JPH024723A - Cyclohexene derivative - Google Patents

Abstract

NEW MATERIAL: A compd. represented by formula [wherein R¹ and R² are each a 1-15C alkyl which may be substituted by CN, F or Cl, a 3-15C alkenyl (wherein one CH₂ in a chain can be replaced by -O-, -CO or -O-CO-), m is 0-2, A¹ to A³ are each 1,4-cyclohexenylene, trains 1,4-cyclohexylene or 4-phenylene (wherein CH₂ can be replaced by -O-) and Z¹ and Z² are each -CO-O-, -CH₂O- or -CH₂CH₂-].

EXAMPLE: 4-Pentyl-1-(2,3-difluorophenyl)-1-cyclohexene.

USE: A liquid crystal compd.

PREPARATION: 1,2-Difluorobenzene is metalated to be reacted with a corresponding electrophilic reagent to obtain 1-substituted 2,3-difluorobenzene and reaction is succeedingly performed to obtain the compd. represented by the formula.

COPYRIGHT: (C)1990,JPO

Description

[Detailed description of the invention] The present invention relates to cyclohexene derivatives of formula l.

R1- to 1-71-82-(Z2-83. -R2I, where R and R2 are each independently of the other unsubstituted, substituted with one cyano group, or at least one fluorine group) or an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 3 to 15 carbon atoms substituted with chlorine (provided that one CH in these substituents
2 groups -o--co--o-co--co-o- or -
o-co-o-), or one of these groups R1 and R2 is a cyano group, m is Oll or 2, and A, A and A3 are each other a 1,4-cyclohexenylene group or a trans-1,4-cyclohexylene group, of which one or two non-adjacent CH2 groups may be independently replaced by -0-, or unsubstituted, or is a 1,4-phenylene group which is substituted by one or two fluorines and whose one or two OH groups may be replaced by N, and 2 and Z2 are each independently of the other -co -o--0-
C0--CH2O--OCH--CH2CH2- or 1
single bonds.

However, at least one of the groups A, A and A3 is 2
,3-difluoro-1,4-phenylene group, and A
, A and at least one of the remaining groups of A3 is 1.
It is a 4-cyclohexenylene group.

For simplicity, in the following, Cyc is a 1.4=cyclohexylene group, Dio is a dioxane-2,5-diyl group, Dit is a dithian-2,5-diyl group, and Pyd is a pyridine-2,5-diyl group. , Pyr is pyrimidine-2,5
-diyl group, Pyz is pyridazine-3,5-diyl group,
Phe represents a 1,4-phenylene group, PheF represents a group of the formula, and PheF represents the formula (Che2) and -> (Che 3).

Compounds of formula I are particularly suited for use in twisted oriented cells (twisted cells).
principle of the guest-host effect (guest-h
osteffect), strain effect of aligned phase (effec
to of a defor-1atiOn of al
igned phase) or as a component of a liquid crystal phase for displays based on dynamic scattering effects.

Compounds that are positive dielectrics and have trans-1,4-cyclohexylene and 1,4-cyclohexe-1-disene groups exhibit lower optical anisotropy than those having 14 to phenylene groups. It is known to have a low viscosity (for example, West German Publication Special Edition Kitsuki No. 3.023,368). The 1,4-cyclohexenylene group is preferred over the 1,4-cyclohexyl group because in the former there is no cis/trans isomerism. Their high sensitivity to actinic radiation is a disadvantage. In particular, cyclohexene derivatives whose double bond is conjugated with other π-electron systems undergo chemical changes as a result of the action of light.

Negative anisotropy of permittivity [△ε=ε11−ε above 0, (where ε11 is the permittivity in the direction along the long axis of the molecule, and ε
The dielectric constant in the direction perpendicular to this axis) is oriented in the direction of the electric field, so that the long axis of their molecules is perpendicular to the direction of the electric field. This effect is known and is known in the optical field of various liquid crystal displays, e.g. liquid crystal cells of the light scattering type (dynamic scattering), of the so-called DAP type (distortion of aligned phases) or of the guest/host type (guest/host interaction). Used to control transparency.

When using a liquid crystal with positive dielectric anisotropy, the uniform alignment obtained by treating its surface can be made homeotropic (homeotropic) by applying a potential.
opic). That is, the cell changes from "colored" to "
Can be switched to "colorless". In this way, colorless symbols are displayed on a colored background.

On the other hand, when using a liquid crystal with negative dielectric anisotropy, the homotropic alignment obtained by treating its surface is aligned parallel to the plane of the electrodes by applying a potential, and the colored pixels can be displayed.

The electrically controlled birefringence (ECB) effect or DAP effect is 197
First described in 1991 [M.F. Silagel (H.
F. 5chieckel and F. Fahrenschen, “Deformation of vertically aligned nematic liquid crystals in an electric field.
of nenatc 1iquid crystal
with vertical orientation
in electrical field)”, App
L, Phys, Lett, 19.3912 pages (1
971) Ko. After that, J.F.
, Cabn) [Appl, PMs, Lett,
, 20.1193 (1972)] and J, Robert [J, Appl, P
hys, 44.4869 pages (1973).

J. Robert and F. Clark (F, C1er)
c) [80th Edition SID Technical Literature Digest (SID
80 Digest Techn, Papers),
30 pages (1980)], J.D.
Duchene) [Displa
ys), E, p. 3 (1986)] and H, 5chad) [SID 82 Digest Tech
n, Papers), p. 244 (1982)] states that in order to be able to be used for high transmission displays based on the ECB effect, the liquid crystal phase must have a high value of the elastic constant ratio to 3/1, a high value. Optical anisotropy △n and -0゜5
It is shown that the dielectric anisotropy Δε must have a value of ~-5.

It is known that the elastic constant ratio 3/1 can be advantageously influenced by introducing non-conjugated double bonds [e.g.
China, p. 41.347 (1987)].

Electro-optic display elements based on the ECB effect have a homeotropic orientation (hoIlleotropic edg
eorientation). That is, this liquid crystal phase has negative dielectric anisotropy.

Liquid crystal phases are required for the industrial application of this effect in electro-optical display elements, which have to meet a large number of requirements. Particularly important factors here are the chemical stability against moisture, air and physical influences such as heat, radiation in the infrared, visible and ultraviolet range and direct and alternating electric fields.

A liquid crystalline phase within a suitable temperature range and low viscosity is also expected to be an industrially usable liquid crystalline phase.

Therefore, favorable meso-region, high K3/K1 values,
There is still a great need for liquid crystal phases with high optical anisotropy Δn, negative dielectric anisotropy Δε and a high degree of long-term stability.

Compounds of formula (1) are also suitable for use as components of chirally graded smectic phases.

By adding a suitable chiral doping agent to a mixed substrate containing one or more graded smectic phases,
Chirally graded smectic liquid crystal phases with ferroelectricity can be produced [L.N.B.
, 8, Veresnev) et al., Ho1. Cryst,
L+q, Cryst, 89.327 pages (1982
) and H,R, Bran
d>et al., J.

Physique, 44 (lett,), L-77
1 page (1983)].

This type of facies was described by Clark and Lagerwa [N.N.A.C1ark and S.T. Lagerwa].
I l), ^pp1. Phys, Lett.
, 36.899 (1980) and U.S. Special Kitsuki 4, 3.
No. 67.924] It can be used as a dielectric material for high-speed displays based on the principle of 5SFL technology.

This principle is based on the ferroelectricity of chirally graded phases.

Many liquid crystal compounds with weak negative dielectric anisotropy have already been synthesized. On the other hand, liquid crystal components having a relatively high dielectric constant and negative anisotropy are hardly known at present. Furthermore, the latter generally suffer from drawbacks such as poor solubility in mixtures, high viscosity, high melting points and chemical instability. There is therefore a further need for compounds that have negative dielectric anisotropy and further improve the properties of mixtures for a very wide range of electro-optical applications.

A liquid crystal component having negative dielectric anisotropy and containing two or three rings or covalent bonds bonded by carboxyl groups and having one or more side groups such as halogen atoms, cyan groups or nitro groups. West Germany Special Kitsuki 2,240,864
No. 2.613293, No. 2,835,662 and No. 2,836.086 and European Special Kitsuki 02
It is known by No. 3°728.

2R,' -Chel-Phe-R2 (wherein Phe may be substituted by one or two nitriles and/or halogens) is a West German special kitsuki 3,023
．． No. 368. However, none of the compounds of the above formula according to the invention are mentioned therein. Therefore, from that aspect, a person skilled in the art can simply infer the means by which the compounds of the present invention can be synthesized, or
Or it is not possible to realize that the compounds of the invention have a menophase region which is predominantly and advantageously located and is distinguished by a high negative dielectric anisotropy and at the same time has a low viscosity.

Since the compounds claimed in said patent specification have low smectic properties, no indication is made in that patent specification that the compounds of the invention can be used in displays based on 5SFLC technology.

The invention was based on pointing out stable liquid-crystalline or menogenic compounds with high negative dielectric anisotropy and at the same time low viscosity.

It has been found that the compounds of formula I are very suitable for use as components of liquid-crystalline phases. In particular, these compounds make it possible to produce stable liquid-crystalline phases with a wide mesophase range and a relatively low viscosity.

The compounds of formula I are also suitable for use as components of chirally graded smectic liquid crystal phases.

