DE4222371A1 - New liq. crystal cpds. with terminal chloro or mono-, di- or tri-fluoro gp. - having low viscosity, relatively high dielectric ansiotropy and nematogenity, good performance at low tenmps. and good suppression of smectic phases - Google Patents

Abstract

Liq. crystal cpds. of formula (I) are claimed: R = H, 1-15C alkyl(enyl) opt. substd. with CN or CF3 or one or more halogen, with one or more non-adjacent CH2 gps. opt. substd. by O, S cyclobutandiyl, -CO-, -CO-O-, -O-CO- or -O-CO-O-; Z,Z' = -CH2CH2-, -CH=CH-, -CC-, or a single bond, and one of Z,Z' may also be -(CH2)4- or -CH=CH-CH2CH2-; A,A' = trans-1,4-cyclohexylenyl with 1-2 non-adjacent CH2 gps. opt. substd. by O, or opt. mono- or di F and/or Cl substd. 1,4-phenylene with 1-2 CH gps. opt. substd. by N; m = 0-3; (O+S) = 0-2, with (S+O) greater than or equal to 2; W = O, -COO- or a single bond; Q = O, -CH=CH- or a single bond; r = 1-7; t = 0-7; and y = F, Cl, CF3, OCF3 CHF2, OCHF2 or OCH2F. USE/ADVANTAGE - Liq. crystal and electro-optic indicators contg. liq. crystal media contg. at least two liq. crystal components and at least one cpd. of formula (I) or (II) are claimed. (I) are partic. useful for displays based on the drilled cell, guest-host effect, deformation of phases or dynamic scattering effect principle. The claimed cpds. have comparatively low viscosities, relatively high dielectic anisotropies and nematogenities, good performance at low temps. and the smectic phases are effectively suppressed.

Description

The invention relates to liquid crystalline compounds Formula I,

wherein
RH, an unsubstituted, an alkyl or alkylene radical with 1 to 15 carbon atoms which is simply substituted by CN or CF ₃ or an at least monosubstituted by halogen, with one or more CH ₂ groups in each of these radicals also being independent of one another

-O-CO- or -O-COO- can be replaced so that O atoms are not directly linked,
Z ¹ and Z each independently of one another -CH ₂ CH ₂ -, CH = CH-, -C≡C- or a single bond, one of the radicals Z ¹ and Z also - (CH ₂ ) ₄ - or -CH = CH-CH ₂ CH ₂ -,
A and A ¹ each independently of one another trans-1,4-cyclo hexylene, in which one or two non-adjacent CH ₂ groups can be replaced by -O-, or unsubstituted or one or two times by fluorine and / or Cl atoms substituted 1,4-phenylene, in which one or two CH groups can also be replaced by N,
m 0, 1, 2 or 3, o + s 0, 1 or 2, where (s + o) 2,
W -O-, -COO- or a single bond,
Q -O-, -CH = CH- or a single bond,
r 1 to 7,
t 0 to 7, and
YF, Cl, CF ₃ , OCF ₃ , CHF ₂ , OCHF ₂ or OCH ₂ F
means.

The invention further relates to the use of this Ver bonds as components of liquid crystalline media as well Liquid crystal and electro-optical display elements that the Contain liquid-crystalline media according to the invention.  

The compounds of formula I can be liquid as components crystalline media are used, especially for Displays based on the principle of the twisted cell, the Guest-host effect, the effect of deformation erect Phases or the effect of dynamic scattering.

Have the substances previously used for this purpose certain disadvantages, for example too high melting points low clearing points, insufficient stability towards the Exposure to heat, light or electrical fields, electrical resistance too low, too high Temperature dependence of the threshold voltage, unfavorable elastic and / or dielectric properties.

Especially when displaying Supertwist type (STN) with Ver drilling angles of significantly more than 220 ° or for advertisements The materials used so far have an active matrix Disadvantages.

The invention was based, new stable liquid task to find crystalline or mesogenic compounds which as Components of liquid crystalline media are suitable and especially a comparatively small one at the same time Have viscosity and a relatively high dielectric Anisotropy and high nematogenicity.  

It has now been found that compounds of the formula I as Components of liquid crystalline media are particularly suitable are. In particular, they are comparatively low Viscosities and high nematogenicity. Leave with their help stable liquid-crystalline media with a wide meso phase range and advantageous values for the optical and dielectric anisotropy obtained. These media point also very good low-temperature behavior, i. H. excellent solubility in common LC materials, while the appearance of smectic phases is effectively suppressed.

Liquid crystals of the formula

are already known from WO 8902425. In the JP 59-155485-A2 is a compound of the formula

called. Finally, in EP 278665 connections of the formula

described.  

From DE 31 36 624, DE 32 09 178 and DE 34 10 734 Known compounds of the following formulas:

From J 59 01 684 are 3-fluoro-4-substituted 4-bicyclo hexylbenzenes of the formula

known.

WO 88 05 803 A describes esters of the general formula

treated.  

In EP 0 360 521 A compounds of the general formula

described.

From WO 89 02 884 are trifluoromethyl ethers of the formula

known.

In DE-OS 39 09 802 connections are finally the formula

described.

Liquid crystals are known from EP-OS 0 168 683 following formulas:

The compounds of the formula I with Y = CF ₃ enable STN displays with a very high steepness of the electro-optical characteristic as well as displays with an active matrix with excellent long-term stability. The compounds according to the invention have, in comparison to the non-fluorine-containing compounds, both a higher Δε and a higher ε ₁ . Due to their particularly favorable elastic properties, they are particularly suitable as components for TFT mixtures. By suitable selection of r and s, the threshold voltages can be significantly reduced in both display types.

With regard to the most diverse areas of application of the like connections, however, it was desirable to add more To have connections available to each Applications have precisely tailored properties.

With the provision of compounds of formula I will also generally the range of liquid crystalline Substances that are under different application techni viewpoints for the production of liquid crystalline Mixtures are suitable, considerably widened.

