JP2020513405A - Monofluorinated cyclohexane - Google Patents

Abstract

The present invention provides a 1-fluorocyclohexyl-methoxy-aryl compound of formula (I), wherein R1, R2, A1, A2, m and n are the same as defined in claim 1, It relates to the manufacture, its use as a component in liquid crystal media, as well as to electro-optical display elements containing liquid crystal media according to the invention. These compounds have a negative dielectric anisotropy.

Description

  The present invention relates to a 1-fluorocyclohexyl-methoxy-aryl compound, a method for producing the same, a liquid crystal medium containing the derivative, and an electro-optical display device containing the liquid crystal medium. These compounds have a negative dielectric anisotropy.

  Liquid crystals have found wide application since the discovery of the first commercially applicable liquid crystal compounds about 40 years ago. Known areas of application today are simple digital displays, portable and stationary computer displays, navigator systems, and television receivers, among others. Particularly for video-enabled displays, high demands are made on switching times and image contrast.

The spatial order of molecules in liquid crystals causes many of their properties to be directionally dependent. Important for use in liquid crystal displays is in this case especially the anisotropy in optical, dielectric and elastic mechanical behaviour. Depending on whether the molecules with the vertical axis are oriented vertically or horizontally with respect to both plates of the capacitor, this capacitor has a different capacitance, therefore the dielectric constant ε of the liquid crystal medium is And greatly different. A substance having a larger dielectric constant when the molecular vertical axis is oriented perpendicular to the capacitor plate than in the parallel arrangement is said to be dielectrically positive. In other words, if the permittivity ε _‖ parallel to the vertical axis of the molecule is larger than the permittivity ε _⊥ perpendicular to the vertical axis of the molecule, the dielectric anisotropy Δε = ε _‖ −ε _⊥ is greater than zero. Most liquid crystals used in conventional displays belong to this group.

  Both the polarizability of the molecule and the permanent dipole moment play a certain role in this dielectric anisotropy. When a voltage is applied to the display, the vertical axes of the molecules are aligned so that the larger of these dielectric constants is effective. The strength of the synergistic effect with the electric field depends in this case on the difference between both constants.

  In the case of liquid crystal molecules used in a conventional liquid crystal display device, the dipole moment oriented along the longitudinal axis of the molecule is larger than the dipole moment oriented perpendicular to the longitudinal axis of the molecule.

  Very high performance displays have already been developed using liquid crystals in which a relatively large dipole moment is oriented parallel to the longitudinal axis of the molecule. In this case, in order to achieve a sufficiently wide temperature range of the mesophase and short switching times and low threshold voltages, a mixture of 5 to 20 components is usually used. However, in the case of liquid crystal display devices such as those used for laptops, for example, the strong viewing angle dependence causes difficulties. The best image quality can be achieved when the display surface is perpendicular to the viewing direction of the observer. If the display is tilted with respect to the viewing direction, the image quality is sometimes significantly reduced. For greater comfort, one seeks to maximize the angle at which the display can be tilted from the line of sight of the observer without significantly degrading the image quality. Recently, in order to improve the viewing angle dependence, it has been attempted to use a liquid crystal compound in which the dipole moment perpendicular to the longitudinal axis of the molecule is larger than the dipole moment parallel to the longitudinal axis of the molecule. Has been done. In this case, the dielectric anisotropy Δε is negative. In the field-free state, the molecules with the longitudinal axis are oriented perpendicular to the glass surface of the display. Due to the application of an electric field, the molecules are oriented more or less parallel to the glass surface. With this method, it was possible to improve the viewing angle dependence. This type of display is called a VA-TFT display (derived from English: "vertically aligned").

  Developments in the field of liquid crystal materials are far from complete. In order to improve the characteristics of liquid crystal display devices, there is always an effort to develop new compounds that allow optimization of this type of display.

  West German Patent Application Publication No. 3231707 (DE 3231707 A), German Patent Application Publication No. 19831712 (DE 19831712), US Patent No. 6139737 (US 6139773 A) and German Patent Application Publication No. 10219542 (DE 10219542 A1) discloses fluorocyclohexane for use as a liquid crystal material. These compounds are distinguished from the compounds according to the invention in the characteristic substitution of cyclohexane residues.

