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WO1995013999A1 - 3,5-difluorobenzenes and their use in liquid-crystal mixtures - Google Patents

3,5-difluorobenzenes and their use in liquid-crystal mixtures Download PDF

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Publication number
WO1995013999A1
WO1995013999A1 PCT/EP1994/003533 EP9403533W WO9513999A1 WO 1995013999 A1 WO1995013999 A1 WO 1995013999A1 EP 9403533 W EP9403533 W EP 9403533W WO 9513999 A1 WO9513999 A1 WO 9513999A1
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diyl
liquid crystal
trans
atoms
difluorobenzenes
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German (de)
French (fr)
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Hubert Schlosser
Dietmar Jungbauer
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Hoechst AG
Merck Patent GmbH
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Hoechst AG
Merck Patent GmbH
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C17/00—Preparation of halogenated hydrocarbons
    • C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
    • C07C17/263—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C17/00—Preparation of halogenated hydrocarbons
    • C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
    • C07C17/263—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions
    • C07C17/2635—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions involving a phosphorus compound, e.g. Wittig synthesis
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C17/00—Preparation of halogenated hydrocarbons
    • C07C17/26—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton
    • C07C17/263—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions
    • C07C17/269—Preparation of halogenated hydrocarbons by reactions involving an increase in the number of carbon atoms in the skeleton by condensation reactions of only halogenated hydrocarbons
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C17/00—Preparation of halogenated hydrocarbons
    • C07C17/35—Preparation of halogenated hydrocarbons by reactions not affecting the number of carbon or of halogen atoms in the reaction
    • C07C17/354—Preparation of halogenated hydrocarbons by reactions not affecting the number of carbon or of halogen atoms in the reaction by hydrogenation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C25/00—Compounds containing at least one halogen atom bound to a six-membered aromatic ring
    • C07C25/18—Polycyclic aromatic halogenated hydrocarbons
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C43/00—Ethers; Compounds having groups, groups or groups
    • C07C43/02—Ethers
    • C07C43/20—Ethers having an ether-oxygen atom bound to a carbon atom of a six-membered aromatic ring
    • C07C43/225—Ethers having an ether-oxygen atom bound to a carbon atom of a six-membered aromatic ring containing halogen
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
    • C07C69/017—Esters of hydroxy compounds having the esterified hydroxy group bound to a carbon atom of a six-membered aromatic ring
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
    • C07C69/76—Esters of carboxylic acids having a carboxyl group bound to a carbon atom of a six-membered aromatic ring
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/0403—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit the structure containing one or more specific, optionally substituted ring or ring systems
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/06—Non-steroidal liquid crystal compounds
    • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
    • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
    • C09K19/3001—Cyclohexane rings
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/06—Non-steroidal liquid crystal compounds
    • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
    • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
    • C09K19/3001—Cyclohexane rings
    • C09K19/3003—Compounds containing at least two rings in which the different rings are directly linked (covalent bond)
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/06—Non-steroidal liquid crystal compounds
    • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
    • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
    • C09K19/3001—Cyclohexane rings
    • C09K19/3028—Cyclohexane rings in which at least two rings are linked by a carbon chain containing carbon to carbon single bonds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/06—Non-steroidal liquid crystal compounds
    • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
    • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
    • C09K19/3001—Cyclohexane rings
    • C09K19/3066—Cyclohexane rings in which the rings are linked by a chain containing carbon and oxygen atoms, e.g. esters or ethers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/06—Non-steroidal liquid crystal compounds
    • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
    • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
    • C09K19/3001—Cyclohexane rings
    • C09K19/3066—Cyclohexane rings in which the rings are linked by a chain containing carbon and oxygen atoms, e.g. esters or ethers
    • C09K19/3068—Cyclohexane rings in which the rings are linked by a chain containing carbon and oxygen atoms, e.g. esters or ethers chain containing -COO- or -OCO- groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2601/00—Systems containing only non-condensed rings
    • C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
    • C07C2601/14—The ring being saturated
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/0403—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit the structure containing one or more specific, optionally substituted ring or ring systems
    • C09K2019/0407—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit the structure containing one or more specific, optionally substituted ring or ring systems containing a carbocyclic ring, e.g. dicyano-benzene, chlorofluoro-benzene or cyclohexanone

Definitions

  • Optical effects can be achieved, for example, with the help of birefringence, the incorporation of dichroic dye molecules (guest host mode) or light scattering.
  • thermodynamic and electro-optical variables such as phase sequence and electro-optical variables
  • Phase temperature range refractive index, birefringence and dielectric anisotropy, switching time, threshold voltage, steepness of the electro-optical
  • electromagnetic radiation as well as to the materials with which they are associated during and after the manufacturing process (e.g.
  • Liquid crystal mixtures known see: DE-A 41 16 158,
  • Liquid crystal mixtures are suitable.
  • the present invention therefore relates to new 3,5-difluorobenzenes of the general formula (I), ⁇
  • a 1 , A 2 , A 3 are identical or different 1, 4-phenylene, pyrazine-2,5-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, in which one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, (1,3,4) thiadiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthalene-2,6-diyl, Bicyclo [2.2.2] octane-1,4-diyl or 1,3-dioxaborinane-2,5-diyl;
  • k, l, m, n, o are zero or one, provided that the sum k + m + o is greater than zero; with the following provisos: for k + m + o equal to one is X
  • -CH 2 CH 2 -, -CH CH-, -C ⁇ C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-,
  • -CH 2 CH 2 -, -CH CH-, -C ⁇ C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-,
  • R 1 is a straight-chain alkyl having 1 to 15 carbon atoms
  • a 1 , A 2 , A 3 are identical or different 1, 4-phenylene, in which one or two H atoms can be replaced by F, or trans-1, 4-cyclohexylene;
  • M 1 , M 2 are the same or different -CH 2 CH 2 -, -CH 2 CH 2 CH 2 CH 2 -,
  • k, I, m, n, o are zero or one, provided that the sum k + m + o is greater than zero; with the following provisos: for k + m + o equal to one is X
  • Particularly preferred compounds of the formula (I) are the 3,5-difluorobenzenes of the formulas (11) to (125) listed below:
  • R 1 is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl.
  • the compounds according to the invention can generally be prepared without problems by methods known per se from literature and to the person skilled in the art.
  • 3,5-difluorophenol (II) can be obtained by esterification with carboxylic acids or
  • 3,5-difluorobenzoic acid (III) gives compounds (I) according to the invention by esterification with alcohols of Z 2 (see: Tetrahedron 1980, 36, 2409).
  • bromo-3,5-difluorobenzene (IV) with organometallic derivatives of Z 2 , for example Grignard, lithium and zinc derivatives, and boronic acids of Z 2 using transition metal catalysts, for example dichloro [1, 3-bis (diphenylphosphino) propane] nickel (II), tetrakis (triphenylphosphine) palladium and [1, 1 'bis (diphenylphosphino) ferrocene] palladium (II) chloride
  • the preparation takes place under reaction conditions which are known and suitable for the reactions mentioned. Use can also be made of variants which are known per se and are not mentioned here in detail.
  • EP-A O3 91 203 for compounds with pyridine-2,5-diyl groups
  • Disubstituted pyrimidines can also be found, for example, in the corresponding volumes of the series "The Chemistry of Heterocyclic Compounds" by
  • Dioxane derivatives are useful by reacting an appropriate aldehyde (or one of its reactive derivatives) with one
  • Sulfuric acid, benzene or p-toluenesulfonic acid at temperatures between about 20 ° C and about 150 ° C, preferably between 80 ° C and 120 ° C.
  • Acetals are primarily suitable as reactive derivatives of the starting materials.
  • the aldehydes can be obtained by oxidation of corresponding alcohols or by reduction of nitriles or corresponding carboxylic acids or their derivatives, and the diols can be obtained by reducing corresponding diesters.
  • Esters of the formula (I) can also be correspondingly esterified
  • Carboxylic acids (or their reactive derivatives) with alcohols or
  • the acid halides especially the chlorides and bromides
  • the anhydrides e.g. also mixed anhydrides, azides or esters, in particular alkyl esters with 1 to 4 carbon atoms in the alkyl group.
  • Reactive derivatives of the alcohols or phenols mentioned include, in particular, the corresponding metal alcoholates or phenolates,
  • an alkali metal such as sodium or potassium.
  • esterification is advantageously carried out in the presence of an inert solvent.
  • an inert solvent particularly suitable are ethers, such as diethyl ether,
  • Hydrocarbons such as benzene, toluene or xylene, halogenated hydrocarbons such as carbon tetrachloride, dichloromethane or tetrachlorethylene and sulfoxides such as dimethyl sulfoxide or sulfolane.
  • Ethers of the formula (I) are more appropriate by etherification
  • Hydroxy compounds preferably corresponding phenols, are available, the hydroxyl compound expediently first in a corresponding
  • Metal derivative for example 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 acetone, 1, 2-dimethoxyethane, DMF or dimethyl sulfoxide, or with an excess of aqueous or aqueous-alcoholic NaOH or KOH at temperatures between about 20 and 100 ° C.
  • Light modulators elements for image processing, signal processing or generally in the field of nonlinear optics are suitable. This also applies to compounds that have no liquid-crystalline phases as the pure substance.
  • the compounds of formula (I) are for introduction or
  • the invention therefore also relates to the use of compounds of the formula (I) in liquid-crystal mixtures.
  • the invention further relates to liquid crystal mixtures which contain one or more compounds of the formula (I).
  • the liquid crystal mixtures according to the invention generally consist of 2 to 20, preferably 2 to 15 components, including at least one, preferably 1 to 5, particularly preferably 1 to 3, compounds of the formula (I).
  • the LC mixtures according to the invention can be nematic or chiral nematic, for example.
  • the liquid crystal mixtures generally contain 0.1 to 70 mol%, preferably 0.5 to 50 mol%, in particular 1 to 25 mol%, of the compound (s) of the formula (I) according to the invention.
  • constituents of the mixtures according to the invention are preferably selected from the known compounds with nematic or
  • cholesteric phases include, for example, biphenyls, terphenyls, phenylcyclohexanes, bicyclohexanes, cyclohexylbiphenyls, mono-, di- and Trifluorophenyls.
  • the commercially available liquid crystal mixtures already exist as mixtures of various components, at least one of which is mesogenic, before the addition of the compound (s) according to the invention.
  • Nematic liquid crystal mixtures are examples
  • Phenylcyclohexanes as described for example in DE-A 4 108 448.
  • Liquid-crystalline mixtures which contain compounds of the general formula (I) are particularly suitable for use in electro-optical switching and display devices (displays). Such switching and
  • Display devices generally have, inter alia, the following
  • a liquid-crystalline medium e.g. made of glass or plastic
  • carrier plates e.g. made of glass or plastic
  • transparent electrodes at least one orientation layer
  • spacers spacers
  • adhesive frames at least one orientation layer
  • spacers spacers
  • adhesive frames at least one orientation layer
  • spacers spacers
  • adhesive frames at least one orientation layer
  • spacers spacers
  • adhesive frames at least one orientation layer
  • spacers spacers
  • polarizers polarizers
  • thin color filter layers for color displays.
  • Other possible components are anti-reflective, passivation, compensation and barrier layers as well as electrical nonlinear elements such as thin film transistors (TFT) and metal-insulator-metal (MIM) elements.
  • TFT thin film transistors
  • MIM metal-insulator-metal
  • phase transition temperatures are determined with the help of a polarizing microscope on the basis of the texture changes.
  • the melting point is determined with a DSC device
  • Glass transition (Tg) takes place in ° C and the values are between the phase names in the phase sequence.
  • the values for the optical and dielectric anisotropy and the electro-optical characteristic are recorded at a temperature of 20 ° C.
  • Liquid crystals which do not have a nematic phase at 20 ° C. are mixed in 10% by weight in ZLI-1565 and / or in 20% by weight in ZLI-4792 (commercial nematic liquid crystal mixtures from E. Merck, Darmstadt) and the values are extrapolated from the results of the mixture.
  • Electro-optical characteristics are determined on the basis of the transmission of a measuring cell.
  • the cell is positioned between crossed polarizers in front of a light source.
  • There is a light detector behind the cell the sensitivity of which is optimized by filters for the visible area of the light. Analogous to the gradual increase in the voltage applied to the cell, the change in transmission is recorded. Values such as threshold voltage and slope are determined from this.
  • the optical anisotropy is determined using an Abb ⁇ refractometer (from Zeiss). To orient the liquid crystal, a
  • Orientation layer obtained from a 1% by weight lecithin-methanol solution.
  • Measuring cell attached to the turntable of a polarizing microscope between crossed analyzer and polarizer. To determine the contrast, the measuring cell is positioned by turning it so that a photodiode indicates minimal light transmission (dark state). The microscope illumination is controlled so that the photodiode shows the same light intensity for all cells. After a switching operation, the light intensity (bright state) changes, and the contrast is calculated from the ratio of the light intensity of these states.
  • triphenylphosphine are at 0 ° C in 40 ml
  • Example 11 the substance according to the invention from Example 11 is compared with a reference substance from WO 92/13928 as the pure substance and in a mixture with a commercially available TFT-TN mixture ZLI-4792 (E. Merck, Darmstadt).
  • the substance according to the invention is characterized by a lower melting point (heating), higher nematic-isotropic transition and significantly wider

