Réaction #8524

Équation de réaction

2,3,4-trifluoroaniline

methyl D-lactate

2,6-lutidine

hydrochloric acid

trifluoromethanesulfonic acid

→

title compound

Rendement 90.0%

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

Rendement 90.0%

Solvants

dichloromethane

dichloromethane

Conditions de réaction

Traitement

1. 1
   TempératureUnder ice-cooling
2. 2
   TempératureThen it was cooled to 0° C. again
3. 3
   workup.STIRRINGThe mixture was stirred at the same temperature for 17 hours
4. 4
   Extractionthe mixture was extracted with dichloromethane
5. 5
   LavageThe extract was washed with a saturated aqueous solution of sodium chloride
6. 6
   Séchagedried over magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   AutreAfter evaporating the solvent
9. 9
   Autrethe residue thus obtained

Mode opératoire

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.

Source