DE3731619A1 - Nitrogen-containing compounds for use in liquid-crystalline mixtures - Google Patents

Abstract

The invention relates to nitrogen-containing compounds for use in liquid-crystalline mixtures, of the formula I R<1>-A<1>-Z<1>-A-(Z<2>-A<2>)m-R<2> in which R<1>, A<1>, Z<1>, A, Z<2>, A<2>, m and R<2> are as defined in Claim 1.

Description

The invention relates to liquid-crystalline nitrogen-containing Compounds of formula I.

R¹-A¹-Z¹-A- (Z²-A²) _m -R² (I)

wherein

R¹ and R² each independently of one another H, CN, NCS, F, Cl, -NC or N₃ or alkyl with 1-18 C atoms, in which one or more CH₂ groups can be replaced by O and / or S atoms and / or -CO groups and / or -O-CO and / or -CO-O groups and / or unsubstituted or -CH = CH groups and / or - substituted by halogen, CN, CH₃, -NC or N₃ CH-halogen and / or -CHCN and / or -CHNC and / or -CHN₃ groups and / or unsubstituted or substituted by CH₃ where two heteroatoms are not directly linked to one another, or perfluoroalkyl with 1-18 C atoms, in which one or more CF₂ groups can also be replaced by O and / or S atoms and / or -CH₂ groups and / or - CO groups and / or -OCO and / or -COO groups and / or unsubstituted or substituted by halogen, CN, CH₃, -NC or N₃ -CH = CH groups and / or -CH-halogen and / or -CHCN and / or -CHNC and / or -CHN₃ groups and / or unsubstituted or substituted by CH₃ where two heteroatoms are not directly linked, A, A¹
and A² each independently of one another unsubstituted or one or more times by halogen atoms and / or CN and / or CH₃ groups or simply by -NC or N₃ substituted 1,4-phenylene, in which one or more CH groups can be replaced by N. , 1,4-cyclohexylene, in which one or two non-adjacent CH₂ groups can be replaced by O and / or S atoms, 1,4-bicyclo- (2,2,2) octylene, pyridine-2,5 -diyl, piperidine-1,4-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, trans-decahydronaphthalene-2,6-diyl or a 5-membered, heterocyclic ring system, Z¹ and Z² each independently or unsubstituted or substituted one or more times by CH₃, halogen, nitrile and / or simply by -NC or N₃ -CH₂CH₂-, -CH₂O-, -CH₂CO-, -CH = CH- or a single bond, and
m0, 1 or 2

means with the proviso that

• a) at least one -NC- or N₃ group in R¹, R², A, A¹, A², Z¹ or Z² is included
• b) in the case A¹ = A = 1,4-phenylene, Z¹ = -OCO or -CO-O- and m = 0 at least one N₃ group is included.

For the sake of simplicity, Phe in the following means one 1,4-phenylene group, Cy a 1,4-cyclohexylene group, Dio a 1,3-dioxane-2,5-diyl group, Bi a bicyclo (2,2,2) octylene group, Pyd a pyridine-2,5-diyl group, Pip one Piperidine-1,4-diyl group and pyr a pyrimidine-2,5-diyl group, these groups being unsubstituted or substituted could be. R³ in the following means an N₃- or -NC group.

The compounds of formula I can be used as components liquid crystalline phases are used, in particular for displays based on the principle of the twisted cell (TN displays), the guest host effect, the effect of Deformation of erected phases or the effect of based on dynamic scattering.

The invention was based, new stable task find liquid-crystalline or mesogenic compounds, the as components of liquid crystalline phases are suitable.

It has now been found that the compounds of Formula I excellent as both nematic components are also suitable for liquid crystal phases.  

With the provision of the compounds of formula I is also generally the range of liquid crystalline Substances that are different application aspects for manufacturing liquid-crystalline mixtures are suitable, considerably broadened.

The compounds of formula I have a wide range Scope of application. Depending on the selection of the Substituents can use these compounds as base materials serve from which liquid crystalline phases for the majority are composed; but it can also compounds of the formula I liquid-crystalline base materials added from other classes of compounds be, for example, the dielectric and / or optical anisotropy or other parameters of such To optimize the dielectric. The connections of the Formula I are also suitable as intermediates for Manufacture of other substances that prove to be ingredients Allow liquid crystalline phases to be used.

The compounds of formula I are in a pure state colorless and form liquid-crystalline mesophases in one conveniently located for electro-optical use Temperature ranges.

The invention thus relates to the compounds of Formula I and the use of the compounds of the formula I as components of liquid crystalline phases.

The invention also relates to liquid crystalline Phases containing at least one compound of formula I and liquid crystal display elements, in particular electro-optical display elements, such Phases included.  

The compounds of formula I accordingly include Connections of sub-forms Ia and Ib (with two rings).

R¹-A¹-A-R² (Ia)
R¹-A¹-Z¹-A-R² (Ib)

Ic to If (with three rings)

R¹-A¹-A-A²-R² (Ic)
R¹-A¹-Z¹-A-A²-R² (Id)
R¹-A¹-A-Z²-A²-R² (Ie)
R¹-A¹-Z¹-A-Z²-A²-R² (If)

and Ig to In (with four rings)

R¹-A¹-A-A²-A²-R² (Ig)
R¹-A¹-Z¹-A-A²-A²-R² (Ih)
R¹-A¹-A-Z²-A²-A²-R² (Ii)
R¹-A¹-A-A²-Z²-A²-R² (Ij)
R¹-A¹-Z¹-A-Z²-A²-A²-R² (Ik)
R¹-A¹-Z¹-A-A²-Z²-A²-R² (Il)
R¹-A¹-A-Z²-A²-Z²-A²-R² (Im)
R¹-A¹-Z¹-A-Z²-A²-Z²-A²-R² (In)

These include those of the sub-formulas Ia, Ib, Ic, Id and Ie preferred.

The -NC- or N₃ group can in the above and below Formulas either as an end group on a ring or as lateral substituent on one of the rings A¹, A or A² or in one of the wing groups R¹ and R² or in one the bridge members Z¹ and Z² are.  

Accordingly, preferred compounds include the Sub-formula Ia those of sub-formulas Iaa to Iam:

R¹-Cy-Cy-R³ (Iaa)
R¹-Cy-Cy-CH₂R³ (Iab)
R¹-Cy-Phe-R³ (Iac)

R¹-Phe-Cy-R³ (Iae)

R¹-Pyr-Phe-R³ (Iah)
R¹-Bi-Cy-R³ (Iai)
R¹-Dio-Cy-CH₂-R³ (Iaj)

R¹-Cy-Bi-R³ (Ial)
R¹-Phe-Pyd-R³ (Iam)

Of the compounds of the sub-formulas Ib, Ic, Id, Ie and If are those of the sub-formulas I1 to I38 prefers:

R¹-Cy-Z¹-Cy-R³ (I1)
R¹-Cy-Z¹-Cy-CH₂R³ (I2)
R¹-Cy-Z¹-Phe-R³ (I3)

R¹-Phe-Z¹-Cy-R³ (I5)

R¹-Cy-Z¹-Pyd-R³ (I7)
R¹-Phe-Z¹-Pyd-R³ (I8)

R¹-Pyr-Z¹-Phe-R³ (I10)
R¹-Bi-Z¹-Cy-R³ (I11)
R¹-Dio-Z¹-Cy-CH₂-R³ (I12)

R¹-Phe-Cy-Cy-R³ (I14)
R¹-Cy-Cy-Phe-R³ (I15)

R¹-Dio-Phe-Phe-R³ (I19)
R¹-Pyr-Phe-Cy-CH₂R³ (I20)
R¹-Bi-Phe-Phe-R³ (I21)

R¹-Phe-Z-Phe-Pyd-R³ (I25)
R¹-Phe-Z¹-Phe-Phe-R³ (I26)

R¹-Phe-Z¹-Phe-Z²-Cy-CH₂R³ (I31)

R¹-Bi-Phe-Z²-Cy-R³ (I33)

R¹-Cy-Z¹-Dio-Z²-Phe-R³ (I37)

In the formulas above and below, R 1 and / or R² if they are not the -NC- or the N₃ group contain, preferably alkyl, alkoxy, oxaalkyl or Perfluoroalkyl, and R³ optionally -NC or N₃.

