反应 #84035

反应方程式

Methyl chloroformate

L-Valine

NaOH

sodium carbonate

→

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

反应条件

后处理

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

实验过程

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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