Reaktion #2280039

Reaktionsgleichung

Sodium triacetoxyborohydride

Methyl 3-[(tert-butoxycarbonyl)amino]-L-alaninate hydrochloride

2-methylpropanal

acetic acid

→

compound

methyl 3-[(tert-butoxycarbonyl)amino]-N-(2-methylpropyl)-L-alaninate

Lösungsmittel

1,2-dichloroethane methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred at room temperature for 2 hr
2. 2
   EinengenThe reaction mixture was concentrated under reduced pressure, saturated aqueous sodium hydrogen carbonate
3. 3
   workup.ADDITIONwas added
4. 4
   Extraktionthe mixture was extracted with ethyl acetate
5. 5
   TrocknenThe extract was dried over anhydrous magnesium sulfate
6. 6
   Sonstigethe solvent was evaporated under reduced pressure
7. 7
   Waschenthe fraction eluted with ethyl acetate-hexane (0:1-1:0)
8. 8
   Einengenwas concentrated under reduced pressure

Vorschrift

Methyl 3-[(tert-butoxycarbonyl)amino]-L-alaninate hydrochloride (2.00 g), 2-methylpropanal (860 μl) and acetic acid (450 μl) were dissolved in 1,2-dichloroethane-methanol (5:1, 60 ml), and the mixture was stirred at room temperature for 30 min. Sodium triacetoxyborohydride (4.00 g) was added and the mixture was stirred at room temperature for 2 hr. The reaction mixture was concentrated under reduced pressure, saturated aqueous sodium hydrogen carbonate was added, and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and the solvent was evaporated under reduced pressure. The residue was subjected to basic silica gel column chromatography, and the fraction eluted with ethyl acetate-hexane (0:1-1:0) was concentrated under reduced pressure to give the object compound (1.76 g).

Quelle