A, A¹ and A² are preferably 1,4-phenylene, 1,4-cyclohexylene, Dioxane-2,5-diyl, bicyclo (2,2,2) octylene, pyridine-2,5-diyl or piperidinediyl, these groups unsubstituted or by -NC or by N₃ or also by halogen atom (s) and / or CN and / or CH₃ groups may be substituted.

Z¹ and Z² are preferably single bonds,

in the second place, preferably -CH₂O- or -CH = CH-.

For Z¹ and Z² there are also the reverse bridges, e.g. B.

in question.  

If A¹ = A is 1,4-phenylene and Z¹ are -O-CO or CO-O- and m is 0, at least one N₃ group must be contained in formula I.

If R¹ and / or R² are alkyl radicals, in which also for example an (alkoxy or oxaalkyl) CH₂ group can be replaced by an O atom, so they can be straight-chain or be branched. They are preferably straight chain, have 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 carbon atoms and are therefore preferably ethyl, propyl, Butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl or dodecyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy, Heptoxy, octoxy, nonoxy, decoxy or undecoxy, 2-oxapropyl (= Methoxymethyl), 2 - (= ethoxymethyl) or 3-oxabutyl (= 2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyl or 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.

Compounds of formula I with branched wing groups can occasionally be due to better solubility in the usual liquid crystalline base materials from Be important, especially as chiral dopants, if they are optically active. Branched chains of these Species usually contain no more than one chain branch, however, multiple branching is possible.

Preferred branched radicals R 1 and R² are isopropyl, 2-butyl (= 1-methylpropyl), isobutyl (= 2-methylpropyl), 2-methylbutyl, isopentyl (= 3-methylbutyl), 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, 2-octyl, isopropoxy, 2-methylpropoxy, 2-methylbutoxy, 3-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy, 2-ethylhexoxy,  1-methylhexoxy, 2-octyloxy, 2-oxa-3-methylbutyl, 3-oxa-4-methylpentyl, 4-methylhexyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-methyloctoxy, 6-methyloctanoyloxy, 5-methylheptyloxycarbonyl, 2-methylbutylryloxy, 3-methylvaleryloxy, 4-methylhexanoyloxy, 2-chloropropionyloxy, 2-chloro-3-methylbutyryloxy, 2-chloro-4-methylvaleryloxy, 2-chloro-3-methylvaleryloxy, 2-methyl-3-oxapentyl, 3-methyloxahexyl.

If the compounds of formula I are asymmetrical Containing a carbon atom, the formula I includes racemates and also optically active enantiomers and mixtures of enantiomers.

The -NC- or N₃ group is primarily preferred in one of the wing groups R¹ or R², secondarily preferred it is a lateral substituent in one of the rings contain.

Compounds of the formula I which are particularly preferred are contain either an -NC- or an N₃ group, the -NC group can be obtained by converting an N₃ group can.

The compounds of formula I are known per se Methods produced as described in the literature (e.g. in standard works such as Houben Weyl, Methods of Organic Chemistry, Georg-Thieme-Verlag, Stuttgart) are described, namely under reaction conditions, known and suitable for the above-mentioned implementations are. You can also from well-known, here make use of variants not mentioned.  

If desired, the starting materials can also be in situ are formed such that they can be removed from the reaction mixture not isolated, but immediately to the Reacts compounds of formula I.

Esters of formula I (R¹ and / or R² = alkyl, wherein one or two CH₂ groups by -O-CO- and / or -CO-O groups are replaced and / or Z¹ and / or Z² = -CO-O- or -O-CO-) can also by esterification of appropriate carboxylic acids (or their reactive derivatives) with alcohols or phenols (or their reactive derivatives) be preserved.

As reactive derivatives of the carboxylic acids mentioned the acid halides are particularly suitable, above all the chlorides and bromides, also the anhydrides, azides or esters, especially alkyl esters with 1-4 carbon atoms in the alkyl group.

As reactive derivatives of the alcohols mentioned or Phenols come in particular the corresponding metal alcoholates or phenolates, preferably an alkali metal like Na or K, into consideration.

The esterification is advantageous in the presence of a inert solvent performed. Are well suited in particular ethers such as diethyl ether, di-n-butyl ether, THF, dioxane or anisole, ketones such as acetone, butanone or cyclohexanone, amides such as DMF or phosphoric acid hexamethyltriamide, Hydrocarbons such as benzene, toluene or xylene, halogenated hydrocarbons such as carbon tetrachloride or tetrachlorethylene and sulfoxides such as Dimethyl sulfoxide or sulfolane. Immiscible with water Solvents can also be used at the same time  azeotropic distillation of the formed during the esterification Water can be used. Occasionally, too an excess of an organic base, e.g. B. pyridine, Quinoline or triethylamine as a solvent for the Esterification can be applied. The esterification can also in the absence of a solvent, e.g. B. by simple Heating the components in the presence of sodium acetate, be performed. The reaction temperature is usually between -50 ° and + 250 °, preferably between -20 ° and + 80 °. At these temperatures the esterification reactions are usually after 15 minutes to 48 hours completed.

In particular, the reaction conditions depend on the Esterification largely depends on the nature of the used Starting materials. So is a free carboxylic acid a free alcohol or phenol usually in the presence a strong acid, for example a mineral acid such as hydrochloric acid or sulfuric acid. A preferred reaction is the reaction of an acid anhydride or in particular an acid chloride with a Alcohol, preferably in a basic environment, where as bases in particular alkali metal hydroxides such as sodium or potassium hydroxide, alkali metal carbonates or bicarbonates like sodium carbonate, sodium hydrogen carbonate, Potassium carbonate or potassium hydrogen carbonate, alkali metal acetates such as sodium or potassium acetate, alkaline earth metal hydroxides like calcium hydroxide or organic bases like Triethylamine, pyridine, lutidine, collidine or quinoline are important. Another preferred embodiment the esterification is that you have the alcohol or the phenol first in the sodium or potassium alcoholate or -phenolate transferred, e.g. B. by treatment with ethanolic sodium or potassium hydroxide solution, this isolated  and together with sodium bicarbonate or potassium carbonate suspended in acetone or diethyl ether with stirring and this suspension with a solution of the acid chloride or anhydrides in diethyl ether, acetone or DMF offset, expedient at temperatures between about -25 ° and + 20 °.

