Reaktion #8524

Reaktionsgleichung

2,3,4-trifluoroaniline

methyl D-lactate

2,6-lutidine

hydrochloric acid

trifluoromethanesulfonic acid

→

title compound

Ausbeute 90.0%

Methyl (2S)-2-(2,3,4-trifluoroanilino)propionate

Ausbeute 90.0%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturUnder ice-cooling
2. 2
   TemperaturThen it was cooled to 0° C. again
3. 3
   workup.STIRRINGThe mixture was stirred at the same temperature for 17 hours
4. 4
   Extraktionthe mixture was extracted with dichloromethane
5. 5
   WaschenThe extract was washed with a saturated aqueous solution of sodium chloride
6. 6
   Trocknendried over magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   SonstigeAfter evaporating the solvent
9. 9
   Sonstigethe residue thus obtained

Vorschrift

Under ice-cooling, methyl D-lactate (8.5 g) and 2,6-lutidine (11.4 g) were dissolved in dichloromethane (100 ml). After dropping anhydrous trifluoromethanesulfonic acid (25.4 g), the mixture was heated to room temperature and stirred for 30 minutes. Then it was cooled to 0° C. again and a solution (30 ml) of 2,3,4-trifluoroaniline (12.0 g) in dichloromethane was dropped therein to. The mixture was stirred at the same temperature for 17 hours. To the resultant solution, hydrochloric acid (0.5 mol/l) was added and the mixture was extracted with dichloromethane. The extract was washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and filtered. After evaporating the solvent, the residue thus obtained was subjected to silica gel column chromatography. Thus, 17.1 g (90%) of the title compound was obtained as an oily substance. The optical purity determined by HPLC was 97% ee.

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