Heterocyclic compounds

Abstract

Compounds of the formula I R.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --R.sup.2 I wherein R.sup.1 and R.sup.2 are each an alkyl group having 1-10 C atoms, in which one or two non-adjacent CH.sub.2 groups can also be replaced by O atoms and/or CO groups and/or --OCO-- groups and/or --COO-- groups and/or --CH.dbd.CH-- groups, or are F, Cl, Br, CN or R.sup.3 --A.sup.3 --Z.sup.2 --, A.sup.1 is --A--, --A.sup.4 --A-- or --A--A.sup.4 --, A is a 1,3-dioxane-2,5-diyl or 1,3-dithiane-2,5-diyl group which is monosubstituted or polysubstituted in the 2-position and/or 4-position by alkyl each having 1-10 C atoms and/or in the 5-position by alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy each having 1-5 C atoms, or by F, Cl, Br or CN, A.sup.2, A.sup.3 and A.sup.4 each are 1,3-dithiane-2,5-diyl, piperidine-1,4-diyl, 1,4-bicyclo[2,2,2]octylene, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, 1,4-phenylene, 1,4-phenylene which is substituted by one or two F and/or Cl atoms and/or CH.sub.3 groups and/or CN groups and in which one or two CH groups can also be replaced by N atoms, or 1,4-cyclohexylene in which one or two non-adjacent CH.sub.2 groups can also be replaced by O atoms, Z.sup.1 and Z.sup.2 each are --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O-- or a single bond, and R.sup.3 is H, an alkyl group having 1-10 C atoms, in which one or two non-adjacent CH.sub.2 groups can also be replaced by O atoms and/or --CH.dbd.CH-- groups, or is F, Cl, Br or CN, can be used as components of liquid-crystalline phases.

Dependencies are inferred from the claim text.