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Liquid Crystal Substances (AREA)

Abstract

The invention concerns 3,5-difluorobenzenes of general formula (I) in which the symbols and indices are defined as follows: R1 is H, a straight-chain or branched-chain alkyl (with or without an asymmetric C-atom) with 1 to 15 C-atoms, where one or two non-adjacent CH¿2? groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -O-CO-O-, -CH=CH-, -C C-, cyclopropane-1,2-diyl or -Si(CH3)2- and where one or more H-atoms in the alkyl group may be replaced by F, Cl or CN; A?1, A2 and A3¿, which may be the same or different are 1,4-phenylene, pyrazine-2,5-diyl, pyridine-2,5-diyl or pyrimidine-2,5-diyl in which one or two H-atoms may be replaced by F, trans-1,4-cyclohexylene, (1,3,4)-thiadiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthaline-2,6-diyl, bicyclo[2.2.2]octane-1,4-diyl or 1,3-dioxaborinane-2,5-diyl; M1, M2, which may be the same or different, are -CH¿2?CH2-, -CH=CH-, -C C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- or -O-CO-; k, l, m, n, o are zero or one, provided that the sum k+m+o is greater than zero; with the following provisions: when k+m+o is one, X is -CH2CH2-, -CH=CH-, -C C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- or -O-CO-; and when k+m+o is greater than one, X is -CH2CH2-, -CH=CH-, -C C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-, CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O-, -O-CO- or a single bond. The compounds described are suitable for use as components of nematic liquid-crystal mixtures.

Description

Beschreibung  description

3,5-Difluorbenzole und ihre Verwendung in Flüssigkristallmischungen 3,5-difluorobenzenes and their use in liquid crystal mixtures

Die ungewöhnliche Kombination von anisotropem und fluidem Verhalten der Flüssigkristalle hat zu ihrer Verwendung in elektrooptischen Schalt- und The unusual combination of anisotropic and fluid behavior of the liquid crystals has for their use in electro-optical switching and

Anzeigevorrichtungen geführt. Dabei können ihre elektrischen, magnetischen, elastischen und/oder ihre thermischen Eigenschaften zu Display devices led. Their electrical, magnetic, elastic and / or their thermal properties can increase

Orientierungsänderungen genutzt werden. Optische Effekte lassen sich beispielsweise mit Hilfe der Doppelbrechung, der Einlagerung dichroitischer Farbstoffmoleküle (guest host mode) oder der Lichtstreuung erzielen. Orientation changes can be used. Optical effects can be achieved, for example, with the help of birefringence, the incorporation of dichroic dye molecules (guest host mode) or light scattering.

Die Praxisanforderungen steigen ständig an, nicht zuletzt auch wegen der immer größer werdenden Anzahl von Lichtventiltypen (TN, STN, DSTN, TFT, ECB, DECB, DS, GH, PDLC, NCAP, SSFLC, DHF, SBF etc.). Neben Practical requirements are constantly increasing, not least because of the increasing number of light valve types (TN, STN, DSTN, TFT, ECB, DECB, DS, GH, PDLC, NCAP, SSFLC, DHF, SBF etc.). Next

thermodynamischen und elektrooptischen Größen, wie Phasenfolge und thermodynamic and electro-optical variables, such as phase sequence and

Phasentemperaturbereich, Brechungsindex, Doppelbrechung und dielektrischer Anisotropie, Schaltzeit, Schwellspannung, Steilheit der elektrooptischen Phase temperature range, refractive index, birefringence and dielectric anisotropy, switching time, threshold voltage, steepness of the electro-optical

Kennlinie, elastischen Konstanten, elektrischer Widerstand, Multiplexierbarkeit oder Pitch und/oder Polarisation in chiralen Phasen, ist die Stabilität der Characteristic curve, elastic constants, electrical resistance, multiplexability or pitch and / or polarization in chiral phases, is the stability of the

Flüssigkristalle gegenüber Feuchtigkeit, Gasen, Temperatur und Liquid crystals against moisture, gases, temperature and

elektromagnetischer Strahlung wie auch gegenüber den Materialien, mit denen sie während und nach dem Fertigungsprozeß in Verbindung stehen (z.B. electromagnetic radiation as well as to the materials with which they are associated during and after the manufacturing process (e.g.

Orientierungsschichten), von großer Wichtigkeit. Der toxikologischen und ökologischen Unbedenklichkeit wie auch dem Preis kommen immer mehr Orientation layers), of great importance. The toxicological and ecological harmlessness as well as the price are coming more and more

Bedeutung zu. Meaning too.

Einen breiten Überblick über das Gebiet der Flüssigkristalle bieten beispielsweise die nachstehenden Literaturstellen und die darin enthaltenen Referenzen: The following references and the references contained therein provide a broad overview of the field of liquid crystals:

H. Kelker, H. Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, W.E. De Jeu, Physical Properties of Liquid Crystal Materials, Gordon andH. Kelker, H. Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, WE De Jeu, Physical Properties of Liquid Crystal Materials, Gordon and

Breach, Philadelphia, 1980; H. Kresse, Dielectric Behaviour of Liquid Crystals,Breach, Philadelphia, 1980; H. Kresse, Dielectric Behavior of Liquid Crystals,

Fortschritte der Physik, Berlin 30, 10, 1982, 507-582; Advances in Physics, Berlin 30, 10, 1982, 507-582;

B. Bahadur, Liquid Crystals: Applications and Uses, World Scientific, Singapur, B. Bahadur, Liquid Crystals: Applications and Uses, World Scientific, Singapore,

1990; 1990;

Landolt-Börnstein, New Series, Group IV, Volume 7 Liquid Crystals, 1992-1993 und  Landolt-Börnstein, New Series, Group IV, Volume 7 Liquid Crystals, 1992-1993 and

J.W. Goodby et al., Ferroelectric Liquid Crystals: Principals, Properties and J.W. Goodby et al., Ferroelectric Liquid Crystals: Principals, Properties and

Applications, Gordon Breach, Philadelphia, 1991 . Applications, Gordon Breach, Philadelphia, 1991.

Aus der Literatur sind spezielle Derivate des 3,5-Difluorbenzols als Special derivatives of 3,5-difluorobenzene are known from the literature

Zwischenstufe bei der Flüssigkristallsynthese und zur Verwendung in Intermediate in liquid crystal synthesis and for use in

Flüssigkristallmischungen bekannt (siehe hierzu: DE-A 41 16 158, Liquid crystal mixtures known (see: DE-A 41 16 158,

DE-A 41 05 572 und JP-A O4/169574). DE-A 41 05 572 and JP-A O4 / 169574).

Da aber Einzelverbindungen bislang die vielen verschiedenen Anforderungen nicht simultan erfüllen können, besteht laufend Bedarf an neuen verbesserten Flüssigkristallmischungen und somit an einer Vielzahl mesogener und nicht mesogener Verbindungen unterschiedlicher Struktur, die eine Anpassung der Mischungen an die unterschiedlichsten Anwendungen ermöglichen. Dies gilt sowohl für die Gebiete, bei denen nematische LC-Phasen Anwendung in However, since individual compounds have so far not been able to meet the many different requirements simultaneously, there is a constant need for new, improved liquid crystal mixtures and thus for a large number of mesogenic and non-mesogenic compounds of different structures which enable the mixtures to be adapted to the most varied of applications. This applies both to the areas where nematic LC phases are used in

Lichtventilen finden, als auch für solche mit smektischen Phasen. Find light valves, as well as for those with smectic phases.

Es wurde nun überraschend gefunden, daß sich bestimmte Derivate des It has now surprisingly been found that certain derivatives of

3,5-Difluorbenzols in besonderer Weise zur Verwendung in 3,5-difluorobenzene in a special way for use in

Flüssigkristallmischungen eignen. Liquid crystal mixtures are suitable.

Gegenstand der vorliegenden Erfindung sind daher neue 3,5-Difluorbenzole der allgemeinen Formel (I), ÖThe present invention therefore relates to new 3,5-difluorobenzenes of the general formula (I), Ö

Figure imgf000004_0001
wobei die Symbole und Indizes folgende Bedeutungen haben:
Figure imgf000004_0001
where the symbols and indices have the following meanings:

R1 ist H, ein geradkettiges oder verzweigtes (mit oder ohne asymmetrisches C-Atom) Alkyl mit 1 bis 15 C-Atomen, wobei auch eine oder zwei nicht benachbarte CH2-Gruppen durch -O-, -S-, -CO-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -O-CO-O-, -CH = CH-, -C≡C-, Cyclopropan-1 ,2-diyl oder -Si(CH3)2- ersetzt sein können, und wobei auch ein oder mehrere H-Atome des Alkγlrestes durch F, Cl oder CN substituiert sein können; R 1 is H, a straight-chain or branched (with or without asymmetrical C atom) alkyl with 1 to 15 C atoms, one or two non-adjacent CH 2 groups also being represented by -O-, -S-, -CO- , -CO-O-, -O-CO-, -CO-S-, -S-CO-, -O-CO-O-, -CH = CH-, -C≡C-, cyclopropane-1,2 -diyl or -Si (CH 3 ) 2 - can be replaced, and wherein one or more H atoms of the alkyl radical can be substituted by F, Cl or CN;

A1 , A2, A3 sind gleich oder verschieden 1 ,4-Phenylen, Pyrazin-2,5-diyl, Pyridin-2,5-diyl, Pyrimidin-2,5-diyl, in denen ein oder zwei H-Atome durch F ersetzt sein können, trans-1 ,4-Cyclohexylen, (1 ,3,4)-Thiadiazol-2,5-diyl, 1 ,3-Dioxan-2,5-diyl, Naphthalin-2,6-diyl, Bicyclo[2.2.2]octan-1 ,4-diyl oder 1 ,3-Dioxaborinan-2,5-diyl; A 1 , A 2 , A 3 are identical or different 1, 4-phenylene, pyrazine-2,5-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, in which one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, (1,3,4) thiadiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthalene-2,6-diyl, Bicyclo [2.2.2] octane-1,4-diyl or 1,3-dioxaborinane-2,5-diyl;

M1 , M2 sind gleich oder verschieden -CH2CH2-, -CH =CH-, -C≡C-, M 1 , M 2 are the same or different -CH 2 CH 2 -, -CH = CH-, -C≡C-,

-CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-,

-O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; k, l, m, n, o sind Null oder Eins, unter der Bedingung, daß die Summe k + m + o größer Null ist; mit den folgenden Maßgaben: für k + m + o gleich Eins ist X -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O- or -O-CO-; k, l, m, n, o are zero or one, provided that the sum k + m + o is greater than zero; with the following provisos: for k + m + o equal to one is X

-CH2CH2-, -CH = CH-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -CH 2 CH 2 -, -CH = CH-, -C≡C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-,

-O-CH2CH2CH2-, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; und für k + m + o größer Eins ist X -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O - or -O-CO-; and for k + m + o greater than one, X is

-CH2CH2-, -CH = CH-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -CH 2 CH 2 -, -CH = CH-, -C≡C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-,

-O-CH2CH2CH2-, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O-, -O-CO- oder eine Einfachbindung. -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O -, -O-CO- or a single bond.