Furthermore, by providing compounds of the formula (2), the range of suitable liquid-crystalline substances for preparing liquid-crystalline mixtures from various aspects of technical performance is very generally considerably widened.

Compounds of formula I have a wide range of uses. By choosing the substituents, these compounds of formula I can be modified to change the optical anisotropy and/or viscosity and/or spontaneous polarization and/or phase area and/or tilt angle and/or pitch. Compounds can also be added to liquid crystal substrates belonging to other types of compounds.

The compounds of formula (1) are also suitable for use as intermediates for the production of other materials that can be used as elements of liquid-crystalline dielectrics.

The compounds of formula I are colorless in the pure state and form a liquid-crystalline mesophase within a temperature range that is advantageous for electro-optical applications. These compounds are very stable to chemicals, heat and light.

The present invention therefore relates to compounds of formula I, in particular compounds of formula ■.

1, 11222 rt-(8)-Che-2-(^-2)-
8-RIIQ 1 In the formula, R1, R2, zl, Z2, A1, A2 and m have the same meanings as shown above, Ao is trans-1,4-cyclohexylene group, Che is ÷ and n is 0 or 1.

The invention also relates to the use of compounds of formula I as components of liquid-crystalline phases. The invention also relates to liquid-crystal phases comprising at least one compound of formula (1) and to liquid-crystal display elements comprising such phases. Phases of this type have particularly advantageous elastic constants. These phases have a low Δε/ε upper value and are therefore particularly suitable for thin film transistor (TPT) mixtures.

In the above and following specifications, R1, R2A°, A
1, A2, Zl, Z2 and m have the same meanings as above unless otherwise defined.

Therefore, compounds of formula (1) have formulas 1a and Ib: R-Che-
PheF -R2 Ia R-Che-21-PheF -R2 Ib -〇- is ÷, and a compound having two rings; Formulas 1c to 11: R-Cyc
-CM-PheF2-R R-Cyc-CM-! -PheF2-RR-Che-
^-PheF2-R R-Che-PheF-^2-R2 It-Che-Z-^-PheF2-ItR-Che-
Z-PheF -A2-R2R-Che-PheF2-
Z -8 -RR-Che-8 -Z -PheF
-It''R-Che-2-A -PheF2-Itl
l -Che-Z -PheF -12-82-
Compounds having three rings of R2; and formulas Inl to Iz6
R-Cyc-Chc-PheF2-^-RR-Cyc-
Che-A1-PheF-R"R-Cyc-Che-
2-A-PheF2-RR-Cyc-Che-7-P
heF2-A -RR-Cyc-Che-PheF2-
Z -A -RR-Cyc-Che-A -7-Phe
F2-RR-Cyc-Che-2-^-1-PheF2
-Itl 1 222 R-Cyc-Che-2-Pl+eF2-Z -A -
RR'-Che-PheF-A"-82-R2R-
Che-A -PheF2-8 -6R'-Che-
A1-82-PheF -R"R-Che-Z -
^ -8 -PheF2-1? R'-Che-Zl-81-PheF -82-R2ft'-Che-2'-
PheF -A2-A2-R2R-Che-8-Z
-PheF2-A -fll 122
2 R-Che-A-1-A-PheF2-nI! '−
Che-he1-82-22-PhaF -R2R1-
Che-8'-PheF -Z2-82-R2R'-
Che-PheF-to 2-72-82-82-11
Includes compounds with two rings.

In the above formulas 1a to Iz6, Che is the formula g)-1
= (D- or -()- CheI Chc2 Chc3 14
-cyclohexenylene group.

In compounds where the Chc group is adjacent to the PheF2 group and the adjacent group A1 is Phc, PheF, Pyr or pyd, Che is Chel or Chc2
, especially Chel is preferred.

In the compounds of formulas 1a to Iz6 above, Zl and Z are -CO-0--0-C0--CH2O-OCH- or -
CH2CH2'C is present, co-o--o-co-s is -
Preferably it is cH2cH2.

A formula in which Chc group is adjacent to 21 groups and is Chc3! a~
In the compound Iz6, Zl is preferably 10-co
-1-CH20--0CH2- or -CH2CH2-1
In particular, -CH2CH2 or -CH2O is preferred.

In the compound of the above or below formula, R1 and R2 are preferably an alkyl group or an alkoxy group. moreover,
One of the radicals R and R2 may be CN. In the above and below formulas, R2 is preferably CN.

A1 and A2 are Phe, Pyr, Pyd,
Pyz, Cyc, D+o, Dot, PheF or PheF2. The compound of formula ■ is Pher, Py
Preferably it does not contain more than one r, Pyd, Pyz, Dio or Dit group.

In the above or below formulas R1 and R2 preferably have 1 to 13 carbon atoms, in particular 3 to 12 carbon atoms, R and R2 have 1 to 7 carbon atoms, preferably 3
Compounds of the formula I with ~6 carbon atoms are particularly suitable for liquid-crystalline phases for display gray resistors based on the ECB effect.

On the other hand, compounds of formula I in which R1 and R2 have 7 to 15 carbon atoms, preferably 8 to 12 carbon atoms, are suitable for liquid-crystalline phases with ferroelectric properties. It is also possible to substitute one or two CH2 groups in R1 and R2. Only one CH2 group is 10-1-c.

-o-co--co-o- or -〇-COO-1 especially-
It is preferable to substitute with 〇- or C0-0-.

When R2 is a cyan group, the A group adjacent to it is A
is preferably Phe, PheF, PheF2 or Pyr, especially PheF2.

if they are alkyl groups in which one CH group or two non-adjacent CH groups can be replaced by O atoms (“alkoxy” or “oxaalkyl” or “alkoxy-alkoxy” or “dioxaalkyl” respectively); The group is straight-chain or branched. These groups are defined in 2.3.
Preference is given to straight chains having 4.5.6 or 7 carbon atoms. They are therefore preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexyloxy or hebutyloxy, and also methyl, octyl,
nonyl, decyl, undecyl, dodecyl, tridecyl,
Tetradecyl, pentadecyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyloxy,
Also dodecyloxy, tridecyloxy or tetradecyloxy.

Oxaalkyl is a straight chain 2-oxapropyl (=methoxymethyl), 2-oxabutyl (-ethoxymethyl), 3
-oxabutyl (=2-methoxyethyl), 2-53-
or 4-oxapentyl, 2-3-14- or 5-oxahexyl, 2-3-14-5- or 6-oxaheptyl, 2-3-14- 5- 6- or 7-oxaoctyl, 2- 13-14-15-16-57- or 8-oxanonyl, 2-3-14-15-16-17.8- or 9-oxadecyl, 1,3-dioxabutyl (=methoxymethoxy>, t, 3-1゜4- or 2,4-dioxapentyl, 1.3-1.4- 1.5-12.4-
2.5- or 35-dioxahexyl or 1.3-
1.4■, 5-11.6-12.4- 2.5-2.
6-3.5-3.6= or 4.6-thioxaheptyl is preferred.

When R and R2 are each an alknyl group, this group can be straight-chain or branched. This group is linear and has 2
Preferably it has ~10 carbon atoms. Therefore, this group includes especially vinyl, 1-propenyl, 2-propenyl, 1
-2- or 3-butenyl, 1-52-13- or 4-pentenyl, 1-2-13-14- or 5-hexenyl, 1
-12-53-14-15- or 6-heptenyl, 1-
2- 3-14-15-56- or 7 octenyl, ■
-12-13-14-15-6-17- or 8-nonenyl or 1-12-3-14-15-26-17-5
8- or 9-decenyl.

R and R2 each have CHX of 10-C〇- or -
In the case of an alkyl group substituted with C0-0-, this group may be straight-chain or branched. This group is straight chain,
Preferably it has 2 to 6 carbon atoms; this radical is therefore in particular acetoxy, propionyloxy, butyryloxy, pentanoyloxy, hexanoyloxy, acetoxymethyl, 10pionyloxymethyl, butyryloxymethyl, pentanoyl Oxymethyl, 2-ace1
~xymethyl, 2-propionyloxyethyl, 2-butyryloxyethyl, 3-acetoxybutyl, 3-propionyloxypropyl, 4-acetoxybutyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl,
Methoxycarbonylmethyl, ethoxycarbonylmethyl, propoxycarbonylmethyl, butoxycarbonylmethyl, 2-(methoxycarbonyl)ethyl, 2-(ethoxycarbonyl)ethyl, 2-(propoxycarbonyl)ethyl, 3-(methoxycarbonyl)propyl, 3-
(ethoxycarbonyl)propyl or 4-(methoxycarbonyl)butyl.

Branched terminal groups R1 and/S are sometimes important for conventional liquid crystal substrates as they improve the solubility of compounds of formula #J with R2, but if they are optically active. , is particularly important as a chiral doping agent. Smectic compounds of this type are suitable for use as components of ferroelectric materials.