The compounds of formula I have a wide range of uses area of application. Depending on the choice of Substi These compounds can be used as base materials serve from which liquid-crystalline media predominate the part is composed; but it can also connect gene of formula I from liquid crystalline base materials other classes of compounds can be added, for example the dielectric and / or optical anisotropy to influence such dielectric and / or in order to To optimize threshold voltage and / or its viscosity.  

The compounds of the formula I are colorless in the pure state and form liquid crystalline mesophases in one for the electro-optic use conveniently located temperature Area. They are stable chemically, thermally and against light.

The invention thus relates to the compounds of Formula I and the use of these compounds as a compo nenten liquid-crystalline media. Subject of the invention are also liquid crystalline media containing at least one compound of formula I and liquid crystal display elements, in particular electro-optical displays elements that contain such media.

Above and below, R, A ¹ , A, Z ¹ , Z, W, Q, Y, m, o, s, r and t have the meaning given, unless expressly stated otherwise. If A ¹ and A are a substituted 1,4-phenylene ring, the phenylene ring is preferably substituted in the 2-, 2,3- or 2,6-position by fluorine.

Z ¹ and Z are preferably a single bond or -CH ₂ CH ₂ -.

If one of the radicals Z ¹ and Z is - (CH ₂ ) ₂ -, - (CH ₂ ) ₄ - or -CH = CH-CH ₂ CH ₂ -, the other radical Z ¹ or Z is preferably a single bond.

Preferred connections of this type correspond to the part formula I ′,

wherein Z is - (CH ₂ ) ₄ - or -CH = CH-CH ₂ CH ₂ - and R, r, t, L, W, Q and Y have the meaning given in formula 1.

Also preferred are compounds of sub-formula 1 '',

wherein L is H or F and R, Z ¹ , W, Q, Y, r and t have the meaning given in claim 1. If t = 0, Q is preferably a single bond.

Y can also be H if W = 0 or a single bond mean.

For the sake of simplicity, A '' in the following mean one 1,4-cyclohexylene radical, B is a radical of the formula

in which
L is preferably F. Y is preferably F, Cl or CF ₃ and r and s are preferably 1, 2, 3 or 4. Q is preferably a single bond.

The compounds of formula 1 accordingly include Connections of the sub-formulas

RA ′ ′ - A ′ ′ - BW- (CH₂) _r - (CH₂) _t -Y (I′′a)

RA ′ ′ - A ′ ′ - BW- (CH₂) _r -O- (CH₂) _t -Y (I′′b)

RA ′ ′ - Z¹-A ′ ′ - BW- (CH₂) _r - (CH₂) _t -Y (I′′c)

RA ′ ′ - Z¹-A ′ ′ - BW- (CH₂) _r -O- (CH₂) _t -Y (I′′d)

RA ′ ′ - A ′ ′ - Z²-BW- (CH₂) _r - (CH₂) _t -Y (I′′e)

RA ′ ′ - A ′ ′ - Z²-BW- (CH₂) _r -O- (CH₂) _t -Y (I′′f)

RA ′ ′ - Z¹-A ′ ′ - Z²-BW- (CH₂) _r - (CH₂) _t -Y (I′′g)

RA ′ ′ - Z¹-A ′ ′ - Z²-BW- (CH₂) _r -O- (CH₂) _t -Y (I′′h)

Among them, those of the sub-formulas I''a, I''b, I''e and I''f are particularly preferred. In the compounds of the partial formulas I''c to 1''h, Z ¹ and Z are -CH ₂ CH ₂ -, -CH = CH- or -C≡C-, preferably -CH ₂ CH ₂ -.

The compounds of Formula IA,

wherein n is 0 to 7, D -O-, -CH = CH- or a single bond, a is 1 to 5, b is 0 or 1 and Z, A, o, s and r are the in Claim 1 have the meaning given.

Particularly preferred sub-formulas of the compounds IA are

• the compounds of the formula Ia, wherein a 1 to 5, b 0 or 1, s 1 or 2 and A, Z, o and r have the meaning given in claim 1.
• the compounds of the formula Ib, wherein n is 1 to 7, s is 1 or 2, b is 0 or 1 and A, Z, o and r have the meaning given in claim 1.
• the compounds of the formula Ic wherein L ^{1 is} H, F or Cl, L ² F or Cl and R, A ¹ , Z ¹ , Z, m and s have the meaning given in claim 1.

If R in formula I is an alkyl radical and / or an alkoxy radical means, this can be straight-chain or branched. It is preferably straight-chain, has 2, 3, 4, 3, 6 or 7 C atoms and therefore preferably means ethyl, propyl, butyl, Pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, Hexoxy or heptoxy, furthermore methyl, octyl, nonyl, decyl, Undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, Octoxy, nonoxy, decoxy, undecoxy, dodecoxy, tridecoxy or Tetradecoxy.

Oxaalkyl preferably means straight-chain 2-oxapropyl (= Methoxymethyl), 2- (= ethoxymethyl) or 3-oxabutyl (= 2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyl, 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.  

If R represents an alkenyl radical, this can be straight be chain or branched. It is preferably straight-chain and has 2 to 10 carbon atoms. It therefore means special Vinyl, prop-1, or prop-2-enyl, but-1-, 2- or but-3-enyl, Pent-1-, 2-, 3- or Pent-4-enyl, Hex-1-, 2-, 3-, 4- or Hex-5-enyl, hept-1-, 2-, 3-, 4-, 5- or hept-6-enyl, oct-1-, 2-, 3-, 4-, 5-, 6- or oct-7-enyl, non-1-, 2-, 3-, 4-, 5-, 6-, 7- or non-8-enyl, Dec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- or Dec-9-enyl.

If R is an alkyl radical in which one CH ₂ group has been replaced by -O- and one has been replaced by -O-, these are preferably adjacent. Thus, they contain an acyloxy group -CO-O- or an oxycarbonyl group -O-CO-. These are preferably straight-chain and have 2 to 6 carbon atoms.