In einer bevorzugten Ausführung der Erfindung haben die Symbole und Indizes in der Formel (I) folgende Bedeutungen: In a preferred embodiment of the invention, the symbols and indices in the formula (I) have the following meanings:

R1 ist ein geradkettiges Alkyl mit 1 bis 15 C-Atomen; R 1 is a straight-chain alkyl having 1 to 15 carbon atoms;

A1 , A2, A3 sind gleich oder verschieden 1 ,4-Phenylen, in dem ein oder zwei H-Atome durch F ersetzt sein können, oder trans-1 ,4-Cyclohexylen; A 1 , A 2 , A 3 are identical or different 1, 4-phenylene, in which one or two H atoms can be replaced by F, or trans-1, 4-cyclohexylene;

M1 , M2 sind gleich oder verschieden -CH2CH2-, -CH2CH2CH2CH2-, M 1 , M 2 are the same or different -CH 2 CH 2 -, -CH 2 CH 2 CH 2 CH 2 -,

-CH2CH2CH2-O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; k, I, m, n, o sind Null oder Eins, unter der Bedingung, daß die Summe k + m + o größer Null ist; mit den folgenden Maßgaben: für k + m + o gleich Eins ist X -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O- or -O-CO-; k, I, m, n, o are zero or one, provided that the sum k + m + o is greater than zero; with the following provisos: for k + m + o equal to one is X

-CH2CH2-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-,-CH 2 CH 2 -, -C≡C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -,

-CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; und für k + m + o größer Eins ist X -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O- or -O-CO-; and for k + m + o greater than one, X is

-CH2CH2-, -C≡C-, -CH2CH2CH2CH2~, -CH2CH2CH2-O-, -O-CH2CH2CH2-,-CH 2 CH 2 -, -C≡C-, -CH 2 CH 2 CH 2 CH 2 ~, -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -,

-CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O-, -O-CO- oder eine-CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O-, -O-CO- or one

Einfachbindung. Insbesondere bevorzugte Verbindungen der Formel (I) sind die nachfolgend aufgeführten 3,5-Difluorbenzole der Formeln (11 ) bis (125):Single bond. Particularly preferred compounds of the formula (I) are the 3,5-difluorobenzenes of the formulas (11) to (125) listed below:

Figure imgf000007_0001
Figure imgf000007_0002
Figure imgf000007_0003
Figure imgf000007_0004
Figure imgf000007_0005
Figure imgf000007_0006
Figure imgf000008_0001
Figure imgf000008_0002
Figure imgf000008_0003
Figure imgf000008_0004
Figure imgf000007_0001
Figure imgf000007_0002
Figure imgf000007_0003
Figure imgf000007_0004
Figure imgf000007_0005
Figure imgf000007_0006
Figure imgf000008_0001
Figure imgf000008_0002
Figure imgf000008_0003
Figure imgf000008_0004

Figure imgf000008_0005
Figure imgf000008_0006
Figure imgf000009_0001
Figure imgf000009_0002
Figure imgf000009_0003
Figure imgf000009_0004
Figure imgf000009_0005
Figure imgf000008_0005
Figure imgf000008_0006
Figure imgf000009_0001
Figure imgf000009_0002
Figure imgf000009_0003
Figure imgf000009_0004
Figure imgf000009_0005

Figure imgf000009_0006
Figure imgf000010_0001
Figure imgf000010_0002
Figure imgf000010_0003
Figure imgf000010_0004
Figure imgf000010_0005
Figure imgf000010_0006
Figure imgf000011_0001
wobei
Figure imgf000009_0006
Figure imgf000010_0001
Figure imgf000010_0002
Figure imgf000010_0003
Figure imgf000010_0004
Figure imgf000010_0005
Figure imgf000010_0006
Figure imgf000011_0001
in which

R1 Methyl, Ethyl, Propyl, Butyl, Pentyl, Hexyl, Heptyl, Octyl, Nonyl oder Decyl bedeutet. R 1 is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl.

Die Herstellung der erfindungsgemäßen Verbindungen kann nach an sich literatur- und dem Fachmann bekannten Methoden in der Regel problemlos erfolgen. The compounds according to the invention can generally be prepared without problems by methods known per se from literature and to the person skilled in the art.

Hervorragende Ausgangsverbindungen zur, in Schema 1 veranschaulichten, Synthese der erfindungsgemäßen 3,5-Difluorbenzole (I) sind die kommerziell erhältlichen Verbindungen 3,5-Difluorphenol (II), 3,5-Difluorbenzoesäure (III), 3,5-Difluorbrombenzol (IV), 3,5-Difluorbenzaldehyd (V) und Excellent starting compounds for the synthesis of the 3,5-difluorobenzenes (I) according to the invention illustrated in Scheme 1 are the commercially available compounds 3,5-difluorophenol (II), 3,5-difluorobenzoic acid (III), 3,5-difluorobromobenzene (IV ), 3,5-difluorobenzaldehyde (V) and

3,5-Difluorbenzylalkohol (VI). 3,5-difluorobenzyl alcohol (VI).

3,5-Difluorphenol (II) läßt sich durch Veresterung mit Carbonsäuren bzw. 3,5-difluorophenol (II) can be obtained by esterification with carboxylic acids or

Carbonsäurehalogeniden von Z2 oder durch Veretherung mit Hydroxymethylbzw. Halogenmethylderivaten von Z2 zu 3,5-Difluorbenzolderivaten (I) umsetzen (siehe hierzu: Tetrahedron 1980, 36, 2409; Organic Synthesis, Coll. Vol. 5, 1973, 258; Journal of the American Chemical Society 1947, 69, 2451 ; Carboxylic acid halides of Z 2 or by etherification with hydroxymethyl or. Convert halomethyl derivatives of Z 2 to 3,5-difluorobenzene derivatives (I) (see: Tetrahedron 1980, 36, 2409; Organic Synthesis, Coll. Vol. 5, 1973, 258; Journal of the American Chemical Society 1947, 69, 2451;

Synthesis 1981 , 1 ). Synthesis 1981, 1).

3,5-Difluorbenzoesäure (III) liefert durch Veresterung mit Alkoholen von Z2 erfindungsgemäße Verbindungen (I) (siehe hierzu: Tetrahedron 1980, 36, 2409). Durch Kreuzkupplung von Brom-3,5-difluorbenzol (IV) mit metallorganischen Derivaten von Z2, z.B. Grignard-, Lithium- und Zinkderivaten, sowie Boronsäuren von Z2 unter Verwendung von Übergangsmetallkatalysatoren, z.B. Dichloro[1 ,3-bis(diphenylphosphino)propan]nickel (II), Tetrakis(triphenylphosphin)palladium und [1 ,1 '-Bis(diphenylphosphino)ferrocen]palladium(ll)chlorid werden 3,5-difluorobenzoic acid (III) gives compounds (I) according to the invention by esterification with alcohols of Z 2 (see: Tetrahedron 1980, 36, 2409). By cross-coupling bromo-3,5-difluorobenzene (IV) with organometallic derivatives of Z 2 , for example Grignard, lithium and zinc derivatives, and boronic acids of Z 2 using transition metal catalysts, for example dichloro [1, 3-bis (diphenylphosphino) propane] nickel (II), tetrakis (triphenylphosphine) palladium and [1, 1 'bis (diphenylphosphino) ferrocene] palladium (II) chloride

erfindungsgemäße 3,5-Difluorbenzole der Formel (I) erhalten (siehe hierzu: 3,5-difluorobenzenes of the formula (I) according to the invention are obtained (see:

P. W. Jolly, Comprehensive Organometallic Chemistry, Vol. 8, 1982, 721 ; P. W. Jolly, Comprehensive Organometallic Chemistry, Vol. 8, 1982, 721;

M. Miyaura et al., Synthetic Communications 1981 , 1 1 , 513; T. Hayashi et al., Journal of the American Chemical Society, 1984, 106, 158; Paul L. Castle et al., Tetrahedron Letters 1986, 27, 6013). Miyaura, M. et al., Synthetic Communications 1981, 1 1, 513; T. Hayashi et al., Journal of the American Chemical Society, 1984, 106, 158; Paul L. Castle et al., Tetrahedron Letters 1986, 27, 6013).

3,5-Difluorbenzaldehyd (V) führt in Wittig-Olefinierung mit 3,5-difluorobenzaldehyde (V) leads in Wittig olefination

Methylphosphoniumsalzen von Z2 und anschließender Hydrierung der Methylphosphonium salts of Z 2 and subsequent hydrogenation of the

olefinischen Zwischenstufe zu erfindungsgemäßen Spezies (I) (siehe hierzu: I. Gosney, A. G. Rowley in Organophosphorous Reagents in Organic Synthesis, Academic Press, New York, 1979, Chpt. 2). olefinic intermediate to species (I) according to the invention (see: I. Gosney, A.G. Rowley in Organophosphorous Reagents in Organic Synthesis, Academic Press, New York, 1979, Chpt. 2).

Verbindungen der Formel (I) lassen sich auch aus 3,5-Difluorbenzylalkohol(VI) durch Veretherung desselben mit Alkoholen und Halogeniden von Z2 erhalten (siehe hierzu: H. O. House in Modern Synthetic Reactions, Benjamin, New York, 1972, S. 49; Journal of the American Chemical Society 1947, 69, 2451 ; Compounds of formula (I) can also be obtained from 3,5-difluorobenzyl alcohol (VI) by etherification thereof with alcohols and halides of Z 2 (see: HO House in Modern Synthetic Reactions, Benjamin, New York, 1972, p. 49 ; Journal of the American Chemical Society 1947, 69, 2451;

Synthesis 1981 , 1 ). Synthesis 1981, 1).

Figure imgf000013_0001
Figure imgf000013_0001

Die Synthese des Restes R1(-A1 )k(-M1 )l(-A2)m(-M2)n(-A3)o bzw. eines geeigneten Vorläufers erfolgt nach an sich bekannten, dem Fachmann geläufigen Methoden. The synthesis of the radical R 1 (-A 1 ) k (-M 1 ) 1 (-A 2 ) m (-M 2 ) n (-A 3 ) o or a suitable precursor is carried out in accordance with known and familiar to the person skilled in the art Methods.

Die Herstellung erfolgt dabei unter Reaktionsbedingungen, die für die genannten Umsetzungen bekannt und geeignet sind. Dabei kann man auch von an sich bekannten, hier nicht näher erwähnten Varianten Gebrauch machen. The preparation takes place under reaction conditions which are known and suitable for the reactions mentioned. Use can also be made of variants which are known per se and are not mentioned here in detail.

