Реакция #84041

Уравнение реакции

Methyl chloroformate

NaOH

L-Threonine

sodium carbonate

→

foam

(2S,3R)-3-hydroxy-2-(methoxycarbonylamino)butanoic acid

Условия реакции

Обработка

1. 1
   Другоеreach room temperature
2. 2
   ПромывкаThe reaction mixture is washed with CH2Cl2 (3×50 mL)
3. 3
   Другоеthe aqueous layer is contained in a round bottom flask
4. 4
   Температураcooled over an ice-water bath
5. 5
   workup.ADDITIONConcentrated HCl (aq) is added drop wise until pH 2
6. 6
   Другоеis brought to room temperature
7. 7
   Другоеthe water is removed in vacuum
8. 8
   workup.ADDITIONThe residue was taken up in a 2:1 mixture of MeOH/CH2Cl2 (150 mL
9. 9
   Фильтрацияfiltered
10. 10
    Промывкаwashed with 2:1 mixture of MeOH/CH2Cl2 (50 mL)
11. 11
    КонцентрированиеThe filtrate was concentrated
12. 12
    Другоеdried in vacuum at 40° C.

Методика

An aqueous NaOH (1 M, 167 mL) solution is added, while stirring, to L-Threonine (20 g, 30.5 mmol) in a round bottom flask (1 L). To this solution was added sodium carbonate (9.8 g, 92.3 mmol). The flask is cooled to 0° C. in an ice-water bath. Methyl chloroformate (14.3 mL, 184.7 mmol) is added drop wise and the reaction mixture is allowed to stir for 15 hours and reach room temperature. The reaction mixture is washed with CH2Cl2 (3×50 mL), and the aqueous layer is contained in a round bottom flask and cooled over an ice-water bath. Concentrated HCl (aq) is added drop wise until pH 2. The aqueous solution is brought to room temperature and the water is removed in vacuum. The residue was taken up in a 2:1 mixture of MeOH/CH2Cl2 (150 mL, filtered and washed with 2:1 mixture of MeOH/CH2Cl2 (50 mL). The filtrate was concentrated and dried in vacuum at 40° C., resulting in white foam (29.1 g, 98%).

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