Accordingly, they mean especially acetyloxy, propionyloxy, Butyryloxy, pentanoyloxy, hexanoyloxy, acetyloxymethyl, Propionyloxymethyl, butyryloxymethyl, pentanoyloxymethyl, 2-acetyloxyethyl, 2-propionyloxyethyl, 2-butyryloxyethyl, 3-acetyloxypropyl, 3-propionyloxypropyl, 4-acetyloxybutyl, Methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxy carbonyl, pentoxycarbonyl, methoxycarbonylmethyl, ethoxy carbonylmethyl, propoxycarbonylmethyl, butoxycarbonylmethyl, 2- (methoxycarbonyl) ethyl, 2- (ethoxycarbonyl) ethyl, 2- (propoxycarbonyl) ethyl, 3- (methoxycarbonyl) propyl, 3- (ethoxycarbonyl) propyl, 4- (methoxycarbonyl) butyl.

If R is an alkenyl radical in which a CH ₂ group adjacent to the vinyl group has been replaced by CO or CO-O or O-CO-, this can be straight-chain or branched.

It is preferably straight-chain and has 4 to 13 carbon atoms. He accordingly means especially acryloyloxymethyl, 2-acryloyloxy ethyl, 3-acryloyloxypropyl, 4-acryloyloxybutyl, 5-acryloyl oxypentyl, 6-acryloyloxyhexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl, 9-acryloyloxynonyl, 10-acryloyloxydecyl, Methacryloyloxymethyl, 2-methacryloyloxyethyl, 3-methacrylic oyloxypropyl, 4-methacryloyloxy-butyl, 5-methacryloyloxy pentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl, 8-methacryloyloxyoctyl, 9-methacryloyloxynonyl.

If R is a monosubstituted by CN or CF ₃ alkyl or alkenyl radical, this radical is preferably straight-chain and tion substitution by CN or CF ₃ in ω-Posi.

If R is at least one substituted by halogen Alkyl or alkenyl radical, this radical is preferred as straight-chain and halogen is preferably F or Cl. At Multiple substitution is preferably halogen F. The resul residues also include perfluorinated residues. At Single substitution can be the fluorine or chlorine substituent in any position, but preferably in the ω position.

Compounds of formula I which are used for polymerization suitable wing groups R are suitable to represent liquid crystalline polymers.  

Compounds of the formulas I with branched wing groups R can occasionally be important because of their better solubility in the customary liquid-crystalline base materials, but in particular as chiral dopants if they are optically active. Smectic compounds of this type are suitable as components for ferroelectric materials. Compounds of formula I with S _A phases are suitable for example for thermally addressed displays.

Branched groups of this type usually do not contain more than a chain branch. Preferred branched residues R are isopropyl, 2-butyl (= 1-methylpropyl), isobutyl (= 2-methylpropyl), 2-methylbutyl, isopentyl (= 3-methyl butyl), 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, isopropoxy, 2-methylpropoxy, 2-methylbutoxy, 3-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy, 2-ethyl hexoxy, 1-methylhexoxy, 1-methylheptoxy.

If R represents an alkyl radical in which two or more CH ₂ groups have been replaced by -O- and / or -CO-O-, this can be straight-chain or branched. It is preferably branched and has 3 to 12 carbon atoms. Accordingly, it means especially bis-carboxy-methyl, 2,2-bis-carboxy-ethyl, 3,3-bis-carboxy-propyl, 4,4-bis-carboxy-butyl, 5,5-bis-carboxy-pentyl, 6 , 6-bis-carboxy-hexyl, 7,7-bis-carboxy-heptyl, 8,8-bis-carboxy-octyl, 9,9-bis-carboxy-nonyl, 10,10-bis-carboxy decyl, bis- (methoxycarbonyl) methyl, 2,2-bis (methoxycarbonyl) ethyl, 3,3-bis (methoxycarbonyl) propyl, 4,4-bis (methoxycarbonyl) butyl, 5,5-bis ( methoxycarbonyl) pentyl, 6,6-bis (methoxycarbonyl) hexyl, 7,7-bis (methoxycarbonyl) heptyl, 8,8-bis (methoxycarbonyl) octyl, bis (ethoxy carbonyl) - methyl, 2,2-bis (ethoxycarbonyl) ethyl, 3,3-bis (ethoxycarbonyl) propyl, 4,4-bis (ethoxycarbonyl) butyl, 5,5-bis (ethoxycarbonyl) hexyl.

Among these compounds of formula I and the sub formulas are preferred in which at least one of the residues contained therein is one of the preferred Has meanings.

Some particularly preferred smaller groups from Verbin are those of the sub-formulas I1 to I50, in which L H or F, n = 1-14 and r and t each mean 1-7.

The compounds of formula I are known per se Methods presented as they are in the literature (e.g. in the Standard works such as Houben-Weyl, Methods of Organic Chemistry, Georg-Thieme-Verlag, Stuttgart Vol. IX, pp. 867 ff.) are described, under reaction conditions that are known and suitable for the implementations mentioned. It is also possible to do so from those known per se, but not here make use of the variants mentioned.

The compounds of formula 1 according to the invention with W = -O- and A =

can e.g. B. made by one Compound of formula II,

in which L is H or F and R, Z ¹ and Z have the meaning given, metalized according to the following reaction scheme and then reacted with a suitable electrophile:

The compounds of formula II with L = F are new and thus also subject of the invention. There are also connections of formula III with L = F object of the invention.

The invention further relates to liquid crystalline Media containing at least one compound of the Formula II.

The compounds obtained from the phenol of the formula III obtained gen of formula I.

according to known etherification methods, e.g. B. by reaction with Hal- (CH ₂ ) _r -Q- (CH ₂ ) _t -Y (Hal = I, Br or Cl) in acetone / K ₂ CO ₃ , optionally in the presence of catalytic amounts of KI.

The compounds of the invention can also be obtained from Bromine derivative IV

Further synthetic methods for the phenyl ethers according to the invention are obvious to the person skilled in the art. For example, 1,3-difluoro benzene compounds or monofluorinated analogs (L = H) corresponding to the 5-position can be substituted into the 2-O- (CH ₂ ) _r -Q- (CH ₂ ) _t -Y-1 according to the above scheme , 3-difluoro compounds or monofluorinated analogues (L = H) are transferred and the rest

then by in the Reactions commonly used in liquid crystal chemistry (e.g. Ver etherification or couplings z. B. according to the article E. Poetsch, Contacts (Darmstadt) 1988 (2), p. 15).

