A solution of 14 g (0.041 mole) of 1-bromo-3-(7-chlorodibenzofuran-3-yloxy)-propane and 7.9 g (0.05 mole) of N-benzylimidazole in 25 ml of dry dioxane and 25 ml of dry acetonitrile was stirred for 40 hours at 70° C. The mixture was cooled to 15° C. in an ice bath, and the crystalline precipitate formed was then filtered off under suction, washed with 30 ml of ether and finally with 50 ml of n-pentane, and dried. 15 g (73.2% of theory) of N1 -benzyl-N3 -[3-(7-chlorodibenzofuran-3-yloxy)-propyl]-imidazolium bromide of melting point 162°-166° C. were obtained.
