Ethyl 4-(trifluoromethyl)benzoate → Ethyl 4-(trifluoromethyl)cyclohexane-1-carboxylate
Reaktionsgleichung
[F:1][C:2]([F:15])([F:14])[C:3]1[CH:13]=[CH:12][C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][CH:4]=1>[Rh].C(O)C>[F:1][C:2]([F:14])([F:15])[CH:3]1[CH2:4][CH2:5][CH:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[CH2:12][CH2:13]1Komponenten
4
Edukt 1
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 2
Versuchsvorschrift
A mixture of 0.47 mol of ethyl 4-trifluoromethylbenzoate (prepared from 4-trifluoromethylbenzoyl chloride, ethanol and pyridine), 1000 ml of ethanol and 20 g of rhodium/activated charcoal (5%) is hydrogenated for 5 hours under a pressure of 5 bar and at a temperature of 60° C. The ethyl 4-trifluoromethylcyclohexanecarboxylate (cis/trans =87%/13%) obtained after removal of the catalyst by filtration and removal of the solvent is, without prior purification, suspended in 300 ml of water and treated with 70 g of 30% sodium hydroxide solution, and the mixture is briefly heated to boiling and stirred at room temperature for 18 hours. Acidification using hydrochloric acid gives the carboxylic acid as a cis/trans mixture.