The compounds of formula II can, for example, according to following synthesis scheme:

The synthesis of some particularly preferred compounds is specified below:

Phenyl ethers of the formula I can be obtained by etherification corresponding to the hydroxy compounds, preferably corresponding phenols, the hydroxy compound expediently first being converted into a corresponding metal derivative, e.g. B. by treatment with NaH, NaNH ₂ , NaOH, KOH, Na ₂ CO ₃ or K ₂ CO _{3 is converted} into the corresponding alkali metal alcoholate or alkali metal phenolate. This can then be reacted with the corresponding alkyl halide, sulfonate or dialkyl sulfate, advantageously in an inert solvent such as. B. acetone, 1,2-dimethoxy ethane, DMF or dimethyl sulfoxide or with an excess of aqueous or aqueous-alcoholic NaOH or KOH at temperatures between about 20 and 100 ° C.

Furthermore, the alkyl ethers can also be obtained from Mitsunobu corresponding phenols and a hydroxy compound in counter were from triphenylphosphine and diethylazodicarboxylate (S. Bittner, Y. Assaf, Chemistry and Industry, 281 (1975); M. S. Manhas, W. H. Hoffman, B. Lal, A. K. Bose, J. Chem. Soc. Perkin I, 461 (1975)):

The starting materials for the manufacturing process are either known or can be analogous to known verbin be manufactured.

The compounds of the formula I ′ ′ ′ with Z = - (CH ₂ ) ₄ - can be prepared according to the following scheme (n = 1-8):

In the Pd (II) -catalyzed coupling reaction, either the target product I ′ ′ ′ is formed directly or a precursor in which the radical -O- (CH ₂ ) _r -Q- is completely analogous to the above methods for compounds of the formula I (CH ₂ ) _t -Y is introduced.

The phenyl esters of the formula I (Q = -COO-) according to the invention is obtained from the compounds of formula II according to the following Reaction scheme:

The benzene derivatives of the formula I according to the invention, in which Q means a single bond is obtained according to the following Schemes:

The trifluoroalkyl and alkenyl ethers of the formula

are according to known etherification methods, for. B. by reacting 4-substituted phenols with Hal- (CH ₂ ) _r - (CH = CH) _0.1 -CF ₃ , where Hal is I, Br or Cl, in acetone and potassium carbonate, optionally in the presence of catalytic amounts of potassium iodide available.

The etherification is advantageous in the presence of an inert Solvent carried out. Are particularly suitable Ethers such as diethyl ether, di-n-butyl ether, THF, dioxane or Anisole, ketones such as acetone, butanone or cyclohexanone, coal Hydrogen such as benzene, toluene or xylene, halogen carbons Hydrogen such as carbon tetrachloride, dichloromethane or Tetrachlorethylene.

The synthesis of the trifluoroalkyl and -alkenyl compounds is shown in the following schemes remove:

The compounds of formula Ic

are from the 4-bromo-2-fluorophenol- (2,2,2-trifluoro ethyl) ether IB,

obtainable by the reaction of 4-bromo-2-fluorophenolate with 2,2,2-trifluoroethyl methyl sulfonate in the presence of 1,3-di methyl-2-imidazoldinone (DMEU) as in Scheme 14 shown.

The liquid-crystalline media according to the invention contain preferably in addition to one or more of the invention Compounds as further components 2 to 40, in particular 4 to 30 components. Very particularly preferably included these media in addition to one or more of the invention Connections 7 to 25 components. This further inventory parts are preferably selected from nematic or nematogenic (monotropic or isotropic) substances, in particular their substances from the classes of azoxybenzenes, benzylidene anilines, biphenyls, terphenyls, phenyl- or cyclohexyl benzoates, cyclohexane-carboxylic acid-phenyl- or cyclohexyl esters, phenyl or cyclohexyl esters of cyclohexylbenzoe acid, phenyl or cyclohexyl ester of cyclohexylcyclo hexane carboxylic acid, cyclohexyl phenyl ester of benzoic acid, cyclohexane carboxylic acid, or cyclohexylcyclohexane carboxylic acid, phenylcyclohexanes, cyclohexylbiphenyls, Phenylcyclohexylcyclohexane, cyclohexylcyclohexane, Cyclohexylcyclohexylcyclohexenes, 1,4-bis-cyclohexylbenzenes, 4,4'-bis-cyclohexylbiphenyls, phenyl or cyclohexyl pyrimidines, phenyl or cyclohexyl pyridines, phenyl or Cyclohexyldioxanes, phenyl- or cyclohexyl-1,3-dithiane, 1,2-diphenylethane, 1,2-dicyclohexylethane, 1-phenyl-2-cyclo hexylethane, Icyclohexyl-2- (4-phenyl-cyclohexyl) ethane, 1-cyclohexyl-2-biphenylylethane, 1-phenyl-2-cyclohexyl phenylethanes, optionally halogenated stilbenes, benzyl phenyl ether, tolanes and substituted cinnamic acids. The 1,4-phenylene groups in these compounds can also be fluorinated.  

The most important as further components of the invention Media connections are possible through the Characterize formulas 1, 2, 3, 4 and 5:

R′-LER ′ ′ (1)
R′-L-COO-ER ′ ′ (2)
R′-L-OOC-ER ′ ′ (3)
R′-L-CH ₂ CH ₂ -ER ′ ′ (4)
R′-LC≡CER ′ ′ (5).