Beispielsweise sei verwiesen auf DE-A 23 44 732, 24 50 088, 24 29 093, 25 02 94, 26 36 684, 27 01 591 und 27 52 975 für Verbindungen mit For example, reference is made to DE-A 23 44 732, 24 50 088, 24 29 093, 25 02 94, 26 36 684, 27 01 591 and 27 52 975 for connections with

1 ,4-Cyclohexylen und 1 ,4-Phenylen-Gruppen; DE-A 26 41 724 für 1,4-cyclohexylene and 1,4-phenylene groups; DE-A 26 41 724 for

Verbindungen mit Pyrimidin-2,5-diyl-Gruppen; DE-A 40 26 223 und Compounds with pyrimidine-2,5-diyl groups; DE-A 40 26 223 and

EP-A O3 91 203 für Verbindungen mit Pyridin-2,5-diyl-Gruppen; EP-A O3 91 203 for compounds with pyridine-2,5-diyl groups;

WO-A 92/16500 für Naphthalin-2,6-diyl-Gruppen; EP-A 309 514 für WO-A 92/16500 for naphthalene-2,6-diyl groups; EP-A 309 514 for

Verbindungen mit (1 ,3,4)-Thiadiazol-2,5-diyl-Gruppen, DE-A 37 10 890 für BicycIo[2.2.2]octan-1 ,4-diyl-Gruppen und K. Seto et al., J. Chem. Soc. Chem. Comm. 1988, 56 für Dioxoborinan-2,5-diyl-Gruppen. Compounds with (1, 3,4) thiadiazole-2,5-diyl groups, DE-A 37 10 890 for Bicyclo [2.2.2] octane-1,4-diyl groups and K. Seto et al., J. Chem. Soc. Chem. Comm. 1988, 56 for dioxoborinan-2,5-diyl groups.

Die Herstellung disubstituierter Pyridine, disubstituiertes Pyridazine und The production of disubstituted pyridines, disubstituted pyridazines and

disubstituierter Pyrimidine findet sich beispielsweise auch in den entsprechenden Bänden der Serie "The Chemistry of Heterocyclic Compounds" von Disubstituted pyrimidines can also be found, for example, in the corresponding volumes of the series "The Chemistry of Heterocyclic Compounds" by

A. Weissberger und E.C. Taylor (Herausgeber). A. Weissberger and E.C. Taylor (editor).

Dioxanderivate werden zweckmäßig durch Reaktion eines entsprechenden Aldehyds (oder eines seiner reaktionsfähigen Derivate) mit einem Dioxane derivatives are useful by reacting an appropriate aldehyde (or one of its reactive derivatives) with one

entsprechenden 1 ,3-Diol (oder einem seiner reaktionsfähigen Derivate) corresponding 1,3-diol (or one of its reactive derivatives)

hergestellt, vorzugsweise in Gegenwart eines inerten Lösungsmittels, wie Benzol oder Toluol, und/oder eines Katalysators, z.B. einer starken Säure, wie prepared, preferably in the presence of an inert solvent such as benzene or toluene and / or a catalyst e.g. a strong acid like

Schwefelsäure, Benzol- oder p-Toluolsulfonsäure, bei Temperaturen zwischen etwa 20°C und etwa 150°C, vorzugsweise zwischen 80°C und 120°C. Als reaktionsfähige Derivate der Ausgangsstoffe eignen sich in erster Linie Acetale. Die genannten Aldehyde und 1 ,3-Diole sowie ihre reaktionsfähigen Derivate sind zum Teil bekannt, zum Teil können sie ohne Schwierigkeiten nach Sulfuric acid, benzene or p-toluenesulfonic acid, at temperatures between about 20 ° C and about 150 ° C, preferably between 80 ° C and 120 ° C. Acetals are primarily suitable as reactive derivatives of the starting materials. Some of the aldehydes and 1,3-diols mentioned and their reactive derivatives are known, and some of them can be copied without difficulty

Standardverfahren der Organischen Chemie aus literaturbekannten Standard methods of organic chemistry from literature

Verbindungen hergestellt werden. Beispielsweise sind die Aldehyde durch Oxydation entsprechender Alkohole oder durch Reduktion von Nitrilen oder entsprechenden Carbonsäuren oder ihrer Derivate, die Diole durch Reduktion entsprechender Diester erhältlich. Connections are made. For example, the aldehydes can be obtained by oxidation of corresponding alcohols or by reduction of nitriles or corresponding carboxylic acids or their derivatives, and the diols can be obtained by reducing corresponding diesters.

Verbindungen, worin ein aromatischer Ring mindestens ein F-Atom als Compounds in which an aromatic ring has at least one F atom as

Subtituent trägt, können auch aus den entsprechenden Diazoniumsalzen durch Austausch der Diazoniumgruppe gegen ein Fluoratom, z.B. nach den Methoden von Balz und Schiemann, erhalten werden. Can also be substituted from the corresponding diazonium salts by exchanging the diazonium group for a fluorine atom, e.g. according to the methods of Balz and Schiemann.

Was die Verknüpfung der Ringsysteme miteinander angeht, sei beispielsweise verwiesen auf: Regarding the connection of the ring systems with each other, reference is made to:

N. Miyaura, T. Yanagai und A. Suzuki, Synth. Comm. 1981 , 11 , 513-519; N. Miyaura, T. Yanagai and A. Suzuki, Synth. Comm. 1981, 11, 513-519;

DE-C-39 30 663; M.J. Sharp, W. Cheng, V. Snieckus, Tetrahedron LettersDE-C-39 30 663; M.J. Sharp, W. Cheng, V. Snieckus, Tetrahedron Letters

1987, 28, 5093; G.W. Gray, J. Chem. Soc. Perkin Trans II 1989, 2041 und1987, 28, 5093; G.W. Gray, J. Chem. Soc. Perkin Trans II 1989, 2041 and

Mol. Cryst. Liq. Cryst. 1989, 172, 165; 1991 , 204, 43 und 91 ; Mol. Cryst. Liq. Cryst. 1989, 172, 165; 1991, 204, 43 and 91;

EP-A O 449 015; WO-A 89/12039; WO-A 89/03821 und EP-A O 354 434 für die direkte Verknüpfung von Aromaten und Heteroaromaten; DE-A 32 01 721 für Verbindungen mit -CH2CH2-Brückengliedern und Koji Seto et al., LiquidEP-A-0 449 015; WO-A 89/12039; WO-A 89/03821 and EP-A 0 354 434 for the direct linking of aromatics and heteroaromatics; DE-A 32 01 721 for connections with -CH 2 CH 2 bridge members and Koji Seto et al., Liquid

Crystals 1990, 8, 861 -870 für Verbindungen mit -C≡C-Brückengliedem. Crystals 1990, 8, 861 -870 for connections with -C≡C bridge members.

Ester der Formel (I) können auch durch Veresterung entsprechender Esters of the formula (I) can also be correspondingly esterified

Carbonsäuren (oder ihrer reaktionsfähigen Derivate) mit Alkoholen bzw. Carboxylic acids (or their reactive derivatives) with alcohols or

Phenolen (oder ihren reaktionsfähigen Derivaten) oder nach der DCC-Methode (DCC = Dicyclohexylcarbodiimid) erhalten werden. Phenols (or their reactive derivatives) or by the DCC method (DCC = dicyclohexylcarbodiimide) can be obtained.

Die entsprechenden Carbonsäuren und Alkohole bzw. Phenole sind bekannt und können in Analogie zu bekannten Verfahren hergestellt werden. Als reaktionsfähige Derivate der genannten Carbonsäuren eignen sich The corresponding carboxylic acids and alcohols or phenols are known and can be prepared in analogy to known processes. Suitable reactive derivatives of the carboxylic acids mentioned are

insbesondere die Säurehalogenide, vor allem die Chloride und Bromide, ferner die Anhydride, z.B. auch gemischte Anhydride, Azide oder Ester, insbesondere Alkylester mit 1 bis 4 C-Atomen in der Alkylgruppe. especially the acid halides, especially the chlorides and bromides, furthermore the anhydrides, e.g. also mixed anhydrides, azides or esters, in particular alkyl esters with 1 to 4 carbon atoms in the alkyl group.

Als reaktionsfähige Derivate der genannten Alkohole bzw. Phenole kommen insbesondere die entsprechenden Metallalkoholate bzw. Phenolate, Reactive derivatives of the alcohols or phenols mentioned include, in particular, the corresponding metal alcoholates or phenolates,

vorzugsweise eines Alkalimetalls, wie Natrium oder Kalium, in Betracht. preferably an alkali metal such as sodium or potassium.

Die Veresterung wird vorteilhaft in Gegenwart eines inerten Lösungsmittels durchgeführt. Gut geeignet sind insbesondere Ether, wie Diethylether, The esterification is advantageously carried out in the presence of an inert solvent. Particularly suitable are ethers, such as diethyl ether,

Di-n-butylether, THF, Dioxan oder Anisol, Ketone, wie Aceton, Butanon oder Cyclohexanon, Amide, wie DMF oder Phosphorsäurehexamethyltriamid, Di-n-butyl ether, THF, dioxane or anisole, ketones such as acetone, butanone or cyclohexanone, amides such as DMF or phosphoric acid hexamethyltriamide,

Kohlenwasserstoffe, wie Benzol, Toluol oder Xylol, Halogenkohlenwasserstoffe, wie Tetrachlorkohlenstoff, Dichlormethan oder Tetrachlorethylen und Sulfoxide, wie Dimethylsulfoxid oder Sulfolan. Hydrocarbons such as benzene, toluene or xylene, halogenated hydrocarbons such as carbon tetrachloride, dichloromethane or tetrachlorethylene and sulfoxides such as dimethyl sulfoxide or sulfolane.

Ether der Formel (I) sind durch Veretherung entsprechender Ethers of the formula (I) are more appropriate by etherification

Hydroxyverbindungen, vorzugsweise entsprechender Phenole, erhältlich, wobei die Hydroxyverbindung zweckmäßig zunächst in ein entsprechendes Hydroxy compounds, preferably corresponding phenols, are available, the hydroxyl compound expediently first in a corresponding

Metallderivat, z.B. durch Behandeln mit NaH, NaNH2, NaOH, KOH, Na2CO3 oder K2CO3 in das entsprechende Alkalimetallalkoholat oder Alkalimetallphenolat überführt wird. Dieses kann dann mit dem entsprechenden Alkylhalogenid, Sulfonat oder Dialkylsulfat umgesetzt werden, zweckmäßig in einem inerten Lösungsmittel, wie Aceton, 1 ,2-Dimethoxyethan, DMF oder Dimethylsulfoxid, oder auch mit einem Überschuß an wäßriger oder wäßrig-alkoholischer NaOH oder KOH bei Temperaturen zwischen etwa 20 und 100°C. Metal derivative, for example 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 acetone, 1, 2-dimethoxyethane, DMF or dimethyl sulfoxide, or with an excess of aqueous or aqueous-alcoholic NaOH or KOH at temperatures between about 20 and 100 ° C.

Was die Synthese spezieller Reste R1 angeht, sei zusätzlich beispielsweise verwiesen auf EP-A O 355 008 für Verbindungen mit siliziumhaltigen With regard to the synthesis of special R 1 radicals, reference is also made, for example, to EP-A 0 355 008 for compounds with silicon-containing compounds

Seitenketten und EP-A O 292 954 und EP-A O 398 155 für Verbindungen mit Cyclopropylgruppen in der Seitenkette. Die erfindungsgemäßen Verbindungen der allgemeinen Formel (I), sind chemisch und photochemisch stabil. Sie verfügen über niedrige Schmelzpunkte und im allgemeinen breite flüssigkristalline Phasen, insbesondere breite nematische. Side chains and EP-A O 292 954 and EP-A O 398 155 for compounds with cyclopropyl groups in the side chain. The compounds of the general formula (I) according to the invention are chemically and photochemically stable. They have low melting points and generally broad liquid-crystalline phases, in particular broad nematic ones.