Dioxane derivatives or dithiane derivatives of the formula I (wherein one of the groups A¹ and / or A² and / or A a 1,3- Dioxane-2,5-diyl group or a 1,3-dithiane-2,5-diyl group Group means) are expedient by reaction of one corresponding aldehyde with a corresponding 1,3-diol or a corresponding 1,3-dithiol (or a of its reactive derivatives), preferably in the presence of an inert solvent such as Benzene or toluene and / or a catalyst e.g. B. a strong acid such as sulfuric acid, benzene or p-toluenesulfonic acid, at temperatures between about 20 ° and about 150 °, preferably between 80 ° and 120 °. As reactive derivatives of the starting materials are suitable primarily acetals.

The above aldehydes, 1,3-diols and 1,3-dithiols as well some of their reactive derivatives are known, some of them can be done without difficulty using standard procedures of organic chemistry from literature Connections are made. For example the aldehydes by oxidation of corresponding alcohols or by reducing corresponding carboxylic acids or of their derivatives, the diols by reducing corresponding ones Diester, as well as the dithiols by implementing corresponding ones Dihalides available with NaSH.  

For the preparation of nitriles of formula I (wherein R¹ or R² means CN) corresponding acid amides can be dehydrated will. The amides are e.g. B. from corresponding Esters or acid halides by reaction with ammonia available. Suitable water-releasing agents are, for example inorganic acid chlorides such as SOCl₂, PCl₅, POCl₃, SO₂Cl₂, COCl₂, also P₂O₅, P₂S₅, AlCl₃ (e.g. as a double compound with NaCl), aromatic sulfonic acids and sulfonic acid halides. You can do it in the present or absence of an inert solvent at temperatures work between about 0 ° and 150 °; as a solvent come z. B. bases such as pyridine or triethylamine, aromatic hydrocarbons such as benzene, toluene or Xylene or amides such as DMF can be considered.

For the preparation of the nitriles mentioned above Formula I can also be acid halides, preferably the chorides, react with sulfamide, appropriate in an inert solvent such as tetramethyl sulfone at temperatures between about 80 ° and 150 °, preferably at 120 °. After the usual workup can you isolate the nitriles directly.

Ethers of formula I (wherein R¹ and / or R² is an alkyl group means in which one or two CH₂ groups by O atoms are replaced, and / or wherein Z¹ and / or Z² is a -OCH₂- or is a -CH₂O group) are corresponding by etherification Hydroxy compounds, preferably corresponding Phenols, available being the hydroxy compound expediently first in a corresponding metal derivative, e.g. B. by treatment with NaH, NaNH₂, NaOH, KOH, Na₂CO₃ or K₂CO₃ in the corresponding alkali metal alcoholate or alkali metal phenolate is converted. This can then with the corresponding alkyl halide, sulfonate  or Dialkylsulfonat be implemented, appropriately in an inert solvent such as acetone, 1,2-dimethoxyethane, DMF or dimethyl sulfoxide or an excess of aqueous or aqueous-alcoholic NaOH or KOH at temperatures between about 20 ° and 100 °.

For the preparation of nitriles of formula I (wherein R¹ or R² is CN and / or A¹ and / or A² and / or A³ at least one CN group is also substituted) corresponding chlorine or bromine compounds of the formula I. be reacted with a cyanide, advantageously with a Metal cyanide such as NaCN, KCN or Cu₂ (CN) ₂, e.g. B. in the present of pyridine in an inert solvent such as DMF or N-methylpyrrolidone at temperatures between 20 ° and 200 °.

For the production of laterally substituted fluorine or Chlorine compounds of formula I (wherein A¹ and / or A² and / or A mean aromatics, R¹ and R² the usual Corresponding aniline derivatives can have meanings with sodium nitrite and either with tetrafluoroboric acid (to introduce an F atom) or with Copper (I) chloride (for the introduction of a Cl atom) too the diazonium salts are implemented, which then at Temperatures between 100 ° -140 ° are thermally decomposed.

The introduction of the N₃ groups also takes place after methods known from the literature. So can azide compounds are produced, for example by substitution of halogen compounds or by adding hydrochloric acid to corresponding olefins. These Reactions are described in the literature (e.g. from Smith, P.A.S. in "Open-Chain Nitrogen Compounds",  Benjamin, New York, 1966, Vol. II, pp. 211 or from A. Hassner et al. in J. Org. Chem. 1984, 49, 4237). In the respective syntheses, one can also do it in itself known, not mentioned variants use do.

The conversion of the N₃ group into the corresponding -NC group takes place according to methods known from the literature. So can the isonitrile compounds by reductive cleavage of the Azides, for example with hydrogen and transition metal catalysts, preferably platinum or palladium, in particular Palladium / activated carbon, subsequent formylation with the mixed anhydride of formic and acetic acid, preferably in situ from formic acid and acetic anhydride generated, and then obtained dehydration will. As water-releasing agents, for example an arylsulfonyl chloride in pyridine or quinoline or Phosgene in the presence of a tertiary amine or phosphorus oxychloride together with pyridine and potassium tert-butoxide, but particularly preferably triphenylphosphine and triethylamine, used (e.g. Liebigs Ann. Chem. 1976, 969-977).

The introduction of the -NC group can also at Pyridylisonitriles on the Chichibabin reaction accessible pyridylamines take place.

Access to the 1-axially alkylated 1-isonitriles is not just about the 1-axially alkylated 1-azides in the above described way possible, but also by deprotonation and subsequent alkylation of the 1-axially unsubstituted 1-isonitrile.  

Deprotonation can, preferably with amide bases in inert solvents such as hydrocarbons and ethers take place, lithium diisopropylamide in a mixture from tetrahydrofuran with hexane is particularly preferred. Alkyl halides, preferably alkyl iodides, can be used for the alkylation be used.

The liquid-crystalline phases according to the invention consist from 2 to 15, preferably 3 to 12 components, including at least one compound of formula I. The others Components are preferably selected from the nematic or nematogenic substances, especially the known substances from the classes of azoxybenzenes, Benzylidenanilines, biphenyls, terphenyls, phenyl or Cyclohexylbenzoate, cyclohexane carboxylic acid phenyl or cyclohexyl esters, phenylcyclohexanes, cyclohexylbiphenyls, Cyclohexylcyclohexanes, cyclohexylnaphthalenes, 1,4-bis-cyclohexylbenzenes, 4,4'-bis-cyclohexylbiphenyls, phenyl or cyclohexylpyrimidines, phenyl- or cyclohexyldioxanes, Phenyl- or cyclohexyl-1,3-dithiane, 1-phenyl-2-cyclohexylethane, if applicable, holographic style level, Benzylphenyl ether, tolanes and substituted cinnamic acids.