In formulas 1, 2, 3, 4 and 5, L and E mean the same or can be different, each independently a bivalent residue from the from -Phe-, -Cyc-, -Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -Pyr-, -DiD-, -G-Phe- and -G-Cyc- as well whose mirror images formed group, whereby Phe unsubsti tuiert or fluorine substituted 1,4-phenylene, Cyc trans-1,4-cyclohexylene or 1,4-cyclohexylene, pyr pyrimidine 2-5-diyl or pyridine-2,5-diyl, bio 1,3-dicxan-2,5-diyl and G 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 radicals L and E is Cyc, Phe or Pyr. E is preferably Cyc, Phe or Phe-Cyc. Preferably ent hold the media according to the invention one or more Components selected from the compounds of the formulas 1, 2, 3, 4 and 5, wherein L and E are selected from the group Cyc, Phe and Pyr and one or more components at the same time selected from the compounds of the formulas 1, 2, 3, 4 and 5, wherein one of the radicals L and E is selected from the  Group Cyc, Phe and Pyr and the other residue is selected from the group -Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -G-Phe- and -G-Cyc-, and optionally one or more components selected from the compounds of the formulas 1, 2, 3, 4 and 5, wherein the residues L and E are selected from the group -Phe- Cyc-, Cyc-Cyc-, -G-Phe- and -G-Cyc-.

R 'and R' 'mean in a smaller subset of the verb extensions of formulas 1, 2, 3, 4 and 5 each independently of each other alkyl, alkenyl, alkoxy, alkoxyalkyl, alkenyloxy or Alkanoyloxy with up to 8 carbon atoms. The following will this smaller subgroup is called Group A and the verb are with the sub-formulas 1a, 2a, 3a, 4a and 5a designated. For most of these compounds, R 'and R '' different from each other, with one of these residues mostly Is alkyl, alkenyl, alkoxy or alkoxyalkyl.

In another smaller group, referred to as group B, of the compounds of the formulas 1, 2, 3, 4 and 5, R ′ ′ -F, -Cl, -NCS or - (O) _i CH _{3- (k + 1)} F _k Cl ₁ , where i is 0 or 1 and k + 1 is 1, 2 or 3; the compounds in which R '' has this meaning are designated by the sub-formulas 1b, 2b, 3b, 4b and 5b. Those compounds of the sub-formulas 1b, 2b, 3b, 4b and 5b are particularly preferred in which R '' has the meaning -F, -Cl, -NCS, -CF ₃ , -OCHF ₂ or -OCF ₃ .

In the compounds of sub-formulas 1b, 2b, 3b, 4b and 5b R 'the specified for the compounds of sub-formulas 1a-5a Meaning and is preferably alkyl, alkenyl, alkoxy or Alkoxyalkyl.  

In another smaller subset of the compounds of the Formulas 1, 2, 3, 4 and 5 mean R ′ ′ -CN; this subset is hereinafter referred to as group C and the connection This subgroup is created with sub-formulas 1c, 2c, 3c, 4c and 5 c. In the connections of the R 'has sub-formulas 1c, 2c, 3c, 4c and 5c for the verb and the meanings of the sub-formulas 1a-5a preferably alkyl, alkoxy or alkenyl.

In addition to the preferred compounds of groups A, B and C are also other compounds of the formulas 1, 2, 3, 4 and 5 with other variants of the proposed substituents in use. All of these substances are according to literature known methods or by analogy.

In addition to the compounds of the formula I according to the invention, the media according to the invention preferably contain one or more compounds which are selected from group A and / or group B and / or group C. The mass fractions of the compounds from these groups in the media according to the invention are preferred
Group A: 0 to 90%, preferably 20 to 90%, in particular 30 to 90%
Group B: 0 to 80%, preferably 10 to 80%, in particular 10 to 65%
Group C: 0 to 80%, preferably 5 to 80%, in particular 5 to 50%
wherein the sum of the mass fractions of the compounds from groups A and / or B and / or C contained in the respective media according to the invention is preferably 5 to 90% and in particular 10 to 90%.

The media according to the invention preferably contain 1 to 40%, particularly preferably 5 to 30% of the invention appropriate connections. Media are also preferred, containing more than 40%, in particular 45 to 90% compounds of the invention. The media contain preferential as three, four or five compounds of the invention.

The media according to the invention are produced in yourself in the usual way. Usually the components dissolved in one another, expediently at elevated temperature. By The liquid-crystalline phases can be followed by suitable additives the invention can be modified so that it has been used in all known types of liquid crystal display elements can be used. Such additives are known to the person skilled in the art known and described in detail in the literature (H. Kelker / R. Hatz, Handbook of Liquid Crystals, Verlag Chemistry, Weinheim, 1980). For example, pleochroiti dyes for the production of colored guest-host systems or substances for changing the dielectric aniso tropie, the viscosity and / or the orientation of the nemati phases are added.  

The following examples are intended to illustrate the invention without limiting it. "Conventional work-up" means: water is added, the mixture is extracted with methylene chloride, the mixture is separated off, the organic phase is dried, evaporated and the product is purified by crystallization and / or chromatography. Percentages above and below mean percentages by weight. All temperatures are given in degrees Celsius. Mp. Means melting point and Kp. = Clearing point. Furthermore, K = crystalline state, N = nematic phase S = smectic phase and I = isotropic phase. The data between these symbols represent the transition temperatures. Δn means optical anisotropy (589 nm, 20 ° C). The viscosity (mm ² / sec) was determined at 20 ° C.

The following abbreviations are used:
BuLi butyllithium
DAST Diethylaminosulfur trifluoride
DCC dicyclohexylcarbodiimide
DIBALH diisobutyl aluminum hydride
DMAP 2-dimethylaminopyridine
DDQ dichloride dicyanobenzoquinone
KOT potassium tertiary butanolate
NH ₄ Cl ammonium chloride
THF tetrahydrofuran
TMEDA tetramethylethylenediamine
pTSOH p-toluenesulfonic acid.

Example 1

To a mixture consisting of 26 mmol of 1-trans-4- (trans-4-n-propylcyclohexyl) cyclohexyl-3-fluorobenzene (prepared according to scheme 1), 4.1 g of potassium tert-butoxide and 60 ml of THF 26 mmol n-BuLi were added dropwise at -100 ° C. After stirring for one hour at -100 ° C, 36 mmol trimethyl borate are added dropwise at -85 to -90 ° C. The mixture is stirred for a further 0.5 h and then 42 mmol of acetic acid are added dropwise at -20 ° C. The mixture is then heated to 30 ° C. and 4.2 ml of H ₂ O _{2 are added} dropwise at this temperature and the mixture is stirred at 50 to 60 ° C. for two hours. The mixture is allowed to cool to room temperature and a 5% sodium dithione solution is added to the mixture. After phase separation and customary workup, the phenol is obtained.