In general, branched groups of this type do not contain more than one branch, preferred branching groups R1 and/or R2 are isopropyl, 2-butyl (=1-methylpropyl), isobutyl (=2-methyl 10 pills), 2-methylbutyl,
Impentyl (=3-methylbutyl), 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-
Propylpentyl, isopropoxy, 2-methylpropoxy, 2-methylbutoxy, 3-methylbutoxy, 2-
Methylpentoxy, 3-methylpentoxy, 2-ethylhexyloxy, 1-methylhexyloxy, 1-methylhebutyloxy, 2-oxa3-methylbutyl, 3-
Oxa-4-methylpentyl, 4-methylhexyl, 2
-nonyl, 2-decyl, 2-dodecyl, 6-methyloctyloxy, 6-methyloctanonyloxy, 5-methylhebutyloxycarbonyl, 2-methylbutyryloxy, 3-methylvaleryloxy, 4-methylhexa Nonyloxy, 2-chloropropionyloxy, 2-chloro-3-methylbutyryloxy, 2-chloro-4-methylvaleryloxy, 2-chloro-3-methylvaleryloxy, 2-methyl3-oxaventyls is 2-methyl-3
-Oxahexyl.

Formula I also includes racemates, optical pairs and mixtures thereof of these compounds.

Preferred compounds of formula (1) and La to Iz6 are those in which at least one group contained has one of the preferred meanings indicated.

Among the trinuclear compounds of formulas 1a and Ib, the following formulas 11 to I6
Compounds are preferred.

R1-Chel-PheF-R211 R-Che2-PheF2-R12 R-Che3-PheF2-R 112I4 R-Chel-2-PheF2-R R-Che2-21-PheF-R215R-Che3
-21-PheF-R216 Among the trinuclear compounds of formulas 1c and 11, compounds of the following formulas I7 to 150 are preferred.

2I7 R-Cyc-Chel-PheF, -RR-Cyc-
Che2-PheF2-R2I9 R-Cyc-Che3-PheF2-RR-Chel-
Phe-PheF2-RR-Che2-Phe-Phe
F,,-RR-Chel-Cyc-PheF2-RRl
-Cyc-Chel-Zl-PheF-R2113R'
-Chel-Zl-Cyc-PheF -R2R1-C
hel-PheF-Z'-Phe-R2R1-Che
2-PheF -Z'-Phe-R2R'-Che3-
PheF -7'-Phe-R''R-Che3-Phe
F24-Cyc-RR-Che2-PheF2-,?
-Cyc-RR-Chel-PheF2-Z-Cyc-
RR-Chel-Phe-7'-PheF-R2It
-Che3-Cyc-Z -PheF2-RR-Ch
el-1'-PheF-Z2-Phe-R2R-Ch
e2-2'-PheF -Z2-Phe-R2R1-C
he3-2'-PheF-Z2-Phe-R2R'-
Chel-7'-PheF-2l-Che3-R2R
1-Che2-21-PheF-2l-Che2-1
2R-Chel-Z -PheF2-Z -C'yc-
RR'-Che2-Z'-PheF-7l-Cyc-
R2R-Che3,2-PheF2-! -Cyc-R
Among the tetranuclear compounds of formula (1) and Iz6, compounds of ~162 are preferred.

R-Cyc-Chel-PheF2-Phe-RR1-
Cyc-Che3-PheF-Phe-R2152R1
-Cyc-Che3-PheF-Cyc-R2153I
t -Cyc-Chel-PheF2-Cyc-RR'
-Chel-PheF-Phe-Phe-R2I55R
'-Che3-PheF-Phe-Phe-R2156
R'-Che3-PheF-Chel-Phe-R21
57R'-Che3-PheF-Cyc-Phe-R2
15811'-Che3-PheF-Cyc-Cyc-
R2159R1-Chel-PheF-Cyc-Cy
c-R” 160R1-Chel-PheF
The compounds of formulas la to Iz6 and 11 to 162 above with the group -Cyc-Phe-R2161Pyr may in each case contain two possible 2.5-positional isomers.

In the above compound, Zl and 22 groups each independently represent 100-0-1-0-CO--CHO--0C
H-s is -CH2CH2, preferably -C〇-o--o
-co- or -CH2CH2-.

Compounds of the formula I can be prepared in particular under reaction conditions known and suitable for the reactions mentioned, as described in the literature [e.g.
thods of Organic Chen+1st
ry) J, Georg-Th 1
ene) by methods known per se, such as those described in standard books such as the publisher, Sud'7 Ttgart.

In this connection, it is also possible to use other methods which are known per se but are not mentioned in detail here.

If desired, the starting materials can also be produced in situ by a process in which they are immediately further reacted to give the compounds of formula I without isolating them from the reaction mixture.

To obtain compounds of formula I, it is convenient to start from 1,2-difluorobenzene.

This compound can be prepared using known processes [e.g.
-(E, H, Roe) et al., J. CheIl, Sa
c, Chen+.

Com1. ．． 22, p. 582 (1965)] and reacted with the corresponding electrophile. Using the 1-substituted 23-difluorobenzene thus obtained, the following reaction can be carried out subsequently. In this way, a 1,4-disubstituted 2,3-difluorobenzene derivative of formula (1) is obtained. 12-difluorobenzene or 1
-Substituted 2,3-difluorobenzene is diethyl ether, tetrahydrofuran, dimethoxyethane, tert
, -butyl methyl ether or dioxane or a hydrocarbon such as hexane, heptane, cyclohexane, benzene or toluene, or a mixture of these solvents, if appropriate of tetramethylethylenediamine or hexamethylphosphoric acid 1-helamide. react with phenyllithium, lithium tetramethylpiperidine or n-1sec, - or tert, -butyllithium at a temperature of -100°C to +50°C, preferably -78°C to 0°C by adding a complexing agent such as I am made to do so.

The resulting lithium 2,3-difluorophenyl compound is reacted with the corresponding electrophile at -100°C to 0°C, preferably -50°C. Suitable electrophiles are aldehydes; ketones; nitriles; epoxides; esters, carboxylic acid derivatives such as anhydrides or halides; halogenoformates; or carbon dioxide. Particularly suitable electrophiles are cyclohexanone derivatives, especially 1,47 cyclohexanedione monoketals.

Potassium 2,3-difluorophenyl compounds are suitable for reacting with halogenated aliphatic compounds. These potassium compounds can be obtained by subjecting the above lithium compound and potassium tert,-butyrate to a metal exchange reaction at -80 to -120°C.

The lithium 2,3-difluorophenyl compound is transmetalized to react with a compound having several electrophilic reaction nuclei (eg, aldehyde groups as well as ester groups). Titanium 2,3-difluorophenyl compounds are particularly suitable for this purpose.

Compounds of formula I containing Chel or Che3 groups are prepared by reacting the corresponding 4-substituted cyclohexanone with a suitable nucleophile and dehydrating the resulting tertiary alcohol. Suitable nucleophiles are Grignard reagents, organometallic compounds such as organopotassium, organolithium or organotitanium compounds or cyanides such as potassium cyanide, sodium cyanide or trimethylsilyl cyanide.

Known cyclohex-2-ene-carboxylic acid (Z' =
-Co-0-) [For example, Bui Nis Betuborodov (
ν, S, B(!ZbOrOdOV), 2h, Org
16, supra, p. 150 (1987)] or the corresponding butadiene can be used as a starting material to prepare compounds of formula I containing a Cb e 2 group.

1 (one or more reducible groups and/or C-
Compounds of formula I can be prepared by reducing a compound corresponding to a compound of formula I except that it contains a C bond.

Suitable reducible groups are carbonyl groups, preferably geto groups, and also, for example, free or esterified hydroxyl groups or halogen atoms bonded to aromatic rings. Preferred starting materials for the reduction are cyclohexene or cyclohexanone rings instead of cyclohexane rings, and/or -CH=CH- groups instead of -CH2CH2- groups, and/or -C〇- instead of -CH2- groups. The groups and/or correspond to formula I except that instead of the H atom they contain a free or functionally modified OH group (for example in its p-toluenesulfonate form).

Reduction can be carried out, for example, by alcohols such as methanol, ethanol or impropatol; ethers such as tetrahydrofuran (THF) or dioxane; esters such as ethyl acetate; carboxylic acids such as acetic acid; or hydrocarbons such as cyclohexane. This can be carried out, for example, by catalytic hydrogenation at a temperature of from about 0 to about 200°C and a pressure of from about 1 to about 200 bar. 'i! The most important catalysts are preferably noble metals such as PT or Pd;
PtO2 or Pd0) is supported on a carrier (
For example, it can be used in the form of charcoal, calcium carbonate or strontium carbonate (Pd) or in the form of a fine powder.

Reduction of the getone by the Clemensen method (using zinc, zinc amalgam or tin and hydrochloric acid, preferably in hydroalcoholic solution or in a heterogeneous phase using water/toluene at a temperature of about 80-120°C) also reduces the alkyl Corresponding compounds of formula (1) containing groups and/or CH2CH2-bridges can be obtained.

Reduction using complex hydrides is also possible. For example, an arylsulfonyloxy group can be reductively removed with LiAIH4. Specifically, a p-toluenesulfonyloxymethyl group can be reduced to a methyl group in an inert solvent, preferably diethyl ether or THF, at a temperature of about 0-100°C. Double bonds can be hydrogenated with NaBH4 or tributyltin hydride in methanol. By esterifying the corresponding carboxylic acid (or its reactive derivative) with alcohols or phenols (or its reactive derivative),
Esters of formula (2) can also be obtained.

Suitable reactive derivatives of the carboxylic acids mentioned are, in particular, acid halides, especially chlorides and bromides, and also anhydrides, such as mixed anhydrides, azides and esters, especially those containing 1 to 4 carbons in the alkyl group. It is an alkyl ester having an atom.