Verbindungen der Formel (I) lassen sich beispielsweise zur Herstellung von nematischen oder auch chiral nematischen Flüssigkristallmischungen Compounds of the formula (I) can be used, for example, for the preparation of nematic or chiral nematic liquid-crystal mixtures

verwenden, die für die Anwendung in elektrooptischen oder vollständig optischen Elementen, z.B. Anzeigeelementen, Schaltelementen, use that are for use in electro-optical or fully optical elements, e.g. Display elements, switching elements,

Lichtmodulatoren, Elementen zur Bildbearbeitung, Signalverarbeitung oder allgemein im Bereich der nichtlinearen Optik geeignet sind. Dies gilt auch für Verbindungen, die als Reinsubstanz keine flüssigkristallinen Phasen aufweisen. Allgemein sind die Verbindungen der Formel (I) zur Einführung oder Light modulators, elements for image processing, signal processing or generally in the field of nonlinear optics are suitable. This also applies to compounds that have no liquid-crystalline phases as the pure substance. In general, the compounds of formula (I) are for introduction or

Verbreiterung einer nematischen Phase in LC-Mischungen geeignet. Suitable for widening a nematic phase in LC mixtures.

Gegenstand der Erfindung ist daher auch die Verwendung von Verbindungen der Formel (I) in Flüssigkristallmischungen. The invention therefore also relates to the use of compounds of the formula (I) in liquid-crystal mixtures.

Gegenstand der Erfindung sind weiterhin Flüssigkristallmischungen, die eine oder mehrere Verbindungen der Formel (I) enthalten. The invention further relates to liquid crystal mixtures which contain one or more compounds of the formula (I).

Die erfindungsgemäßen Flüssigkristallmischungen bestehen im allgemeinen aus 2 bis 20, vorzugsweise 2 bis 15 Komponenten, darunter mindestens eine, vorzugsweise 1 bis 5, besonders bevorzugt 1 bis 3, Verbindungen der Formel (I). Die erfindungsgemäßen LC-Mischungen können beispielsweise nematisch oder chiral nematisch sein. Von dem oder den erfindungsgemäßen Verbindungen der Formel (I) enthalten die Flüssigkristallmischungen im allgemeinen 0,1 bis 70 Mol-%, bevorzugt 0,5 bis 50 Mol-%, insbesondere 1 bis 25 Mol-%. The liquid crystal mixtures according to the invention generally consist of 2 to 20, preferably 2 to 15 components, including at least one, preferably 1 to 5, particularly preferably 1 to 3, compounds of the formula (I). The LC mixtures according to the invention can be nematic or chiral nematic, for example. The liquid crystal mixtures generally contain 0.1 to 70 mol%, preferably 0.5 to 50 mol%, in particular 1 to 25 mol%, of the compound (s) of the formula (I) according to the invention.

Weitere Bestandteile der erfindungsgemäßen Mischungen werden vorzugsweise ausgewählt aus den bekannten Verbindungen mit nematischen oder Further constituents of the mixtures according to the invention are preferably selected from the known compounds with nematic or

cholesterischen Phasen; dazu gehören beispielsweise Biphenyle, Terphenyle, Phenylcyclohexane, Bicyclohexane, Cyclohexylbiphenyle, Mono-, Di- und Trifluorphenyle. Im allgemeinen liegen die im Handel erhältlichen Flüssigkristallmischungen bereits vor der Zugabe der erfindungsgemäßen Verbindung(en) als Gemische verschiedener Komponenten vor, von denen mindestens eine mesogen ist. cholesteric phases; these include, for example, biphenyls, terphenyls, phenylcyclohexanes, bicyclohexanes, cyclohexylbiphenyls, mono-, di- and Trifluorophenyls. In general, the commercially available liquid crystal mixtures already exist as mixtures of various components, at least one of which is mesogenic, before the addition of the compound (s) according to the invention.

Geeignete weitere Bestandteile erfindungsgemäßer nematischer bzw. chira! nematischer Flüssigkristallmischungen sind beispielweise Suitable further components of nematic or chira according to the invention! Nematic liquid crystal mixtures are examples

4-Fluorbenzole, wie beispielsweise in EP-A 494 368, WO 92/06 148, EP-A 460 436, DE-A 4 1 1 1 766, DE-A 4 1 12 024, DE-A 4 1 12 001 , DE-A 4 100 288, DE-A 4 101 468, EP-A 423 520, DE-A 392 3064, EP-A 406 468, EP-A 393 577, EP-A 393 490 beschrieben, 4-fluorobenzenes, for example in EP-A 494 368, WO 92/06 148, EP-A 460 436, DE-A 4 1 1 1 766, DE-A 4 1 12 024, DE-A 4 1 12 001, DE-A 4 100 288, DE-A 4 101 468, EP-A 423 520, DE-A 392 3064, EP-A 406 468, EP-A 393 577, EP-A 393 490,

3,4-Difluorbenzole, wie beispielsweise in DE-A 4 108 448, EP-A 507 094 und EP-A 502 407 beschrieben, 3,4-difluorobenzenes, as described for example in DE-A 4 108 448, EP-A 507 094 and EP-A 502 407,

3,4,5-Trifluorbenzole, wie beispielsweise in DE-A 4 108 448, 3,4,5-trifluorobenzenes, as for example in DE-A 4 108 448,

EP-A 387 032 beschrieben,  EP-A 387 032,

4-Benzotrifluoride, wie beispielsweise in DE-A 4 108 448 beschrieben, 4-benzotrifluorides, as described for example in DE-A 4 108 448,

Phenylcyclohexane, wie beispielsweise in DE-A 4 108 448 beschrieben. Phenylcyclohexanes, as described for example in DE-A 4 108 448.

Flüssigkristalline Mischungen, die Verbindungen der allgemeinen Formel (I) enthalten, sind besonders für die Verwendung in elektrooptischen Schalt- und Anzeigevorrichtungen (Displays) geeignet. Solche Schalt- und Liquid-crystalline mixtures which contain compounds of the general formula (I) are particularly suitable for use in electro-optical switching and display devices (displays). Such switching and

Anzeigevorrichtungen (LC-Displays) weisen im allgemeinen u.a. folgende Display devices (LC displays) generally have, inter alia, the following

Bestandteile auf: ein flüssigkristallines Medium, Trägerplatten (z.B. aus Glas oder Kunststoff), beschichtet mit transparenten Elektroden, mindestens eine Orientierungsschicht, Abstandshalter, Kleberahmen, Polarisatoren sowie für Farbdisplays dünne Farbfilterschichten. Weitere mögliche Komponenten sind Antireflex-, Passivierungs-, Ausgleichs- und Sperrschichten sowie elektrisch- nichtlineare Elemente, wie Dünnschichttransistoren (TFT) und Metall-Isolator-Metall-(MIM)-Elemente. Im Detail ist der Aufbau von Flüssigkristalldisplays bereits in einschlägigen Monographien beschrieben (z.B. E. Kaneko, "Liquid Crystal TV Displays: Principles and Applications of Liquid Crystal Displays", KTK Scientific Publishers, 1987, Seiten 12-30 und 63-172). Components on: a liquid-crystalline medium, carrier plates (e.g. made of glass or plastic), coated with transparent electrodes, at least one orientation layer, spacers, adhesive frames, polarizers and thin color filter layers for color displays. Other possible components are anti-reflective, passivation, compensation and barrier layers as well as electrical nonlinear elements such as thin film transistors (TFT) and metal-insulator-metal (MIM) elements. The structure of liquid crystal displays has already been described in detail in relevant monographs (eg E. Kaneko, "Liquid Crystal TV Displays: Principles and Applications of Liquid Crystal Displays", KTK Scientific Publishers, 1987, pages 12-30 and 63-172).

Beispiele Examples

Zur physikalischen Charakterisierung der erfindungsgemäßen Verbindungen werden verschiedene Meßmethoden verwandt. Various measurement methods are used to physically characterize the compounds according to the invention.

Die Phasenumwandlungstemperaturen werden beim Aufheizen mit Hilfe eines Polarisationsmikroskops anhand der Texturänderungen bestimmt. Die The phase transition temperatures are determined with the help of a polarizing microscope on the basis of the texture changes. The

Bestimmung des Schmelzpunkts wird hingegen mit einem DSC-Gerät The melting point, however, is determined with a DSC device

durchgeführt. Die Angabe der Phasenumwandlungstemperaturen zwischen den Phasen carried out. The indication of the phase transition temperatures between the phases

Isotrop (I) Isotropic (I)

Nematisch (N bzw. N*) Nematic (N or N * )

Smektisch-C (Sc bzw. Sc *) Smectic-C (S c or S c * )

Smektisch-A (SA bzw. SA *) Smectic-A (S A or S A * )

Kristallin (X)  Crystalline (X)

Glasübergang (Tg) erfolgt in °C, und die Werte stehen zwischen den Phasenbezeichnungen in der Phasenfolge.  Glass transition (Tg) takes place in ° C and the values are between the phase names in the phase sequence.

Bei unterschiedlichen Werten für Heizen und Kühlen sind die letzteren in With different values for heating and cooling, the latter are in

Klammern gesetzt, oder es ist die Phasenfolge aufsteigend und abfallend in der Temperatur angegeben. Elektrooptische Untersuchungen erfolgen nach literaturbekannten Methoden (z.B. B. Bahadur: Liquid Crystals Application and Uses, Vol. I, World Scientific, Singapur, 1990). Parentheses are set, or the phase sequence is given ascending and descending in temperature. Electro-optical investigations are carried out according to methods known from the literature (for example B. Bahadur: Liquid Crystals Application and Uses, Vol. I, World Scientific, Singapore, 1990).

Für nematische Flüssigkristalle (rein oder in Mischung) werden die Werte für die optische und dielektrische Anisotropie und der elektrooptischen Kennlinie bei einer Temperatur von 20°C aufgenommen.  For nematic liquid crystals (pure or in a mixture), the values for the optical and dielectric anisotropy and the electro-optical characteristic are recorded at a temperature of 20 ° C.

Flüssigkristalle, die bei 20°C keine nematische Phase aufweisen, werden zu 10 Gew.- % in ZLI-1565 und/oder zu 20 Gew.-% in ZLI-4792 (kommerzielle nematische Flüssigkristallmischungen der Firma E. Merck, Darmstadt) gemischt und die Werte aus den Ergebnissen der Mischung extrapoliert. Liquid crystals which do not have a nematic phase at 20 ° C. are mixed in 10% by weight in ZLI-1565 and / or in 20% by weight in ZLI-4792 (commercial nematic liquid crystal mixtures from E. Merck, Darmstadt) and the values are extrapolated from the results of the mixture.

Elektrooptische Kennlinien werden anhand der Transmission einer Meßzelle ermittelt. Dazu wird die Zelle zwischen gekreuzten Polarisatoren vor einer Lichtquelle positioniert. Hinter der Zelle befindet sich ein Lichtdetektor, dessen Empfindlichkeit durch Filter auf den sichtbaren Bereich des Lichtes optimiert ist. Analog zur schrittweisen Erhöhung der an der Zelle angelegten Spannung wird die Änderung der Transmission aufgezeichnet. Größen wie Schwellspannung und Steilheit werden daraus bestimmt. Electro-optical characteristics are determined on the basis of the transmission of a measuring cell. For this purpose, the cell is positioned between crossed polarizers in front of a light source. There is a light detector behind the cell, the sensitivity of which is optimized by filters for the visible area of the light. Analogous to the gradual increase in the voltage applied to the cell, the change in transmission is recorded. Values such as threshold voltage and slope are determined from this.

Die optische Anisotropie wird mit einem Abbέ-Refraktometer (Firma Zeiss) bestimmt. Zur Orientierung des Flüssigkristalls wird auf das Prisma eine The optical anisotropy is determined using an Abbέ refractometer (from Zeiss). To orient the liquid crystal, a

Orientierungsschicht, erhalten aus einer 1 gew.-%igen Lecithin-Methanol-Lösung, aufgebracht. Orientation layer obtained from a 1% by weight lecithin-methanol solution.