The phenol obtained is covered with methyl iodide in acetone Reflux to potassium ether in the presence of potassium carbonate implemented. After usual work-up and chromatography Silica gel with hexane gives the ether in pure form.  

The following ethers of the formula become analogous

produced.

Example 2

The fluorophenol produced in Example 1 a) is with 1-chloro-3-fluoropropane in boiling acetone in the presence of Potassium carbonate and a catalytic amount of potassium iodide Phenol ether implemented. After usual work-up and chroma topography on silica gel with hexane gives the ether in pure form.

The fluorophenol produced in Example 1 a) is with 1-chloro-3-iodopropane analogous to Example 2a) in the phenol ether transferred.  

Similarly, you get from the corresponding preliminary stages following compounds of the formula according to the invention

Example 3

Add to a solution of 6.0 g magnesium shavings in 60 ml ether you get two drops of bromine. Then the solution of 48.2 g of 3,5-difluorobromobenzene in 60 ml of ether were added dropwise. Man stir for 0.5 h and then a solution of drips at 20-25 ° C 44.5 g of 4-trans- (4-propylcyclohexyl) cyclohexanone in 50 ml Ether to the Grignard reagent. It is stirred for two hours poured onto 500 ml of water, with 30 ml of conc. hydrochloric acid acidified and shaken with ether. The organic phase is evaporated to the residue and then with 1000 ml Toluene and 120 ml of 20% sulfuric acid at reflux for 1 h cooked.  

After phase separation and neutralization with saturated Sodium bicarbonate solution is added with 10 g Pd / C (5%) 1 bar and 60 ° C hydrogenated. Then it is filtered and constricted. After flash chromatography you get the pure Product. K 60 ° N 87.6 ° I, Δε = 3.3

To a mixture of 47 mmol 4-trans- (4-n-propylcyclohexyl) - cyclohexyl-1-trans- (3,5-difluorobenzene), 50 mmol TMEDA and 150 ml THF at -65 ° C to -70 ° C 31 ml n-BuLi (15% added dropwise in hexane) and it is left at -70 ° C for one hour stirred. Then at -85 to -90 ° C initially 57 mmol Boric acid trimethyl ester, then at -20 ° C 65 mmol acetic acid dripped.

Analogously to Example 2a), the difluorophenol is added 1-chloro-3-fluoropropane converted to the phenol ether.

Analogously to Example 2 b), the one prepared in Example 4 b) Difluorophenol reacted with 1-chloro-3-iodopropane. K 50 N 157.2 I, Δε = 5.7

Example 4

To a solution consisting of 1 mmol 4-trans- (4-n-propyl cyclohexyl) cyclohexyl-1-trans- (3,5-difluorophenol), 1 mmol Triphenylphosphine, 1 mmol 2-fluoroethanol and 25 ml THF 1 mmol of diethyl azodicarboxylate was added dropwise at 0-10 ° C. Then one hour at room temperature stirred and then worked up as usual. K 82 N 165.5 I, Δε = 2.07

Analogously to Example 4 a), 1 mmol of 4-trans- (4-n-propylcyclo hexyl) -cyclohexyl-1-trans- (3,5-difluorophenol) with methanol implemented. K 41 N 151.8 I, Δn = 0.088  

Similarly, you get from the corresponding preliminary stages following compounds of the formula according to the invention

Example 5

To 78 mmol of 1- (4- (4-n-pentylcyclohexyl) cyclohexyl) methylene triphenylphosphonium iodide and 78 mmol 3,5-difluorobenzaldehyde dissolved in 50 ml THF, 78 mmol potassium tert.- at -5 ° C Butylate dissolved in 80 ml of THF added dropwise. Then at same temperature stirred for 15 minutes and another 1.5 h at room temperature. The reaction mixture is hydrolyzed and neutralized with hydrochloric acid. Then, as usual worked up.

Analogously to Example 3 c), that produced in Example 5 a) Product converted to phenol ether with 1-chloro-3-fluoropropane.

Analogously to Example 3 d), that produced in Example 5 a) Product converted with 1-chloro-3-iodopropane to the phenol ether.

Analogously one obtains the corresponding preliminary stages of Formula II (L = F) the following compounds of the invention against the formula

Example 6

9 mmol of product from Example 5 a) are dissolved in 30 ml of THF, treated with 0.3 g of 4% Pd-C and hydrogenated. Then will filtered off from the catalyst and the filtrate in vacuo Residue concentrated. This is carried over a silica gel column Chromatographed pentane.

You get analog

Analogously to Example 3 c), that obtained in Example 6 a) is obtained Product reacted with 1-chloro-3-fluoropropane.

Analogously to Example 3 d), that produced in Example 6 a) Product converted with 1-chloro-3-iodopropane to the phenol ether.  

Analogously one obtains the corresponding preliminary stages of Formula II (L = F) the following compounds of formula

Example 7

0.1 mol of 4- (4-n-pentylcyclohexyl) - (cyclohexylbutyl bromide) are placed in 150 ml of a solvent mixture of THF / toluene (1: 4), then 11.5 g of anhydrous zinc bromide and 1.4 g of lithium granules are then added. The mixture is treated with ultrasound for 4 hours between 0 ° C. and 10 ° C. with argon and stirring. The resulting organic zinc compound is mixed with 0.1 mol of 3,5-difluoro-1-bromobenzene and 2 mol% of 1,1′-bis (diphenylphosphino) ferrocene palladium (II) dichloride and after removal of the ultrasonic bath and the cooling was stirred for 24 hours at room temperature. It is decomposed with 100 ml of saturated NH ₄ Cl solution with stirring, the organic phase is separated off, the aqueous phase is extracted with toluene. The combined organic extracts are dried, concentrated and chromatographed on silica gel.

