Reacción #84035

Ecuación de reacción

Methyl chloroformate

L-Valine

NaOH

sodium carbonate

→

(S)-2-(methoxycarbonylamino)-3-methylbutanoic acid

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroreach room temperature
2. 2
   OtroThe reaction mixture was separated with ether (3×200 mL)
3. 3
   Otrothe aqueous layer was contained in a round bottom flask
4. 4
   Temperaturacooled in a ice-water bath
5. 5
   workup.ADDITIONConcentrated HCl (aq) was added drop wise until pH 2
6. 6
   Otrowas brought to room temperature
7. 7
   Extracciónextracted with dichloromethane (3×200 mL)
8. 8
   Secadodried (sodium sulfate)
9. 9
   Otrothe solids were removed by filtration
10. 10
    OtroThe solvents of the filtrate were removed under reduced pressure
11. 11
    Otroto afford a white solid
12. 12
    OtroThe white solid was further dried in vacuum (25.3 g, 86%)

Procedimiento

To L-Valine (20 g, 167.3 mmol) in a stirred aqueous NaOH (1M, 167 mL) solution in a round bottom flask (1 L), sodium carbonate (8.866 g, 83.6 mmol) was added. The flask was cooled to 0° C. in an ice-water bath. Methyl chloroformate (17.4 g, 184 mmol) was added drop wise and the reaction mixture was allowed to stir for 15 hours and reach room temperature. The reaction mixture was separated with ether (3×200 mL), and the aqueous layer was contained in a round bottom flask and cooled in a ice-water bath. Concentrated HCl (aq) was added drop wise until pH 2. The mixture was brought to room temperature and extracted with dichloromethane (3×200 mL). The organic layers were pooled, dried (sodium sulfate), and the solids were removed by filtration. The solvents of the filtrate were removed under reduced pressure to afford a white solid. The white solid was further dried in vacuum (25.3 g, 86%).

Fuente