JPH058180B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel liquid crystal compound, namely, the general formula In the formula, X ² represents a single covalent bond or an ester group -COO-; X ¹ represents a single covalent bond, an ester group -COO- ^, an ethylene group -CH ₂ CH ₂ -, or When expressing −COO−,
Also p-C ₆ H ₄ −, p-C ₆ H ₄ −CH ₂ CH ₂ −, −CH ₂
CH ₂ -p-C ₆ H ₄ -, p-C ₆ H ₄ -COO- or -COO-p-C ₆ H ₄ -; ring A represents a benzene ring or trans-1,4-cyclohexylene; ; Ring B is a benzene ring, or X ² represents an ester group -COO- and X ¹ is a single covalent bond;
Ester group -COO- or ethylene group _-CH2
When representing CH ₂ −, also trans-1,4
- cyclohexylene; Z ¹ , Z ² and Z ³ are hydrogen or also halogen, cyano or methyl on the benzene ring which is not directly bonded to another ring via a single covalent bond; ; ^Y2 is cyano, nitro, 2,2-dicyanovinyl, or when ^Y1 represents hydrogen,
It also represents 2,2-dicyano-1-methylvinyl; Y ¹ is halogen, cyano, C ₁ -C ₃ -alkyl, or X ¹ has a benzene ring or ester group, or Y ² represents nitro; Z ¹
and/or if Z ² is different _from hydrogen, it also represents hydrogen; and R ¹ also represents C _{1 -C 12} -alkyl or on the benzene ring
-Tetracyclic and pentacyclic esters of -alkoxy. The present invention also relates to the preparation of compounds of the above formula,
It relates to its use for optical purposes and to liquid crystal mixtures containing compounds of the formula. In the above definition, the term "benzene ring" refers to lateral halogens,
Represents p-phenylene with a cyano or methyl substituent. p-C ₆ H ₄ - represents p-phenylene. The term "halogen" stands for fluorine, chlorine and bromine, and " _C1 - _C3 -alkyl" stands for methyl, ethyl, propyl and isopropyl. The term " _C1 - _C12 -alkyl" includes straight-chain and branched alkyl groups, especially n-alkyl groups,
thus including methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl, and isoalkyl groups, namely isopropyl, isobutyl, isopentyl, isoheptyl, isooctyl, isononyl, isodecyl, isoundecyl and isododecyl. . The term " _C1 - _C12 -alkoxy" embraces alkoxy groups in which the alkyl portion has the above meaning. The lateral groups Z ¹ , Z ² and Z ³ are either hydrogen or the benzene ring to which they are “isolated”, i.e. connected via a single covalent bond to a further ring (p-phenylene or trans-1,4- When bonded to p-phenylene which is not directly bonded to cyclohexylene), it also represents halogen, cyano or methyl. Liquid crystals have gained considerable importance in recent years as dielectrics in display devices, since the optical properties of such materials can be influenced by applied voltage.
Electro-optical devices based on liquid crystals are well known to those skilled in the art and can be used to detect various effects such as dynamic scattering, deformation of aligned phases (DAP type), Schadt-Helfrich -Helfrich effect (rotating cell), “guest-host effect” (“guest-host effect”) or cholesteric nematic
−nematic) can be based on phase dislocations. Typically, static operation of liquid crystals in display devices has been largely replaced in the past by so-called multiplex control. In this case, amplitude-selective multiplex pro-cedure
However, in most cases only a multiplex ratio of about 1:8 to 1:10 has been achieved by the commonly used methods. In order to achieve higher multiplexing ratios in the adjustment of liquid crystal displays, a two-frequency matrix addressing method (two-frequency matrix addressing method) is therefore used.
frequency matrix addressing procedure) has been proposed (for example, German Patent Application No. 2856134 and German Patent Application No. 2907940). In the case of this two-frequency method, when a low frequency voltage is applied, the positive anisotropy of the dielectric constant (Δε=ε ₁₁ −ε
The fact that the dielectric anisotropy of liquid crystals with ⊥>O, where ε ₁₁ represents the dielectric constant along the longitudinal axis of the molecule and ε⊥ represents the dielectric constant perpendicular to this, is negative at high frequencies. is used. This effect is attributed to the disturbance of the rotation of the long axis of the molecule around the short axis of the liquid crystal molecules [M.Schadt, Mol.Cryst.Liq.Cryst. 66
(1981) 319-336]. In contrast to ε ₁₁ , for ε⊥ the dispersion effect appears only in the ultra-high frequency range;
The reason is due to the slight rotational disturbance of the molecule around its longitudinal axis. In the frequency range of interest here, ε⊥ is therefore constant, while ε ₁₁ and thus also Δε are frequency dependent. ε ₁₁ = ε⊥
The dielectric constant relaxation frequency at is expressed in technical terminology as the "crosser frequency" (fc). The most common nematic liquid crystals generally have an alternating frequency of approximately
Has 100KHz and above. To operate a display device according to the two-frequency method, two alternating current sources are used, whereby the frequency of one of the sources must be above the alternating frequency, and the frequency of the other source is Must be below the alternating frequency. Furthermore, the voltage ratio of the signal to the switch-on state and the switch-off state must be above a certain value. The higher the voltage ratio, the more lines can be drawn, ie, the higher the multiplexing ratio. In addition, the two-frequency method not only detects the switch-on process by applying a corresponding alternating voltage.
It also has the advantage of directly influencing the switch-off process, thereby accelerating the switch-off process. For example, in the case of a liquid crystal display device with a twisted nematic structure (rotating cell), the uniformly oriented liquid crystal can be aligned in the direction of the electric field by applying a low frequency (< c) voltage, and the high frequency ( By applying a voltage >c), the orientation can be changed to a twisted uniform orientation again. Furthermore, the guest-host effect [Applied Physics Letters 13 (1968) 91; J.
Appl. Phys. 45 (1974), especially p. 4718], liquid crystals with positive dielectric anisotropy can generally be used only for reading colorless image elements on a colored background; The reason is that common colored substances exhibit positive dichroism. homeotropic wall orientation
With adjustment in the wall orientation) and two-frequency method, such liquid crystals can be used to produce colored image elements (uniformly oriented by application of a high frequency voltage) on a colorless background. However, the two-frequency method has the disadvantage of high energy consumption, not only because of the amplification of the applied alternating voltage, but also because of the high frequency. It is therefore important to be able to keep the operating voltage low in order to reduce energy consumption. For similar reasons, the alternator frequency should be relatively small (thereby reducing capacitive losses). The compounds in the present invention were found to have a large mesophase range with a high clearing point, the optically active compounds (containing an asymmetric carbon atom in the side chain R ¹ ) generally exhibit a cholesteric mesophase, and the rest Compounds generally exhibit a nematic mesophase. Further, the compound of the present invention is characterized by having large anisotropy in dielectric constant and at the same time having extremely low alternating frequency. Furthermore, the compound has good chemical and photochemical stability and, despite its molecular size, it has very good solubility in other liquid crystals. The compounds according to the invention can be used in principle in all liquid-crystalline mixtures, whereby, based on the above-mentioned properties, they are primarily suitable for dielectric anisotropy and clearing point enhancement. however,
The compounds according to the invention are particularly suitable as components of liquid crystal dielectrics which are adjusted according to the two-frequency method. In the above formula, ring B is preferably a benzene ring. Preferably Z ¹ , Z ² and Z ³ represent hydrogen or at most two of Z ¹ , Z ² and Z ³ (preferably Z ² and/or Z ³ ) also represent chlorine.
X ¹ is preferably a single covalent bond, an ester group -
Represents COO- or p-phenylene. Y ¹ preferably represents hydrogen, fluorine, chlorine, cyano or methyl, especially hydrogen, chlorine or cyano. Y ²
preferably represents cyano or nitro. Y ¹
Particular preference is given to compounds in which is chlorine and Y ² is cyano or nitro. Furthermore, Y ¹ represents hydrogen, and Y ² represents 2,2-dicyano-
Also preferred are compounds of the formula representing 1-methylvinyl. Generally ring A is preferably trans-1,4-
Represents cyclohexylene. R ¹ preferably represents a linear alkyl or alkoxy group or an isoalkyl or isoalkoxy group. Particularly preferred groups represented by R ¹ are straight-chain alkyl and alkoxy groups, especially straight-chain alkyl groups. R ¹ preferably contains 3 to 10 carbon atoms, especially 5 to 9 carbon atoms.
Particularly preferred radicals represented by R ¹ are pentyl, hexyl and heptyl. A preferred group of compounds of the formula is the general formula In the formula, R ¹ , X ² and Y ² have ^the above meaning;
is a single covalent bond, an ester group -COO- or
When X ² represents an ester group -COO-, p-C ₆ H ₄ -, p-C ₆ H ₄ -CH ₂ CH ₂ -, -CH _2
CH2 -p- _C6H4- , p- _{C6H4 -} COO- or -COO-p- _C6H4- ; Ring A represents p-phenylene or trans- _{1,4 -} cyclohexylene. Representation: Z ² is hydrogen, or when X ¹ and X ² represent an ester group -COO-, it also represents chlorine; Z ³ is hydrogen or X ² is an ester group -
When representing COO−, it also represents chlorine;
And Y ¹ is fluorine, chlorine, cyano, methyl or, when X ¹ has a benzene ring or an ester group or Y ² represents nitro, it also represents hydrogen. X ¹ in the formula is preferably a single covalent bond,
Represents an ester group -COO- or p-phenylene. Ring A preferably represents trans-1,4-cyclohexylene and Z ² preferably represents hydrogen. Preferred examples of compounds according to the invention are those in which Z ² represents hydrogen and R ¹ , ring A, X ¹ , X ² , Z ³ , Y ¹
and Y ² have the meanings shown in Table 1 [C ₆ H ₄ represents p-phenylene, C ₆ H ₁₀ represents trans-1,4-cyclohexylene, and the dash (-) represents a single covalent bond. ] as well as additional compounds of the formula named in the Examples below.

