Reacción #87114

Ecuación de reacción

triphenylphosphine

imidazole

(S)-methyl 2-((tert-butoxycarbonyl)amino)-3-hydroxypropanoate

iodide

→

(R)-methyl 2-((tert-butoxycarbonyl)amino)-3-iodopropanoate

Rendimiento 68.1%

Disolventes

DCM

DCM

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe cooling bath was removed
2. 2
   TemperaturaAfter the mixture was re-cooled to 0° C.
3. 3
   workup.ADDITIONAfter the addition
4. 4
   Otrothe cooling bath was removed
5. 5
   Temperaturato warm to ambient temperature
6. 6
   workup.STIRRINGstirred for 1.5 h
7. 7
   FiltraciónThe mixture was filtered
8. 8
   Concentraciónthe filtrate was concentrated
9. 9
   Otroto remove most of the solvent
10. 10
    workup.ADDITIONMTBE (400 mL) was added to the residue
11. 11
    Filtraciónthe mixture was filtered
12. 12
    Otroto remove triphenylphosphine oxide
13. 13
    ConcentraciónThe filtrate was concentrated
14. 14
    Otrothe residue was purified by flash column chromatography on silica gel

Procedimiento

A mixture of triphenylphosphine (131 g, 0.500 mol) and imidazole (34 g, 0.50 mol) in DCM (600 mL) was cooled to 0° C. and iodide (127 g, 0.50 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 (S)-methyl 2-((tert-butoxycarbonyl)amino)-3-hydroxypropanoate (73 g, 0.33 mol) in DCM (300 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 to afford (R)-methyl 2-((tert-butoxycarbonyl)amino)-3-iodopropanoate (74.0 g, 68% yield) as a colorless solid.

Fuente