The most important as part of such liquid crystalline Leave phases in question are characterized by Formula II,

R′-L-G-E-R ″ (II)

where L and E each have a carbocyclic or heterocyclic ring system from 1,4-disubstituted benzene and cyclohexane rings, 4,4'-disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted Pyrimidine and 1,3-dioxane rings, 2,6-disubstituted Naphthalene, di- and tetrahydronaphthalene, Quinazoline and tetrahydroquinazoline formed group,

-CH = CH - N (O) = N- -CH = CY - CH = N (O) - -C = C - CH₂-CH₂- -CO-O - CH₂-O- -CO-S - CH₂-S- -CH = N - COO-Phe-COO-

or a C-C single bond, Y halogen, preferably Chlorine, or CN, and R ′ and R ″ alkyl, alkoxy, alkanoyloxy or alkoxycarbonyloxy with up to 18, preferably up to to 8 carbon atoms, or one of these residues also CN, NC, NO₂, CH₃, F, Cl or Br mean.

Most of these compounds have R 'and R ″ apart different, one of these residues usually one Is alkyl or alkoxy group. But also other variants the proposed substituents are common. Lots such substances or mixtures thereof are commercially available available. All of these substances are known from the literature Methods can be produced.

The phases according to the invention contain about 0.1 to 99, preferably 10 to 95%, one or more compounds of formula I.  

Dielectrics according to the invention are further preferred containing 0.1 to 40, preferably 0.5 to 30%, one or more compounds of formula I.

Compounds of formula I with an optically active wing group are suitable as components of nematic liquid crystalline Phases to avoid reverse twist and to improve the elastic constants.

Furthermore, the optically active compounds of formula I also as components of chirally tilted smectic liquid crystalline phases suitable.

These phases are included in the achiral base mixture in addition to chiral compounds of formula I at least one other component with a negative or smaller amount positive dielectric anisotropy.

As further components with negative dielectric Anisotropy are suitable compounds containing the Structural element A, B or C.

Preferred compounds of this type correspond to the Formulas IVa, IVb and IVc:

R′-Q³-Q⁴-R ′ ′ ′ (IVc)

R 'and R ″ each preferably represent straight-chain Alkyl or alkoxy groups, each with 2 to 10 carbon atoms. Q¹ and Q² each represent 1,4-phenylene, trans-1,4-cyclohexylene, 4,4'-biphenylyl, 4- (trans-4-cyclohexyl) phenyl, trans, trans-4,4'-bicyclohexyl or one of the groups Q¹ and Q² also a single bond.

Q³ and Q⁴ each represent 1,4-phenylene, 4,4'-biphenylyl or trans-1,4-cyclohexylene. One of the groups Q³ and Q⁴ can also mean 1,4-phenylene, in which at least one CH group is replaced by N. R '' 'is an optical active residue with an asymmetric carbon atom the structure

Particularly preferred Compounds of formula IVc are those of the formula IVc ′:

wherein A is 1,4-phenylene or trans-1,4-cyclohexylene and n is 0 or 1.

The dielectrics according to the invention are produced in the usual way. As a rule, the components dissolved in one another, expediently at elevated temperature.  

By means of suitable additives, the liquid crystalline Dielectrics are modified according to the invention that they are known in all types of Liquid crystal display elements can be used. Such additives are known to the expert and in the Literature described in detail. For example, you can Conductive salts, preferably ethyl dimethyl dodecyl ammonium 4-hexyloxybenzoate, Tetrabutylammonium tetraphenylboranate or complex salts of crown ethers (cf. e.g. I. Haller et al., Mol. Cryst. Liq. Cryst. Volume 24, pages 249-258 (1973)) to improve conductivity, dichroic Dyes for the production of colored guest-host systems or substances for changing the dielectric anisotropy, the viscosity and / or the orientation of the nematic phases are added. Such substances are z. B. in DE-OS 22 09 127, 22 40 854, 23 21 632, 23 38 281, 24 50 088, 26 37 430, 28 53 728 and 29 02 177 described.

The following examples are intended to illustrate the invention, without limiting it. F. = melting point, K. = clearing point. Percentages above and below mean percentages by weight; all temperatures are in degrees Celsius specified. "Usual work-up" means: one gives Add water, extract with methylene chloride or toluene, separates, dries the organic phase, evaporates and purifies the product by crystallization and / or chromatography.

example 1

A mixture of 30.2 g of cis-4- (trans-4-butylcyclohexyl) cyclohexyl bromide, 150 ml of N-methylpyrrolidone and 7.2 g NaN₃ is heated to 70 ° for about 16 hours. After cooling pour on water and extract with toluene, wash, dries and evaporates. The residue is purified by chromatography purified and cis-4- (trans-4-butyl cyclohexyl) -1-azido-cyclohexane with F. = -19 °, K: = 8.7 ° C.  The following are produced analogously:

cis-4- (trans-4-methylcyclohexyl) -1-azido-cyclohexane
cis-4- (trans-4-ethylcyclohexyl) -1-azido-cyclohexane
cis-4- (trans-4-propylcyclohexyl) -1-azido-cyclohexane
F. 0 °, K. 4.2 °
cis-4- (trans-4-pentylcyclohexyl) -1-azido-cyclohexane
F. 20 °, K. 29 °
cis-4- (trans-4-hexylcyclohexyl) -1-azido-cyclohexane
cis-4- (trans-4-heptylcyclohexyl) -1-azido-cyclohexane
cis-4- (trans-4-octylcyclohexyl) -1-azido-cyclohexane
cis-4- (trans-4-nonylcyclohexyl) -1-azido-cyclohexane
cis-4- (trans-4-decylcyclohexyl) -1-azido-cyclohexane

cis-4- (trans-4-methylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-ethylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-propylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-butylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-pentylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-hexylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-heptylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-octylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-nonylphenyl) -1-azido-cyclohexane
cis-4- (trans-4-decylphenyl) -1-azido-cyclohexane

Example 2

A mixture of 0.05 mol p- (trans-4-propylcyclohexyl) aniline and 65 ml of glacial acetic acid with 60 ml of 30% sulfuric acid transferred. At 5-10 °, 0.052 mol of sodium nitrite is added in 10 ml of water, stir for about 30 minutes 1.2 g urea and after a further 15 minutes 3.6 g Sodium azide in 10 ml of water. Moved after 1 hour one with water, takes up the solution in ether and works on. After recrystallization from methanol to use 1-azido-4- (trans-4-propylcyclohexyl) benzene F. = 8 ° and K. (extr.) = 0 °.  The following are produced analogously:

1-Azido-4- (trans-4-butylcyclohexyl) benzene
1-Azido-4- (trans-4-pentylcyclohexyl) benzene
1-Azido-4- (trans-4-hexylcyclohexyl) benzene
1-Azido-4- (trans-4-heptylcyclohexyl) benzene
1-Azido-4- (trans-4-octylcyclohexyl) benzene
1-Azido-4- (trans-4-nonylcyclohexyl) benzene
1-Azido-4- (trans-4-decylcyclohexyl) benzene

Example 3

To a mixture of 0.01 mol of 1-hydroxy-4- (trans-4-propyl cyclohexyl) bicyclo (2,2,2) octane and 10 ml chloroform 10 ml of 57% sulfuric acid and then at 0-5 ° with stirring 0.02 mol sodium azide. After stirring for 3 hours, you pour on ice water and work up as usual. To Recrystallization gives 1-azido-4- (trans-4-propyl cyclohexyl) bicyclo (2.2.2) octane.