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【table】

【table】

[Table] According to the present invention, compounds of formula In the formula, R ¹ , A, B, X ¹ , X ² , Z ¹ , Z ² and Z ³ have the meanings shown in the formula. in which Y ¹ and Y ² have the meanings indicated in the formula, and optionally the resulting compound of the formula in which Z ¹ , Z ² or Z ³ represents bromine is cyanated. It can be produced by reacting with copper (), sodium cyanide or potassium cyanide. The esterification of acids of the formula or their reactive derivatives (for example acid chlorides or anhydrides) with phenols of the formula can be carried out according to methods known per se. Acid chloride (this one comes from the acid in the formula,
A preferred method is the reaction of a phenol of the formula (e.g., obtained by heating with thionyl chloride) with a phenol of the formula. This reaction is carried out using inert organic solvents such as diethyl ether, tetrahydrofuran, dimethylformamide, benzene, toluene, cyclohexane,
It is advantageously carried out in carbon tetrachloride or the like. It is advantageous to use acid binding agents such as tertiary amines, pyridine, etc. to bind the hydrogen chloride liberated during the reaction. It is preferred to use a large excess of the acid binder, so that it can simultaneously serve as a solvent. Temperature and pressure are not critical, and the reaction is generally carried out at atmospheric pressure and a temperature between room temperature and the boiling point of the reaction mixture. Compounds of the formula in which Z ¹ , Z ² or Z ³ represent cyano can be obtained in the manner described above, but they are preferably obtained by first preparing the corresponding bromo compound of the formula (as described above) and then using this bromo compound. It is prepared by converting the compound into the cyanide in a manner known per se with copper cyanide, sodium cyanide or potassium cyanide. The reaction is advantageously carried out in an inert organic solvent, such as ethylene glycol, tetrahydrofuran, N-methylpyrrolidone, dimethylformamide, dimethylsulfoxide, pyridine or acetonitrile. Reaction with copper cyanide () in dimethylformamide is preferred. The temperature and pressure at which this reaction is carried out are not critical. The reaction is advantageously carried out at atmospheric pressure and at a temperature between room temperature and the boiling point of the reaction mixture. Compounds of the formula in which Y ² represents 2,2-dicyanovinyl can be prepared by converting 3-Y ¹ -anisole into 4-methoxy-2- Y ¹ -benzaldehyde, then hydrolyzing the methoxy group (e.g. by heating under reflux with pyridinium chloride,
and subsequent fractional distillation) and then the resulting 4-hydroxy-2-Y ¹ -benzaldehyde by Knoevenagel condensation with malononitrile (e.g. catalytic amounts of glacial acetic acid and acetic acid in boiling toluene). (in the presence of sodium) to a compound of the formula in which ^Y2 represents 2,2-dicyanovinyl. The remaining compounds of the formula are known or are homologs of known compounds. The compounds of the formula are likewise known or are analogs of known compounds and can be prepared according to known methods. A compound of the formula in which X ² represents an ester group -COO- is, for example, a compound of the general formula In the formula, X ¹ is a single covalent bond, an ester group -
COO-, ethylene group -CH ₂ CH ₂ - or p-C ₆
H ₄ −, p−C ₆ H ₄ −CH ₂ CH ₂ −, −CH ₂ CH ₂ −p−
C ₆ H ₄ , p-C ₆ H ₄ -COO- or -COO-p
- represents C ₆ H ₄ and R ¹ , A, B, Z ¹ and Z ²
has the meaning given in the formula, a compound of 4-hydroxy-2-Z ³ in methylene chloride in the presence of dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine
- can be prepared by esterification with benzaldehyde and converting the resulting aldehyde to the acid of the corresponding formula by Jones' oxidation with chromic acid and sulfuric acid. X ¹ has an ethylene group -CH ₂ CH ₂ -, and
In preparing acids of the formula in which X ² represents a single covalent bond and acids of the formula in which X ¹ has an ethylene group -COO-, the ring bond is formed by Fouquet-Schlosser reaction. Alternatively, it is advantageously carried out by a Wittig reaction. For example, 4-(bromomethyl)-2-Z ² -benzonitrile, 4'-(bromomethyl)-4-biphenylcarbonitrile, trans-4-(tosyloxymethyl)cyclohexanecarbonitrile, etc. (4- ^R2-2 - ^Z1 -phenyl)methylmagnesium bromide, (trans-4- ^R1 -cyclohexyl)methylmagnesium bromide, etc., and the resulting nitrile is reacted with the desired acid It can be hydrolyzed into Furthermore, for example, 4-R ¹ -2-Z ¹ -benzaldehyde, trans-4-R ¹ -cyclohexanecarboxaldehyde, etc., are added to a base (e.g., sodium methylate).
In the presence of (4-methoxycarbonyl-
3-Z ² -phenyl)methyl-triphenylphosphonium bromide, (4'-methoxycarbonyl-
4-biphenylyl)methyl-triphenylphosphonium bromide, etc. (Z ¹ and Z ² are hydrogen, fluorine,
cyano or methyl), then the double bond can be catalytically hydrogenated and finally the ester group can be saponified. The starting materials necessary for these reactions are known or can be prepared according to methods known per se. For example, 4-alkoxy-2-Z ¹ -acetophenone can be converted to 4-alkoxy-2-Z ¹ -benzoic acid by haloform degradation, which can be converted to 4-alkoxy-2-Z 1 -benzoic acid by reduction with lithium aluminum hydride and 4- by bromination (e.g. with tetrabromoethane and triphenylphosphine)
It can be converted to alkoxy-1-(bromomethyl)-2- ^Z1 -benzene. From methyl 2,4-dimethylbenzoate, methyl 4-(bromomethyl)-2-methylbenzoate can be obtained, for example by reaction with N-bromosuccinimide and then isomer separation. Org.Synth.
4-formyl-2- in a similar manner to Coll.V, 825
Methyl-4-alkyl-2-methylbenzoate obtained after reaction with an alkyl-triphenylphosphonium bromide and a base and subsequent catalytic hydrogenation of the double bond can be converted to methyl-4-alkyl-2-methylbenzoate; It can be saponified to an acid with sodium or reduced to an alcohol with lithium aluminum hydride, which is finally converted to 4-alkyl-1-(bromomethyl)-2-methylbenzene with hydrogen bromide. or 4-alkyl-2- by manganese dioxide.
It can be converted to methylbenzaldehyde. 1-Alkyl-3-fluorobenzene can be converted to 4-alkyl-2-fluorobenzoic acid, for example by reaction with butyllithium and carbon dioxide and then hydrolysis, and 1-
Alkyl-3-chlorobenzene or 1-alkyl-3-bromobenzene by Friedel-Crafts acylation with acetyl chloride in the presence of aluminum trichloride and then oxidation with hypobromous acid. can be converted to 4-alkyl-2-(chloro or bromo)benzoic acid; the resulting acid can then be converted to an alcohol by lithium aluminum hydride, which can then be converted to hydrogen bromide. It can thus be converted into bromides or with manganese dioxide into aldehydes. Further, for example, 4-methyl-2-Z ¹ -benzoic acid can be reacted sequentially with thionyl chloride, ammonia and benzenesulfonyl chloride and the resulting 4-methyl-
2-Z ¹ -benzonitrile can be converted to 4-(bromomethyl)-2-Z ¹ -benzonitrile by N-bromosuccinimide. Compounds of the formula may be combined with other liquid crystalline or non-liquid crystalline substances, such as Schiff's base, azobenzenes, azoxybenzenes, phenylbenzoates, cyclohexanecarboxylic acid phenyl esters, cyclohexanecarboxylic acid cyclohexyl esters,
Cinnamic acid derivatives, biphenyls, terphenyls, phenylcyclohexanes, cyclohexylbiphenyls, phenylpyrimidines, diphenylpyrimidines, cyclohexylphenylpyrimidines, phenyldioxanes, 2-cyclohexyl-1-phenylethanes It can be used in the form of a mixture with substances from the group of Such substances are known to those skilled in the art, and furthermore,
Many of these are commercially available products. However, it is preferred that the compounds according to the invention are used as components of liquid crystal dielectrics which are adjusted according to the two-frequency method. These liquid crystal mixtures preferably consist of three components A, B and C, each of which contains one or more compounds, component A having a viscosity of at most about 40 cp, at least about 40 cp.
C. and a dielectric anisotropy between about -2 and about +1, component B has a dielectric anisotropy of less than about -2 and component C has a dielectric anisotropy of greater than about 10, at least Clearing point at about 100℃ and at most about 15KHz at 20℃
and has a frequency in the total mixture of component C
contains at least one compound of formula. Such a mixture preferably contains at least about Component A.
30% by weight, about 3-50% by weight of component B and about 5% by weight of component C.
~40% by weight, especially about 30-87% by weight of component A, component B
about 3-40% by weight and component C about 10-30% by weight. The amount of compound of formula in the total mixture is advantageously at least about 1% by weight, preferably at least about 5% by weight.
Weight%. Compounds and mixtures having the above-mentioned properties necessary for components A, B and C are known in principle to those skilled in the art. The entire mixture must have nematic or cholesteric properties. Component A can be nematic or cholesteric, and component C can be nematic,
If the cholesteric or the whole mixture is smectic, it can also be smectic.
Components A and C are at least monotropic (mo
-notropic) Must have liquid crystal properties. However, mixtures in which at least component C is an enantiotropic liquid crystal are preferred, and mixtures in which components A and C are enantiotropic liquid crystals are particularly preferred. However, the individual compounds and component B in the mixture according to the invention can be liquid-crystalline or non-liquid-crystalline, provided that in the latter case care should be taken not to limit the mesophase range of the total mixture too severely. be. A wide range of compounds and mixtures suitable as component A are known and many of these are commercially available. The following compounds or mixtures thereof are particularly suitable: In the formula, R ³ and R ⁴ represent a linear alkyl group containing 1 to 8 carbon atoms, and R ⁵ represents a linear alkyl group containing 1 to 8 carbon atoms.
represents a linear alkyl or alkoxy group containing 8 groups, and n is 1 or 2; R ⁶ is trans-4-alkylcyclohexyl, 4'-alkyl-4-biphenylyl, p-(trans-4
-alkylcyclohexyl)phenyl, 2-(trans-4-alkylcyclohexyl)ethyl or p-[2-(trans-4-alkylcyclohexyl)ethyl]phenyl, and
R ⁷ represents trans-4-alkylcyclohexyl, or R ⁶ represents trans-4-alkylcyclohexyl, and R ⁷ represents p-(trans-4-alkylcyclohexyl)phenyl,
p-[2-(trans-4-alkylcyclohexyl)ethyl]phenyl or 4'-(trans-
4-alkylcyclohexyl)-4-biphenylyl, or R ⁶ represents p-alkylphenyl and R ⁷ represents p-[2-(trans-
4-alkylcyclohexyl)ethyl]phenyl, the alkyl group in R ⁶ and R ⁷ is a linear group containing 1 to 7 carbon atoms; m is a number of 0
or 1; one of the symbols X ³ and X ⁴ represents an ester group -COO- or -OOC-; the symbol
The remainder of X ³ , X ⁴ , X ⁵ and X ⁶ represents a single covalent bond or one of these symbols also represents an ethylene group -CH ₂ CH ₂ -; rings A ¹ and A ⁵ formula or trans-1,4-cyclohexylene; rings A ² , A ³ and A ⁴ represent groups of formula or they are connected by a single covalent bond to the other two of these rings. Y ³ also represents trans-1,4-cyclohexylene; represents fluorine, chlorine or methyl on one of the rings; and R ¹¹ and R ¹² are linear alkyl containing 1 to 7 carbon atoms or
represents alkoxy having 1 to 7 carbon atoms on the ring of the formula. Particularly preferred are compounds of the formulas, and particularly preferred are compounds of the formula. Suitable compounds or compounds suitable as component B are described, for example, in Z. Chemie 17 , 333 (1977), J. prakt.
