Reaktion #87130

Reaktionsgleichung

triphenylphosphine

imidazole

Cbz-L-Ser-OMe

iodide

→

(R)-methyl 2-(benzyloxycarbonylamino)-3-iodopropanoate

Ausbeute 57.0%

Lösungsmittel

DCM

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe cooling bath was removed
2. 2
   TemperaturAfter the mixture was re-cooled to 0° C.
3. 3
   workup.ADDITIONAfter the addition
4. 4
   Sonstigethe cooling bath was removed
5. 5
   Temperaturto warm to ambient temperature
6. 6
   workup.STIRRINGstirred for 1.5 h
7. 7
   FiltrationThe mixture was filtered
8. 8
   Einengenthe filtrate was concentrated
9. 9
   Sonstigeto remove most of the solvent
10. 10
    workup.ADDITIONMTBE (400 mL) was added to the residue
11. 11
    Filtrationthe mixture was filtered
12. 12
    Sonstigeto remove triphenylphosphine oxide
13. 13
    EinengenThe filtrate was concentrated
14. 14
    Sonstigethe residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=50:1 to 10:1)

Vorschrift

A mixture of triphenylphosphine (23.3 g, 0.890 mol) and imidazole (6.0 g, 0.89 mol) in DCM (100 mL) was cooled to 0° C. and iodide (22.6 g, 0.890 mol) was added in small portions over 0.5 h. The cooling bath was removed and the mixture was stirred for 0.5 h. After the mixture was re-cooled to 0° C., a solution of Cbz-L-Ser-OMe 15.0 g, 0.590 mol) in DCM (100 mL) was added dropwise. After the addition, the cooling bath was removed and the mixture was allowed to warm to ambient temperature and stirred for 1.5 h. The mixture was filtered and the filtrate was concentrated to remove most of the solvent. MTBE (400 mL) was added to the residue and the mixture was filtered to remove triphenylphosphine oxide. The filtrate was concentrated and the residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=50:1 to 10:1) to afford (R)-methyl 2-(benzyloxycarbonylamino)-3-iodopropanoate (12.3 g, 57% yield) as a colorless solid.

Quelle