Zur Bestimmung der dielektrischen Anisotropie werden jeweils eine Meßzelle mit homöotroper und planarer Orientierung angefertigt und deren Kapazitäten und dielektrische Verluste mit einem Multi Frequenz LCR-Meter (Hewlett Packard 4274 A) bestimmt. Die dielektrischen Konstanten werden berechnet wie in der Literatur beschrieben (W. Maier, G. Meier, Z. Naturforsch. 1961 , 16a, 262 und W.H. de Jeu, F. Leenhonts, J. Physique 1978, 39, 869). Die elektrische Größe HR (Holding Ratio) wird entsprechend den Literaturangaben bestimmt (M. Schadt, Linear and nonlinear liquid crystal materials, Liquid Crystals 1993, 14, 73-104). To determine the dielectric anisotropy, a measuring cell with homeotropic and planar orientation is produced and its capacities and dielectric losses are determined with a multi-frequency LCR meter (Hewlett Packard 4274 A). The dielectric constants are calculated as described in the literature (W. Maier, G. Meier, Z. Naturforsch. 1961, 16a, 262 and WH de Jeu, F. Leenhonts, J. Physique 1978, 39, 869). The electrical variable HR (holding ratio) is determined according to the literature (M. Schadt, Linear and nonlinear liquid crystal materials, Liquid Crystals 1993, 14, 73-104).

Zur Bestimmung von Schaltgeschwindigkeit (τ) und Kontrast (K) wird die To determine the switching speed (τ) and contrast (K), the

Meßzelle auf dem Drehtisch eines Polarisationsmikroskops zwischen gekreuztem Analysator und Polarisator befestigt. Für die Bestimmung des Kontrastes wird die Meßzelle durch Drehen so positioniert, daß eine Photodiode minimalen Lichtdurchgang anzeigt (Dunkelzustand). Die Mikroskop-Beleuchtung wird so geregelt, daß die Photodiode für alle Zellen die gleiche Lichtintensität anzeigt. Nach einem Schaltvorgang ändert sich die Lichtintensität (Hellzustand), und der Kontrast wird aus dem Verhältnis der Lichtintensität dieser Zustände berechnet. Measuring cell attached to the turntable of a polarizing microscope between crossed analyzer and polarizer. To determine the contrast, the measuring cell is positioned by turning it so that a photodiode indicates minimal light transmission (dark state). The microscope illumination is controlled so that the photodiode shows the same light intensity for all cells. After a switching operation, the light intensity (bright state) changes, and the contrast is calculated from the ratio of the light intensity of these states.

Beispiel 1 : Example 1 :

1-[Trans-4-(trans-4-pentylcyclohexyl)cyclohexyl]-3,5-difluorbenzol 1- [Trans-4- (trans-4-pentylcyclohexyl) cyclohexyl] -3,5-difluorobenzene

5,77 g (18,30 mmol) Trans-4-(trans-4-pentylcyclohexyl)bromcyclohexan werden in 50 ml Toluol/Tetrahydrofuran (4:1 ) mit 2,06 g (9,15 mmol) Zinkbromid und 0,25 g (36,60 mmol) dünn gehämmerten Lithiumscheiben in einem 5.77 g (18.30 mmol) of trans-4- (trans-4-pentylcyclohexyl) bromocyclohexane are dissolved in 50 ml of toluene / tetrahydrofuran (4: 1) with 2.06 g (9.15 mmol) of zinc bromide and 0.25 g (36.60 mmol) of thinly hammered lithium disks in one

Ultraschallbad dem Ultraschall ausgesetzt, bis kein Lithium mehr erkennbar ist. Anschließend werden 0,21 g Tetrakis(triphenylphosphin)palladium (O) und 3,53 g (18,30 mmol) Brom-3,5-difluorbenzol zugegeben und 18 Stunden bei Raumtemperatur gerührt. Anschließend wird mit Wasser und Dichlormethan extrahiert, die organische Phase über Natriumsulfat getrocknet und eingedampft. Nach Chromatographie mit Hexan:Ethylacetat = 9:1 an Kieselgel werden 4,62 g Produkt erhalten. Ultrasonic bath exposed to ultrasound until lithium is no longer recognizable. Then 0.21 g of tetrakis (triphenylphosphine) palladium (O) and 3.53 g (18.30 mmol) of bromo-3,5-difluorobenzene are added and the mixture is stirred at room temperature for 18 hours. The mixture is then extracted with water and dichloromethane, the organic phase is dried over sodium sulfate and evaporated. After chromatography with hexane: ethyl acetate = 9: 1 on silica gel, 4.62 g of product are obtained.

Figure imgf000021_0001
Beispiel 2:
Figure imgf000021_0001
Example 2:

1-(Trans-4-pentylcyclohexylmethoxy)-3,5-difluorbenzol 1- (trans-4-pentylcyclohexylmethoxy) -3,5-difluorobenzene

4,38 g (16,70 mmol) Triphenylphosphin werden bei 0°C in 40 ml 4.38 g (16.70 mmol) triphenylphosphine are at 0 ° C in 40 ml

Tetrahydrofuran mit 2,62 ml (16,70 mmol) Azodicarbonsäurediethylester versetzt und 0,5 Stunden bei Raumtemperatur gerührt. Danach werden 3,08 g (16,70 mmol) Trans-4-pentylcyclohexylmethanol und 1 ,44 g (1 1 ,10 mmol) 3,5-Difluorphenol zugegeben und 18 Stunden bei Raumtemperatur gerührt. Nach Abdampfen des Lösungsmittels und Chromatographie an Kieselgel mit Hexan werden 3,18 g Produkt erhalten. Tetrahydrofuran with 2.62 ml (16.70 mmol) of diethyl azodicarboxylate and stirred for 0.5 hours at room temperature. Then 3.08 g (16.70 mmol) of trans-4-pentylcyclohexylmethanol and 1.44 g (11.1, 10 mmol) of 3,5-difluorophenol are added and the mixture is stirred at room temperature for 18 hours. After evaporation of the solvent and chromatography on silica gel with hexane, 3.18 g of product are obtained.

Figure imgf000022_0001
Figure imgf000022_0001

Phasenfolge: Tg -76 X 29 (1 ) I Phase sequence: Tg -76 X 29 (1) I

Analog Beispiel 2 werden hergestellt: The following are prepared as in Example 2:

Beispiel 3: Example 3:

1-[Trans-4-(trans-4-pentylcyclohexyl)cyclohexylmethoxy]-3,5-difluorbenzol 1- [Trans-4- (trans-4-pentylcyclohexyl) cyclohexylmethoxy] -3,5-difluorobenzene

Figure imgf000022_0002
Figure imgf000022_0002

Phasenfolge: X 81 (55) N 8 I Beispiel 4: Phase sequence: X 81 (55) N 8 I Example 4:

1-[4-Trans-4-pentylcyclohexyl)phenylmethoxy]-3,5-difluorbenzol 1- [4-Trans-4-pentylcyclohexyl) phenylmethoxy] -3,5-difluorobenzene

Figure imgf000023_0001
Figure imgf000023_0001

Phasenfolge: X 51 (19) I Phase sequence: X 51 (19) I

Beispiel 5: Example 5:

1 -[2-Fluor-4-(trans-4-butylcyclohexyl)phenylmethoxy]-3,5-difluorbenzol 1 - [2-Fluoro-4- (trans-4-butylcyclohexyl) phenylmethoxy] -3,5-difluorobenzene

Figure imgf000023_0002
Figure imgf000023_0002

Beispiel 6: Example 6:

1 -[2,6-Difluor-4-(trans-4-pentylcyclohexyl)phenylmethoxy]-3,5-difluorbenzol 1 - [2,6-difluoro-4- (trans-4-pentylcyclohexyl) phenylmethoxy] -3,5-difluorobenzene

Figure imgf000023_0003
Figure imgf000023_0003

Beispiel 7: Example 7:

4-(Trans-4-propylcyclohexyl)phenyl-3,5-difluorphenylmethylether 4- (Trans-4-propylcyclohexyl) phenyl-3,5-difluorophenyl methyl ether

Figure imgf000023_0004
Figure imgf000023_0004

Phasenfolge: X 73 (54) I Beispiel 8: Phase sequence: X 73 (54) I Example 8:

2-Fluor-4-(trans-4-butylcyclohexyl)phenyl-3,5-difluorphenylmethylether 2-fluoro-4- (trans-4-butylcyclohexyl) phenyl-3,5-difluorophenyl methyl ether

Figure imgf000024_0003
Figure imgf000024_0003

Beispiel 9: Example 9:

2,6-Difluor-4-(trans-4-pentylcyclohexyl)phenyl-3,5-difluorphenylmethylether 2,6-difluoro-4- (trans-4-pentylcyclohexyl) phenyl-3,5-difluorophenyl methyl ether

Figure imgf000024_0002
Figure imgf000024_0002

Beispiel 10: Example 10:

Trans-4-pentylcyclohexancarbonsäure-3,5-difluorphenylester Trans-4-pentylcyclohexane carboxylic acid 3,5-difluorophenyl ester

2,29 g (1 1 ,10 mmol) Dicyclohexylcarbodiimid, 2,20 g (1 1 ,10 mmol) Trans-4-pentylcyclohexancarbonsäure und 1 ,44 g (1 1 ,10 mmol) 3,5-Difluorphenol werden mit 10 mg 4-N,N-Dimethylaminopyridin in 50 ml Dichlormethan 18 Stunden bei Raumtemperatur gerührt. Nach Filtration, Abdampfen des Lösungsmittels und chromatographischer Reinigung (Kieselgel; 2.29 g (1 1, 10 mmol) of dicyclohexylcarbodiimide, 2.20 g (1 1, 10 mmol) of trans-4-pentylcyclohexane carboxylic acid and 1, 44 g (1 1, 10 mmol) of 3,5-difluorophenol are mixed with 10 mg 4-N, N-dimethylaminopyridine in 50 ml dichloromethane stirred for 18 hours at room temperature. After filtration, evaporation of the solvent and chromatographic purification (silica gel;

Hexan:Dichlormethan = 9: 1 ) werden 2,76 g Produkt erhalten. Hexane: dichloromethane = 9: 1) 2.76 g of product are obtained.

Figure imgf000024_0001
Figure imgf000024_0001

Phasenfolge: Tg -79 X 21 (-2) I Analog Beispiel 10 werden hergestellt: Phase sequence: Tg -79 X 21 (-2) I The following are prepared as in Example 10:

Beispiel 1 1 : Example 1 1:

Trans-4-(trans-4-pentylcyclohexyl)cyclohexancarbonsäure-3,5-difluorphenylester Trans-4- (trans-4-pentylcyclohexyl) cyclohexane carboxylic acid 3,5-difluorophenyl ester

Figure imgf000025_0003
Figure imgf000025_0003

Phasenfolge: X 58 (31 ) N 115 I Phase sequence: X 58 (31) N 115 I

Beispiel 12: Example 12:

4-(Trans-4-pentylcyclohexyl)benzoesäure-3,5-difluorphenylester 4- (Trans-4-pentylcyclohexyl) benzoic acid 3,5-difluorophenyl ester

Figure imgf000025_0002
Figure imgf000025_0002

Phasenfolge: X 86 (60) N (79) I Phase sequence: X 86 (60) N (79) I

Beispiel 13: Example 13:

2-Fluor-4-(trans-4-propylcyclohexyl)benzoesäure-3,5-difluorphenylester 3,5-difluorophenyl 2-fluoro-4- (trans-4-propylcyclohexyl) benzoate

Figure imgf000025_0001
Beispiel 14:
Figure imgf000025_0001
Example 14:

2,6-Difluor-4-(trans-4-butylcyclohexyl)benzoesäure-3,5-difluorphenylester 2,6-difluoro-4- (trans-4-butylcyclohexyl) benzoic acid 3,5-difluorophenyl ester

Figure imgf000026_0004
Figure imgf000026_0004

Beispiel 15: Example 15:

3,5-Difluorbenzoesäure-4-(trans-4-pentylcyclohexyl)phenylester 4- (Trans-4-pentylcyclohexyl) phenyl 3,5-difluorobenzoate

