반응 #84035

반응 방정식

Methyl chloroformate

L-Valine

NaOH

sodium carbonate

→

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

반응 조건

후처리

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

실험 절차

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%).

출처