Chemie 151 , 221 (1938), Z.Chemie 6 , 467
(1966) and Mol.Cryst.Liq.Cryst. 25 , 299 (1974)
pyridazine derivatives, such as phenylpyridazines and diphenylpyridazines, and in particular the compounds having two lateral cyano groups on the benzene ring as described in DE 2933563 and DE 2937700. It is. Particularly preferred compounds have the general formula In the formula, R ³ and R ⁴ represent a linear alkyl group containing 1 to 8 carbon atoms, and ring C represents a p-phenylene or trans-1,4-disubstituted cyclohexane ring. Dicyanophenyl ester, general formula In the formula, R ¹⁹ and R ²⁰ are linear C ₁ -C ₁₂ -alkyl or also linear C ₁ -C ₁₂ - on an aromatic ring.
represents alkoxy, or one of R ¹⁹ and R ²⁰ is of the general formula X ⁸ and X ⁹ represent a single covalent bond or one of X ⁸ and X ⁹ also represents an ethylene group -CH ₂ CH ₂ -; rings A ⁶ and A ⁷ are ,4
-phenyl or when X ⁸ or X ⁹ represents an ethylene group -CH ₂ CH ₂ -, also trans-
represents 1,4-cyclohexylene; and R ²¹
is a linear _C1 - _C12 -alkyl or aromatic ring ^A7
Dicyanobenzene representing the above linear C ₁ -C ₁₂ -alkoxy and the general formula In the formula, R ⁸ represents a linear alkyl containing 1 to 12 carbon atoms, and R ⁹ represents alkyl, alkoxy,
Cyclohexylpyridazine represents a p-alkylphenyl, p-alkoxyphenyl or trans-4-alkylcyclohexyl group, and the alkyl and alkoxy groups in ^R9 are linear groups containing 1 to 10 carbon atoms. It is. In the case of a non-liquid crystal component, the "dielectric anisotropy" of component B above refers to the extrapolated value of dielectric anisotropy at a temperature 10°C lower than the extrapolated (actual) clearing point (a liquid crystal mixture containing this component). Please understand that For example, the above-mentioned pyridazines have a dielectric anisotropy of about -9. Suitable as component C are, for example, compounds containing 3 or 4 p-phenylene or trans-1,4-cyclohexylene groups, a polar end group and optionally lateral halogen or cyanide substituents.
Such compounds are partly known and include, for example
Mol.Cryst.Liq.Cryst. 63 , 129 (1981) and German Patent Application Publication No. 2736772;
It is described in No. 2752975 and No. 3046872. It has been found that the compounds of the above formula and those named as particularly preferred are particularly suitable compounds for component C. These compounds have high clearing points, good stability and generally clear
It has a large nematic or cholesteric mesophase with an alternator frequency that is below 10KHz.
Furthermore, at frequencies below the alternating frequency, the compound has a large positive dielectric anisotropy, and at frequencies above the alternating frequency, the compound has a large negative dielectric anisotropy. These properties enable particularly high multiplexing rates and low energy consumption when operating the display according to the two-frequency method. In addition to the compound of formula, also the general formula In the formula, R ² represents hydrogen, fluorine, chlorine, bromine or a cyano group, Y ⁴ represents 2,2-dicyanovinyl, 2,2-dicyano-1-methylvinyl or cyano, and R ¹⁰ and E represent Together p-
R ¹⁰ -phenyl, trans-4-R ¹⁰ -cyclohexyl, 4'-R ¹⁰ -4-biphenylyl, p-(trans-4-R ¹⁰ -cyclohexyl)phenyl, p
-(5-R ¹⁰ -2-pyrimidinyl)phenyl, p
−[2-(p′-R ¹⁰ -phenyl)ethyl]phenyl,
p-[2-(trans-4- ^R10 -cyclohexyl)ethyl]phenyl, trans-4-[2-(p
-R ¹⁰ -phenyl)ethyl]cyclohexyl or trans-4-[2-(trans-4-R ¹⁰ -cyclohexyl)ethyl]cyclohexyl, and R ¹⁰ is a straight-chain alkyl containing 1 to 12 carbon atoms. group or 1 carbon atom on the benzene ring
Particularly suitable for component C are compounds representing straight-chain alkoxy groups containing ~12. These compounds also have a large nematic mesophase range,
It has a low alternating frequency and a large absolute dielectric anisotropy. Mixtures according to the invention with a cross-over frequency of at most about 10 KHz at 20° C. are preferred, and mixtures with a cross-over frequency of at most about 5 KHz are particularly preferred. The mixtures according to the invention also contain optically active compounds (depending on the character of components A, B and C), such as biphenylyls and/or dichroic coloring substances, such as azo, azoxy or anthraquinone coloring substances. can include. The amount of such compound is determined by solubility, desired pitch, color, absorbance, etc. The amount of optically active compound is preferably at most about 4% by weight and the amount of dichroic coloring material is preferably at most about
10% by weight, based on the total mixture. The liquid crystal mixture in the present invention can be produced by a method known per se, for example, by heating a mixture of each component to a temperature slightly above the clearing point and then cooling the mixture. The production of electro-optical devices containing the mixture according to the invention can also be carried out in a manner known per se, for example by emptying a suitable cell and introducing the mixture into this emptied cell. . The compound of formula is new. These can be prepared as illustrated in Schemes 1 and 2 below: where R ¹⁵ is trans-4-alkylcyclohexyl, 4'-alkyl-4-biphenylyl, p-(trans -4-alkylcyclohexyl)phenyl or 2-(trans-4-alkylcyclohexyl)ethyl, and R ¹⁶ represents trans-4-alkylcyclohexyl, or R ¹⁵ represents trans-4-alkylcyclohexyl, and R ¹⁶ is p
-(trans-4-alkylcyclohexyl)phenyl, p-[2-(trans-4-alkylcyclohexyl)ethyl]phenyl or 4'-(trans-4-alkylcyclohexyl)-4-biphenylyl, or R ¹⁵ represents p-alkylphenyl, and R ¹⁶ represents p-[2-(trans-4-alkylcyclohexyl)ethyl]phenyl, and the alkyl groups in R ¹³ , R ¹⁴ and R ¹⁵ and R ¹⁶ have 1 carbon atom It is a straight-chain alkyl group containing ~7. The compound of formula R ¹⁶ -CHO in Reaction Scheme 1 can be obtained in a simple manner from known compounds; for example, trans-4-alkylcyclohexanecarboxaldehyde can be obtained by Rosenmund reduction of the corresponding acid chloride. and the remaining compounds can be obtained by reducing the corresponding cyano compounds. According to reaction scheme 2, compounds of formula or compounds of formula B in which R ¹³ and R ¹⁴ have the same meaning can be obtained directly by reaction of a compound of formula with a Grignard reagent. When at least about 2 moles of Grignard reagent are used per mole of compound of formula B, the compound of formula B generally results directly. The compounds of formula are also new. These can be obtained according to esterification methods known per se (for example in a manner analogous to the preparation of compounds of the formula). The starting materials necessary for the preparation of the esters of the formula are known or are analogs of known compounds and can be prepared according to known methods. The compound of formula L is also new. These may be used in a manner known per se to prepare compounds of the formula L in which: (a) R ²⁰ represents linear C ₁ -C ₁₂ -alkyl or a radical of the formula L; In the formula, ²⁰ represents a linear _C1 - _C12 -alkyl or a group of formula L, and ^R19 , ^X8 and ring ^A6
has the abovementioned meaning, by oxidizing (e.g. by 2,3-dichloro-5,6-dicyano-p-benzoquinone in dioxane or by catalytic dehydrogenation in the presence of a palladium catalyst) ), (b) in order to prepare compounds of the formula L in which R ²⁰ represents linear C ₁ -C ₁₂ -alkyl or a radical of the formula L, the general formula In the formula, R ²⁰ represents a linear C ₁ -C ₁₂ ^-alkyl or a group of formula L, and R ¹⁹ , (e.g. by cesium fluoride in dimethylformamide), or (c) to prepare compounds of the formula L in which R ²⁰ represents linear C ₁ -C ₁₂ -alkoxy, the general formula In the formula, R ²⁰ represents linear C ₁ -C ₁₂ -alkoxy, and R ¹⁹ , X ⁸ and ring A ⁶ have the above meanings. Diels-Alder reaction, e.g. tetrahydrofuran] and then cleavage of ethylene (e.g. by heating). Compounds of formula L may for example have the general formula In the formula, R ¹⁹ , X ⁸ and ring A ⁶ have the meanings shown in formula L, and the aldehyde of formula where R ²⁰ has the meaning given in formula L, and the resulting diene is reacted with a phosphonium salt of formula L by Diels-Alder reaction with dicyanoacetylene in tetrahydrofuran.
It can be obtained by converting it into a compound. Compounds of formula L and compounds of formula L in which X ⁸ represents a single covalent bond are known or are homologs of known compounds. Compounds of formula L in which X ⁸ represents an ethylene group are, for example,
The corresponding compound of formula L in which X ⁸ represents a single covalent bond is heated at reflux in benzene with (C ₆ H ₅ ) ₃ P=CH-COOC ₂ H ₅ and the resulting α,β-unsaturated ester is catalytically hydrogenated in ethanol in the presence of a palladium catalyst, the resulting ester is reduced with lithium aluminum hydride in diethyl ether, and the resulting alcohol is converted to the desired aldehyde with pyridinium chlorochromate in methylene chloride. It can be obtained by oxidation. Compounds of formula L can be prepared, for example, by reacting an aldehyde of formula L with a phosphonium salt of formula in anhydrous diethyl ether in the presence of butyllithium, and reacting the resulting diene with tetracyanoethylene in diethyl ether.
It can be converted into a compound of formula L by an Alder reaction. Compounds of formula L may, for example, have the general formula In the formula, R ²⁰ represents linear C ₁ -C ₁₂ -alkoxy, and R ¹⁰ , X ⁸ and ring A ⁶ have the meanings given in formula L. (in a diethyl ether/ethanol mixture). Generally 1,4-diene or 1,3-diene (formula L
A mixture of 1,4-diene and 1,4-diene is obtained. Isomerization to 1,3-diene can be carried out using, for example, 2,3-dichloromaleic anhydride. This isomerization is preferably performed with respect to the subsequent Diels-Alder reaction [method (c)].
