Reaktion #84041

Reaktionsgleichung

Methyl chloroformate

NaOH

L-Threonine

sodium carbonate

→

foam

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

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigereach room temperature
2. 2
   WaschenThe reaction mixture is washed with CH2Cl2 (3×50 mL)
3. 3
   Sonstigethe aqueous layer is contained in a round bottom flask
4. 4
   Temperaturcooled over an ice-water bath
5. 5
   workup.ADDITIONConcentrated HCl (aq) is added drop wise until pH 2
6. 6
   Sonstigeis brought to room temperature
7. 7
   Sonstigethe 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
   Filtrationfiltered
10. 10
    Waschenwashed with 2:1 mixture of MeOH/CH2Cl2 (50 mL)
11. 11
    EinengenThe filtrate was concentrated
12. 12
    Sonstigedried in vacuum at 40° C.

Vorschrift

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%).

Quelle