Реакция #84035

Уравнение реакции

Methyl chloroformate

L-Valine

NaOH

sodium carbonate

→

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

Условия реакции

Обработка

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

Методика

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%).

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