반응 #158933

반응 방정식

ammonium chloride

Sodium triacetoxyborohydride

2,2-bis(tert-butoxycarbonylamino)-5-oxo-pentanoic acid benzyl ester

alanine ethyl ester hydrochloride

→

2,2-bis(tert-butoxycarbonylamino)-5-(1-ethoxycarbonyl-ethylamino)-pentanoic acid benzyl ester

수율 41.8%

용매

dichloromethane

반응 조건

후처리

1. 1
   추출The aqueous phase was extracted with dichloromethane (2×15 mL)
2. 2
   건조the combined organic phases were dried over sodium sulfate
3. 3
   여과filtered
4. 4
   기타the solvent was removed under reduced pressure
5. 5
   기타the solvent was removed under reduced pressure

실험 절차

Sodium triacetoxyborohydride (5 g, 23.5 mmol) was added to a solution of 2,2-bis(tert-butoxycarbonylamino)-5-oxo-pentanoic acid benzyl ester (3.34 g, 7.9 mmol) and alanine ethyl ester hydrochloride (3.62 g, 23.5 mmol) in dichloromethane (30 mL). After 1 hour saturated ammonium chloride (10 mL) was added and the mixture was stirred for 5 minutes. The aqueous phase was extracted with dichloromethane (2×15 mL), and the combined organic phases were dried over sodium sulfate, filtered and the solvent was removed under reduced pressure. The resulting residue was subjected to flash chromatography with eluent of (10% methanol in ethyl acetate) and hexane. The product-containing fractions were combined and the solvent was removed under reduced pressure to provide 2,2-bis(tert-butoxycarbonylamino)-5-(1-ethoxycarbonyl-ethylamino)-pentanoic acid benzyl ester (1.7 g, 3.3 mmol, 41%). C27H42N2O8 calculated 522.3 observed [M+1]+ 523.3; rt=2.08 min.

출처