The following are produced analogously:

1-Azido-4- (trans-4-butylcyclohexyl) bicyclo (2,2,2) octane
1-Azido-4- (trans-4-pentylcyclohexyl) bicyclo (2,2,2) octane
1-Azido-4- (trans-4-hexylcyclohexyl) bicyclo (2,2,2) octane
1-Azido-4- (trans-4-heptylcyclohexyl) bicyclo (2,2,2) octane
1-Azido-4- (trans-4-octylcyclohexyl) bicyclo (2,2,2) octane
1-Azido-4- (trans-4-nonylcyclohexyl) bicyclo (2,2,2) octane
1-Azido-4- (trans-4-decylcyclohexyl) bicyclo (2,2,2) octane

Example 4

To a mixture of 0.01 mol of 1-hydroxy-1-pentyl-4- (trans- 4-propylcyclohexyl) cyclohexane (can be prepared from 4- (trans- 4-propylcyclohexyl) cyclohexanone and C₅H₁₁Ti [OCH (CH₃) ₂] ₃) and 80 ml of an approximately 1.7 N solution of HN₃ in choroform are given at room temperature with stirring 0.01 M TiCl₄.  The mixture is stirred for 12 hours and filtered over Al₂O₃ and evaporates. 1-Azido-1-pentyl- 4- (trans-4-propylcyclohexyl) cyclohexane after recrystallization.

The synthesis can also be carried out with 1-phenyl-4- (trans-4- propylcyclohexyl) cyclohexene (1), producible from the perform appropriate alcohol, HN₃ and AlCl₃.

The following are produced analogously:

1-Azido-1-pentyl-4- (trans-4-butylcyclohexyl) cyclohexane
1-Azido-1-pentyl-4- (trans-4-pentylcyclohexyl) cyclohexane
1-Azido-1-pentyl-4- (trans-4-hexylcyclohexyl) cyclohexane
1-Azido-1-pentyl-4- (trans-4-heptylcyclohexyl) cyclohexane
1-Azido-1-pentyl-4- (trans-4-octylcyclohexyl) cyclohexane
1-Azido-1-pentyl-4- (trans-4-nonylcyclohexyl) cyclohexane
1-Azido-1-pentyl-4- (trans-4-decylcyclohexyl) cyclohexane

1-Azido-1-butyl-4- (trans-4-propylcyclohexyl) cyclohexane
1-Azido-1-butyl-4- (trans-4-butylcyclohexyl) cyclohexane
1-Azido-1-butyl-4- (trans-4-pentylcyclohexyl) cyclohexane
1-Azido-1-butyl-4- (trans-4-hexylcyclohexyl) cyclohexane
1-Azido-1-butyl-4- (trans-4-heptylcyclohexyl) cyclohexane
1-Azido-1-butyl-4- (trans-4-octylcyclohexyl) cyclohexane
1-Azido-1-butyl-4- (trans-4-nonylcyclohexyl) cyclohexane
1-Azido-1-butyl-4- (trans-4-decylcyclohexyl) cyclohexane

1-Azido-1-propyl-4- (trans-4-propylcyclohexyl) cyclohexane
1-Azido-1-propyl-4- (trans-4-butylcyclohexyl) cyclohexane
1-Azido-1-propyl-4- (trans-4-pentylcyclohexyl) cyclohexane
1-Azido-1-propyl-4- (trans-4-hexylcyclohexyl) cyclohexane
1-Azido-1-propyl-4- (trans-4-heptylcyclohexyl) cyclohexane
1-Azido-1-propyl-4- (trans-4-octylcyclohexyl) cyclohexane
1-Azido-1-propyl-4- (trans-4-nonylcyclohexyl) cyclohexane
1-Azido-1-propyl-4- (trans-4-decylcyclohexyl) cyclohexane

1-Azido-1-ethyl-4- (trans-4-propylcyclohexyl) cyclohexane
1-Azido-1-ethyl-4- (trans-4-butylcyclohexyl) cyclohexane
1-Azido-1-ethyl-4- (trans-4-pentylcyclohexyl) cyclohexane
1-Azido-1-ethyl-4- (trans-4-hexylcyclohexyl) cyclohexane
1-Azido-1-ethyl-4- (trans-4-heptylcyclohexyl) cyclohexane
1-Azido-1-ethyl-4- (trans-4-octylcyclohexyl) cyclohexane
1-Azido-1-ethyl-4- (trans-4-nonylcyclohexyl) cyclohexane
1-Azido-1-ethyl-4- (trans-4-decylcyclohexyl) cyclohexane

1-Azido-1-hexyl-4- (trans-4-propylcyclohexyl) cyclohexane
1-Azido-1-hexyl-4- (trans-4-butylcyclohexyl) cyclohexane
1-Azido-1-hexyl-4- (trans-4-pentylcyclohexyl) cyclohexane
1-Azido-1-hexyl-4- (trans-4-hexylcyclohexyl) cyclohexane
1-Azido-1-hexyl-4- (trans-4-heptylcyclohexyl) cyclohexane
1-Azido-1-hexyl-4- (trans-4-octylcyclohexyl) cyclohexane
1-Azido-1-hexyl-4- (trans-4-nonylcyclohexyl) cyclohexane
1-Azido-1-hexyl-4- (trans-4-decylcyclohexyl) cyclohexane

Example 5

A mixture of 0.01 mol of 1,2-bis (trans-4-pentylcyclohexyl) - ethanol tosylate and 30 ml DMF is mixed with 0.01 mol sodium azide transferred. The mixture is stirred at 80 ° for 24 hours and poured on 100 ml of water and works up as usual. You get 1-Azido-1,2-bis (trans-4-pentylcyclohexyl) ethane.

The following are produced analogously:

1-Azido-1- (trans-4-pentylcyclohexyl) -2- (trans-4-propylcyclohexyl) eth-an
1-Azido-1- (trans-4-pentylcyclohexyl) -2- (trans-4-butylcyclohexyl) etha-n
1-Azido-1- (trans-4-pentylcyclohexyl) -2- (trans-4-hexylcyclohexyl) etha-n
1-Azido-1- (trans-4-pentylcyclohexyl) -2- (trans-4-heptylcyclohexyl) eth-an

1-Azido-1- (trans-4-propylcyclohexyl) -2- (trans-4-butylcyclohexyl) etha-n
1-Azido-1- (trans-4-propylcyclohexyl) -2- (trans-4-hexylcyclohexyl) etha-n
1-Azido-1- (trans-4-propylcyclohexyl) -2- (trans-4-heptylcyclohexyl) eth-an

1-Azido-1,2-bis (trans-4-propylcyclohexyl) ethane
1-azido-1,2-bis (trans-4-butylcyclohexyl) ethane
1-azido-1,2-bis (trans-4-hexylcyclohexyl) ethane

Example 6

A mixture of 0.01 mol of 4- (trans-4-pentylcyclohexyl) - cyclohexylmethyl tosylate, 0.01 mol sodium azide and 30 ml of acetonitrile is heated for 48 hours. Then it will be worked as usual. This is obtained after chromatography and recrystallization 4- (trans-4-pentylcyclo hexyl) cyclohexyl methyl azide with F. 10 ° and K. 53 °.