Suitable reactive derivatives of the abovementioned alcohols or phenols are in particular the respective corresponding metal alcoholades or phenolates, preferably of alkali metals such as Na or K.

The esterification reaction is advantageously carried out in the presence of an inert solvent. Very suitable solvents are in particular ether necks such as diethyl ether, di-n-butyl ether, THF, dioxane and anisole; ketones such as acetone, butanone and cyclohexanone; amides such as DMF and hexamethylphosphoric triamide; Hydrocarbons such as benzene, toluene and xylene - halogenated hydrocarbons such as carbon tetrachloride and tetrachloroethylene;
Sulfoxides such as dimethyl sulfoxide: as well as sulporan. It is advantageous to use a water-immiscible solvent in order to remove the water formed during the esterification reaction by azeotropic distillation. Sometimes an excess of organic base, such as pyridine, quinoline or triethylamine, can also be used as a solvent for the esterification reaction. The esterification reaction can also be carried out without the presence of a solvent, for example by simply heating the components in the presence of sodium acetate. The reaction temperature is usually -50 to +250°C, preferably -20 to +80°C. At these temperatures, the esterification reaction is generally complete after 15 minutes to 48 hours.

A further preferred method for producing esters is to react the carboxylic acid with the alcohol or phenol in the presence of a dehydrating agent, if appropriate using an organic base as a catalyst.

Particularly preferred dehydrating agents are molecular sieves and e.g.
A carbodiimide such as dicyclohexylcarbodiimide. A particularly preferred basic catalyst is 4-dimethylaminopyridine.

In each case, the reaction conditions for the esterification depend to a large extent on the nature of the starting materials used.

Therefore, the free carboxylic acid is generally reacted with the free alcohol or phenol in the presence of a strong acid, for example a mineral acid such as hydrochloric acid or sulfuric acid. A preferred reaction procedure is to react an acid anhydride or especially an acid chloride with an alcohol, preferably in a basic medium. In this reaction, the important bases involved are alkali metal hydroxides, especially sodium hydroxide and potassium hydroxide; sodium carbonate,
Alkali metal carbonates and bicarbonates such as sodium bicarbonate, potassium carbonate and potassium bicarbonate; alkali metal acetates such as sodium acetate and potassium acetate; alkaline earth metal hydroxides such as calcium hydroxide; and Organic bases such as triethylamine, pyridine, lutidine, collidine and quinoline. Even better implementation! In mode 3, the esterification reaction is preferably about -2
The alcohol or phenol is first converted into a sodium or potassium alcoholade or phenolate, for example by treatment with an ethanolic solution of sodium hydroxide or potassium hydroxide, at a temperature of 5°C to +20°C, and this alcoholade or phenolate is isolated. , by suspending it in acetone or diethyl ether with stirring with sodium bicarbonate or potassium bicarbonate and then adding a diethyl ether, acetone or DMF solution of the acid chloride or anhydride to this 1v suspension. conduct.

Ethers of formula I are obtained by etherification of the corresponding hydroxy compounds, preferably the corresponding phenols. This hydroxy compound is first converted into a corresponding metal derivative such as NaH, NaNH2, NaOH, KOH.
Preferably, it is converted to the corresponding alkali metal alcoholade or alkali metal phenolate by treatment with 1Na2C03 or 2CO3. Next, the alcoholade or phenolate with preferably about 20-100'
Acetone, 1,2-dimethoxyethane, DM at a temperature of C
F can be reacted with the corresponding alkyl halide or sulfonate or dialkyl sulfonate in an inert solvent such as dimethyl sulfoxide or in an aqueous or aqueous-alcoholic solution of excess NaOH or KOH.

Nitriles are of the class [He1v, Chin, ^cta, ,
J. Schudreit (J.
, 5treith) from the corresponding aldehyde using hydroxylamine-0-sulfonic acid.

The liquid-crystalline medium according to the invention comprises, in addition to one or more compounds according to the invention, as further constituents 2 to 40, preferably 4
Preferably it contains 30 ingredients.

In particular, it is more preferred that these media contain from 7 to 25 components in addition to the one or more compounds of the invention.

These further added components are nematic or nematic-generating (isotropic or monomodified) substances, in particular azoxybenzene, benzylideneaniline, biphenyl, terphenyl, phenyl benzoate and cyclohexyl benzoate, phenyl cyclohexanecarboxylate and cyclohexanecarboxylic acid. Cyclohexyl, phenyl cyclohexylbenzoate and cyclohexyl cyclohexylbenzoate, phenyl cyclohexylcyclohexanecarboxylate and cyclohexyl cyclohexylcyclohexanecarboxylate,
Cyclohexylphenyl benzoate, cyclohexanecarboxylic acid, cyclohexylcyclohexanecarboxylic acid, phenylcyclohexane, cyclohexyl biphenyl, phenylcyclohexylcyclohexane, cyclohexylcyclohexane, cyclohexylcyclohexene, cyclohexylcyclohexylcyclohexene, 1.4 - and sucyclohexylbenzene, 4.4'- and sucyclohexyl biphenyl, phenylpyrimidine, cyclohexylpyrimidine, phenylpyridine, cyclohexylpyridine, phenyldioxane, cyclohexyldioxane, phenyl-1°3-dithiane, cyclohexyl-1
, 3-dithiane, 1.2-diphenylethane, 1.2-
Dicyclohexylethane, 1-phenyl-2-cyclohexylethane, 1-cyclohexyl-2-(4-phenylcyclohexyl)ethane, 1-cyclohexyl-2-
Preference is given to selecting substances from the class of biphenylylethane, 1-phenyl-2-cyclohexylphenylethane, optionally halogenated stilbenes, benzylphenyl ethers, tolanes and substituted ginnamic acids. The 1,4-phenylene group of these compounds can also be fluorinated.

The most important compounds suitable for use as further components of the media of the invention can be characterized by the following formulas 1.2.3.4 and 5.

R'-L-E-R"IR'-L-C
oo-E-R'2R'-L-00C-E-R
'3R'-L-CHCH-F,-4"
4R'-L-C3C-E-R” 5 formula 1.2
．． In 3.4 and 5, E may be the same or different, and each independently represents -Phe-1-Cyc-1-P
he-Phe--Phe-Cyc-1-Cyc-Cyc
-1-Pyr--Dio--G-Phe- and -〇-C
It is a divalent group belonging to the group consisting of yc- and their gA@ forms.

Here, Phe is 1,4-phenylene unsubstituted or substituted with fluorine, and CyC is trans-1,
4-cyclohexylene or 1,4-cyclohexenylene, Pyr is pyrimidine-2°5-diyl or pyridine-2,5-diyl, and Dio is 1,3-dioxane-2,5-diyl. and G is 2-(trans-1,4-cyclohexyl)ethyl, pyrimidine-2,
5-diyl, pyridine-2,5-diyl or 1,3-dioxane-2,5-diyl.

Preferably, one of the groups and E is Cyc, Phe or Pyr. E is Cyc, Phe or phe-cy
It is preferable that it is c. The medium according to the invention comprises one or more components selected from compounds of formulas 1.2.3.4 and 5, in which the radical and E are selected from the group consisting of Cyc, Phe and Pyr; 1 of the base and E at the same time
is selected from the group consisting of Cyc, Phe and Pyr and the other group is -Phe-Phe-1-Phe-Cyc
-1-Cyc-Cyc--G-Phe- and -〇-Cy
Formulas 1.2.3.4 and 5 selected from the group consisting of c-
and if appropriate, the group and E are -Phe-Cyc-1-Cy
comprising one or more components selected from compounds of formulas 1.2.3.4 and 5 selected from the group consisting of c-Cyc-1-G-Phe- and -〇-Cyc- preferable.

Compounds of formula 1a in which R' and R'' are each independently an alkyl, alkenyl, alkoxy, argenyloxy or alkanoyloxy group having up to 8 carbon atoms
, 2a, 3a, 4a and 5a.

In most of these compounds, R' and R'' are different from each other, although mostly alkyl or alkenyl groups. Compounds in which R'' is -CN, -CF F, 3'C1 or -NC3 are defined by formula 1b. , 2b, 3b,
4b and 5b, R' is represented by formula 1a-
It has the meaning given for compound 5a and is preferably an alkyl or alkenyl group. However, a variety of other possible substituents are also customary for compounds of formulas 1.2.3.4 and 5. Many substances of this type and mixtures thereof are commercially available. All these substances can be obtained by methods known from the literature or analogous thereto.

Group of compounds 1a, 2a, 3a, 4a and 5a (group 1)
In addition to the components belonging to
, 2b, 3b, 4b and 5b (group 2). Preferably, their proportions are as follows.

1st group: 20-90%, especially 30-90% 2nd group = 10
~80%, in particular 10-50% The sum of the proportions of the compounds of the invention and the compounds belonging to the first and second groups amounts to 100%.

The medium according to the invention contains 1 to 40%, particularly preferably 5 to 3%
Preferably it contains 0% of the compound of the invention. Preference is also given to media containing more than 40%, especially from 45 to 90%, of the compounds of the invention. Preferably, the medium contains 3 to 5 compounds of the invention.

The preparation of the medium according to the invention takes place in a manner customary per se. Generally, the components are dissolved together, preferably at elevated temperatures. Since the liquid crystal phases according to the invention can be modified by suitable additives, they can also be used in any liquid crystal display element disclosed hitherto. Additives of this type are known to those skilled in the art and are available in the literature [
Ecchi Gelker (11, Kelker)/Alu
Hutz (R.

