3-(2,5-Difluoro-phenyl)-acrylic acid → 3-(2,5-Difluorophenyl)propanoic acid
Reaktionsgleichung
[F:1][C:2]1[CH:12]=[CH:11][C:10]([F:13])=[CH:9][C:3]=1[CH:4]=[CH:5][C:6]([OH:8])=[O:7]>C(O)C.[Pd]>[F:1][C:2]1[CH:12]=[CH:11][C:10]([F:13])=[CH:9][C:3]=1[CH2:4][CH2:5][C:6]([OH:8])=[O:7]Komponenten
4
Edukt 1
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 2
Versuchsvorschrift
2,5-Difluorocinnamic acid (5.0 g, 27.2 mmol) was dissolved in 25 ml of ethanol and a catalytic amount of 10% Pd on carbon was added. The reaction mixture was hydrogenated at normal pressure for a period of 3 hrs. Filtration through celite and evaporation of the solvent afforded crude 3-(2,5-difluorophenyl)-propionic acid. This acid was dissolved in 75 ml of toluene and 5 ml of thionyl chloride was added. The reaction mixture was heated at +110° C. for a period of 2 hrs. Evaporation of the solvent afforded crude 3-(2,5-difluorophenyl)-propionyl chloride, which was dissolved in 25 ml of carbon disulfide and added drop wise to a suspension of 4 g of aluminium chloride in 100 ml of carbon disulfide. The reaction mixture was refluxed for 2 hrs and gave after work up and re-crystallization from ethanol 975 mg (22%) of 4,7-difluoro-1-indanone.