.015 mmoles) of 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical (TEMPO), 0.1 g (0.97 mmoles) of sodium bromide, 2.8 mL of ethyl acetate and 0.34 mL of water. The mixture was cooled to 0° C. and an aqueous solution of 4.2 mL of 5% household bleach containing 0.23 g (3.0 mL, 2.738 mmoles) of sodium bicarbonate was added slowly over 30 minutes. The mixture was stirred at 0° C. for 10 minutes. Three more additions (0.4 mL each) of bleach was added followed by stirring for 10 minutes after each addition to consume all the stating material. The two phase mixture was allowed to separate. The aqueous layer was extracted twice with 8 mL of toluene. The combined organic layer was washed with 1.25 mL of a solution containing 0.075 g of potassium iodide, sodium bisulfate (0.125 g) and water (1.1 mL), 1.25 mL of 10% aqueous sodium thiosulfate solution, 1.25 mL of pH 7 phosphate buffer and 1.5 mL of brine solution. The organic solution was dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 0.32 g (100% yield) of N-(t-Butoxycarbonyl)-N-benzyl-L-phenylalaninal.

Quelle