1.9 g of 2,3-difluoro-4-heptyloxybenzoic acid, 2 g of 4-[4-(trans-4-pentylcyclohexyl)-1-butyl]phenol and 0.1 g of 4-(dimethylamino)pyridine were dissolved in 250 ml of dichloromethane and the solution was treated portionwise within 10 minutes while stirring with 1.6 g of N,N'-dicyclohexylcarbodiimide. The mixture was stirred at room temperature overnight and then filtered. The filtrate was diluted with dichloromethane, washed twice with 50 ml of saturated sodium carbonate solution each time and then with water, dried over magnesium sulfate, filtered and then concentrated. Chromatography of the residue on silica gel with toluene/ethyl acetate (vol. 4:1) and recrystallization from ethanol gave 2 g of 2,3-difluoro-4-heptyloxybenzoic acid 4-[4-(trans-4-pentylcyclohexyl)-1-butyl]phenyl ester with m.p. (C-SC) 67° C., SC -N 70° C. and cl.p. (N-I) 128° C.
