Reaktion #8570

Reaktionsgleichung

water

potassium hydroxide

(2S)-2-(2,3,4-trifluoroanilino)propanol

diethylethoxymethylenemalonate

→

title compound

Ausbeute 90.2%

Diethyl [2,3,4-trifluoro[(1S)-2-hydroxy-1-methylethyl]anilino]methylenemalonate

Ausbeute 90.2%

Lösungsmittel

DMF

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe liquid reaction mixture
2. 2
   Extraktionwas extracted with a solvent mixture of ethyl acetate and n-hexane (3:2)
3. 3
   WaschenThe organic layer was washed with water
4. 4
   Trocknendried over anhydrous magnesium sulfate
5. 5
   SonstigeAfter evaporating the solvent, IPE
6. 6
   workup.ADDITIONwas added to the obtained residue
7. 7
   SonstigeThe crystals thus precipitated
8. 8
   Filtrationwere collected by filtration
9. 9
   Sonstigethe moist product thus obtained
10. 10
    Sonstigewas dried under reduced pressure

Vorschrift

At room temperature, potassium hydroxide (330 mg) and tetrabutylammonium hydrogensulfate (82.7 mg) were dissolved in DMF (15 ml). After adding a solution (5 ml) of (2S)-2-(2,3,4-trifluoroanilino)propanol (1 g, 99.8% ee) and diethylethoxymethylenemalonate (2.09 g) in DMF, the resultant mixture was stirred for 1 hour. After adding water, the liquid reaction mixture was extracted with a solvent mixture of ethyl acetate and n-hexane (3:2). The organic layer was washed with water and dried over anhydrous magnesium sulfate. After evaporating the solvent, IPE was added to the obtained residue and the mixture was stirred at 0° C. for 1 hour. The crystals thus precipitated were collected by filtration and the moist product thus obtained was dried under reduced pressure. Thus, the title compound (1.65 g, 99. 8% ee) was obtained as colorless crystals. The 1H-NMR and IR spectral data of this product was identical with those of the compound obtained in Example 63.

Quelle