Réaction #84035

Équation de réaction

Methyl chloroformate

L-Valine

NaOH

sodium carbonate

→

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

Conditions de réaction

Traitement

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

Mode opératoire

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%).

Source