2.23 g (5 mmoles) of (E)-1-[4-(2-bromoethoxy)-phenyl]-1,2-diphenyl-3,3,3-trifluoro-propene, prepared as described in Example 7, are dissolved in a mixture of 5.0 g (50 mmoles) of n-hexylamine and 10 ml of 2-methoxyethanol. The mixture is boiled for 30 minutes, then evaporated, and the residue is passed through a chromatographic column filled with 50 g of silica gel. The column is eluted with benzene. The fractions which are chromatographically uniform are combined and evaporated, the residue is dissolved in 5 ml of isopropanol, and a solution of 1.20 g (6 mmoles) of p-toluenesulfonic acid in 6 ml of isopropanol is added. The separated crystals are filtered off and washed with ether. 2.14 g (91.8%) of the aimed compound are obtained; m.p.: 151°-153° C.
