Reaktion #47587

Reaktionsgleichung

triethylsilane

triethylsilane

(S)-2-benzyloxycarbonylamino-4,4-difluoro-pentanoic acid methyl ester

Triethylsilane

→

(S)-2-amino-4,4-difluoro-pentanoic acid methyl ester

Ausbeute 43.4%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeIn a flask under argon was placed
2. 2
   workup.STIRRINGthe mixture was stirred for 30 min
3. 3
   workup.STIRRINGthe mixture was stirred for 30 min
4. 4
   FiltrationThe mixture was filtered
5. 5
   Sonstigeto remove the catalyst
6. 6
   Waschenthe solids washed with methanol
7. 7
   EinengenThe filterate was concentrated in vacuo
8. 8
   Sonstigeazeotroped with toluene
9. 9
   workup.DISSOLUTIONdissolved in dichloromethane
10. 10
    Einengenconcentrated in vacuo with silica gel (2 g)
11. 11
    SonstigePurification by Biotage flash chromatography (Aspire 40 g column, 100% ethyl acetate)

Vorschrift

In a flask under argon was placed (S)-2-benzyloxycarbonylamino-4,4-difluoro-pentanoic acid methyl ester (626 mg, 2.08 mmol), methanol (8 mL) and 10% palladium on activated carbon (100 mg). Triethylsilane (3 mL) was added slowly and the mixture stirred at 25° C. for 30 min. Another portion of 10% palladium on activated carbon (100 mg) and triethylsilane (3 mL) was added and the mixture was stirred for 30 min. A third portion of 10% palladium on activated carbon (100 mg) and triethylsilane (3 mL) was added and the mixture was stirred for 30 min. The mixture was filtered to remove the catalyst and the solids washed with methanol. The filterate was concentrated in vacuo, azeotroped with toluene, dissolved in dichloromethane and concentrated in vacuo with silica gel (2 g). Purification by Biotage flash chromatography (Aspire 40 g column, 100% ethyl acetate) afforded (S)-2-amino-4,4-difluoro-pentanoic acid methyl ester (151 mg) as a clear colorless liquid.

Quelle