Reaktion #640535

Reaktionsgleichung

N-benzyloxycarbonyl-L-phenylalanine chloromethyl ketone

sodium borohydride

→

N-benzyloxycarbonyl-3(S)-amino-1-chloro-4-phenyl-2(S)-butanol

Ausbeute 43.0%

Lösungsmittel

methanol

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvents were removed under reduced pressure at 40° C.
2. 2
   workup.DISSOLUTIONthe residue dissolved in ethyl acetate (approx. 1 L)
3. 3
   WaschenThe solution was washed sequentially with 1M potassium hydrogen sulfate, saturated sodium bicarbonate
4. 4
   TrocknenAfter drying over anhydrous magnesium sulfate
5. 5
   Filtrationfiltering
6. 6
   Sonstigethe solution was removed under reduced pressure
7. 7
   workup.ADDITIONTo the resulting oil was added hexane (approx. 1 L)
8. 8
   TemperaturAfter cooling to room temperature
9. 9
   Sonstigethe solids were collected
10. 10
    Waschenwashed with 2 L of hexane
11. 11
    SonstigeThe resulting solid was recrystallized from hot ethyl acetate and hexane

Vorschrift

To a solution of 75.0 g (0.226 mol) of N-benzyloxycarbonyl-L-phenylalanine chloromethyl ketone in a mixture of 807 mL of methanol and 807 mL of tetrahydrofuran at −2° C., was added 13.17 g (0.348 mol, 1.54 equiv.) of solid sodium borohydride over one hundred minutes. The solvents were removed under reduced pressure at 40° C. and the residue dissolved in ethyl acetate (approx. 1 L). The solution was washed sequentially with 1M potassium hydrogen sulfate, saturated sodium bicarbonate and then saturated sodium chloride solutions. After drying over anhydrous magnesium sulfate and filtering, the solution was removed under reduced pressure. To the resulting oil was added hexane (approx. 1 L) and the mixture warmed to 60° C. with swirling. After cooling to room temperature, the solids were collected and washed with 2 L of hexane. The resulting solid was recrystallized from hot ethyl acetate and hexane to afford 32.3 g (43% yield) of N-benzyloxycarbonyl-3(S)-amino-1-chloro-4-phenyl-2(S)-butanol, mp 150-151° C. and M+Li+=340.

Quelle