  The object of the present invention is to provide compounds with advantageous properties for use in liquid crystal media. In particular, these compounds preferably have a negative dielectric anisotropy, which makes them particularly suitable for use in liquid crystal media for VA displays. Compounds having a desirable combination of applied technical parameters, independent of the dielectric anisotropy corresponding to the display type, are desirable. Among these parameters to be optimized at the same time, among other things, high clearing point, low rotational viscosity, optical anisotropy in the application interval, as well as properties useful for achieving mixtures with the desired liquid crystal phase over a wide temperature range ( Low melting point, miscibility with other liquid crystal components of the desired type). Among other things, the chemical stability of the compounds and the mixtures prepared with them is also an important aspect in the development of new materials.

［式中、
ｍは、０、１または２、好ましくは１であり、
ｎは、１または２、好ましくは１であり、
Ｒ¹およびＲ²は、互いに無関係に、１〜１５のＣ原子を有するアルキル基またはアルコキシ基を表し、これらの基中で、１つ以上のＣＨ₂基は、それぞれ互いに無関係に、Ｏ／Ｓ原子が互いに直接結合しないように、−Ｃ≡Ｃ−、−ＣＦ₂Ｏ−、−ＯＣＦ₂−、−ＣＨ＝ＣＨ−、

−Ｏ−、−Ｓ−、−ＣＯ−Ｏ−または−Ｏ−ＣＯ−に置き換えられていてよく、かつ１つ以上のＨ原子は、ハロゲンに置き換えられていてよく、またはＨを表し、
好ましくは、互いに無関係に、それぞれ任意に１箇所以上ハロゲン化されている、１〜１５の炭素原子を有する非置換のアルキル基、アルコキシ基またはアルキルスルファニル基、または２〜１５のＣ原子を有するアルケニル基、アルケニルオキシ基、アルケニルスルファニル基またはアルキニル基を表し、
Ａ¹は、それぞれ互いに無関係に、次の群
ａ）トランス−１，４−シクロヘキシレンおよび１，４−シクロヘキセニレンからなり、ここで、１つ以上の隣接しないＣＨ₂基は、−Ｏ−および／または−Ｓ−に置き換えられていてもよく、かつ１つ以上のＨ原子は、ＦまたはＣｌに置き換えられていてもよい群、および
ｂ）テトラヒドロピラン−２，５−ジイル、１，３−ジオキサン−２，５−ジイル、テトラヒドロフラン−２，５−ジイル、シクロブタン−１，３−ジイル、ピペリジン−１，４−ジイル、チオフェン−２，５−ジイルおよびセレノフェン−２，５−ジイルからなり、これらは１箇所以上基Ｌで置換されていてもよい群、
から選択される基を表し、
Ｌは、それぞれ出現する場合に、無関係にＦ、Ｃｌ、ＣＮ、ＳＣＮ、ＳＦ₅または直鎖のもしくは分枝した、それぞれ任意にフッ素化された、１〜１２のＣ原子を有するアルキル、アルコキシ、アルキルカルボニル、アルコキシカルボニル、アルキルカルボニルオキシまたはアルコキシカルボニルオキシを表し、かつ
Ａ²は、それぞれ互いに無関係に、次の群

から選択される基を表す］の化合物により解決される。 This problem is solved according to the invention by the general formula I

[In the formula,
m is 0, 1 or 2, preferably 1,
n is 1 or 2, preferably 1,
R ¹ and R ² independently of one another represent an alkyl or alkoxy group having 1 to 15 C atoms, in which one or more CH ₂ groups independently of one another are O / S as atoms are not linked directly to one _{another, -C≡C -, - CF 2 O} -, - OCF 2 -, - CH = CH-,

-O-, -S-, -CO-O- or -O-CO-, and one or more H atoms may be replaced by halogen, or represent H,
Preferably, independently of one another, an unsubstituted alkyl radical having 1 to 15 carbon atoms, an alkoxy radical or an alkylsulfanyl radical, or an alkenyl having 2 to 15 C atoms, each optionally halogenated in one or more places. A group, an alkenyloxy group, an alkenylsulfanyl group or an alkynyl group,
A ¹ , independently of one another, consists of the following groups a) trans-1,4-cyclohexylene and 1,4-cyclohexenylene, wherein one or more non-adjacent CH ₂ groups are —O— And / or -S-, and one or more H atoms may be replaced by F or Cl, and b) tetrahydropyran-2,5-diyl, 1,3 -Dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobutane-1,3-diyl, piperidine-1,4-diyl, thiophene-2,5-diyl and selenophene-2,5-diyl , A group which may be substituted with a group L at one or more positions,
Represents a group selected from
L is each independently F, Cl, CN, SCN, SF ₅ or linear or branched, optionally fluorinated, alkyl, alkoxy having 1 to 12 C atoms, when each occurs. Represents alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, and A ² is, independently of each other, the following groups

Representing a group selected from].

