Reaktion #161992

Reaktionsgleichung

pentafluorophenyl trifluoroacetate

#196

1,2-dimethyl-D-prolyl-N-[(2R,3S,4S)-1-carboxy-2-methoxy-4-methylhexan-3-yl]-N-methyl-L-valinamide

pyridine

→

compound #197

1,2-dimethyl-D-prolyl-N-[(3R,4S,5S)-3-methoxy-5-methyl-1-oxo-1-(pentafluorophenoxy)heptan-4-yl]-N-methyl-L-valinamide

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenthe solvent was concentrated in vacuo
2. 2
   SonstigeThe residue was purified by silica gel chromatography (Gradient: 1 to 10% methanol in dichloromethane)

Vorschrift

To a cooled solution (0° C.) of #196 (4.0 g, 9.4 mmol, 1 eq.) in dichloromethane (40 mL) was added dropwise pyridine (2.95 g, 37.6 mmol, 4 eq.) followed by a solution of pentafluorophenyl trifluoroacetate (3.9 g, 13.6 mmol, 1.4 eq.) in dichloromethane (5 mL). The mixture was stirred at room temperature for one hour, and the solvent was concentrated in vacuo. The residue was purified by silica gel chromatography (Gradient: 1 to 10% methanol in dichloromethane) to afford compound #197 (4.5 g, 81.2% (over three steps) as white solid.

Quelle