Hatz), “Liquid Crystal Handbook (Handbook)
of Liquid Crystals”, Verlag Chemie, Weinheim (19
1980)]. For example, dichroic dyes can be added to form colored guest-host systems. Also, substances can be added to alter the dielectric anisotropy, viscosity and/or orientation of the nematic phase.

The following examples are illustrative of the invention and are not intended to limit it. In the examples, H and P stand for the melting point, and c and p stand for the clearing point. In the above and following specifications, % is by weight, and all temperatures are expressed in °C. In the following, "processing according to the established law" means the following. That is, water is added, the mixture is extracted with methylene chloride, the phases are separated, the organic phase is dried and evaporated, and the product is then purified by crystallization and/or chromatography.

Furthermore, C means the state of crystalline solid, S (this indicator characterizes the type of phase) means smectic phase, N
means nematic phase, ch means cholesteric phase, and ■ means isotropic phase. The number between the two symbols indicates the transition temperature in °C.

Example 1 4-alkyl-1-(2,3-difluorophenyl)-
1-Cyclohexene: A solution of 0.3 mol of n-butyllithium in 188n+l hexane is diluted with 0.3 mol of 1°2- at 60°C to -70°C.
Added to a mixture of difluorobenzene, 600 nl of tetrahydrofuran and 0.3 mol of tetramethylethylenediamine. After stirring for 3 hours at −60° C., a solution of 0.32 mol of 4-pentylcyclohexanone in 1001 tetrahydrofuran was added. After working up according to the standard method, the residue was dissolved in 10011 of toluene and 3.5% dissolved in a water separator.
Heat with 10 g of p-)luenesulfonic acid for an hour.

4-pentyl-1-(2,3-difluorophenyl)-1-cyclohexene (b, p, 1
23°C/0, 5 lnHg).

The following compounds were prepared by similar treatment: 4-ethyl-1-(2,3-difluorophenyl)-1-cyclohexene; 4-propyl-1-(23-difluorophenyl)-1
-cyclohexene; 4-butyl-1-(2,3-difluorophenyl)-1
-Cyclohexene; 4-hexyl-1-(2,3-difluorophenyl)-
1-cyclohexene; 4-hebutyl-1-(2,3-difluorophenyl)-
1-cyclohexene; 4-octyl-1-(2,3-difluorophenyl)-
1-cyclohexene; 4-nonyl-1-(2,3-difluorophenyl)-1
-cyclohexene; 4-decyl-1-(2,3-difluorophenyl)-1
-Cyclohexene; 4-dodecyl-1-(2,3-difluorophenyl)-
1-cyclohexene; 4-ethoxy-1-(2,3-difluorophenyl)-
1-Cyclohexene; 4-10boxy-1-(2,3-difluorophenyl)
-1-cyclohexene; 4-butoxy-1-(2,3-difluorophenyl)-
1-cyclohexene: 4-pentoxy-1-(2,3-difluorophenyl)
-1-cyclohexene; 4-hexyloxy-1-(2,3-difluorophenyl)-1-cyclohexene; 4-hebutyloxy-1-(2,3-difluorophenyl)-1-cyclohexene; 4-octyloxy -1-(2,3-difluorophenyl)-1-cyclohexene; 4-nonyloxy-1-(2,3-difluorophenyl)-1-cyclohexene; 4-decyloxy-1-(2,3-difluorophenyl)- 1-cyclohexene; and 4-undecyloxy-
1-(2,3-difluorophenyl)-1-cyclohexene.

Oran ■U1-(2,3-difluorophenyl)-4-(p-alkylphenyl)-1-cyclohexene: 790.105 mol of n-butyllithium of 60111 was added to 70
0.1 mole of 1,2-difluorobenzene and 200 °C
1 was added to the mixture with tetrahydrofuran. After stirring for 6 hours, a mixture of 0.1 mol of 4-(glopylphenyl)cyclohexanone and 5 On+l of tetrahydrofuran was added. After stirring for 2 hours, the mixture was heated to room temperature and treated according to a conventional method to obtain 1-(2,3-difluorophenyl)-4-(1)-propylphenyl)-1-cyclohexene.

The following compounds were prepared by similar treatment: 1-(2,3
-difluorophenyl)-4-(p-ethylphenyl)
-1-cyclohexene: 1-(2,3-difluorophenyl)-4-(p-butylphenyl)-1-cyclohexene; 1-(2,3-difluorophenyl)-4-(p-pentylphenyl)-1 -Cyclohexene; 1-(2,3-difluorophenyl)-4-(1)-hexylphenyl)-1-cyclohexene: 1-(2,3-difluorophenyl)-4-(p-hegetylphenyl)-1- Cyclohexene; 1-(2,3-difluorophenyl)-4-(p-octylphenyl)-1-cyclohexene: 1-(2,3-difluorophenyl)-4-(p-nonylphenyl)-1-cyclohexene: 1-(2,3-difluorophenyl)-4-(p-decylphenyl)-1-cyclohexene; 1-(2,3-difluorophenyl)-4-(p-dodecylphenyl)-1-cyclohexene; 1- (2,3-difluorophenyl)-4-(1)-ethoxyphenyl)-1-cyclohexene; 1-(23-difluorophenyl)-4-(p-pentoxyphenyl)-1-cyclohexene: 1-(2 ,3-difluorophenyl)-4-(p-octyloxyphenyl)-1-cyclohexene: and 1-
(2,3-difluorophenyl)-4-(p-dodecyloxyphenyl)-1-cyclohexene.

4-(4-alkylcyclohexyl) as starting compound
Using cyclohexanone, the following compounds were similarly obtained: 1(2,3-difluorophenyl 4-(4-ethylcyclohexyl)-1-cyclohexene;
difluorophenyl)-4-(4-pentylcyclohexyl)-1-cyclohexene; 1-(2,3-difluorophenyl)-4-(4-octylcyclohexyl)-
1-cyclohexene; 1-(2,3-difluorophenyl)-4-(4-dodecylcyclohexyl)-1-cyclohexene; and 1-(2,3-difluorophenyl)-
4-(4-pentoxycyclohexyl)-1-cyclohexene.

Fire” Kuchikuyu■-(4-alkyl-2,3-difluorophenyl)-
4-Alkyl-1-cyclohexene: 0.2 mol of n-butyllithium in 1251 hexane at -100°C.
．． 2 moles of 1-(2,3-difluorophenyl)-4-
pentyl-1-cyclohexene (prepared as in Example 1), 0.2111 potassium tert, -
Added to a mixture of butyrate and 4001 tetrahydrofuran.

After stirring for 10 minutes at -100°C, a solution of 0.22 mol of iodoethane, 0.22 mol of dimethylpropylene urea and 80 ml of tetrahydrofuran was added. −
1-(
4-ethyl-2,3-difluorophenyl)-4-pentyl-1-cyclohexene was obtained.

The following compounds were prepared by similar treatment: 1-(4-propyl-2,3-difluorophenyl)-4-pentyl-1-cyclohexene; 1-(4-butyl-2,3-difluorophenyl)-4 -Pentyl-1-cyclohexene; 1-(4-pentyl-2,3-difluorophenyl)-4-pentyl-1-cyclohexene; 1-(4-hexyl-2,3-difluorophenyl)-4-pentyl-1- Cyclohexene: 1-(4-hebutyl-2,3-
difluorophenyl)-4-pentyl-1-cyclohexene; 1-(4-octyl-2,3-difluorophenyl)-4-pentyl-1-cyclohexene; 1-(4-
Propyl-2,3-Schiff,fluorophenyl)-4-ethyl-1-cyclohexene; 1-(4-butyl-2,3-
difluorophenyl)-4-ethyl-1-cyclohexene; 1-(4-pentyl-2,3-difluorophenyl)-4-ethyl-1-cyclohexene; 1-(4-hexyl-2,3-difluorophenyl)- 4-ethyl-1
-Cyclohexene; 1-(4-hebutyl-2,3-difluorophenyl)-4-ethyl-1-cyclohexene;
1-(4-octyl-2,3-difluorophenyl)-
4-ethyl-1-cyclohexene: 1-(4-propyl-2,3-difluorophenyl)-4-octyl-1-
Cyclohexene; 1-(4-butyl-2,3-difluorophenyl)-4-octyl-1-cyclohexene; 1
-(4-pentyl-2,3-difluorophenyl)-4
-Octyl-1-cyclohexene; 1-(4-hexyl-2,3-difluorophenyl)-4-octyl-1-
Cyclohexene: 1-(4-hegtyl-2,3-difluorophenyl)-4-octyl-1-cyclohexene:
1-(4-octyl-2,3-difluorophenyl)-
4-octyl-1-cyclohexene; 1-(4-ethoxy-2,3-difluorophenyl)-4-[2-(trans-4-propylcyclohexyl)-ethyl]-1-
Cyclohexene Cr73°C N 139°C ■; 1-(4-propoxy-2,3-difluorophenyl)
-4-[2-(trans-4-propylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-butoxy-2,3-difluorophenyl)-
4-[2-() lance-4-propylcyclohexyl)
-ethyl]-1-cyclohexene: 1-(4-pentoxy-2,3-difluorophenyl)-4-[2-(trans-4-propylcyclohexyl)-ethyl]-1-
Cyclohexene; 1-(4-hexyloxy-2,3-difluorophenyl)-4-[2-(trans-4-propylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-hexyloxy-2, 1-(4-octyloxy-2,3-difluorophenyl)-4-[2-(3-difluorophenyl)-4-[2-()trans-4-propylcyclohexyl)-ethyl]-1-cyclohexene; ) lance-4-propylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-globoxy2,3-difluorophenyl'
)-4-[2-(trans-4-pentylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-butoxy-2,3-difluorophenyl)-
4-[2-(trans-4-pentylcyclohexyl)
-ethyl]-1-cyclohexene; 1-(4-pentoxy-2,3-difluorophenyl)-4-[2-(trans-4-pentylcyclohexyl)-ethyl]-1-
Cyclohexene: 1-(4-hexyloxy-2,3-difluorophenyl)-4-[2-(trans-4-pentylcyclohexyl)-ethyl]-1-cyclohexene: 1-(4-hebutyloxy-2,3 -difluorophenyl) -4-[2-(trans-4-pentylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-octyloxy-2,3-difluorophenyl)-4-[2-()trans -4-pentylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-globoxy2,3-difluorophenyl)
-4-[2-()trans-4-octylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-butoxy-2,3-difluorophenyl)-
4-[2-()-trans-4-octylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-pentoxy-2,3-difluorophenyl)-4-[2-(trans-4-octylcyclohexyl) )-ethyl]-1
-cyclohexene; 1-(4-hexyloxy-2,3-difluorophenyl)-4-[2-(trans-4-octylcyclohexyl)-ethyl]-1-cyclohexene; 1-(4-hebutyloxy-2, 3-difluorophenyl)-4-[2-(trans-4-octylcyclohexyl)-ethyl]-1-cyclohexene; and 1-(4-octyloxy-2,3-difluorophenyl)-4-[2-( trans-4-octylcyclohexyl)-ethyl]-1-cyclohexene.