The implementation of difluorobenzene with BuLi and boric acid tri methyl ester to difluorophenol is carried out analogously to Example 1.

Analogously to example 3 c), the difluorophenol from example 7 b) implemented with 1-chloro-3-fluoropropane to the phenol ether.

Analogously to Example 3 d), the product from Example 7 b) is also used 1-chloro-3-iodopropane implemented.

Analogously one obtains the corresponding preliminary stages of Formula II (L = H or F) the following according to the invention Compounds of the formula

Example 8

To a suspension of 26 mmol 4-trans- (4-pentylcyclohexyl) cyclohexyl-1-trans-3,5-difluorobenzoic acid (manufactured according to Scheme 7) in 160 ml dichloromethane, 26 mm 2-fluoroethanol and 0.1 g DMAP. A solution then becomes with stirring 6.6 g of DCC in 40 ml of dichloromethane were added dropwise. It is about Stirred at room temperature overnight. Oxalic acid is added, stir for one hour, chromatographed with hexane and crystallizes around. K 63 N 148.8 I  

The following compounds of the formula are obtained analogously:

Example 9

A suspension of 50 mmol of 4-trans- (4-pentylcyclohexyl) cyclohexyl-1-trans-3,5- (difluorobenzoic acid) in 150 ml of THF is added dropwise to a suspension of 50 mmol of lithium aluminum hydride in 50 ml of THF. The mixture is then stirred under reflux for 1 h. It is cooled in an ice bath and hydrolysed by adding 6 ml of 10% NaHCO ₃ solution. After adding 12 ml of 20% sodium hydroxide solution, the organic phase is separated off, dried and concentrated.

Add to a solution of 30 mmol sodium hydride in 30 ml DMSO a solution of 28 mmol of the difluorobenzyl alcohol A in 90 ml THF. Then 31 mmol of 3-chloro-1-iodopropane are added Reaction mixture and stirred overnight at 50 ° C. According to Hydro lysis and customary workup gives the ether B.

The following compounds of the formula are obtained analogously

Example 10

14.5 g (0.065 mol) of 4, (4-propylcyclohexyl) cyclohexanol are dissolved in 15 ml of THF and successively with 12.5 g (0.065 mol) of trifluorobutyl bromide, 1.2 g of cetyltrimethylammonium bromide, 5.2 g (0.13 mol ) Sodium hydroxide solution and 0.3 ml of water added. The mixture is stirred at 70 ° C. overnight. The mixture is then allowed to cool to room temperature and the mixture is taken up in diethyl ether. After the usual extractive work-up, the ether is obtained, which is purified by chromatography on silica gel (hexane: ethyl acetate = 9: 1). K 10 S _B 47 I.

The following trifluoroalkyl ethers of the formula become analogous

manufactured:

Example 11

Add to a suspension of 0.1 mol Wittigsalz in 200 ml THF 11.5 g of potassium tert-butoxide are added in portions at 0-10 ° C. Then you conduct at the same temperature for so long Trifluoroacetaldehyde gas one, DIS the orange one Ylid suspension decolorized. Then 24 hours at Stirred at room temperature, poured onto water, neutralized, extracted several times with toluene and the toluene extract after Evaporated to dryness and filtered through silica gel with hexane.

0.065 mol 4- (4-propylcyclohexyl) cyclohexanol, 15 ml THF, 0.065 mol 1,1,1-trifluoro-4-bromobut-2-ene, 1.2 g cetyltri methylammonium bromide, 0.13 mol sodium hydroxide solution and 0.3 ml water are implemented analogously to Example 1.

The following trifluoroalkenyl ethers of the formula become analogous

manufactured:

Example 12

0.1 mole of 4- (4-pentylcyclohexyl) phenol, 0.102 mole of triphenyl phosphine and 0.1 mol of trifluorobutan-4-ol are in 250 ml Tetrahydrofuran at room temperature with drops 0.102 mol of diethyl azodicarboxylate are added with cooling. The mixture is then stirred overnight. After evaporation the residue is filtered through silica gel with toluene.

The following trifluoroalkyl ethers of the formula become analogous

manufactured:

Example 13

0.1 mol of 4- (4-pentylcyclohexyl) phenol and 0.1 mol of 1,1,1-tri fluoro-4-bromobut-2-enes are reacted analogously to Example 3.

The following trifluoroalkenyl ethers of the formula become analogous

produced.

Example 14

0.085 mol of 4-bromo-2-fluorophenolate are dissolved in 100 ml of 1,3-di methyl-2-imidazolidinone dissolved, heated to 140 ° C and dropwise with 0.09 ml of 2,2,2-trifluoroethyl methyl sulfonate transferred. The solution is stirred at 140 ° C. for 24 h. Then it is mixed with 500 ml of ice water and how worked up as usual.

0.015 mol of 4-bromo-2-fluorophenol (2,2'2-trifluoroethyl) ether, with 0.05 ml of trans-n-propyl-cyclohexylphenylboronic acid, 20 ml of toluene, 10 ml of ethanol, 0.030 mol of sodium carbonate and 0.86 mmol of tetrakis (triphenylphosphine) palladium (O) were added and the mixture was boiled under reflux for 2 h. After adding 100 ml of petroleum ether (40-80 °) the mixture is worked up as usual. K 81 S _B 101 S _A 133 N 139.6 I, Δn = 0.152

The following compounds of the formula become analogous

manufactured:

Example 15

Analogously to Example 14 a), 0.085 mol of 4-bromo-2,6-difluoro phenolate dropwise at 140 ° C with 2,2,2-trifluoroethyl added methyl sulfonate.

0.01 mol of trans-4-n-propylcyclohexyl bromide in 15 ml submitted a solvent mixture of THF / toluene (1: 4) and ver with 1.2 g zinc chloride and 0.14 g lithium granules puts. The mixture is under protective gas and stirring for 4 hours between 0 and 10 ° C treated with ultrasound. The received organic zinc compound is mixed with 0.01 mol of 4-bromo-2,6-di fluorophenol (2,2,2-trifluoroethyl ether) and 2 mol% 1,1′-bis (Diphenylphosphino) ferrocene palladium (II) dichloride added and after removing the ultrasonic bath and cooling for 24 hours stirred at room temperature. It becomes saturated with 10 ml Ammonium chloride solution added, the organic phase abge separates and processed as usual. K 5 I, Δn = 0.038

The following compounds of the formula become analogous

manufactured:

Example 16

0.035 mol 3,5-difluorobenzaldehyde, 0.35 mol propanediol and 3.5 g of p-toluenesulfonic acid are dissolved in 500 ml of toluene and cooked on the water separator.