This is done by using the product obtained in the above reduction directly and adding 2,3-dichloromaleic anhydride to the reaction mixture. The compound of formula is also new. These compounds can be prepared by a method known per se (a) where R ⁹ is alkyl, p-alkylphenyl, p-
- alkoxyphenyl or trans-4-alkylcyclohexyl group, the general formula In the formula, R ¹⁷ is alkyl, p-alkylphenyl, p-alkoxyphenyl or trans-
4-alkylcyclohexyl group;
The alkyl and alkoxy groups in R ¹⁷ are straight-chain groups containing 1 to 10 carbon atoms, and
R ⁸ has the above meaning, or oxidizes a compound of sodium, by isopentyl nitrite in glacial acetic acid,
or (b) preferably by catalytic dehydrogenation with palladium, platinum etc.), or (b) in order to prepare compounds of the formula in which R ⁹ represents an alkoxy group. In the formula, X ⁷ represents chlorine or bromine and R ⁸ has the abovementioned meaning, which can be prepared by reacting a compound of with an alkali metal alcoholate (for example sodium methylate). Compounds of formula can be rearranged into tautomeric compounds by movement of the double bond in the dihydropyridazine ring. Such rearrangements can be brought about, for example, in the presence of trace amounts of acids or bases. However, since tautomeric dihydropyridazines can also be oxidized to compounds of formula under the above conditions, not only compounds of formula but also tautomeric dihydropyridazines or mixtures of such compounds can be used according to process (a). can be reacted. The formulas and starting materials are new. These products can be produced as shown in the following reaction formulas 3 to 6;
R ⁸ , R ¹⁷ and X ⁷ have the meanings given above, and R ¹⁸
represents a straight-chain alkyl or alkoxy group containing 1 to 10 carbon atoms. The starting materials of the formulas L, L, L and L are known or are analogs of known compounds and can be prepared in known methods. For example, aldehydes of formula L can be prepared by Rosenmund reduction of acid chlorides of formula. The addition of aldehydes to compounds of formula L, L or L is carried out according to Stetter [Chem.Ber. 114
(1981) 581] in the presence of a 1,3-thiazolium salt catalyst. A preferred catalyst for the addition of aldehydes of formula L or aldehydes of formula L in which R ¹⁷ represents alkyl or trans-4-alkylcyclohexyl is 3-benzyl-5-(2-hydroxyethyl)-
A preferred catalyst for the addition of aldehydes of formula L which is 4-methyl-1,3-thiazolium chloride and R ¹⁷ represents p-alkylphenyl or p-alkoxyphenyl is 3,4-dimethyl- 5-(2-hydroxyethyl)-1,3-
It is thiazolium iodide. The coupling between the compound of formula L and the compound of formula is described by T. Sato et al. in Bull.Chem.
It can be carried out according to the method described in Soc. Japan 54 (1981) 505. As noted above, compounds of the formula can also exist in tautomeric forms or as mixtures of isomeric forms. Some of the compounds of the formula are new compounds.
These can be prepared by esterification in the same manner as the compounds of formula. The acid required for the preparation of the compound of formula can be obtained as shown in Scheme 7;
R ² , R ¹⁰ and E have the meanings given in the above formula: Compounds of formula and are known or can be prepared according to methods known per se. The present invention also relates to all novel compounds, mixtures, methods of preparation, uses and devices as described herein. In the following mixture examples and manufacturing examples:
C stands for crystalline phase, S stands for smectic phase, N stands for nematic phase, Ch stands for cholesteric phase and I stands for isotropic phase. _c represents the alternating frequency, Δε ₁ represents the low frequency (“static”) dielectric anisotropy (obviously measured at a frequency lower than the alternating frequency),
Δε _h represents the high frequency dielectric anisotropy (obviously measured at frequencies higher than the alternating frequency) and η represents the viscosity (bulk viscosity). The following mixture examples are examples of preferred mixtures according to the invention suitable for conditioning according to the two-frequency method. The relationship of the individual components of the total mixture to components A, B and C has already been indicated in detail. Mixture Example 1 Trans-4-butylcyclohexanecarboxylic acid p-ethoxyphenyl ester 11.4% by weight, trans-4-butylcyclohexanecarboxylic acid p-pentyloxyphenyl ester 16.0% by weight, trans-4-pentylcyclohexanecarboxylic acid p -Methoxyphenyl ester 10.3% by weight, trans-4-pentylcyclohexanecarboxylic acid p-propyloxyphenyl ester 12.4% by weight, 2-(trans-4-pentylcyclohexyl)-
1-(p-ethoxyphenyl)ethane 7.0% by weight, 3-propyl-6-(trans-4-ethylcyclohexyl)pyridazine 2.8% by weight, 3-propyl-6-(trans-4-pentylcyclohexyl)pyridazine 6.9% by weight %, 3-propyl-6-(trans-4-heptylcyclohexyl)pyridazine 4.4% by weight, 3-pentyl-6-(trans-4-pentylcyclohexyl)pyridazine 8.8% by weight, 4'-hexyl-4-biphenylcarvone Acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester 10.0% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4 -cyanophenoxy)carbonyl]phenyl ester 10.0% by weight; melting point (C-N) <0°C, clearing point (N-I) 73°C; _c (22°C) = 3.4KHz, Δε ₁ (22°C) = 8.24, Δε _h (2
2
°C) = −4.48; η (22 °C) = 73 cp. Mixture Example 2 Trans-4-butylcyclohexanecarboxylic acid p-ethoxyphenyl ester 10.0% by weight, trans-4-butylcyclohexanecarboxylic acid p-pentyloxyphenyl ester 14.0% by weight, trans-4-pentylcyclohexanecarboxylic acid p -Methoxyphenyl ester 9.0% by weight, trans-4-pentylcyclohexanecarboxylic acid p-propyloxyphenyl ester 10.9% by weight, 2-(trans-4-pentylcyclohexyl)-
1-(p-ethoxyphenyl)ethane 6.1% by weight, 3-propyl-6-(trans-4-ethylcyclohexyl)pyridazine 4.0% by weight, 3-propyl-6-(trans-4-pentylcyclohexyl)pyridazine 9.6% by weight %, 3-propyl-6-(trans-4-heptylcyclohexyl)pyridazine 6.1% by weight, 3-pentyl-6-(trans-4-pentylcyclohexyl)pyridazine 12.3% by weight, 4'-heptyl-4-biphenylcarvone Acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester 6.0% by weight, 4'-hexyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4 -nitrophenoxy)carbonyl]phenyl ester 6.0% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester 6.0% by weight; Melting point ( C-N)<0°C, clearing point (N-I) 63°C. Mixture Example 3 Trans-4-butylcyclohexanecarboxylic acid p-ethoxyphenyl ester 10.2% by weight, trans-4-butylcyclohexanecarboxylic acid p-pentyloxyphenyl ester 14.3% by weight, trans-4-pentylcyclohexanecarboxylic acid p -Methoxyphenyl ester 9.2% by weight, trans-4-pentylcyclohexanecarboxylic acid p-propyloxyphenyl ester 11.1% by weight, 2-(trans-4-pentylcyclohexyl)-
1-(p-ethoxyphenyl)ethane 6.2% by weight, 4-pentyl-1-(trans-4-propylcyclohexyl)benzene 9.1% by weight, 3-propyl-6-(trans-4-ethylcyclohexyl)pyridazine 2.6% by weight %, 3-propyl-6-(trans-4-pentylcyclohexyl)pyridazine 6.3% by weight, 3-propyl-6-(trans-4-heptylcyclohexyl)pyridazine 4.0% by weight, 3-pentyl-6-(trans-4 -pentylcyclohexyl)pyridazine 8.0% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(p-cyanophenoxy)carbonyl]phenyl ester 4.5% by weight, p-[2-(trans-4 -heptylcyclohexyl)ethyl]benzoic acid 3-chloro-4-[(p-cyanophenoxy)carbonyl]phenyl ester
4.5% by weight, p-[2-(trans-4-heptylcyclohexyl)ethyl]benzoic acid 3-chloro-4-[(p-
(2,2-dicyano-1-methylvinyl)phenoxy)carbonyl]phenyl ester 3.6% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy) Carbonyl] phenyl ester 6.4% by weight; melting point (C-N)<0℃, clearing point (N-I) 70℃; _c (22℃) = 3KHz, Δε ₁ (22℃) = 4.39, Δε _h (22
℃)
=-4.0. Mixture Example 4 Trans-4-butylcyclohexanecarboxylic acid p-ethoxyphenyl ester 9.49% by weight, trans-4-butylcyclohexanecarboxylic acid p-pentyloxyphenyl ester 13.36% by weight, trans-4-pentylcyclohexanecarboxylic acid p -Methoxyphenyl ester 8.58% by weight, trans-4-pentylcyclohexanecarboxylic acid p-propyloxyphenyl ester 10.36% by weight, 2-(trans-4-pentylcyclohexyl)-
1-(p-ethoxyphenyl)ethane 5.83% by weight, 4-(trans-4-pentylcyclohexyl)-
4'-[2-(trans-4-butylcyclohexyl)ethyl]biphenyl 4.77% by weight, 3-propyl-6-(trans-4-ethylcyclohexyl)pyridazine 3.76% by weight, 3-propyl-6-(trans-4 -pentylcyclohexyl)pyridazine 9.15% by weight, 3-pentyl-6-(trans-4-pentylcyclohexyl)pyridazine 11.71% by weight, 3-propyl-6-(trans-4-heptylcyclohexyl)pyridazine 5.86% by weight, 4'- Hexyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester 5.71% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4- [(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester 5.71% by weight, 4'-hexyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl Ester 5.71% by weight; melting point (C-N) <-10°C, clearing point (N-I) 73.7
℃; _c (22℃) = 3.5KHz, Δε ₁ (22℃) = 5.22, Δε
_h
(22℃) = −5.2; η (22℃) = 67.4cp. Mixture Example 5 Trans-4-butylcyclohexanecarboxylic acid p-ethoxyphenyl ester 5.40% by weight, trans-4-pentylcyclohexanecarboxylic acid p-methoxyphenyl ester 4.95% by weight, trans-4-pentylcyclohexanecarboxylic acid p- Propyloxyphenyl ester 8.35% by weight, trans-4-pentylcyclohexanecarboxylic acid trans-4-propylcyclohexyl ester 9.06% by weight, 2-(trans-4-pentylcyclohexyl)-
1-(p-ethoxyphenyl)ethane 13.42% by weight, 1-[2-(trans-4-butylcyclohexyl)ethyl]-4-(trans-4-pentylcyclohexyl)benzene 6.45% by weight, 4-(trans- 4-pentylcyclohexyl)-
4'-[2-(trans-4-butylcyclohexyl)ethyl]biphenyl 4.76% by weight, 3-propyl-6-(trans-4-ethylcyclohexyl)pyridazine 3.76% by weight, 3-propyl-6-(trans-4 -pentylcyclohexyl)pyridazine 9.15% by weight, 3-pentyl-6-(trans-4-pentylcyclohexyl)pyridazine 11.72% by weight, 3-propyl-6-(trans-4-heptylcyclohexyl)pyridazine 5.85% by weight, 4'- Hexyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester 5.71% by weight, 4'-hexyl-4-biphenylcarboxylic acid 3-chloro-4- [(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester 5.71% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl Ester 5.71% by weight; melting point (C-N) <-10°C, clearing point (N-I) 70.1
℃; _c (22℃) = 2.5KHz, Δε ₁ (22℃) = 5.2, Δε _h
(22℃) = −5.2; η (22℃) = 65cp. Mixture Example 6 Trans-4-butylcyclohexanecarboxylic acid p-ethoxyphenyl ester 8.48% by weight, trans-4-pentylcyclohexanecarboxylic acid p-methoxyphenyl ester 7.77% by weight, trans-4-pentylcyclohexanecarboxylic acid p- Propyloxyphenyl ester 13.11% by weight, trans-4-pentylcyclohexanecarboxylic acid trans-4-propylcyclohexyl ester 14.22% by weight, 2-(trans-4-pentylcyclohexyl)-