0.2 mol of 1-(2□3-difluorophenyl)-4
-Pentyl-1-cyclohexene was deprotonated with n-butyllithium as in Example 1. The resulting product was reacted with 3-propylcyclohexanone. After dehydration, treatment was performed according to a conventional method to obtain 1-(4-pentyl-1-cyclohexenyl)-4-(propyl-1-cyclohexenyl)-2,3-difluorobenzene.

The following compounds were prepared by similar treatment: 1.4-di(4-ethyl-1-cyclohexenyl)-2,3-difluorobenzene: 1.4-di(4-propyl-1-cyclohexenyl)-2,3-difluorobenzene xenyl)-2,3-difluorobenzene, K
59℃ N 120.5℃■; 14-G (4-
Butyl-1,-cyclohexenyl)-2,3-difluorobenzene: 14-di(4-pentyl-1-cyclohexenyl)-2,3-difluorobenzene: 1,4-di(4-hexyl-1 -cyclohexenyl)-2,3-
Difluorobenzene: 1,4-di(4-hebutyl-1
-cyclohexenyl)-2,3-difluorobenzene;
1.4-di(4-octyl-1-cyclohexenyl)
-2,3-difluorobenzene; 1-(4-pentyl-
1-cyclohexenyl)4-(ethyl-1-cyclohexenyl)-2゜3-difluorobenzene; 1-(4-pentyl-1-cyclohexenyl)4-(butyl-1-cyclohexenyl)-23 -difluorobenzene; ■-(4-pentyl-1-cyclohexenyl)4-(hexyl-1-cyclohexenyl)-23-difluorobenzene: 1-(4-pentyl-1-cyclohexenyl)4-(heptyl -1-cyclohexenyl)-2゜3-difluorobenzene; 1-(4-pentyl-1-cyclohexenyl)-4-(
octyl-1-cyclohexenyl)-2゜3-difluorobenzene; ■-(4-propyl-1-cyclohexenyl)-4-(
Ethyl-1-cyclohexenyl)-2゜3-difluorobenzene; 1-(4-propyl-1-cyclohexenyl)4-(butyl-1-cyclohexenyl)-2゜3-difluorobenzene: 1-( 4-propyl-1-cyclohexenyl)-4-(
hexyl-1-cyclohexenyl)-2゜3-difluorobenzene; 1-(4-propyl-1-cyclohexenyl)4-(heptyl-1-cyclohexenyl)-2゜3-difluorobenzene; 1- (4-propyl-1-cyclohexenyl)-4-(
Octyl-1-cyclohexenyl)-2°3-difluorobenzene.

Koshimeiho 1-(4-cyano-2,3-difluorophenyl)-3
-Production of (4-alkyl-1-cyclohexenyl)ethane: a) A solution of 0.11 mol of 2-(2,3-difluorophenyl)ethyl bromide and ethylene oxide in tetrahydrofuran (1501) was heated to -50°C for 0.1 mol. Added to a mixture of 1 mole of 2°3-difluorophenyllithium (prepared as in Example 1), 2001n+ tetrahydrofuran, 0.1 mole of tetramethylethylenediamine and 6511 hexane.

The temperature was raised to +10°C, neutralized with a saturated ammonium chloride solution of 501, and then treated according to the usual method to obtain 2-(2,3
-difluorophenyl)ethanol was obtained. A mixture of triphenylphosphine and acetonitrile and bromine were then added to the alcohol.

The mixture was stirred at room temperature for 12 hours and treated according to a conventional method to obtain a bromine compound.

b) 2-(2,3-difluorophenyl) -(4
-pentyl-1-cyclohexenyl)ethane 2-(2,3-difluorophenyl)ethylmagnesium bromide (prepared from 0.1 mol of the above bromine compound and 0.1 mol magnesium) in Example 1 The alcohol was reacted with 0.1 mol of 4-pentylcyclohexanone in the same manner as in Example 1, and the resulting alcohol was dehydrated in the same manner as in Example 1. This was treated according to a conventional method to obtain a 1-cyclohexene derivative.

C) Introduction of cyano group 0.1 mol of 2-(2,3-difluorophenyl)-1
-(4-pentyl-1-cyclohexenyl)ethane was deprotonated with n-butyllithium as in Example 1 and the product was reacted with 0.1 mol of N-formylpiperidine.

The reactant was treated according to a conventional method to obtain 1-(4-formyl-2
,3-difluorophenyl) -2-(4benzenyl 1
-cyclohexenyl)ethane was obtained.

This compound [e.g., Streith
et al., flelv, Chin, Acta, 59.27
86 (1976)] with hydroxylamine-0-sulfonic acid. 1-(4-cyano-2,3-difluorophenyl) by treatment according to a conventional method
-2=(4-pentyl-1-cyclohexenyl)ethane was obtained.

The following compounds were prepared by similar treatment: 1-(4-cyano-2,3-,difluorophenyl)-2-(4-ethyl-1-cyclohexenyl)ethane; 2,3-difluorophenyl)-2
-(4-propyl-1-cyclohexenyl)ethane: 1-(4-cyano-2,3-difluorophenyl)-2
-(4-butyl-1-cyclohexenyl)ethane; 1-(4-cyano-2,3-difluorophenyl)-2
-(4-hexyl-1-cyclohexenyl)ethane; 1-(4-cyano-2,3-difluorophenyl)-2
-(4-heptyl-1-cyclohexenyl)ethane: and 1-(4-cyano-2,3-difluorophenyl)-2
-(4-octyl-1-cyclohexenyl)ethane.

Example 6 l-(4-alkyl-2,3-difluorophenyl)-
Preparation of 2-(4-alkyl-1-cyclohexenyl)ethane: n-butyllithium/potassium tert,-butyrate was added as in Example 3 to 0.1 mol of 2=(23-
In addition to difluorophenyl)-1-(4-pentyl-1-cyclohexenyl)ethane [prepared in Example 5b)], the product was reacted with 0.1 mol of iodoethane. It was treated by a conventional method to obtain 1-(4-ethyl-2-
,3-difluorophenyl)-2-(4-benzenyl 1
cyclohexenyl)ethane was obtained.

=1-(4-ethyl-2,3-difluorophenyl)-2-(4-ethyl-1-cyclohexenyl)ethane; 1-(4-propyl-2) prepared by treating the following compounds in the same manner. ,3-difluorophenyl)-
2-(4-ethyl-1-cyclohexenyl)ethane: 1-(4-butyl-2,3-difluorophenyl)2-
(4-ethyl-1-cyclohexenyl)ethane; 1-(4-pentyl-2,3-difluorophenyl)-
2-(4-ethyl-1-cyclohexenyl)ethane: 1-(4-hexyl-2,3-difluorophenyl)-
2-(4-ethyl-1-cyclohexenyl)ethane: 1-(4-hebutyl-2,3-difluorophenyl)-
2-(4-ethyl-1-cyclohexenyl)ethane; 1-(4-octyl-2,3-difluorophenyl)-
2-(4-ethyl-1-cyclohexenyl)ethane; 1-(4-ethyl-2,3-difluorophenyl)-2
-(4-propyl-1-cyclohexenyl)ethane; 1-(4-propyl-2,3-difluorophenyl)-
2-(4-propyl-1-cyclohexenyl)ethane; 1-(4-butyl-2,3-difluorophenyl)-2
-(4-propyl-1-cyclohexenyl)ethane; ■-(4-pentyl-2,3-difluorophenyl)-
2-(4-propyl-1-cyclohexenyl)ethane; 1-(4-hexyl-2,3-difluorophenyl)
-2-(4-propyl-1-cyclohexenyl)ethane; 1-(4-hebutyl-2,3-difluorophenyl)
-2-(4-7"ropyru-1-cyclohexenyl)ethane; 1-(4-octyl-2,3-difluorophenyl)-
2-(4-7′-pyr-1-cyclohexenyl)ethane: 1-(4-ethyl-2,3-difluorophenyl)-2
-(4-octyl-1-cyclohexenyl)ethane: 1-(4-propyl-2,3-difluorophenytN-
2-(4-octyl-1-cyclohexenyl)ethane: 1-(4-butyl-2,3-difluorophenyl)2-
(4-octyl-1-cyclohexenyl)ethane; 1-(4-pentyl-2,3-difluorophenyl)-
2-(4-octyl-1-cyclohexenyl)ethane; 1-(4-hexyl-2,3-difluorophenyl)-
2-(4-octyl-1-cyclohexenyl)ethane; 1-(4-hebutyl-2,3-difluorophenyl)-
2-(4-octyl-1-cyclohexenyl)ethane;
and 1-(4-octyl-2,3-difluorophenyl)-
2-(4-octyl-1-cyclohexenyl)ethane.

