反応 #84035

反応方程式

Methyl chloroformate

L-Valine

NaOH

sodium carbonate

→

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

反応条件

後処理

1. 1
   その他reach room temperature
2. 2
   その他The reaction mixture was separated with ether (3×200 mL)
3. 3
   その他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
   その他was brought to room temperature
7. 7
   抽出extracted with dichloromethane (3×200 mL)
8. 8
   乾燥dried (sodium sulfate)
9. 9
   その他the solids were removed by filtration
10. 10
    その他The solvents of the filtrate were removed under reduced pressure
11. 11
    その他to afford a white solid
12. 12
    その他The white solid was further dried in vacuum (25.3 g, 86%)

実験手順

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%).

出典