1-(p-ethoxyphenyl)ethane 21.05% by weight, 1-[2-(trans-4-butylcyclohexyl)ethyl]-4-(trans-4-pentylcyclohexyl)benzene 10.12% by weight, 4-(trans- 4-pentylcyclohexyl)-
4'-[2-(trans-4-butylcyclohexyl)ethyl]biphenyl 2.91% by weight, 3-propyl-6-(trans-4-ethylcyclohexyl)pyridazine 0.60% by weight, 3-propyl-6-(trans-4 1.46% by weight of 3-pentyl-6-(trans-4-pentylcyclohexyl)pyridazine, 0.93% by weight of 3-propyl-6-(trans-4-heptylcyclohexyl)pyridazine, 4' Hexyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester 5.83% by weight, 4'-hexyl-4-biphenylcarboxylic acid 3-chloro-4- [(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester 5.83% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl Ester 5.83%; Melting point (C-N) <-10°C, Clearing point (N-I) 85.1
℃; _c (22℃) = 2KHz, Δε ₁ (22℃) = 5.2, Δε _h (
twenty two
°C) = −2.2; η (22 °C) = 55 cp. Mixture Example 7 Trans-4-butylcyclohexanecarboxylic acid p-ethoxyphenyl ester 5.88% by weight, trans-4-pentylcyclohexanecarboxylic acid p-methoxyphenyl ester 5.39% by weight, trans-4-pentylcyclohexanecarboxylic acid p- Propyloxyphenyl ester 9.09% by weight, trans-4-pentylcyclohexanecarboxylic acid trans-4-propylcyclohexyl ester 9.86% by weight, 2-(trans-4-pentylcyclohexyl)-
1-(p-ethoxyphenyl)ethane 14.61% by weight, 1-[2-(trans-4-butylcyclohexyl)ethyl]-4-(trans-4-pentylcyclohexyl)benzene 7.02% by weight, 4-(trans- 4-pentylcyclohexyl)-
4'-[2-(trans-4-butylcyclohexyl)ethyl]biphenyl 7.41% by weight, 3-propyl-6-(trans-4-ethylcyclohexyl)pyridazine 3.66% by weight, 3-propyl-6-(trans-4 -pentylcyclohexyl)pyridazine 8.90% by weight, 3-pentyl-6-(trans-4-pentylcyclohexyl)pyridazine 11.39% by weight, 3-propyl-6-(trans-4-heptylcyclohexyl)pyridazine 5.69% by weight, 4'- Hexyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester 3.70% by weight, 4'-hexyl-4-biphenylcarboxylic acid 3-chloro-4- [(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester 3.70% by weight, 4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl Ester 3.70% by weight; melting point (C-N) <-10°C, clearing point (N-I) 70.0
℃; _c (22℃) = 3KHz, Δε ₁ (22℃) = 2.2, Δε _h (
twenty two
°C) = −5.2; η (22 °C) = 55 cp. The following examples illustrate the preparation of compounds of formula and the preparation of starting materials. Example 1 11.4 g of 2-chloro-4-[[p-(p-hexylphenyl)benzoyl]oxy]benzoic acid was boiled with 5.35 g of thionyl chloride in 100 ml of benzene for 2.5 hours. The solvent and excess thionyl chloride were distilled off under vacuum, the residue was taken up twice in each 50 ml of toluene and concentrated in each case. The obtained crude 2-chloro-4-[[p-(p-
Hexylphenyl)benzoyl]oxy]benzoyl chloride was dissolved in 250 ml of benzene and then added dropwise to a solution of 4.0 g of 3-chloro-4-cyanophenol in 100 ml of pyridine. The mixture was stirred overnight at a bath temperature of 65°C, then poured into ice-cold diluted hydrochloric acid and extracted with diethyl ether. 3N extract
Wash several times with hydrochloric acid, then with water to make it neutral,
Dry and evaporate. The crude 4′-
Hexyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester was chromatographed on silica gel with toluene/dichloromethane (1:1). A virtually pure fraction (8.2 g) by thin layer chromatography was recrystallized once from ethyl acetate and once from ethyl acetate and a small amount of hexane; melting point (C-N).
95°C, clearing point (N-I) 235°C. 2-chloro-4-[[p-
(p-hexylphenyl)benzoyl]oxy]
Benzoic acid was prepared as follows: (a) N,N'-dicyclohexylcarbodiimide
37.2 g of 4'-hexyl-4-biphenylcarboxylic acid, 23.5 g of 2-chloro-4-hydroxybenzaldehyde in 1500 ml of dichloromethane.
and 1.5 g of 4-(dimethylamino)pyridine in portions within 10 minutes. The mixture was stirred at room temperature for 3 hours, then the precipitated N,
N'-dicyclohexylurea was separated by suction.
The liquid was washed twice with 200 ml each of 2N sodium hydroxide solution, four times with 200 ml each of water, dried over sodium sulfate, filtered and concentrated. (b) The obtained crude 2-chloro-4-[[p-(p
-hexylphenyl)benzoyl]oxy]benzaldehyde (67.1 g) was dissolved in 2500 ml of acetone. Add 80 ml of Jones's reagent to this solution.
It was added dropwise within minutes and the mixture warmed up somewhat.
The mixture was stirred for a further 3 hours, then the precipitated inorganic material was filtered off with suction and the acetone was distilled off on a rotary evaporator. The residue was suspended in water and the suspension was filtered off with suction. The resulting crude 2-chloro-4-[[p-(p-hexylphenyl)benzoyl]oxy]benzoic acid was washed neutral with water on a filter and then boiled with methanol for purification. , cooled, separated and dried. Yield 58.5g; melting point 163.8-165.5°C. The following compounds were prepared in a similar manner: 4'-heptyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C-
N) 95°C, clearing point (N-I) 229°C; 4'-heptyl-4-biphenylcarboxylic acid p-
[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C-N) 112°C,
Clearing point (N-I) 289°C; 4'-(pentyloxy)-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; Melting point (C- N) 115.5°C, clearing point (N-I) 272°C; 4'-heptyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(3,4-dicyanophenoxy)carbonyl]phenyl ester; melting point (C-N)
146℃, clearing point (N-I) 211.5℃; 4'-heptyl-4-biphenylcarboxylic acid p-
[(3,4-dicyanophenoxy)carbonyl] phenyl ester; melting point (C-N) 162°C, clearing point (N-I) 266.5°C; 4'-pentyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(4-nitrophenoxy)carbonyl]phenyl ester; melting point (C-N) 124°C,
Clearing point (N-I)>290℃;4'-heptyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(4-nitrophenoxy)carbonyl]phenyl ester; melting point (C-N) 96.5°C,
Clearing point (N-I)>280℃;4'-hexyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester; melting point (C-
N) 94°C, clearing point (N-I) 203°C; 4'-heptyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester; melting point (C-
N) 102.5℃, clearing point (N-I) 199.5℃; 4'-hexyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(3-methyl-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C-
N) 110°C, clearing point (N-I) 237°C; 4'-heptyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(3-methyl-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C-
N) 101.5℃, clearing point (N-I) 232℃; 4'-hexyl-4-biphenylcarboxylic acid 3-
Chloro-4-[(3,4-dicyanophenoxy)carbonyl]phenyl ester; melting point (C-N)
145°C, clearing point (N-I) 219°C; Example 2 A suspension of 2.6 g of 4"-pentyl-4-terphenyl-4'-carboxylic acid in 25 ml of thionyl chloride was heated to boiling for 2.5 hours. thionyl chloride is distilled off,
The residue was taken up twice in 50 ml of toluene each time and concentrated in each case. The crude 4″-pentyl-4-terphenyl-4′ carbonyl chloride obtained was dissolved in 50 ml of benzene and then added dropwise to a solution of 1.15 g of 3-chloro-4-cyanophenol in 30 ml of pyridine. Heated in an oil bath at 70°C with stirring, then poured into ice water and extracted with dichloromethane. The extract was
Washed several times with 3N hydrochloric acid, then 2N sodium carbonate and water, dried and evaporated. The crude 4″-pentyl-4-terphenyl obtained
4'-Carboxylic acid 3-chloro-4-cyanophenyl ester was chromatographed on silica gel with toluene/dichloromethane (4:1). Virtually pure fractions were recrystallized twice from ethyl acetate by thin layer chromatography:
Yield 2.3g; melting point (C-N) 161℃, clearing point (N-
I) 299°C Example 3 In a similar manner to the method described in Example 1, 2-chloro-4-[[p-(p-heptylphenyl)benzoyl]oxy]benzoic acid and 3-chloro-4-
From (2,2-dicyanovinyl)phenol,
4'-heptyl-4-biphenylcarboxylic acid 3-chloro-4-[(3-chloro-4-(2,2-dicyanovinyl)phenoxy)carbonyl] phenyl ester was prepared; melting point (C-N) 120.5℃, clearing point (N-I) 240.5℃. 3-chloro-4-(2,
2-dicyanovinyl)phenol was prepared as follows: 3-chloro-4-hydroxybenzaldehyde
3.2g, malononitrile 1.6g, ammonium acetate
A mixture of 0.31 g, 0.23 ml of glacial acetic acid and 100 ml of toluene was heated and boiled overnight with a water separator attached. The mixture was allowed to cool and some of the product precipitated. The precipitated product was diluted into solution with diethyl ether. The mixture was then washed with saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated. The residue was dissolved in hot toluene and the solution was filtered. 3-chloro-4-, melting point 161-162°C
3.2 g of (2,2-dicyanovinyl)phenol crystallized from the liquid. Example 4 In a similar manner to the method described in Example 1, ring A represents trans-1,4-cyclohexylene,
It was possible to prepare compounds of the formula in which X ¹ represents an ethylene group -CH ₂ CH ₂ - and ring B represents p-phenylene. The carboxylic acid used as a starting material was p-[2
-(trans-4-heptylcyclohexyl)ethyl]benzoic acid could be produced as described below. 21.3 g p-[2-(trans-4-heptylcyclohexyl)ethylbenzonitrile and potassium hydroxide (85%) in 500 ml ethylene glycol
14.0g of solution was heated to boiling for 8 hours (bath temperature 210
℃). After cooling, the mixture was poured into water and acidified with 3N hydrochloric acid. The precipitated p-[2-(trans-4-heptylcyclohexyl)ethyl]benzoic acid was filtered off with suction, washed with water on a suction filter and then taken up in diethyl ether. The solution was dried over sodium sulphate and evaporated. Thin layer chromatography yielded 22.9 g of pure product; melting point 184-187°C, clearing point 220-223°C. Example 5 In a similar manner to the method described in Example 1, ring A is p
- represents phenylene, and X ¹ is an ethylene group -CH ₂
It was possible to prepare a compound of the formula CH ₂ -, ring B represents trans-1,4-cyclohexylene and X ² represents the ester group -COO-. The trans-4-[2-(p
-R ¹ -phenyl)ethyl]cyclohexanecarboxylic acid could be prepared as follows based on the pentyl compound: (a) (p-pentylphenyl) in 30 ml of t-butyl methyl ether. A mixture of 2.51 g of methyl-triphenylphosphonium bromide and 615 mg of 4-cyanocyclohexanecarboxaldehyde (approximately 1:1 cis/trans mixture) was placed in a sulfonation flask at 0° C. under argon gas to form solid potassium t-butyrate. 673mg 2
Processed within minutes and then stirred for a further 1.5 hours at 0°C. Next, add 100 ml of water to the red-brown homogeneous mixture.