Figure imgf000026_0003
Figure imgf000026_0003

Phasenfolge: X 87 (56) Sx 97 I Phase sequence: X 87 (56) S x 97 I

Beispiel 16: Example 16:

3,5-Difluorbenzoesäure-2-fluor-4-(trans-4-butylcyclohexyl)phenylester 3,5-difluorobenzoic acid 2-fluoro-4- (trans-4-butylcyclohexyl) phenyl ester

Figure imgf000026_0001
Figure imgf000026_0001

Beispiel 17: Example 17:

3,5-Difluorbenzoesäure-2,6-difluor-4-(trans-4-propylcyclohexyl)phenylester 2,6-difluoro-4- (trans-4-propylcyclohexyl) phenyl 3,5-difluorobenzoate

Figure imgf000026_0002
Beispiel 18:
Figure imgf000026_0002
Example 18:

1-(3,5-Difluorphenyl)-2-(trans-4-pentylcyclohhexyl)ethan 1- (3,5-difluorophenyl) -2- (trans-4-pentylcyclohhexyl) ethane

1 ,85 g (3,64 mmol) Trans-4-pentylcyclohexylmethyltriphenylphosphoniumbromid werden in 20 ml Tetrahydrofuran mit 0,44 g (4,00 mmol) Kaliumtertiärbutylat versetzt und 1 Stunde gerührt. Danach werden 0,52 g 1.85 g (3.64 mmol) of trans-4-pentylcyclohexylmethyltriphenylphosphonium bromide are mixed in 20 ml of tetrahydrofuran with 0.44 g (4.00 mmol) of potassium tertiary butylate and stirred for 1 hour. Then 0.52 g

(3,64 mmol) 3,5-Difluorbenzaldehyd in 3 ml Tetrahydrofuran zugetropft und 18 Stunden bei Raumtemperatur gerührt. Nach Extraktion mit Ether und verdünnter Salzsäure wird die organische Phase über Na2SO4 getrocknet, eingeengt und chromatographisch (Kieselgel, Dichlormethan) gereinigt. Es werden 0,96 g 1-(Trans-4-pentylcyclohexyl)-2-(3,5-difluorphenyl)ethan erhalten, (3.64 mmol) of 3,5-difluorobenzaldehyde in 3 ml of tetrahydrofuran was added dropwise and the mixture was stirred at room temperature for 18 hours. After extraction with ether and dilute hydrochloric acid, the organic phase is dried over Na 2 SO 4 , concentrated and purified by chromatography (silica gel, dichloromethane). 0.96 g of 1- (trans-4-pentylcyclohexyl) -2- (3,5-difluorophenyl) ethane are obtained,

Figure imgf000027_0002
welches in 20 ml Tetrahydrofuran unter Verwendung von 10 mg Palladium 10 % auf Aktivkohle bis zur Aufnahme der berechneten Wasserstoffmenge hydriert, vom Katalysator abfiltriert und eingeengt wird. Nach Chromatographie an Kieselgel mit Hexan:Ethylacetat = 9:1 werden 0,81 g Produkt erhalten.
Figure imgf000027_0002
which is hydrogenated in 20 ml of tetrahydrofuran using 10 mg of 10% palladium on activated carbon until the calculated amount of hydrogen has been taken up, filtered off from the catalyst and concentrated. After chromatography on silica gel with hexane: ethyl acetate = 9: 1, 0.81 g of product is obtained.

Figure imgf000027_0001
Figure imgf000027_0001

Phasenfolge: X1 4 X2 6 (-29) I Analog Beispiel 18 werden hergestellt: Phase sequence: X 1 4 X 2 6 (-29) I The following are prepared as in Example 18:

Beispiel 19: Example 19:

1-(3,5-Difluorphenyl)-2-[4-(trans-4-pentylcyclohexyl)phenyl]ethan 1- (3,5-difluorophenyl) -2- [4- (trans-4-pentylcyclohexyl) phenyl] ethane

Figure imgf000028_0003
Figure imgf000028_0003

Phasenfolge: X 44 (32) I Phase sequence: X 44 (32) I

Beispiel 20: Example 20:

1 -(3,5-Difluorphenyl)-2-[2-fluor-4-(trans-4-butylcyclohexyl)phenyl]ethan 1 - (3,5-difluorophenyl) -2- [2-fluoro-4- (trans-4-butylcyclohexyl) phenyl] ethane

Figure imgf000028_0002
Figure imgf000028_0002

Beispiel 21 : Example 21:

1 -(3,5-DifluorphenyI)-2-[2,6-difluor-4-(trans-4-propylcyclohexyl)phenyl]ethan 1 - (3,5-DifluorophenyI) -2- [2,6-difluoro-4- (trans-4-propylcyclohexyl) phenyl] ethane

Figure imgf000028_0001
Figure imgf000028_0001

Beispiel 22: Example 22:

3',5'-Difluor-4-(trans-4-ethylcyclohexyl)biphenyl 3 ', 5'-difluoro-4- (trans-4-ethylcyclohexyl) biphenyl

0,77 g (4,00 mmol) Brom-3,5-difluorbenzol 0,93 g (4,00 mmol) 4-(Trans-4-ethylcyclohexyl)benzolboronsäure, 1 ,02 g (9,60 mmol) Natriumcarbonat und 0,05 g (0,04 mmol) Tetrakis(triphenylphosphin)palladium (O) werden in 30 ml Toluol, 15 ml Ethanol und 15 ml Wasser für 4 Stunden auf 80°C erhitzt. Danach wird die organische Phase abgetrennt, eingedampft und durch Chromatographie an Kieselgel mit Heptan gereinigt, wonach 0,82 g Produkt erhalten werden. 0.77 g (4.00 mmol) bromo-3,5-difluorobenzene 0.93 g (4.00 mmol) 4- (trans-4-ethylcyclohexyl) benzeneboronic acid, 1.02 g (9.60 mmol) sodium carbonate and 0.05 g (0.04 mmol) of tetrakis (triphenylphosphine) palladium (O) are heated to 80 ° C. for 4 hours in 30 ml of toluene, 15 ml of ethanol and 15 ml of water. The organic phase is then separated off, evaporated and purified by chromatography on silica gel with heptane, after which 0.82 g of product are obtained.

Figure imgf000029_0003
Figure imgf000029_0003

Phasenfolge: X 47 (21 ) I Phase sequence: X 47 (21) I

Analog Beispiel 22 werden hergestellt: The following are prepared as in Example 22:

Beispiel 23: Example 23:

3',5'-Difluor-4-(trans-4-propylcyclohexyl)biphenyl 3 ', 5'-difluoro-4- (trans-4-propylcyclohexyl) biphenyl

Figure imgf000029_0002
Figure imgf000029_0002

Phasenfolge: X 59 (33) I Phase sequence: X 59 (33) I

Beispiel 24: Example 24:

3',5'-Difluor-4-(trans-4-butylcyclohexyl)biphenyl 3 ', 5'-difluoro-4- (trans-4-butylcyclohexyl) biphenyl

Figure imgf000029_0001
Figure imgf000029_0001

Phasenfolge: X 45 (10) I Beispiel 25: Phase sequence: X 45 (10) I Example 25:

3',5'-Difluor-4-(trans-4-pentylcyclohexyl)biphenyl 3 ', 5'-difluoro-4- (trans-4-pentylcyclohexyl) biphenyl

Figure imgf000030_0004
Figure imgf000030_0004

Phasenfolge: X 36 (6) N 42 I Phase sequence: X 36 (6) N 42 I

Beispiel 26: Example 26:

2,3',5'-Trifluor-4-(trans-4-pentylcyclohexyl)biphenyl 2,3 ', 5'-trifluoro-4- (trans-4-pentylcyclohexyl) biphenyl

Figure imgf000030_0003
Figure imgf000030_0003

Beispiel 27: Example 27:

2,6,3',5'-Tetrafluor-4-(trans-4-butylcyclohexyl)biphenyl 2,6,3 ', 5'-tetrafluoro-4- (trans-4-butylcyclohexyl) biphenyl

Figure imgf000030_0001
Figure imgf000030_0001

Beispiel 28: Example 28:

2,6,3',5',3",5"-Hexafluor-4-pentylterphenyl 2,6,3 ', 5', 3 ", 5" -hexafluoro-4-pentylterphenyl

Figure imgf000030_0002
Beispiel 29:
Figure imgf000030_0002
Example 29:

4-(Trans-4-pentylcyclohexyl)phenyl-3,5-difluorphenylmethylether 4- (trans-4-pentylcyclohexyl) phenyl-3,5-difluorophenyl methyl ether

Die Herstellung erfolgt analog Beispiel 2. The production takes place analogously to example 2.

Figure imgf000031_0003
Figure imgf000031_0003

Phasenfolge: X 66 (29) I Phase sequence: X 66 (29) I

Beispiel 30: Example 30:

4-(Trans-4-butylcyclohexyl)phenyl-3,5-difluorphenylmethylether 4- (Trans-4-butylcyclohexyl) phenyl-3,5-difluorophenyl methyl ether

Die Herstellung erfolgt analog Beispiel 2. The production takes place analogously to example 2.

Figure imgf000031_0002
Figure imgf000031_0002

Phasenfolge: X 68 (28) I Phase sequence: X 68 (28) I

Beispiel 31 : Example 31:

4-(Trans-4-ethylcyclohexyl)phenyl-3,5-difluorphenylmethylether 4- (Trans-4-ethylcyclohexyl) phenyl-3,5-difluorophenyl methyl ether

Die Herstellung erfolgt analog Beispiel 2. The production takes place analogously to example 2.

Figure imgf000031_0001
Figure imgf000031_0001

Phasenfolge: X 60 (38) I Beispiel 32: Phase sequence: X 60 (38) I Example 32:

3,5-Difluorbenzoesäure-4-(trans-4-butylcyclohexyl)phenylester 4- (Trans-4-butylcyclohexyl) phenyl 3,5-difluorobenzoate

Die Herstellung erfolgt analog Beispiel 10. The production takes place analogously to example 10.

Figure imgf000032_0002
Figure imgf000032_0002

Phasenfolge: X 84 (X1 75 X2 93) (58) SB 104 I Phase sequence: X 84 (X 1 75 X 2 93) (58) S B 104 I

Beispiel 33: Example 33:

3,5-Difluorbenzoesäure-4-(trans-4-propylcyclohexyl)phenylester 4- (trans-4-propylcyclohexyl) phenyl 3,5-difluorobenzoate

Die Herstellung erfolgt analog Beispiel 10. The production takes place analogously to example 10.

Figure imgf000032_0001
Figure imgf000032_0001

Phasenfolge: X 74 Xre 24 X1 62 X2 70 SB 1 10 I Phase sequence: X 74 X re 24 X 1 62 X 2 70 S B 1 10 I

Beispiel 34: Example 34:

3,5-Difluorbenzoesäure-4-(trans-4-ethylcyclohexyl)phenylester 4- (Trans-4-ethylcyclohexyl) phenyl 3,5-difluorobenzoate

Die Herstellung erfolgt analog Beispiel 10. The production takes place analogously to example 10.

Figure imgf000032_0003
Figure imgf000032_0003

Phasenfolge: X 70 Sx (59) SB 104 I Anwendungsbeispiele Phase sequence: X 70 S x (59) S B 104 I Examples of use

In Tabelle 1 wird die erfindungsgemäße Substanz aus Beispiel 1 1 mit einer Referenzsubstanz aus WO 92/13928 als Reinsubstanz und in Mischung mit einer handelsüblichen TFT-TN Mischung ZLI-4792 (E. Merck, Darmstadt) verglichen. In Table 1, the substance according to the invention from Example 11 is compared with a reference substance from WO 92/13928 as the pure substance and in a mixture with a commercially available TFT-TN mixture ZLI-4792 (E. Merck, Darmstadt).