Chestnut IL 1-(4-alkoxy-2,3-difluorophenyl)
-2-(4-Flu-4-3-cyclohexenyl)ethane production: a) Monoethylene ketal of 4[2(4-ethoxy-2,3-difluoro)ethylcocyclohexanonecyclohexane-1,4-dione A mixture of 0.1 mol and 5011 of tetrahydrofuran was prepared at 0° C. in a similar manner as in 2-(4-ethoxy-2,3-difluorophenyl)ethylmagnesium bromide [Example 5a). And from 0.1 mole of magnesium! ! ! ! ! The child I left behind and 15011
1 and tetrahydrofuran. 5 at room temperature
After stirring for an hour, the resulting mixture was dehydrated as in Example 1. A mixture of the cyclohexane derivative thus obtained, 100 nl of toluene, and 1 g of palladium on activated carbon (10%) was hydrogenated at room temperature and normal pressure until saturated.

After removing the solvent, the residue in 200 nl of acetone is boiled with 25 ml of concentrated hydrochloric acid and heated for 24 hours. Thereafter, it was treated according to a conventional method to obtain 4-[2-(4-ethoxy-2,3-difluoro)ethylcocyclohexanone.

b) Reaction with alkyl Grignard reagent 0.1 mol of the above cyclohexanone is reacted with pentylmagnesium bromide (0
, prepared from 1 mol of pentyl bromide and 0.1 mol of magnesium). It was dehydrated in the same manner as in Example 1 and treated according to a conventional method to obtain 1-(4-ethoxy-
2,3-difluorophenyl)-2-(4-pentyl 3
- cyclohexenyl)ethane.

The following compound was prepared by similar treatment: 1-(4-ethoxy-2,3-difluorophenyl)-2-(4-
-3-cyclohexenyl)ethane: 1-(4-globoxy-2,3-difluorophenyl)
-2-(4-ethyl-3-cyclohexenyl)ethane; ■-(4-butoxy-2,3-difluorophe=7L-
) -2-(4-ethyl-3-cyclohexenyl)ethane: 1-(4-pentoxy-2,3-difluorophenyl)
-2-(4-ethyl-3-cyclohexenyl)ethane: 1-(4-hexyloxy-2,3-difluorophenyl)-2-(4-ethyl-3-cyclohexenyl)ethane: ■- (4-hebutyloxy-2,3-difluorophenyl)-2-(4-ethyl-3-cyclohexenyl)ethane; 1-(4-octyloxy-2,3-difluorophenyl)-2-(4- Ethyl-3-cyclohexenyl)ethane: 1-(4-ethyl-2,3-difluorophenyl) -
2-(4-ethyl-3-cyclohexenyl)ethane; 1-(4-propyl-2,3-difluorophenyl)-
2-(4-ethyl-3-cyclohexenyl)ethane; 1-(4-butyl-2,3-difluorophenyl)-2
-(4-ethyl-3-cyclohexenyl)ethane; 1-(4-pentyl-2,3-difluorophenyl)
-2-(4-ethyl-3-cyclohexenyl)ethane; 1-(4-hexyl-2,3-difluorophenyl)-
2-(4-ethyl-3-cyclohexenyl)ethane; 1-(4-hebutyl-2,3-difluorophenyl)
-2-(4-ethyl-3-cyclohexenyl)ethane: 1-(4-octyl-2,3-difluorophenyl)-
2-(4-ethyl-3-cyclohexenyl)ethane; 1-(4-ethoxy-2,3-difluorophenyl)-
2-<4-heptyl-3-cyclohexenyl)ethane; 1-(4-propoxy-2,3-difluorophenyl)
-2-(4-hebutyl-3-cyclohexenyl)ethane; 1-(4-butoxy-2,3-difluorophenyl)-
2-(4-hebutyl-3-cyclohexenyl)ethane; 1-(4-pentoxy-2,3-difluorophenyl)
-2-(4-hexyloxy-2,3-difluorophenyl)-2-(4-heptyl-3-cyclohexenyl)ethane; 1-(4-hexyloxy-2,3-difluorophenyl)-2-<4-heptyl-3-cyclohexenyl)ethane; 1 -(4-hebutyloxy-2,3-difluorophenyl)-2-(4-heptyl-3-cyclohexenyl)ethane: 1-(4-octyloxy-2,3-difluorophenyl)-2-(4 -hebutyl-3-cyclohexenyl)ethane; 1-(4-ethyl-2,3-difluorophenyl)-2
-(4-hebutyl-3-cyclohexenyl)ethane; 1-(4-propyl-2,3-difluorophenyl)
-2-(4-heptyl-3-cyclohexenyl)ethane; 1-(4-butyl-2,3-difluorophenyl> -
2-(4-hebutyl-3-cyclohexenyl)ethane: 1-(4-pentyl-2,3-difluorophenyl)-
2-(4-hexyl-3-cyclohexenyl)ethane: 1-(4-hexyl-2,3-difluorophenyl)-
2-<4-hebutyl-3-cyclohexenyl)ethane; 1-(4-hebutyl-2,3-difluorophenyl)-
2-(4-hebutyl-3-cyclohexenyl)ethane;
and 1-(4-octyl-2,3-difluorophenyl)-
2-(4-hebutyl-3-cyclohexenyl)ethane.

Preparation of 4-(4-alkyl-1-cyclohexenylcarbonyloxy)-2,3-difluoroalkoxybenzene: 0.1 mol of 2,3-difluoro-4-ethoxyphenol and 10011 methylene chloride 0.1 mol of 4-pentyl-1-cyclohexenyl chloride [Guha et al., B, 71.267
4 (1938) from 4-pentylcyclohexanone and sodium bisulfite and potassium cyanide by treatment with concentrated acid and phosphorus pentachloride], in a mixture of 0.2 mol of pyridine and 150111 methylene chloride. added. By stirring at room temperature for 8 hours, 4-(4-pentyl-1-cyclohexenyloxy)-2,3-difluoroethoxybenzene was obtained.

=4-(4-ethyl-1-cyclohexenylcarbonyloxy)"2.
3-difluoroethylbenzene: 4-(4-propyl-1-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4-butyl-1-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4-pentyl-1-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4-hexyl-1-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4- heptyl-1-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene: 4-(4-octyl-1-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4-ethyl-1-cyclo 4-(4-propyl-1-cyclohexenyloxy)-2,3-difluoropentylbenzene; 4-(4-butyl-1-cyclohexenylcarbonyl) oxy)-2,3-difluoropentylbenzene; 4-(4-pentyl-1-cyclohexenylcarbonyloxy)-2,3-difluoropentylbenzene; 4-(4-hexyl-1-cyclohexenylcarbonyloxy) -2,3-difluoropentylbenzene; 4-(4-heptyl-1-cyclohexenyloxy)-2,3-difluoropentylbenzene; 4-(4-octyl-1-cyclohexenyloxy)-2 , 3-difluoropentylbenzene; 4-(4-ethyl-1-cyclohexenylbenzene-2,3-difluorooctylbenzene 4-(4-propyl-1-cyclohexenylcarbonyloxy)-2. 3-difluorooctylbenzene; 4-(4-butyl-1-cyclohexenylcarbonyloxy)-2,3-difluorooctylbenzene; 4-(4-pentyl-1-cyclohexenylcarbonyloxy)-2.3-difluorooctyl Benzene; 4-(4-hexyl-1-cyclohexenylcarbonyloxy)-2.3-difluorooctylbenzene; 4-(4-hexyl-1-cyclohexenylcarbonyloxy)-2.3-difluorooctylbenzene; 4-(4-octyl-1-cyclohexenylcarbonyloxy)-2,3-difluorooctylbenzene; 4-(4-ethyl-l-cyclohexenylcarbonyloxy)-2,3-difluoropropoxybenzene; 4-( 4-(4-Butyl-1-cyclohexenylcarbonyloxy)-2,3-difluoropropoxybenzene; 4-(4-butyl-1-cyclohexenylcarbonyloxy)-2,3-difluoropropoxybenzene; 1-cyclohexenylcarbonyloxy)-2,3-difluoro10boxybenzene; 4-(4-hexyl-1-cyclohexenylcarbonyloxy)-2,3-difluoropropoxybenzene; 4-(4-hebutyl-1 -cyclohexenylcarbonyloxy)-2,3-difluoro10boxybenzene; 4-(4-octyl-1-cyclohexenylcarbonyloxy)-2,3-difluoropropoxybenzene; 4-(4-ethyl-1-cyclohexenyl 4-(4-propyl-1-cyclohexenyloxy)-2,3-difluoropentoxybenzene; 4-(4-butyl-1-cyclobenzene) 4-(4-pentyl-1-cyclohexyloxy)-2,3-difluoropentoxybenzene: 4-(4-hexyl-1-cyclo hexenylcarbonyloxy)-2,3-difluoropentoxybenzene; 4-(4-hebutyl-1-cyclohexenylcarbonyloxy)-2,3-difluoropentoxybenzene; 4-(4-octyl-1-cycloto 4-(4-ethyl-1-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; 4-(4-propyl-1- cyclohexenyloxy)-2,3-difluorooctyloxybenzene; 4-(4-butyl-1-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; 4-(4-pentyl-1-cyclo 4-(4-hexyl-1-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; hexenylcarbonyloxy)-2,3-difluorooctyloxybenzene: and 4-(4-octyl-1-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene.

