Reaktion #47679

Reaktionsgleichung

[(S)-3-Methyl-1-(pyrazin-2-ylcarbamoyl)-butyl]-carbamic acid t-butyl ester

trifluoroacetic acid dichloromethane

ethyl acetate

→

(S)-2-amino-4-methyl-pentanoic acid pyrazin-2-ylamide

Ausbeute 78.3%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe layers separated
2. 2
   workup.ADDITIONby the addition of solid sodium hydroxide
3. 3
   ExtraktionThe basic aqueous phase was extracted with ethyl acetate (3×)
4. 4
   Trocknendried over sodium sulfate
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated in vacuo

Vorschrift

[(S)-3-Methyl-1-(pyrazin-2-ylcarbamoyl)-butyl]-carbamic acid t-butyl ester (0.645 g, 2.09 mmol) was treated with a 30% trifluoroacetic acid/dichloromethane (10 mL) solution at 0° C. and the resulting mixture allowed to warm to room temperature over 1.5 h. At this time the mixture was partioned between ethyl acetate and water and the layers separated. The aqueous phase was made basic (pH=10) by the addition of solid sodium hydroxide. The basic aqueous phase was extracted with ethyl acetate (3×) and the ethyl acetate layers were combined, dried over sodium sulfate, filtered and concentrated in vacuo to afford (S)-2-amino-4-methyl-pentanoic acid pyrazin-2-ylamide (0.341 g, 78%).

Quelle