Reaktion #531886

Reaktionsgleichung

Et3N

ethyl 3-(3-chloro-4-methyl-2-thienyl)-2-cyano-3-oxopropanoate

POCl3

→

ethyl 3-chloro-3-(3-chloro-4-methyl-2-thienyl)-2-cyanoacrylate

Ausbeute 66.9%

Lösungsmittel

CHCl3

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was refluxed for 4 h
2. 2
   SonstigeThe mixture was evaporated
3. 3
   SonstigeAfter evaporation
4. 4
   workup.ADDITIONthe mixture was diluted with DCM (CH2Cl2) and with ice water
5. 5
   Extraktionwas extracted with DCM (CH2Cl2)
6. 6
   Waschenwashed with brine
7. 7
   Trocknendried over MgSO4 before concentration under reduced pressure

Vorschrift

To a solution of ethyl 3-(3-chloro-4-methyl-2-thienyl)-2-cyano-3-oxopropanoate (15.40 g, 56.67 mmol, 1 eq.) in 200 ml of CHCl3 was added POCl3 (86.9 g, 566 mmol, 10 eq.). Et3N (14.33 g, 141.6 mmol, 2.5 eq.) was added dropwise with stirring at 5° C., and the mixture was refluxed for 4 h. The mixture was evaporated. After evaporation, the mixture was diluted with DCM (CH2Cl2) and with ice water and was extracted with DCM (CH2Cl2) and washed with brine. The organic layers were combined and dried over MgSO4 before concentration under reduced pressure. The residue was subjected to column chromatography on silica gel to give ethyl 3-chloro-3-(3-chloro-4-methyl-2-thienyl)-2-cyanoacrylate (11 g, 66% yield) as a mixture of 2 isomers

Quelle