The following are produced analogously:

4- (trans-4-ethylcyclohexyl) cyclohexyl methyl azide
4- (trans-4-propylcyclohexyl) cyclohexyl methyl azide

F. = 17 ° C, K. = 39 ° C

4- (trans-4-butylcyclohexyl) cyclohexyl methyl azide
4- (trans-4-hexylcyclohexyl) cyclohexyl methyl azide
4- (trans-4-heptylcyclohexyl) cyclohexyl methyl azide
4- (trans-4-octylcyclohexyl) cyclohexyl methyl azide
4- (trans-4-nonylcyclohexyl) cyclohexyl methyl azide
4- (trans-4-decylcyclohexyl) cyclohexyl methyl azide

Example 7

A mixture of 6.5 g cis-4- (trans-4-propylcyclohexyl) - 1-azido-cyclohexane, 100 ml tetrahydrofuran and 3 g palladium / activated carbon (5%) is hydrogenated under normal pressure. After evaporation, 60 ml of formic acid are added, 22.5 ml of acetic anhydride are added dropwise and the mixture is stirred for 44 hours. After concentration, the mixture is taken up in water and extracted with toluene, works up and crystallizes out Ethanol around. 1 g of the compound thus obtained and 10 ml Methylene chloride and 1.34 g triphenylphosphine a solution of 0.55 ml triethylamine in 0.4 ml carbon tetrachloride transferred. The mixture is stirred at room temperature for 24 hours and 18 hours under reflux. After constriction, Work up and recrystallization from acetonitrile one cis-4- (trans-4-propylcyclohexyl) -1-isocyano-cyclohexane with F. = 43 ° and K. = 64.7-65.7 ° C.

The following are produced analogously:

cis-4- (trans-4-methylcyclohexyl) -1-isocyanocyclohexane
cis-4- (trans-4-ethylcyclohexyl) -1-isocyanocyclohexane
cis-4- (trans-4-butylcyclohexyl) -1-isocyanocyclohexane
cis-4- (trans-4-pentylcyclohexyl) -1-isocyanocyclohexane
F. = 63 °, K. 71 °
cis-4- (trans-4-hexylcyclohexyl) -1-isocyanocyclohexane
cis-4- (trans-4-heptylcyclohexyl) -1-isocyanocyclohexane
cis-4- (trans-4-octylcyclohexyl) -1-isocyanocyclohexane
cis-4- (trans-4-nonylcyclohexyl) -1-isocyanocyclohexane
cis-4- (trans-4-decylcyclohexyl) -1-isocyanocyclohexane

1-isocyano-4- (trans-4-propylcyclohexyl) benzene
1-isocyano-4- (trans-4-butylcyclohexyl) benzene
1-isocyano-4- (trans-4-pentylcyclohexyl) benzene
1-isocyano-4- (trans-4-hexylcyclohexyl) benzene
1-isocyano-4- (trans-4-heptylcyclohexyl) benzene
1-isocyano-4- (trans-4-octylcyclohexyl) benzene
1-isocyano-4- (trans-4-nonylcyclohexyl) benzene
1-isocyano-4- (trans-4-decylcyclohexyl) benzene

1-isocyano-4- (trans-4-propylcyclohexyl) bicyclo (2,2,2) octane
1-isocyano-4- (trans-4-butylcyclohexyl) bicyclo (2,2,2) octane
1-isocyano-4- (trans-4-pentylcyclohexyl) bicyclo (2,2,2) octane
1-isocyano-4- (trans-4-hexylcyclohexyl) bicyclo (2,2,2) octane
1-isocyano-4- (trans-4-heptylcyclohexyl) bicyclo (2,2,2) octane
1-isocyano-4- (trans-4-octylcyclohexyl) bicyclo (2,2,2) octane
1-isocyano-4- (trans-4-nonylcyclohexyl) bicyclo (2,2,2) octane
1-isocyano-4- (trans-4-decylcyclohexyl) bicyclo (2,2,2) octane

1-isocyano-1-propyl-4- (trans-4-propylcyclohexyl) cyclohexane
1-isocyano-1-propyl-4- (trans-4-butylcyclohexyl) cyclohexane
1-isocyano-1-propyl-4- (trans-4-pentylcyclohexyl) cyclohexane
1-isocyano-1-propyl-4- (trans-4-hexylcyclohexyl) cyclohexane
1-isocyano-1-propyl-4- (trans-4-heptylcyclohexyl) cyclohexane
1-isocyano-1-propyl-4- (trans-4-octylcyclohexyl) cyclohexane
1-isocyano-1-propyl-4- (trans-4-nonylcyclohexyl) cyclohexane
1-isocyano-1-propyl-4- (trans-4-decylcyclohexyl) cyclohexane

1-isocyano-1-pentyl-4- (trans-4-propylcyclohexyl) cyclohexane
1-isocyano-1-pentyl-4- (trans-4-butylcyclohexyl) cyclohexane
1-isocyano-1-pentyl-4- (trans-4-pentylcyclohexyl) cyclohexane
1-isocyano-1-pentyl-4- (trans-4-hexylcyclohexyl) cyclohexane
1-isocyano-1-pentyl-4- (trans-4-heptylcyclohexyl) cyclohexane
1-isocyano-1-pentyl-4- (trans-4-octylcyclohexyl) cyclohexane
1-isocyano-1-pentyl-4- (trans-4-nonylcyclohexyl) cyclohexane
1-isocyano-1-pentyl-4- (trans-4-decylcyclohexyl) cyclohexane

Example 8

2.33 g of 1-isocyano-4- (trans-propylcyclohexyl) cyclohexane are dissolved in 5 ml of tetrahydrofuran and turned into one -78 ° C cooled solution of lithium diisopropylamide dropped from 1.4 ml of diisopropylamine, 5 ml of tetrahydrofuran and 6.2 ml of 15% butyllithium in hexane is prepared. After stirring for 30 minutes at this temperature 1.4 ml of methyl iodide in a little tetrahydrofuran dripped. After that, another 24 hours Stirred at room temperature and worked up as usual.

The following are produced analogously:

1-isocyano-1-methyl-4- (trans-butylcyclohexyl) cyclohexane
1-isocyano-1-methyl-4- (trans-pentylcyclohexyl) cyclohexane
1-isocyano-1-methyl-4- (trans-hexylcyclohexyl) cyclohexane
1-isocyano-1-methyl-4- (trans-heptylcyclohexyl) cyclohexane
1-isocyano-1-methyl-4- (trans-octylcyclohexyl) cyclohexane
1-isocyano-1-methyl-4- (trans-nonylcyclohexyl) cyclohexane
1-isocyano-1-methyl-4- (trans-decylcyclohexyl) cyclohexane

1-isocyano-1-ethyl-4- (trans-propylcyclohexyl) cyclohexane
1-isocyano-1-ethyl-4- (trans-butylcyclohexyl) cyclohexane
1-isocyano-1-ethyl-4- (trans-pentylcyclohexyl) cyclohexane
1-isocyano-1-ethyl-4- (trans-hexylcyclohexyl) cyclohexane
1-isocyano-1-ethyl-4- (trans-heptylcyclohexyl) cyclohexane
1-isocyano-1-ethyl-4- (trans-octylcyclohexyl) cyclohexane
1-isocyano-1-ethyl-4- (trans-nonylcyclohexyl) cyclohexane
1-isocyano-1-ethyl-4- (trans-decylcyclohexyl) cyclohexane