and extracted three times with 100 ml each of diethyl ether. The organic phase was washed twice with 50 ml each of water and once with 50 ml of saturated sodium chloride solution, dried over magnesium sulphate and concentrated. The residue was suspended in 150 ml of hexane, the triphenylphosphine oxide precipitated by filtration was removed (rinsed with hexane), and the solution was concentrated. The resulting oil (1.36 g) was purified with 3% ethyl acetate/
Low pressure chromatography (0.4 bar) on silica gel with petroleum ether yielded 1.02 g of 4-[2-(p-pentylphenyl)ethenyl]cyclohexanecarbonitrile as a colorless oil.
(81%); R value of this isomer mixture (10
% ethyl acetate/petroleum ether): 0.27 and 0.36. (b) Obtained 4-[2-(p-pentylphenyl)
Ethenyl cyclohexane carbonitrile 956
mg was dissolved in 50 ml of toluene in a sulfonation flask, treated with 150 mg of palladium/carbon (10%) and hydrogenated at normal pressure and room temperature until hydrogen uptake ceased (approximately 30 minutes). Filter the mixture (rinse with toluene), concentrate the liquid and remove the residue (890
4-[2-
788 mg (82%) of (p-pentylphenyl)ethyl]cyclohexanecarbonitrile was obtained. In thin layer chromatography, using different solvent systems as eluents, only one spot appears, but in gas chromatography and
According to NMR spectroscopy, this material was a mixture of cis/trans isomers (approximately 1:3). This material was crystallized twice from pentane at -20°C to finally obtain sufficient purity of trans-4-
[2-(p-pentylphenyl)ethyl]cyclohexanecarbonitrile was obtained (according to gas chromatography analysis, trans compound 98.8
% and cis compound 1.2%); melting point 22.4°C, clearing point (N-I) -14.1°C. (c) trans-4-[2-(p-pentylphenyl)ethyl]cyclohexanecarbonitrile
A mixture of 567 mg and 20 ml of a 10:1 mixture of 2N potassium hydroxide and ethanol was heated under reflux for 2 hours under argon gas in a round bottom flask equipped with a reflux condenser. Pour the cooled mixture into water.
It was diluted with 20 ml and extracted twice with 30 ml each of diethyl ether. The separated aqueous phase was acidified with about 20 ml of 2N sulfuric acid and extracted three times with 50 ml each of diethyl ether. The organic phase was washed twice with 50 ml each of saturated sodium chloride solution, dried over magnesium sulphate and concentrated. Trans-4 as colorless crystals
- 490 mg (81%) of [2-(p-pentylphenyl)ethyl]cyclohexanecarboxylic acid was obtained,
This was further purified by recrystallization from hexane. Example 6 Analogously to the method described in Example 1, rings A and B represent trans-1,4-cyclohexylene, X ¹ represents an ethylene group -CH ₂ CH ₂ - and X ² represents an ester. It was possible to prepare a compound of the formula representing the group -COO-. Trans-4-[2-(trans-4-alkylcyclohexyl)ethyl] used as starting material
Cyclohexanecarboxylic acid could be prepared based on the pentyl compound as described below: (a) 3.79 g of lithium aluminum hydride was placed in 100 ml of anhydrous tetrahydrofuran under argon gas; trans-4-pentylcyclohexanecarboxylic acid
19.83g of solution was processed within 30 minutes. After the addition was complete, the mixture was heated under reflux for 1 hour, then carefully added 200 ml of 2N hydrochloric acid and extracted three times with 100 ml each of diethyl ether. The organic phase was washed with 100 ml of saturated sodium carbonate solution, dried over potassium carbonate and concentrated. The residue (19.2 g) was distilled and in the main fraction 17.7 g (96%) of (trans-4-pentylcyclohexyl)methanol was obtained as a colorless oil (purity 99.9%); boiling point 89° C./0.2 mm Hg. (b) A solution of 3.69 g of (trans-4-pentylcyclohexyl)methanol and 5.51 g of triphenylphosphine in 70 ml of methylene chloride is placed under argon gas at -30°C, such that the internal temperature does not exceed -20°C. solid tetrabromomethane
7.30 g portions were processed within 15 minutes. After the addition was complete, the cooling bath was removed and the mixture was stirred for a further 18 hours while gradually warming to room temperature. The mixture was then concentrated on a rotary evaporator and the resulting semi-crystalline residue was triturated with 200 ml of warm hexane, filtered and
The concentrated solution was chromatographed on a silica gel column with hexane. trans-1-(bromomethyl)-4 as a colorless liquid
- 4.79 g (97%) of pentylcyclohexane were obtained, which was further purified by distillation;
Boiling point: 82℃/0.08mmHg. (c) 1-methoxy-3-(trimethylsilyloxy)-1,3-butadiene [S.Danishefsky et al.
J.Amer.Chem.Soc. 96 , (1974) 7807] 18.9g,
Acrylonitrile 6.4g, dibenzoyl peroxide
A mixture of 100 mg and 50 ml of benzene was heated under reflux for 23 hours under argon gas. After cooling, the volatile components (benzene and excess acrylonitrile) were removed in a rotary evaporator and the residue was dissolved in 100 ml of tetrahydrofuran/1N hydrochloric acid (4:1) for 2 hours.
Heat under reflux for an hour. The cooled mixture was then extracted three times with 100 ml each of methylene chloride. The organic phase was washed twice with 100 ml each of water and once with 100 ml of saturated sodium chloride solution, dried over magnesium sulphate and concentrated. 10.3 g of a yellow oil was obtained, consisting of 87.9% of 4-cyano-3-cyclohexen-1-one and 2.7% of trans-4-cyano-3-methoxycyclohexanone (with hydrolysis products as intermediates). occured). The resulting oil was subjected to bulb-tube distillation (130-140
℃/0.27-0.15 mmHg), 4-cyano-3-cyclohexene-1- as an orange crystallizing oil.
1 and 4-cyano-2-cyclohexene-1
7.64 g of a mixture of -one was obtained. Dissolve this oil in 70 ml of ethanol and add 10% palladium/carbon 764.
Hydrogenation was carried out under normal pressure in the presence of Mg (hydrogen absorption 1425 ml). After filtering the catalyst, washing with methylene chloride, concentrating the liquor, and bulb-tube distillation (130-150°C/0.11 mmHg), 5.45 g (70 g) of 4-cyanocyclohexanone was obtained as a colorless oil.
%); R value [toluene/ethyl acetate (3:1)]: 0.25. (d) 9.6 g of triphenyl(methoxymethyl)phosphonium chloride was t-treated under argon gas.
Suspend in 50 ml of butyl methyl ether at -10°C.
was treated in portions with 3.39 g of solid potassium t-butyrate. After the addition is complete, the mixture is heated to 0-5°C.
Stir for 30 minutes at
- treated within 10 minutes with a solution of 2.30 g of cyanocyclohexanone. In this case, the internal temperature must not exceed 5°C. After the addition was complete, the yellow-orange mixture was warmed to 25°C and stirred for a further 2 hours. Then 50 ml of 2% sodium bicarbonate solution were added and the separated aqueous phase was extracted twice with 50 ml each of diethyl ether. Saturate the organic phase with 50 ml of sodium chloride solution
, dried over potassium carbonate, and concentrated. The remaining semi-crystalline orange oil is diluted with hexane.
Disintegrate with 400 ml, cool to -20°C and remove precipitated triphenylphosphine oxide by filtration (rinsing with cold hexane). The concentrated residue was subjected to low pressure chromatography (0.4 bar) on silica gel with 10% ethyl acetate/petroleum ether as eluent and 1.60 g (56%) of 4-(methoxymethylene)cyclohexanecarbonitrile as a colorless oil. obtained (purity 97
%). (e) The obtained 4-(methoxymethylene)cyclohexanecarbonitrile was dissolved in tetrahydrofuran/
It was heated under reflux for 1.5 hours in 100 ml of 0.2N hydrochloric acid (4:1). The cooled mixture was then poured into 50 ml of water and extracted three times with 50 ml each of diethyl ether.
The organic phase was washed with 50 ml of water and 50 ml of saturated sodium bicarbonate solution, dried over magnesium sulphate and concentrated. 1.35g (94%) colorless oil
was obtained, which, according to gas chromatographic analysis, consisted of 92% of a mixture of cis- and trans-4-cyanocyclohexanecarboxaldehyde (in a ratio of approximately 1:1). This material was used in the next reaction without further purification. R
Value [toluene/ethyl acetate (3:1)]: cis-
4-cyanocyclohexanecarboxaldehyde 0.36, trans-4-cyanocyclohexanecarboxaldehyde 0.32. (f) 40ml of 0.1N methanolic potassium hydroxide solution
A solution of 1.34 g of 4-cyanocyclohexanecarboxaldehyde (cis/trans mixture) in the solution was treated with 378 mg of solid sodium borohydride at 0° C. under argon gas. After addition,
The mixture was stirred for a further 20 minutes at 0°C, then 50ml of water
was added and the mixture was extracted three times with 50 ml each of methylene chloride. The organic phase was washed twice with 50 ml each of water, dried over magnesium sulphate and concentrated. The residue was subjected to low pressure chromatography (0.4 bar) on silica gel with chloroform/ethyl acetate (1:1) to give the 4-
1.22 g (90%) of (hydroxymethyl)cyclohexanecarbonitrile (as an approximately 1:1 mixture of two epimers) was obtained. This material was used in the next tosylation without further purification. 4-(Hydroxymethyl)cyclohexanecarbonitrile
R value [chloroform/ethyl acetate (1:
1)]: 0.29 (long spot). (g) 1.20 g of the resulting 4-(hydroxymethyl)cyclohexanecarbonitrile in 5 ml of pyridine.