Die erfindungsgemäße Substanz zeichnet sich durch niedrigeren Schmelzpunkt (Heizen), höheren nematisch-isotropen Übergang und deutlich breitere The substance according to the invention is characterized by a lower melting point (heating), higher nematic-isotropic transition and significantly wider

nematische Phase aus. Im Gegensatz zur Referenzsubstanz wird keine nematic phase. In contrast to the reference substance, none

ungünstige höhergeordnete smektische Phase beobachtet. unfavorable higher order smectic phase observed.

Auch in Mischung liegt der Schmelzpunkt der erfindungsgemäßen Substanz deutlich niedriger, und die höhergeordnete smektische Phase wird viel stärker unterdrückt. Der Klärpunkt wird angehoben, während die Referenz den Even when mixed, the melting point of the substance according to the invention is significantly lower, and the higher-order smectic phase is suppressed much more strongly. The clearing point is raised, while the reference increases the

Klärpunkt sogar absenkt. Die Werte für Δn und Δ∊ sind nur wenig gegenüber der Grundmischung erniedrigt, was günstig ist. Clarification point even lowered. The values for Δn and Δ∊ are only slightly reduced compared to the basic mixture, which is favorable.

Figure imgf000034_0001
Figure imgf000034_0001

Claims

Patentansprüche: Claims: 1. 3,5-Difluorbenzole der allgemeinen Formel (I) 1. 3,5-difluorobenzenes of the general formula (I)
Figure imgf000035_0001
Figure imgf000035_0001
 wobei die Symbole und Indizes folgende Bedeutungen haben: where the symbols and indices have the following meanings: R1 ist H, ein geradkettiges oder verzweigtes (mit oder ohne asymmetrisches C-Atom) Alkyl mit 1 bis 15 C-Atomen, wobei auch eine oder zwei nicht benachbarte CH2-Gruppen durch -O-, -S-, -CO-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -O-CO-O-, -CH = CH-, -C≡C-, Cyclopropan-1 ,2-diyl oder -Si(CH3)2- ersetzt sein können, und wobei auch ein oder mehrere H-Atome des Alkylrestes durch F, Cl oder CN substituiert sein können; R 1 is H, a straight-chain or branched (with or without asymmetrical C atom) alkyl with 1 to 15 C atoms, one or two non-adjacent CH 2 groups also being represented by -O-, -S-, -CO- , -CO-O-, -O-CO-, -CO-S-, -S-CO-, -O-CO-O-, -CH = CH-, -C≡C-, cyclopropane-1,2 -diyl or -Si (CH 3 ) 2 - can be replaced, and where one or more H atoms of the alkyl radical can be substituted by F, Cl or CN; A1 , A2, A3 sind gleich oder verschieden 1 ,4-Phenylen, Pyrazin-2,5-diyl, Pyridin-2,5-diyI, Pyrimidin-2,5-diyl, in denen ein oder zwei H-Atome durch F ersetzt sein können, trans-1 ,4-Cyclohexylen, (1 ,3,4)-Thiadiazol-2,5-diyl, 1 ,3-Dioxan-2,5-diyl, Naphthalin-2,6-diyl, Bicyclo[2.2.2]octan-1 ,4-diyl oder 1 ,3-Dioxaborinan-2,5-diyl; A 1 , A 2 , A 3 are the same or different 1, 4-phenylene, pyrazine-2,5-diyl, pyridine-2,5-diyI, pyrimidine-2,5-diyl, in which one or two H atoms can be replaced by F, trans-1,4-cyclohexylene, (1,3,4) thiadiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthalene-2,6-diyl, Bicyclo [2.2.2] octane-1,4-diyl or 1,3-dioxaborinane-2,5-diyl; M1 , M2 sind gleich oder verschieden -CH2CH2-, -CH = CH-, -C≡C-, M 1 , M 2 are the same or different -CH 2 CH 2 -, -CH = CH-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; k, I, m, n, o sind Null oder Eins, unter der Bedingung, daß die Summe k + m + o größer Null ist; mit den folgenden Maßgaben: für k + m + o gleich Eins ist X -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O- or -O-CO-; k, I, m, n, o are zero or one, provided that the sum k + m + o is greater than zero; with the following requirements: for k + m + o is one, X is -CH2CH2-, -CH =CH-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -CH 2 CH 2 -, -CH = CH-, -C≡C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; und für k + m + o größer Eins ist X -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O - or -O-CO-; and for k + m + o greater than one, X is -CH2CH2-, -CH = CH-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -CH 2 CH 2 -, -CH = CH-, -C≡C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O-, -O-CO- oder eine Einfachbindung. -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O -, -O-CO- or a single bond. 2. 3,5-Difluorbenzole nach Anspruch 1 , dadurch gekennzeichnet, daß die Symbole und Indizes der allgemeinen Formel (I) folgende Bedeutungen haben: 2. 3,5-difluorobenzenes according to claim 1, characterized in that the symbols and indices of the general formula (I) have the following meanings: R1 ist ein geradkettiges Alkyl mit 1 bis 15 C-Atomen; R 1 is a straight-chain alkyl having 1 to 15 carbon atoms; A1 , A2, A3 sind gleich oder verschieden 1 ,4-Phenylen, in dem ein oder zwei H-Atome durch F ersetzt sein können, oder trans-1 ,4-Cyclohexylen; A 1 , A 2 , A 3 are identical or different 1, 4-phenylene, in which one or two H atoms can be replaced by F, or trans-1, 4-cyclohexylene; M1 , M2 sind gleich oder verschieden -CH2CH2-, -CH2CH2CH2CH2-, M 1 , M 2 are the same or different -CH 2 CH 2 -, -CH 2 CH 2 CH 2 CH 2 -, -CH2CH2CH2-O-, -O-CH2CH2CH2-, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; k, I, m, n, o sind Null oder Eins, unter der Bedingung, daß die Summe k + m + o größer Null ist; mit den folgenden Maßgaben: für k + m + o gleich Eins ist X -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -, -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O- or -O-CO-; k, I, m, n, o are zero or one, provided that the sum k + m + o is greater than zero; with the following provisos: for k + m + o equal to one is X -CH2CH2-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-,-CH 2 CH 2 -, -C≡C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O- oder -O-CO-; und für k + m + o größer Eins ist X -CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O- or -O-CO-; and for k + m + o greater than one, X is -CH2CH2-, -C≡C-, -CH2CH2CH2CH2-, -CH2CH2CH2-O-, -O-CH2CH2CH2-,-CH 2 CH 2 -, -C≡C-, -CH 2 CH 2 CH 2 CH 2 -, -CH 2 CH 2 CH 2 -O-, -O-CH 2 CH 2 CH 2 -, -CH2CH2CO-O-, -O-CO-CH2CH2-, -CH2-O-, -O-CH2-, -CO-O-, -O-CO- oder eine-CH 2 CH 2 CO-O-, -O-CO-CH 2 CH 2 -, -CH 2 -O-, -O-CH 2 -, -CO-O-, -O-CO- or one Einfachbindung. Single bond. 3. 3,5-Difluorbenzole der Formel (I) nach Anspruch 1 und/oder 2, gekennzeichnet durch die Formeln (11 ) bis (125): 3. 3,5-difluorobenzenes of the formula (I) according to claim 1 and / or 2, characterized by the formulas (11) to (125):
Figure imgf000037_0001
Figure imgf000037_0002
Figure imgf000037_0003
Figure imgf000037_0004
Figure imgf000038_0001
Figure imgf000038_0002
Figure imgf000038_0003
Figure imgf000038_0004
Figure imgf000038_0005
Figure imgf000038_0006
Figure imgf000039_0001
Figure imgf000039_0002
Figure imgf000039_0003
Figure imgf000039_0004
Figure imgf000039_0005
Figure imgf000039_0006
Figure imgf000040_0001
Figure imgf000040_0002
Figure imgf000040_0003
Figure imgf000040_0004
Figure imgf000040_0005
Figure imgf000040_0006
Figure imgf000041_0001
Figure imgf000037_0001
Figure imgf000037_0002
Figure imgf000037_0003
Figure imgf000037_0004
Figure imgf000038_0001
Figure imgf000038_0002
Figure imgf000038_0003
Figure imgf000038_0004
Figure imgf000038_0005
Figure imgf000038_0006
Figure imgf000039_0001
Figure imgf000039_0002
Figure imgf000039_0003
Figure imgf000039_0004
Figure imgf000039_0005
Figure imgf000039_0006
Figure imgf000040_0001
Figure imgf000040_0002
Figure imgf000040_0003
Figure imgf000040_0004
Figure imgf000040_0005
Figure imgf000040_0006
Figure imgf000041_0001
Figure imgf000041_0002
Figure imgf000041_0002
Figure imgf000041_0003
wobei
Figure imgf000041_0003
in which R1 Methyl, Ethyl, Propyl, Butyl, Pentyl, Hexyl, Heptyl, Octyl, Nonyl oder Decyl bedeutet. R 1 is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or decyl. 4. Verwendung von 3,5-Difluorbenzolen nach einem oder mehreren der Ansprüche 1 bis 3 in Flüssigkristallmischungen. 4. Use of 3,5-difluorobenzenes according to one or more of claims 1 to 3 in liquid crystal mixtures. 5. Flüssigkristallmischung, enthaltend mindestens eine Verbindung der Formel (I) nach einem oder mehreren der Ansprüche 1 bis 3. 5. A liquid crystal mixture comprising at least one compound of the formula (I) according to one or more of claims 1 to 3. 6. Flüssigkristallmischung nach Anspruch 5, dadurch gekennzeichnet, daß die Flüssigkristallmischung nematisch ist. 6. Liquid crystal mixture according to claim 5, characterized in that the liquid crystal mixture is nematic. 7. Flüssigkristallmischung nach Anspruch 5 oder 6, dadurch gekennzeichnet, daß sie 1 bis 8 Verbindungen der Formel (I) enthält. 7. Liquid crystal mixture according to claim 5 or 6, characterized in that it contains 1 to 8 compounds of formula (I). 8. Flüssigkristallmischung nach einem oder mehreren der Ansprüche 5 bis 7, dadurch gekennzeichnet, daß sie 0,1 bis 70 Mol-% an mindestens einer 8. Liquid crystal mixture according to one or more of claims 5 to 7, characterized in that it contains 0.1 to 70 mol% of at least one Verbindung der Formel (I) enthält. Contains compound of formula (I). 9. Schalt- und/oder Anzeigevorrichtung, enthaltend Trägerplatten, 9. switching and / or display device, comprising carrier plates, Elektroden, mindestens einen Polarisator, mindestens eine Orientierungsschicht sowie ein flüssigkristallines Medium, dadurch gekennzeichnet, daß das flüssigkristalline Medium eine Flüssigkristallmischung nach einem oder mehreren der Ansprüche 5 bis 8 ist. Electrodes, at least one polarizer, at least one orientation layer and a liquid-crystalline medium, characterized in that the liquid-crystalline medium is a liquid crystal mixture according to one or more of claims 5 to 8.
PCT/EP1994/003533 1993-11-10 1994-10-27 3,5-difluorobenzenes and their use in liquid-crystal mixtures Ceased WO1995013999A1 (en)

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JPH04169574A (en) * 1990-11-01 1992-06-17 Seiko Epson Corp Pyrimidine derivative, liquid crystal composition containing the derivative and liquid crystal display element produced by using the same
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JPH04169574A (en) * 1990-11-01 1992-06-17 Seiko Epson Corp Pyrimidine derivative, liquid crystal composition containing the derivative and liquid crystal display element produced by using the same
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Publication number Priority date Publication date Assignee Title
EP1352886A1 (en) * 2002-04-09 2003-10-15 Chisso Corporation Liquid crystal compound having hydrogen as a terminal group, composition comprising the compound, and liquid crystal display element comprising the composition
US7125589B1 (en) 2002-04-09 2006-10-24 Chisso Corporation Liquid crystal compound having hydrogen as a terminal group, composition comprising the compound, and liquid crystal display element comprising the composition

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