Reaktion #536665

Reaktionsgleichung

NaHCO3

Trifluoromethanesulfonic anhydride

methyl (2S)-2-[(tert-butoxycarbonyl)amino]-3-(4-hydroxyphenyl)propanoate

triethylamine

→

(S)-2-tert-butoxycarbonylamino-3-(4-trifluoromethanesulfonyloxy-phenyl)-propionic acid methyl ester

Ausbeute 93.6%

Lösungsmittel

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe reaction was extracted with dichloromethane
2. 2
   WaschenThe organic phase was washed with saturated brine
3. 3
   Trocknendried over magnesium sulfate
4. 4
   Filtrationfiltered
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   SonstigeThe crude product was purified by Flash chromatography on a silica gel column (EtOAc:Hexane, 1:3 to 1:1)

Vorschrift

Trifluoromethanesulfonic anhydride (0.85 mL, 5.1 mmol) was added to a solution of methyl (2S)-2-[(tert-butoxycarbonyl)amino]-3-(4-hydroxyphenyl)propanoate (1 g, 3 mmol) (Aldrich, Cat 469106) and triethylamine (1 mL, 10 mmol) in methylene chloride (30 mL) at −78° C. The reaction was stirred for 1 h. at −78° C. Saturated NaHCO3 was added and the reaction was extracted with dichloromethane. The organic phase was washed with saturated brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by Flash chromatography on a silica gel column (EtOAc:Hexane, 1:3 to 1:1) to obtain (S)-2-tert-butoxycarbonylamino-3-(4-trifluoromethanesulfonyloxy-phenyl)-propionic acid methyl ester (1.2 g, 80%) as light yellow oil. Analytical LCMS (M+H-Boc)+: m/z=327.9.

Quelle