A solution of p-chloride was prepared at room temperature and under argon gas.
Portions were treated with 2.46 g of Tosil. 3.5 at room temperature
After stirring for an hour (formation of a white precipitate), the mixture, cooled to 0°C, was treated with about 2 ml of water, carefully acidified with about 7 ml of concentrated hydrochloric acid, and diluted with diethyl ether.
Extracted three times with 30 ml. The organic phase was washed with 50 ml of water and 50 ml of saturated sodium chloride solution, dried over magnesium sulphate and concentrated, leaving 2.31 g of semi-crystalline oil. Low-pressure chromatography (0.5 bar) on 480 g of silica gel using 30% ethyl acetate/petroleum ether as eluent gave trans-4-4 as a colorless crystallizing oil.
1.06 g (42%) of (tosyloxymethyl)cyclohexanecarbonitrile (melting point 84-85°C) and 1.03 g of cis-4-(tosyloxymethyl)cyclohexanecarbonitrile as a colorless viscous oil.
(41%). R value (30% ethyl acetate/petroleum ether): 0.25 for trans product, 0.25 for cis product
0.20. (h) 121 mg of magnesium strips are covered with 3 ml of anhydrous tetrahydrofuran under argon gas, treated with iodine crystals and then dissolved in trans-1-(bromomethyl)-4-pentylcyclohexane in 7 ml of anhydrous tetrahydrofuran at reflux temperature. Treated with 989 mg of solution [according to section (b)]. After the addition was complete, the mixture was heated under reflux for a further 45 minutes. The mixture, cooled to −78°C, was then dilithium tetrachlorochloride in tetrahydrofuran [M. Tamura et al., SynThesis 1971 ,
303] and a solution of 587 mg of trans-4-(tosyloxymethyl)cyclohexanecarbonitrile in 9 ml of anhydrous tetrahydrofuran. The mixture, warmed to -15 DEG C., was stirred for a further 21 hours, then treated with about 10 ml of saturated ammonium chloride solution and extracted three times with 50 ml each of diethyl ether. The organic phase was washed with 50 ml of saturated sodium chloride solution, dried over magnesium sulphate and concentrated. The residue was subjected to low pressure chromatography (0.5 bar) on silica gel with 3% ethyl acetate/petroleum ether, and besides a large amount of the coupling product of trans-1-(bromomethyl)-4-pentylcyclohexane, trans-
4-[2-(trans-4-pentylcyclohexyl)ethyl]cyclohexanecarbonitrile
164 mg (28.5%) were obtained (353 g of trans-4-(tosyloxymethyl)cyclohexanecarbonitrile could be recovered with 30% ethyl acetate/petroleum ether). 5ml methanol
Recrystallization was performed once from 100% to give 96 mg of trans-4-[2-(trans-4-pentylcyclohexyl)ethyl]cyclohexanecarbonitrile (purity 99.98%) as colorless crystals; solid-solid transition point 39.3°C, melting point 56.3℃, clearing point 72.3℃ (nematake). (i) The obtained nitrile was dissolved in trans-4-[2-(trans-4-pentylcyclohexyl)ethyl] with 2N potassium hydroxide solution and ethanol in a manner similar to that described in Example 5(c). ]
It was possible to saponify to cyclohexanecarboxylic acid. Example 7 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid p-carboxyphenyl ester 3 g, benzene
A mixture of 40 ml and 0.7 ml of thionyl chloride was heated to boiling for 2 hours. Benzene and excess thionyl chloride were distilled off under vacuum, and the residue was dissolved in 25 ml each of toluene.
Taken twice and concentrated in each case. The resulting crude 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid p-(chlorocarbonyl)phenyl ester was dissolved in 70 ml of benzene and then dissolved in 50 ml of pyridine. -chloro-4-nitrophenol
It was added dropwise to 1.04 g of solution. The reaction mixture was heated to a bath temperature of 65°C.
The mixture was stirred overnight, then poured into ice-cold diluted hydrochloric acid, and extracted with diethyl ether. Add the extract to 3N hydrochloric acid
4 times with 50 ml and 1 time with 50 ml of 2N sodium carbonate solution
Washed twice, neutralized with water, dried and concentrated. The crude 2-chloro-4-
[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid p-[(3-chloro-
4-Nitrophenoxy)carbonyl]phenyl ester (3.2 g) was chromatographed on silica gel with hexane/dioxane (3:1 by volume). The thin-layer chromatographically pure fraction (1.8 g) was recrystallized twice from ethyl acetate; melting point (C-N) 138°C, clearing point (N
-I) 237.5°C. 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid p-carboxyphenyl ester used as a starting material was prepared as follows: (a) 2-chloro-4 - 20.61 g of [[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid [prepared similarly to the method described in Example 1(a) and (b)], 70 ml of benzene and 8 ml of thionyl chloride. The mixture was heated to boiling for 1.5 hours. Benzene and excess thionyl chloride were distilled off under vacuum, the residue was diluted with in each case 20 ml of toluene and concentrated in each case. (b) The obtained crude 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoyl chloride was dissolved in benzene.
100 ml and then added dropwise to a solution of 6.61 g of p-hydroxybenzaldehyde in 110 ml of pyridine. The resulting suspension was stirred for 6 hours at a bath temperature of 65°C, then poured into ice-cold diluted hydrochloric acid and extracted with diethyl ether. The extract was washed twice with 100 ml each of 3N hydrochloric acid, once with 200 ml of water, three times with 50 ml each of ice-cold sodium hydroxide solution, once with 50 ml of saturated sodium bicarbonate solution, and then with 100 ml of water.
The crude product was washed once with water, dried and concentrated.
19.1g was obtained. (c) The obtained crude 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid p-formylphenyl ester (19.1 g) was dissolved in 800 ml of acetone.
To this solution, 30 ml of Johns reagent was added dropwise within 15 minutes, and the temperature of the mixture rose slightly. 40 more of the mixture
Stir for a minute, then remove the separated inorganic material with suction and concentrate the liquid. The residue was suspended in water and the resulting suspension was filtered off with suction. The residue was washed with water on a suction filter to neutralize it, and recrystallized from acetone to give 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]
14.6 g of oxy]benzoic acid p-carboxyphenyl ester was obtained; melting point (C-S) 135~
136℃, dislocation point (S-N) 156℃, clearing point (N-
I)>300℃. The following compound was prepared in a similar manner: 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid 3-chloro-4-[[[p-(2,2-dicyano- 1
-Methylvinyl)phenoxy]carbonyl]phenyl ester; melting point (C-N) 95.5°C, clearing point (N-I) 233.5°C; 2-chloro-4-[[(p-hexyl phenyl)
Carbonyl]oxy]benzoic acid p[(3-chloro-
4-Nitrophenoxy)carbonyl]phenyl ester; melting point (C-S) 98°C, phase transition point S-
S104.5℃ and S-N129.5℃, clearing point (N-I)
235℃; 2-chloro-4-[[(p-hexyl phenyl)
Carbonyl]oxy]benzoic acid 3-chloro-4-
[[p-(2,2-dicyano-1-methylvinyl)
Phenoxy]carbonyl]phenyl ester; melting point (C-N) 154°C or 160°C (2 modification), clearing point (N-I) 239°C; 4-[[(p-hexylphenyl)carbonyl]
Oxy]benzoic acid 3-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester; melting point (C-N) 112°C, clearing point (N-
I) 255°C; 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; melting point
194℃; 2-chloro-4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid 3-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl] phenyl ester; melting point
198℃; 4-[[(trans-4-heptylcyclohexyl)carbonyl]oxy]benzoic acid 3-chloro-
4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester; melting point (C-N)
158.5℃, clearing point (N-I) 235.5℃; 4-[[(p-hexylphenyl)carbonyl]
Oxy]benzoic acid 3-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C-N) 112°C, clearing point (N-
I) 251°C; 4-[[(p-hexylphenyl)carbonyl]
Oxy]benzoic acid 3-chloro-4-[(3-methyl-4-nitrophenoxy)carbonyl]phenyl ester; melting point (C-N) 127°C, clearing point (N-
I) 238°C; 2-chloro-4-[[(p-hexyl phenyl)
Carbonyl]oxy]benzoic acid 3-chloro-4-
[(p-cyanophenoxy)carbonyl] phenyl ester; melting point (C-N) 131°C, clearing point (N-
I) 258°C; 4-[[(p-hexylphenyl)carbonyl]
Oxy]benzoic acid 3-chloro-4-[[p-(2,
2-dicyano-1-methylvinyl)phenoxy]
Carbonyl] phenyl ester; melting point (C-N)
118°C, clearing point (N-I) 276.5°C; 2-chloro-4-[[(p-hydroxyphenyl)
carbonyl]oxy]benzoic acid p-[[p-(2,
2-dicyano-1-methylvinyl)phenoxy]
Carbonyl] phenyl ester; melting point (C-N)
145.5℃, clearing point (N-I) 276.5℃. Example 8 4'-(trans-4-pentylcyclohexyl)
-4-biphenylcarboxylic acid 4-carboxy-3
-3.6g of chlorophenyl ester in 150ml of benzene
The mixture was boiled for 4 hours with 2.5 g of thionyl chloride. The solvent and excess thionyl chloride were distilled off under vacuum and the residue was taken up twice in 50 ml each of toluene.
