Reaktion #508777

Reaktionsgleichung

triethylamine

1,3-dicyclohexylcarbodiimide

Boc-alanine

HOBT

→

title compound

Ausbeute 81.5%

(2S)-2-[(tert-Butoxy)carbonylamino]-N-methoxy-N-methylpropanamide

Ausbeute 81.5%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was chilled with an ice water bath
2. 2
   SonstigeThe crude reaction
3. 3
   Temperaturwas then chilled in an ice water bath
4. 4
   Filtrationthe precipitate filtered
5. 5
   WaschenThe resulting organic solution was then washed twice with 1N aqueous sodium hydroxide (50 mL), twice with 10% aqueous citric acid (50 mL)
6. 6
   TrocknenThe solution was then dried over anhydrous sodium sulfate
7. 7
   Filtrationfiltered
8. 8
   Sonstigethe solvent evaporated
9. 9
   SonstigeThe resulting residue was purified by chromatography on a normal phase silica gel column with 30-100% ethyl acetate in hexanes
10. 10
    workup.ADDITIONFractions containing clean product
11. 11
    Sonstigethe solvent evaporated

Vorschrift

To a solution of Boc-alanine (20 grams, 105.7 mmol) in dichloromethane (170 ml) was added HOBT (14.28 g, 105.7 mmol) and N, O-dimethylhydroxylamine hydrochloride (10.31 g, 105.7 mmol). The mixture was chilled with an ice water bath then triethylamine (30 ml, 211.4 mmol) and 1,3-dicyclohexylcarbodiimide (21.81 g, 105.7 mmol) were added. The reaction was stirred in the ice water bath for 1 hour and then allowed to warm to room temperature overnight. The crude reaction was then chilled in an ice water bath and the precipitate filtered. The resulting organic solution was then washed twice with 1N aqueous sodium hydroxide (50 mL), twice with 10% aqueous citric acid (50 mL), and once with brine. The solution was then dried over anhydrous sodium sulfate, filtered, and the solvent evaporated. The resulting residue was purified by chromatography on a normal phase silica gel column with 30-100% ethyl acetate in hexanes. Fractions containing clean product were combined and the solvent evaporated to give the title compound (20 g, 81%): ES-MS (m/z) 233.2 [M+1]+.

Quelle