0.044 mol of the dioxane derivative from Example 16 a) are abs in 130 ml. THF dissolved and cooled to -70 ° C. Then 51 mmol n-BuLi are added dropwise. The mixture is left to stir at -70 ° C. for 0.5 h and then 51 mmol of trimethyl borate are added dropwise to the reaction mixture. Then allowed to warm to -20 ° C and mixed in portions with 5 ml of acetic acid. At a temperature of 30-35 ° C, 132 mmol H ₂ O ₂ are finally added dropwise to the reaction mixture. Then work on as usual.

23 mmol sodium hydride are suspended in 10 ml DMEU and then with 23 mmol of the phenol derivative from Example 16 b) added dropwise in 20 ml of DMEU. Then will Stirred at 45 ° C for 1 h. At 140 ° C 25 mmol 2,2'2-tri fluoroethyl methyl sulfonate in 5 ml DMEU to the reaction mixture added dropwise and stirred at 140 ° C. for 5 h. After hydrolysis acidified and the reaction mixture worked up as usual. K 27 I; Δε = 15.76; Δn = +0.038

The following compounds of the formula become analogous

manufactured:

Example 17

Analogously to Example 16 c), 13 mmol of 2- [2,6-difluoro-4- hydroxyphenyl] -5-pentylpyrimidine with 13 mmol sodium hydride in 300 ml DMEU and 25 mmol 2,2,2-trifluoroethyl methyl sulfonate implemented. K 66 I; Δε = 18.49; Δn = 0.106

The following compounds of the formula are obtained analogously

Claims (22)

1. Liquid-crystalline compounds of the formula I wherein
RH, an unsubstituted, an alkyl or alkylene radical with 1 to 15 carbon atoms which is simply substituted by CN or CF ₃ or an at least monosubstituted by halogen, with one or more CH ₂ groups in each of these radicals being independent of one another or -O-CO-O- can be replaced so that O atoms are not directly linked to one another,
Z ¹ and Z each independently of one another -CH ₂ CH ₂ -, -CH = CH-, -C≡C- or a single bond, one of the radicals Z ¹ and Z also - (CH ₂ ) ₄ - or -CH = CH- CH ₂ CH ₂ -,
A and A ¹ each independently of one another trans-1,4-cyclohexylene, in which one or two non-adjacent CH ₂ groups can also be replaced by -O-, or unsubstituted or mono- or disubstituted by fluorine and / or Cl atoms 1 , 4-phenylene, in which one or two CH groups can also be replaced by N,
m 0, 1, 2 or 3,
o + s 0, 1 or 2, where (s + o) 2,
W -O-, -COO- or a single bond,
Q -O-, -CH = CH- or a single bond,
r 1 to 7,
t 0 to 7, and
YF, Cl, CF ₃ , OCF ₃ , CHF ₂ , OCHF ₂ or OCH ₂ F
means. 2. Compounds of formula I, wherein the ring adjacent to W- (CH ₂ ) _r -Q- (CH ₂ ) _t -Y is. 3. Compounds of formula I '', wherein L is H or F and R, Z ¹ , Z, W, Y, r and t have the meaning given in claim 1. 4. Compound of the formula IA, wherein n is 0 to 7, D is -O-, -CH = CH- or a single bond, a is 1 to 5, b is 0 or 1 and Z, A, o, r and s have the meaning given in claim 1. 5. Compounds of the formula Ia wherein a 1 to 5, b 0 or 1, s 1 or 2 and A, Z, o and r have the meaning given in claim 1. 6. Compounds of the formula Ib, wherein n is 1 to 7, s is 1 or 2, b is 0 or 1 and A, Z, o and r have the meaning given in claim 1. 7. Compounds of the formula Ic wherein L ^{1 is} H, F or Cl, L ² F or Cl and R, A ₁ , Z ¹ , Z, m and s have the meaning given in claim 1. 8. Compounds of the formula II wherein L is, and R, Z ¹ and Z have the meaning given in claim 1. 9. Compounds of formula III wherein L is, and R, Z ¹ and Z have the meaning given in claim 1. 10. Compounds of formula Ib, according to claim 6, characterized characterized in that s = 2 and Z is a single bond. 11. Compounds of formula Ib according to claim 6, characterized characterized in that s = 1 and A = 1,4-phenylene. 12. Compounds of formula Ib according to claim 10, characterized characterized in that Z = single bond. 13. Compounds of formula Ib according to claim 10, characterized in that Z = - (CH ₂ ) ₂ -. 14. Compounds of formula Ib according to claim 10, characterized in that Z = - (CH ₂ ) ₄ -. 15. Compounds of formula IV wherein L, W, Q, Y, r and t have the meaning given in claim 1. 16. Compounds of formula IB where L is H or F. 17. Process for the preparation of the compounds IB where L is H or F,
characterized in that 4-bromo-2-fluorophenolate or 4-bromo-2, 6-difluorophenolate is reacted with 2,2,2-trifluoroethyl methyl sulfonate in the presence of 1,3-dimethyl-2-imidazole dinone. 18. Use of compounds of the formulas I, II and III as Components of liquid crystalline media. 19. Liquid crystalline medium with at least two liquid crystalline components, characterized in that they contains at least one compound of formula I. 20. Liquid crystalline medium with at least two liquid crystalline components, characterized in that they contains at least one compound of formula II. 21. Liquid crystal display element, characterized in that it is a liquid crystalline medium according to claim 19 or contains 20. 22. Electro-optical display element, characterized in that that as a dielectric it is a liquid crystalline medium according to claim 19 or 20 contains.