Reaktion #1552025

Reaktionsgleichung

Toluene

p-toluenesulfonic acid monohydrate

3-butyl-1-(4-ethoxy-2,3-difluorophenyl)cyclopentanol

→

1-(3-butylcyclopent-1-enyl)-4-ethoxy-2,3-difluorobenzene

Ausbeute 91.2%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeobtained in the second step, in a reaction vessel
2. 2
   Sonstigeequipped with a Dean-Stark apparatus under an atmosphere of nitrogen
3. 3
   TemperaturThe mixture was refluxed for 30 minutes
4. 4
   Sonstigewas removed with a Dean-Stark apparatus
5. 5
   Waschenwas washed with water
6. 6
   TrocknenThe solution was dried over anhydrous magnesium sulfate
7. 7
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure
8. 8
   SonstigeThe residue was purified by silica gel chromatography (eluent: ethyl acetate/n-heptane=1/9 by volume)

Vorschrift

Toluene (50 ml) and p-toluenesulfonic acid monohydrate (0.14 g) were added to 3-butyl-1-(4-ethoxy-2,3-difluorophenyl)cyclopentanol (2.8 g) obtained in the second step, in a reaction vessel equipped with a Dean-Stark apparatus under an atmosphere of nitrogen. The mixture was refluxed for 30 minutes, while forming water was removed with a Dean-Stark apparatus. The reaction solution was cooled to room temperature and was washed with water. The solution was dried over anhydrous magnesium sulfate and the solvent was distilled off under reduced pressure. The residue was purified by silica gel chromatography (eluent: ethyl acetate/n-heptane=1/9 by volume) to give a mixture (2.4 g) of 1-(3-butylcyclopent-1-enyl)-4-ethoxy-2,3-difluorobenzene and 1-(4-butylcyclopent-1-enyl)-4-ethoxy-2,3-difluorobenzene.

Quelle