4.0 g of trans-3-n-pentylcyclopentanecarbonyl chloride (obtainable from 5-n-pentylcyclohexanone through chlorination, Faworski rearrangement of the α-chloroketone using sodium alcoholate in ether, hydrolysis of the ethyl 3-n-pentylcyclopentanecarboxylate, alkaline isomerization of the acid and subsequent reaction with thionyl chloride) are added dropwise at 100° to a solution of 4.4 g of 4-(trans-4-n-propylcyclohexyl)-phenol and 1.6 g of pyridine in 10 ml of toluene. The mixture is allowed to react for a further 3 hours, the pyridine hydrochloride is filtered off under suction, the filtrate is washed with water and dried, and the solvent is evaporated. The residue is crystallized from ethanol. 4-(trans-4-propylcyclohexyl)-phenyl trans-3-pentylcyclopentanecarboxylate is obtained; smectic B/isotropic phase transition: 49°.
