Reaktion #2396851

Reaktionsgleichung

trans-4-pentylcyclohexanol

3,4-difluorobenzoyl chloride

→

3,4-difluorobenzoic acid-trans-4-pentylcyclohexyl ester

Ausbeute 70.0%

Lösungsmittel

toluene

pyridine

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeseparating the toluene layer
2. 2
   Waschenwashing it with 6N hydrochloric acid
3. 3
   Trocknenwith 2N-NaOH aqueous solution and further with water, drying with anhydrous sodium sulfate
4. 4
   workup.DISTILLATIONdistilling off toluene from the resulting toluene solution
5. 5
   Sonstigerecrystallizing the remaining oily product from ethanol

Vorschrift

To a solution of trans-4-pentylcyclohexanol (1.9 g 0.011 mol) dissolved in dry pyridine (5 ml) was added a solution of 3,4-difluorobenzoyl chloride (2.0 g, 0.011 mol) dissolved in dry toluene (10 ml), followed by heating the mixture at 60° C. for 3 hours, thereafter pouring the reaction mixture in water (100 ml), separating the toluene layer, washing it with 6N hydrochloric acid, then with 2N-NaOH aqueous solution and further with water, drying with anhydrous sodium sulfate, distilling off toluene from the resulting toluene solution and recrystallizing the remaining oily product from ethanol to obtain the objective 3,4-difluorobenzoic acid-trans-4-pentylcyclohexyl ester (2.4 g, 0.0077 mol) (yield: 70%). This product has a m.p. of 26.9° C., and its N-I point sought from a mixture thereof with trans-4-alkyl-(4-cyanophenyl)cyclohexanes according to extrapolation method was -6.0° C. Further its elemental analysis values were as follows: C: 70.03%, H: 7.81% (calculated values, C: 69.65% and H: 7.79%).

Quelle