1-isocyano-1-butyl-4- (trans-propylcyclohexyl) cyclohexane
1-isocyano-1-butyl-4- (trans-butylcyclohexyl) cyclohexane
1-isocyano-1-butyl-4- (trans-pentylcyclohexyl) cyclohexane
1-isocyano-1-butyl-4- (trans-hexylcyclohexyl) cyclohexane
1-isocyano-1-butyl-4- (trans-heptylcyclohexyl) cyclohexane
1-isocyano-1-butyl-4- (trans-octylcyclohexyl) cyclohexane
1-isocyano-1-butyl-4- (trans-nonylcyclohexyl) cyclohexane
1-isocyano-1-butyl-4- (trans-decylcyclohexyl) cyclohexane

Example 9

2.84 g of 2-amino-5- (4-heptyloxyphenyl) pyridine from 5.4 g of 3- (4-heptyloxyphenyl) pyridine using the Chichibabin reaction, are in the formyl compound transferred. This is with without further purification 3.35 g triphenylphosphine dissolved in 25 ml methylene chloride and with a mixture of 1.38 ml triethylamine and 1 ml Carbon tetrachloride added dropwise. After usual Working up gives 2-isocyano-5- (4-heptyloxylphenyl) pyridine.

Analog are manufactured

2-isocyano-5- (4-methyloxyphenyl) pyridine
2-isocyano-5- (4-ethyloxyphenyl) pyridine
2-isocyano-5- (4-propyloxyphenyl) pyridine
2-isocyano-5- (4-butyloxyphenyl) pyridine
2-isocyano-5- (4-pentyloxyphenyl) pyridine
2-isocyano-5- (4-hexyloxyphenyl) pyridine
2-isocyano-5- (4-octyloxyphenyl) pyridine
2-isocyano-5- (4-nonyloxyphenyl) pyridine
2-isocyano-5- (4-decyloxyphenyl) pyridine

Example 10

A mixture of 30.2 g of trans-4- (trans-4-propylcyclohexyl) cyclohexylmethyl bromide, 150 ml of N-methylpyrrolidone and 7.2 g of sodium azide is heated to 70 ° C. for 10 hours. To Cooling and customary working up gives trans-4- (trans-4-propylcyclohexyl) -1-azidomethylcyclohexane with F. = 17 ° C, K. = 39 ° C.

The following are produced analogously:

trans-4- (trans-4-ethylcyclohexyl) -1-azidomethylcyclohexane
trans-4- (trans-4-butylcyclohexyl) -1-azidomethylcyclohexane
trans-4- (trans-4-pentylcyclohexyl) -1-azidomethylcyclohexane
with F. = 10 ° C, K. = 53.4 ° C
trans-4- (trans-4-hexylcyclohexyl) -1-azidomethylcyclohexane
trans-4- (trans-4-heptylcyclohexyl) -1-azidomethylcyclohexane
trans-4- (trans-4-octylcyclohexyl) -1-azidomethylcyclohexane

trans-4- (trans-4-ethylcyclohexyl) -1- (2-azidoethyl) cyclohexane
trans-4- (trans-4-propylcyclohexyl) -1- (2-azidoethyl) cyclohexane
trans-4- (trans-4-butylcyclohexyl) -1- (2-azidoethyl) cyclohexane
trans-4- (trans-4-pentylcyclohexyl) -1- (2-azidoethyl) cyclohexane
with F. = -8 ° C, K. = 62 ° C
trans-4- (trans-4-hexylcyclohexyl) -1- (2-azidoethyl) cyclohexane
trans-4- (trans-4-heptylcyclohexyl) -1- (2-azidoethyl) cyclohexane
trans-4- (trans-4-octylcyclohexyl) -1- (2-azidoethyl) cyclohexane

trans-4- (trans-4-ethylcyclohexyl) -1- (3-azidopropyl) cyclohexane
trans-4- (trans-4-propylcyclohexyl) -1- (3-azidopropyl) cyclohexane
trans-4- (trans-4-butylcyclohexyl) -1- (3-azidopropyl) cyclohexane
trans-4- (trans-4-pentylcyclohexyl) -1- (3-azidopropyl) cyclohexane
trans-4- (trans-4-hexylcyclohexyl) -1- (3-azidopropyl) cyclohexane
trans-4- (trans-4-heptylcyclohexyl) -1- (3-azidopropyl) cyclohexane
trans-4- (trans-4-octylcyclohexyl) -1- (3-azidopropyl) cyclohexane

1-azidomethyl-4- (trans-4-ethylcyclohexyl) benzene
1-azidomethyl-4- (trans-4-propylcyclohexyl) benzene
1-azidomethyl-4- (trans-4-butylcyclohexyl) benzene
1-azidomethyl-4- (trans-4-pentylcyclohexyl) benzene
1-azidomethyl-4- (trans-4-hexylcyclohexyl) benzene
1-azidomethyl-4- (trans-4-heptylcyclohexyl) benzene
1-azidomethyl-4- (trans-4-octylcyclohexyl) benzene

1- (2-Azidoethyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (2-Azidoethyl) -4- (trans-4-propylcyclohexyl) benzene
1- (2-Azidoethyl) -4- (trans-4-butylcyclohexyl) benzene
1- (2-Azidoethyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (2-Azidoethyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (2-Azidoethyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (2-Azidoethyl) -4- (trans-4-octylcyclohexyl) benzene

1- (3-Azidopropyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (3-Azidopropyl) -4- (trans-4-propylcyclohexyl) benzene
1- (3-Azidopropyl) -4- (trans-4-butylcyclohexyl) benzene
1- (3-Azidopropyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (3-Azidopropyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (3-Azidopropyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (3-Azidopropyl) -4- (trans-4-octylcyclohexyl) benzene

1- (1-Azidoethyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (1-Azidoethyl) -4- (trans-4-propylcyclohexyl) benzene
1- (1-Azidoethyl) -4- (trans-4-butylcyclohexyl) benzene
1- (1-Azidoethyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (1-Azidoethyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (1-Azidoethyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (1-Azidoethyl) -4- (trans-4-octylcyclohexyl) benzene

1- (1-Azidopropyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (1-Azidopropyl) -4- (trans-4-propylcyclohexyl) benzene
1- (1-Azidopropyl) -4- (trans-4-butylcyclohexyl) benzene
1- (1-Azidopropyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (1-Azidopropyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (1-Azidopropyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (1-Azidopropyl) -4- (trans-4-octylcyclohexyl) benzene

Example 11

A mixture of 3.9 g trans-4- (trans-4-propylcyclohexyl) - cyclohexylmethylformamide, made from the corresponding Azide from Example 10 according to Example 7.50 ml Methylene chloride and 5.2 g triphenylphosphine is with a solution of 2.2 ml triethylamine and 1.5 ml carbon tetrachloride transferred. After stirring for 24 hours Room temperature, concentration and usual workup to make trans-4- (trans-4-propylcyclohexyl) -1-isocyanomethylcyclohexane with F. = 52 ° C and K. = 60 ° C.  

