DIOXANYLPYRIDINE, ITS MANUFACTURE AND ITS USE

摘要

Compounds of the formula I wherein X1 represents fluorine or chlorine; X2 denotes hydrogen, fluorine or chlorine; and R1 signifies an alkyl group in which optionally a >CH-CH< group is replaced by >C=C< and/or a methylene group is replaced by oxygen, their manufacture, liquid crystalline mixtures which contain such compounds and their use for electro-optical purposes.