and concentrated in each case. The obtained crude 4'-(trans-4-pentylcyclohexyl)-4-biphenylcarboxylic acid 3
-Chloro-4-(chlorocarbonyl)phenyl ester was dissolved in 150 ml of benzene and then added dropwise to a solution of 1.2 g of 3-chloro-4-nitrophenol in 110 ml of dry pyridine. The mixture was stirred at 65° C. overnight, poured into a mixture of 500 ml of ice water and 100 ml of concentrated hydrochloric acid, and extracted with diethyl ether. 3N extract
Wash 3 times with 100 ml each of hydrochloric acid and 3 times with 200 ml each of water,
It was then dried and evaporated. The resulting crude
4'-(trans-4-pentylcyclohexyl)-
4-biphenylcarboxylic acid 3-chloro-4-[(3
-chloro-4-nitrophenoxy)carbonyl]
The phenyl ester was chromatographed on silica gel with toluene/acetone (19:1 by volume). The nearly pure fraction (2.8 g) was recrystallized twice from ethyl acetate by thin layer chromatography; melting point (C-N) 132 DEG C., clearing point >250 DEG C. (decomposed). 4'-(trans-4-pentylcyclohexyl)-4-biphenylcarboxylic acid 4-carboxy-3-chlorophenyl ester used as starting material was prepared as follows: (a) As described in Example 2. Similarly to the method, 4′−
(trans-4-pentylcyclohexyl)-4
- biphenylcarboxylic acid is converted to the acid chloride with thionyl chloride, which is converted into 2-chloro-
Esterification was carried out with 3.1 g of 4-hydroxybenzaldehyde. Thus, the crude 4′-(trans-
7.7 g of 4-pentylcyclohexyl)-4-biphenylcarboxylic acid 3-chloro-4-formylphenyl ester were obtained. (b) The crude aldehyde obtained according to section (a) above was oxidized to the carboxylic acid with John's reagent in 1500 ml of acetone in a manner similar to that described in Example 1, section (b). The resulting crude 4'-(trans-4-pentylcyclohexyl)-4-
The biphenylcarboxylic acid was washed with water and methanol on a suction filter, then dried and used without further purification. The following compound was prepared in a similar manner: 4'-(trans-4-pentylcyclohexyl)
-4-biphenylcarboxylic acid 3-chloro-4-
[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C-N) 133°C,
Clearing point (N-I) 361℃; 4'-(trans-4-pentylcyclohexyl)
-4-biphenylcarboxylic acid 3-chloro-4-
[[p-(2,2-dicyano-1-methylvinyl)
Phenoxy]carbonyl]phenyl ester; melting point (C-N) 168.5°C, clearing point (N-I) approximately 360
°C; 4″-pentyl-4-terphenylcarboxylic acid 3
-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C
-N) 167°C, clearing point (N-I) 372°C; 4″-pentyl-4-terphenylcarboxylic acid 3
-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester; melting point (C
-N) 177°C, clearing point (N-I)>300°C; 4″-hexyl-4-terphenylcarboxylic acid 3
-chloro-4-[(3-chloro-4-cyanophenoxy)carbonyl]phenyl ester; melting point (C
-N) 151.5°C, clearing point (N-I) 355°C; 4″-hexyl-4-terphenylcarboxylic acid 3
-chloro-4-[(3-chloro-4-nitrophenoxy)carbonyl]phenyl ester; melting point (C
-N) 162.5℃, clearing point (N-I)>270℃.

Claims (1)

[Claims] 1. General formula In the formula, X ² represents a single covalent bond or an ester group -COO-; X1 represents a single covalent bond, an ester group -COO- ^, an ethylene group -CH ₂ CH ₂ -, or When representing COO-, p-C ₆ H ₄ -, p-C ₆ H ₄ -CH ₂ CH ₂ -,
-CH ₂ CH ₂ -p-C ₆ H ₄ -, p-C ₆ H ₄ -COO- or -COO-p-C ₆ H ₄ -; Ring A is a benzene ring or trans-1,4-cyclohexyl represents silene; Ring B is a benzene ring or when X ² represents an ester group -COO- and X ¹ represents a single covalent bond, an ester group -COO- or an ethylene group -CH ₂ CH ₂ -; , also represents trans-1,4-cyclohexylene; Z ¹ , Z ² and Z ³ are hydrogen or hydrogen on the benzene ring which is not directly bonded to another ring via a single covalent bond. also represents halogen, cyano or methyl; Y ² is cyano, nitro, 2,2
-dicyanovinyl or, when Y ¹ represents hydrogen, also represents 2,2-dicyano-1-methylvinyl; Y ¹ is halogen, cyano, C ₁ -C ₃ -
Alkyl or, if X ¹ has a benzene ring or an ester group or Y ² represents nitro or Z ¹ and/or Z ² are different from hydrogen, also represents hydrogen; and R ¹ C ₁
Compounds of ~ _C12 -alkyl or also representing _C1 - _C12 -alkoxy on the benzene ring. 2 X ¹ is a single covalent bond, ester group -COO-,
When ethylene group -CH ₂ CH ₂ - or X ² represents an ester group -COO-, it also represents p-phenylene, and Y ¹ is halogen, cyano,
C ₁ -C ₃ -alkyl or X ¹ represents p-phenylene or Y ² represents nitro or
Compounds according to claim 1, which, if Z ¹ and/or Z ² are different from hydrogen, also represent hydrogen. 3. The compound according to claim 1 or 2, wherein ring B represents a benzene ring. 4 Z ¹ , Z ² and Z ³ represent hydrogen or
4. A compound according to any one of claims ¹ to 3, wherein at most two of Z1, ^Z2 and ^Z3 represent chlorine. 5. A compound according to any one of claims 1 to 4 ^, wherein Y1 represents hydrogen, fluorine, chlorine, cyano or methyl. 6 General formula In the formula, R ¹ , X ² and Y ² have the meanings described in claim 1; X ¹ is a single covalent bond, an ester group -COO-, or X ² is an ester group -COO
-, also p-C ₆ H ₄ -, p-C ₆
H ₄ −CH ₂ CH ₂ −, −CH ₂ CH ₂ −p−C ₆ H ₄ −, p−
C ₆ H ₄ -COO- or -COO-p-C ₆ H ₄ -; ring A is p-phenylene or trans-
represents 1,4-cyclohexylene; Z ² is hydrogen or, when X ¹ and X ² represent an ester group -COO-, also represents chlorine; Z ³ is hydrogen or
When X ² represents an ester group -COO-, it also represents chlorine; and Y ¹ is fluorine, chlorine, cyano, methyl or X ¹ has a benzene ring or an ester group or Y ² has a nitro 2. The compound according to claim 1, which is a compound of: 7. A compound according to any one of claims 1 to 6, wherein Z ² represents hydrogen. 8 X ¹ is a single covalent bond, ester group -COO-
Alternatively, when X ² represents an ester group -COO-, it also represents p-phenylene, the compound according to any one of claims 1 to 7. 9. A compound according to any one of claims 1 to 8, wherein ^Y1 represents hydrogen, chlorine or cyano. 10. A compound according to any one of claims 1 to 9, wherein ^Y2 represents cyano or nitro. 11. A compound according to claim 10, wherein Y ¹ represents chlorine and Y ² represents cyano or nitro. 12 Y ¹ represents hydrogen, and Y ² represents 2,2-
A compound according to any one of claims 1 to 9, which represents dicyano-1-methylvinyl. 13. The compound according to any one of claims 1 to 12, wherein ring A represents trans-1,4-cyclohexylene. 14. The compound according to any one of claims 1 to 13, wherein R ¹ represents a linear alkyl group. 15. Compounds according to any of claims 1 to 14, wherein the alkyl or alkoxy group ^R1 contains 3 to 10 carbon atoms, preferably 5 to 9 carbon atoms. 16 At least one of the components has a general formula In the formula, X ² represents a single covalent bond or an ester group -COO-; X ¹ represents a single covalent bond, an ester group -COO- ^, an ethylene group -CH ₂ CH ₂ -, or When expressing −COO−,
Also p-C ₆ H ₄ −, p-C ₆ H ₄ −CH ₂ CH ₂ −, −CH ₂
CH ₂ -p-C ₆ H ₄ -, p-C ₆ H ₄ -COO- or -COO-p-C ₆ H ₄ -; ring A represents a benzene ring or trans-1,4-cyclohexylene; ; Ring B is a benzene ring, or X ² represents an ester group -COO- and X ¹ is a single covalent bond;
Ester group -COO- or ethylene group _-CH2
When representing CH ₂ −, also trans-1,4
- cyclohexylene; Z ¹ , Z ² and Z ³ are hydrogen or also halogen, cyano or methyl on the benzene ring which is not directly bonded to another ring via a single covalent bond; ; ^Y2 is cyano, nitro, 2,2-dicyanovinyl, or when ^Y1 represents hydrogen,
It also represents 2,2-dicyano-1-methylvinyl; Y ¹ is halogen, cyano, C ₁ -C ₃ -alkyl, or X ¹ has a benzene ring or ester group, or Y ² represents nitro; Z ¹
and/or if Z ² is different _from hydrogen, it also represents hydrogen; and R ¹ also represents C _{1 -C 12} -alkyl or on the benzene ring
- A liquid crystal mixture comprising at least two components representing alkoxy. 17 consisting of three components A, B and C, each of which contains one or more compounds, component A having a viscosity of at most about 40 cp, at least about 40°C
component B has a dielectric anisotropy of less than about -2 and component C has a dielectric anisotropy of greater than about +10, at least about Clearing point at 100℃ and at most about 20℃
It has a crossover frequency in the total mixture of 15KHz,
17. Liquid-crystalline mixture according to claim 16, characterized in that component C comprises at least one compound of the formula. 18 At least about 30% by weight of component A, about 3% by weight of component B
18. A liquid crystal mixture according to claim 17, comprising about 5% to 40% by weight of component C. 19 General formula In the formula, X ² represents a single covalent bond or an ester group -COO-; X ¹ represents a single covalent bond, an ester group -COO- ^, an ethylene group -CH ₂ CH ₂ -, or When expressing −COO−,
Also p-C ₆ H ₄ −, p-C ₆ H ₄ −CH ₂ CH ₂ −, −CH ₂
CH ₂ -p-C ₆ H ₄ -, p-C ₆ H ₄ -COO- or -COO-p-C ₆ H ₄ -; ring A represents a benzene ring or trans-1,4-cyclohexylene; ; Ring B is a benzene ring, or X ² represents an ester group -COO- and X ¹ is a single covalent bond;
Ester group -COO- or ethylene group _-CH2
When representing CH ₂ −, also trans-1,4
- cyclohexylene; Z ¹ , Z ² and Z ³ are hydrogen or also halogen, cyano or methyl on the benzene ring which is not directly bonded to another ring via a single covalent bond; and R ¹ is C ₁ -C ₁₂ -alkyl or also C ₁ -C ₁₂ -alkoxy on the benzene ring; In the formula, ^Y2 is cyano, nitro, 2,2-dicyanovinyl, or when ^Y1 represents hydrogen,
It also represents 2,2-dicyano-1-methylvinyl; and Y ¹ is halogen, cyano, C ₁ -C ₃ -alkyl, or X ¹ has a benzene ring or an ester group, or Y ² represents nitro. or if Z ¹ and/ ^or Z ² are different from hydrogen, also representing hydrogen, and esterification with the ^{phenol of} A general formula characterized by reacting a compound of the following formula with copper cyanide (), sodium cyanide, or potassium cyanide In the formula, R ¹ , A, B, X ¹ , X ² , Y ¹ , Y ² , Z ¹ , Z ²
and Z ³ have the above meanings. 20. Use of compounds of the formula defined in claim 1 for electro-optical purposes.