The following are produced analogously:

trans-4- (trans-4-ethylcyclohexyl) -1-isocyanomethylcyclohexane
trans-4- (trans-4-butylcyclohexyl) -1-isocyanomethylcyclohexane
trans-4- (trans-4-pentylcyclohexyl) -1-isocyanomethylcyclohexane
with F. = 54 ° C and K. = 67 ° C
trans-4- (trans-4-hexylcyclohexyl) -1-isocyanomethylcyclohexane
trans-4- (trans-4-heptylcyclohexyl) -1-isocyanomethylcyclohexane
trans-4- (trans-4-octylcyclohexyl) -1-isocyanomethylcyclohexane

trans-4- (trans-4-ethylcyclohexyl) -1- (2-isocyanoethyl) cyclohexane
trans-4- (trans-4-propylcyclohexyl) -1- (2-isocyanoethyl) cyclohexane
with F. = 52 ° C and K. = 60 ° C
trans-4- (trans-4-butylcyclohexyl) -1- (2-isocyanoethyl) cyclohexane
trans-4- (trans-4-pentylcyclohexyl) -1- (2-isocyanoethyl) cyclohexane
with F. = 33 ° C and K. = 90 ° C
trans-4- (trans-4-hexylcyclohexyl) -1- (2-isocyanoethyl) cyclohexane
trans-4- (trans-4-heptylcyclohexyl) -1- (2-isocyanoethyl) cyclohexane
trans-4- (trans-4-octylcyclohexyl) -1- (2-isocyanoethyl) cyclohexane

trans-4- (trans-4-ethylcyclohexyl) -1- (3-isocyanopropyl) cyclohexane
trans-4- (trans-4-propylcyclohexyl) -1- (3-isocyanopropyl) cyclohexane
trans-4- (trans-4-butylcyclohexyl) -1- (3-isocyanopropyl) cyclohexane
trans-4- (trans-4-pentylcyclohexyl) -1- (3-isocyanopropyl) cyclohexane
trans-4- (trans-4-hexylcyclohexyl) -1- (3-isocyanopropyl) cyclohexane
trans-4- (trans-4-heptylcyclohexyl) -1- (3-isocyanopropyl) cyclohexane
trans-4- (trans-4-octylcyclohexyl) -1- (3-isocyanopropyl) cyclohexane

1-isocyanomethyl-4- (trans-4-ethylcyclohexyl) benzene
1-isocyanomethyl-4- (trans-4-propylcyclohexyl) benzene
1-isocyanomethyl-4- (trans-4-butylcyclohexyl) benzene
1-isocyanomethyl-4- (trans-4-pentylcyclohexyl) benzene
1-isocyanomethyl-4- (trans-4-hexylcyclohexyl) benzene
1-isocyanomethyl-4- (trans-4-heptylcyclohexyl) benzene
1-isocyanomethyl-4- (trans-4-octylcyclohexyl) benzene

1- (2-isocyanoethyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (2-isocyanoethyl) -4- (trans-4-propylcyclohexyl) benzene
1- (2-isocyanoethyl) -4- (trans-4-butylcyclohexyl) benzene
1- (2-isocyanoethyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (2-isocyanoethyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (2-isocyanoethyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (2-isocyanoethyl) -4- (trans-4-octylcyclohexyl) benzene

1- (3-isocyanopropyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (3-isocyanopropyl) -4- (trans-4-propylcyclohexyl) benzene
1- (3-isocyanopropyl) -4- (trans-4-butylcyclohexyl) benzene
1- (3-isocyanopropyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (3-isocyanopropyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (3-isocyanopropyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (3-isocyanopropyl) -4- (trans-4-octylcyclohexyl) benzene

1- (1-isocyanoethyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (1-isocyanoethyl) -4- (trans-4-propylcyclohexyl) benzene
1- (1-isocyanoethyl) -4- (trans-4-butylcyclohexyl) benzene
1- (1-isocyanoethyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (1-isocyanoethyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (1-isocyanoethyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (1-isocyanoethyl) -4- (trans-4-octylcyclohexyl) benzene

1- (1-isocyanopropyl) -4- (trans-4-ethylcyclohexyl) benzene
1- (1-isocyanopropyl) -4- (trans-4-propylcyclohexyl) benzene
1- (1-isocyanopropyl) -4- (trans-4-butylcyclohexyl) benzene
1- (1-isocyanopropyl) -4- (trans-4-pentylcyclohexyl) benzene
1- (1-isocyanopropyl) -4- (trans-4-hexylcyclohexyl) benzene
1- (1-isocyanopropyl) -4- (trans-4-heptylcyclohexyl) benzene
1- (1-isocyanopropyl) -4- (trans-4-octylcyclohexyl) benzene

Claims (5)

1. Nitrogen-containing compounds for use in liquid-crystalline mixtures of the formula I R¹-A¹-Z¹-A- (Z²-A²) _m -R² (I) wherein R¹ and R² each independently of one another H, CN, NCS, F, Cl, -NC or N₃ or alkyl with 1-18 C atoms, in which one or more CH₂ groups can also be replaced by O and / or S atoms and / or -CO groups and / or -O-CO- and / or -CO -O groups and / or unsubstituted or substituted by halogen, CN, CH₃, -NC or N₃ -CH = CH groups and / or -CH-halogen and / or -CHCN- and / or -CHNC- and / or -CHN₃ groups and / or unsubstituted or substituted by CH₃ where two heteroatoms are not directly linked to one another, or perfluoroalkyl with 1-18 C atoms, in which one or more CF₂ groups can also be replaced by O and / or S atoms and / or -CH₂ groups and / or - CO groups and / or -OCO and / or -COO groups and / or unsubstituted or -CH = CH groups and / or -CH-halogen and / or - substituted by halogen, CN, CH₃, -NC or N₃ CHCN and / or -CHNC and / or -CHN₃ groups and / or unsubstituted or substituted by CH₃ where two heteroatoms are not directly linked, A, A¹
and A² each independently of one another unsubstituted or one or more times by halogen atoms and / or CN and / or CH₃ and / or -NC groups or simply by N₃-substituted 1,4-phenylene, in which one or more CH groups by N 1,4-cyclohexylene, in which one or two non-adjacent CH₂ groups can also be replaced by O and / or S atoms, 1,4-bicyclo (2,2,2) octylene, pyridine-2 , 5-diyl, piperidine-1,4-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, trans-decahydronaphthalene-2,6-diyl or a 5-membered, heterocyclic ring system, Z¹ and Z² each independently or unsubstituted or substituted one or more times by CH₃, halogen, nitrile and / or simply by -NC or N₃ -CH₂CH₂-, -CH₂O-, -CH₂CO-, -CH = CH- or a single bond, and
m means 0, 1 or 2, with the provisos that

• a) at least one -NC- or N₃ group is contained in R¹, R², A, A¹, A², Z¹ or Z²
• b) in the case A¹ = A = 1,4-phenylene, Z¹ = -OCO or -CO-O- and m = 0 at least one N₃ group is included.

2. Use of the compound of formula I after Claim 1 as components of liquid crystalline Phases. 3. Liquid crystalline phase with at least 2 liquid crystalline phases Components, characterized in that they have at least one compound of formula I according to claim 1 contains. 4. liquid crystal display element, characterized in that it is a liquid crystalline phase according to claim 3 contains. 5. Electro-optical display element, characterized in that it is a liquid crystalline dielectric Phase according to claim 3 contains.