Preparation of 4-(4-alkyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroalkylbenzene: 0.1 mol of triingloboxypentyl titanium (with the corresponding Grignard reagent and triisopropylchlorotitanium) ) was reacted as in Example 1 with 0.1 mol of ethyl cyclohexane-4onecarboxylate. Dehydrated and treated by standard method to obtain 4-pentyl-3
- Ethyl cyclohexenylcarboxylate was obtained. After genification with aqueous ethanolic solution of potassium hydroxide, this compound was dissolved in methylene chloride with 0.1 mol of dicyclohexylcarbodiimide and 1 mmol of 4-N.

Using N-dimethylaminopyridine to prepare 0.1 mole of 4-
Esterified with propyl-2,3-difluorophenol. The esterified product is treated according to a conventional method to obtain 4-(4-
pentyl-3-cyclohexenyl-(luponyloxy)-
2,3-difluoropropylbenzene was obtained.

=4-(4-ethyl-3-cyclohexenyloxy)-2, which was prepared by treating the following compound in the same manner.
3-difluoroethylbenzene; 4-(4-propyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4-butyl-3-cyclohexenylcarbonyloxy)-23-difluoroethylbenzene; 4- (4-pentyl-3-cyclohexenyloxy)-2,3-difluoroethylbenzene:.

4-(4-hexyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4-hexyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene: 4-(4 -octyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethylbenzene; 4-(4-ethyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentylbenzene; 4-(4-propylene) -3-cyclohexenylcarbonyloxy)-2,3-difluoropentylbenzene; 4-(4-butyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentylbenzene; 4-(4-pentyl-3 -cyclohexenylcarbonyloxy)-2,3-difluoropentylbenzene; 4-(4-hexyl-3-cyclohexenylcarbonyloxy?)-2,3-difluoropentylbenzene; 4-(4-hebutyl-3 -cyclohexenylcarbonyloxy)-2,3-difluoropentylbenzene; 4-(4-ethyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentylbenzene; 4-(4-ethyl-3-cyclo 4-(4-propyl-3-cyclohexenyloxy)-2,3-difluorooctylbenzene; 4-(4-butyl-3-cyclohexenylcarbonyloxy) )-2,3-difluorooctylbenzene; 4-(4-pentyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctylbenzene; 4-(4-hexyl-3-cyclohexenylcarbonyloxy)-2 ,3-difluorooctylbenzene; 4-(4-hebutyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctylbenzene; 4-(4-octyl-3-cyclohexenylcarbonyloxy)-2,3 -difluorooctylbenzene; 4-(4-ethyl-3-cyclohexenyloxy)-2,3-difluoroethoxybenzene; 4-(4-propyl-3-cyclohexenyloxy)-2,3-difluoro Ethoxybenzene; 4-(4-butyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethoxybenzene; 4-(4-pentyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethoxybenzene; 4 -(4-hexyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethoxybenzene; 4-(4-hexyl-3-cyclohexenylcarbonyloxy)-2,3-difluoroethoxybenzene; 4 -(4-octyl-3-cyclohexenylluponyloxy)-2,3-difluoroethoxybenzene; 4-(4-ethyl-3-cyclohexenylluponyloxy)-2,3-difluoropentoxybenzene; 4- (4-propyl-3-cyclohexenylcarponyloxine-2,3-difluoropentoxybenzene; 4-(4-butyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentoxybenzene; 4-( 4-pentyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentoxybenzene; 4-(4-hexyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentoxybenzene; 4-( 4-(4-octyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentoxybenzene; 4-(4-octyl-3-cyclohexenylcarbonyloxy)-2,3-difluoropentoxybenzene; 4-ethyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; 4-(4-propyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; -butyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; 4-(4-benzenyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; 4-(4-to xyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; 4-(4-heguthyl-3-cyclohexenylcarbonyloxy)-2,3-difluorooctyloxybenzene; -octyl-3-cyclohexenyloxy)-2,3-difluorooctyloxybenzene.

Estop51U4-(4-benthyl-1-cyclohexenyl)-2,3
Preparation of 4-propylphenyl-difluorobenzoate: 0.1 mol of 4-benzene-1-(2,3-difluorophenyl)-1-cyclohexene (prepared in Example 1) was mixed with 0.1 mol of n- Deprotonated with butyllithium. The product was carboxylated by adding perisodic carbonate. A mixture of 0.12 mol of dicyclohexylcarbodiimide and 301 methylene dichloride was added at room temperature to a mixture of the benzoic acid thus obtained, 0.1 mol of p-propylphenol and 10 (II) methylene dichloride. The product was stirred for 20 hours and treated as a colorless solid, C51°C 5c.
63°C N 150.8°C (2) was obtained.

The following compounds were prepared by similar treatment: 4-propylphenyl 4-(4-ethyl-1-cyclohexenyl)-2,3-difluorobenzoate; xenyl)-2,3
-4-propylphenyl difluorobenzoate; 4-(4-butyl-1-cyclohexenyl)-2,3-
4-10pylphenyl difluorobenzoate; 4-(4-hexyl-1-cyclohexenyl) = 2,3
-4-propylphenyl difluorobenzoate; 4-(4-hebutyl-1-cyclohexenyl)-2,3
-4-propylphenyl difluorobenzoate; and 4-(4-octyl-1-cyclohexenyl)-2,3
-4-propylphenyl difluorobenzoate.

A nematic liquid crystal phase consisting of the following composition was characterized by a wide nematic phase region and low birefringence: p-trans-4-pro and 13% hexylbenzonitrile trans-1-11 -Methoxypheny 20%-4-propylcyclohexanetrans-1-D-butoxyphenyl 13%4-propylcyclohexane1-ethoxybenzeneprobylcyclohexylbentylcyclohexylsancarboxylic acidtrans-4-bentylcyclohexyllopylcyclohexyllobiphenyl Biphenyl Biphenyl Handmade Koneho Seisho (Spontaneous) April 10, 1999

Claims (1)

[Claims] 1. Cyclohexene derivative of formula I. R^1-A^1-Z^1-A^2 (Z^2-A^3)_
m-R^2 [wherein R^1 and R^2 are each independently unsubstituted or
an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 3 to 15 carbon atoms substituted by one cyano group or substituted by at least one fluorine or chlorine, provided that these substitutions -O-, -CO-, -O-CO-, -C
O-O-s can also be replaced by -O-CO-O-), or these groups R^1 and R^2
One of them is a cyano group, m is 0, 1 or 2, and A^1, A^2 and A^3 are each independently one or two non-adjacent CH_2 1,4-cyclohexenylene group or trans-1,4-cyclohexylene group, which group may be replaced by -O-, or unsubstituted or substituted with one or two fluorine groups, and one of them or a 1,4-phenylene group in which two CH groups may be replaced by N, and Z^1 and Z^2 are each independently -CO-
O-, -O-CO-, -CH_2O--OCH_2-,
-CH_2CH_2- or one single bond. However, at least one of the groups A^1, A^2 and A^3 is a 2,3-difluoro-1,4-phenylene group, and A
At least one of the remaining groups ^1, A^2 and A^3 is a 1,4-cyclohexenylene group. ]2. The cyclohexene derivative according to claim 1, characterized by formula II. R^1-(A^・)_n-Che-Z^1-(A^1-
Z^2)_m-A^2-R^2II In the formula, R^1, R^2, Z^1, Z^2, A^1, A^2 and m have the same meanings as in claim 1. , A^・ is a trans-1,4-cyclohexylene group, Che is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲mathematical formulas,
There are chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, and n is 0 or 1. 3, R^1 and R^2 are each independently 1 to 1
The cyclohexene derivative according to claim 1 or 2, which is a straight-chain alkyl or alkoxy group having 5 carbon atoms. 4. A liquid crystal phase using the cyclohexene derivative according to claim 1 or 2 as a component. 5. A liquid crystal phase containing at least two liquid crystal components, characterized in that at least one of the components is the cyclohexene derivative according to claim 1 or 2. 6. A liquid crystal display element comprising the liquid crystal phase according to claim 5. 7. An electro-optical display element according to claim 6, comprising the liquid crystal phase according to claim 5 as a dielectric.