The compounds of the formula I according to the invention are characterized by an axially fluorinated trans-1,4-cyclohexane ring and a linked bridging member --CH ₂ O-- which is linked to the aromatic ring element A ^2. .. These compounds have a characteristic negative Δε and are therefore particularly suitable for use in liquid crystal mixtures for VA-TFT displays. Preferably, the compounds according to the invention have Δε ≦ −5, more preferably Δε ≦ −6. These compounds show good miscibility with the usual substances used in liquid crystal mixtures for displays, ie they have a good solubility therein. The rotational viscosity of the compound and the resulting liquid crystal mixture is advantageously low.

  Other physical, physicochemical or electro-optical parameters of the compounds according to the invention are also advantageous for the use of the compounds in liquid crystal media. Liquid crystal media containing these compounds have in particular a sufficient width of the nematic phase and good low-temperature and long-term stability and a sufficiently high clearing point. This low melting point of the compounds according to the invention suggests an advantageous mixing behavior. Furthermore, the compounds according to the invention of the formula I have very suitable values for the optical anisotropy Δn for use in VA-TFT displays. Preferably, the compounds according to the invention have a Δn greater than 0.05 and less than 0.10. Furthermore, these compounds are relatively easy to prepare and are extremely chemically stable. The balanced combination of these favorable properties shows the clear advantages of the mixture components available for VA mixtures.

  The invention will now be described in detail and preferred embodiments disclosed.

  The parameters m and n of the formula I have a sum of m + n, preferably a value of 1, 2 or 3, particularly preferably 2. Therefore, m is preferably 0 or 1, particularly preferably 1, and n is preferably 1.

Preferably, R ¹ represents an alkoxy group, an alkyl group or an alkenyl group each having 1 to 7 or 2 to 7 carbon atoms.

Preferably, R ² is an unsubstituted alkyl group, S-alkyl group (alkylsulfanyl group), S-alkenyl group (alkenylsulfanyl group) or an alkoxy group having 1 to 15 carbon atoms, or 2 to 15 C Represents an alkenyl group, alkenyloxy group or alkynyl group having atoms, each of which is optionally halogenated at one or more sites. Particularly preferably, R ² in the general formula I is an alkoxy group or an alkylsulfanyl group having 1 to 7 C atoms, particularly preferably 2 to 5 C atoms, very particularly 2 C atoms. ..

The total number of carbon atoms in R ¹ and R ² is preferably 3, 4, 5, 6, 7, 8, 9 or 10, particularly preferably 4, 5, 6, 7, 8 or 9.

R ¹ and R ^{2 in} formula I are either straight-chain or branched, so long as they each independently represent an alkyl radical. Preferably, each of these groups is straight-chain and has 1, 2, 3, 4, 5, 6 or 7 C atoms unless otherwise stated, therefore preferably methyl, ethyl , Propyl, butyl, pentyl, hexyl or heptyl.

R ¹ and R ^{2 in} formula I are straight-chain or branched, so long as they each independently represent an alkoxy group. Preferably, each of these groups is straight-chain and has 1, 2, 3, 4, 5, 6 or 7 C atoms unless otherwise stated, therefore preferably methoxy, ethoxy, It is propoxy, butoxy, pentoxy, hexoxy or heptoxy.

R ² in the formula I are straight-chain or branched, so long as they each independently represent an alkylsulfanyl group (synonymous with an S-alkyl group). Preferably, this group is straight-chain and has 1, 2, 3, 4, 5, 6 or 7 C atoms unless otherwise stated, therefore preferably methylsulfanyl, ethylsulfanyl, Propylsulfanyl, butylsulfanyl, pentylsulfanyl, hexylsulfanyl or heptylsulfanyl.

R ¹ and R ^{2 in} formula I are each, independently of one another, alkenyl having 2 to 15 C atoms which are straight-chain or branched and which have at least one C—C double bond. It may be a base. Preferably, this group is straight-chain and has 2 to 7 C atoms. Thus, preferably vinyl, prop-1- or prop-2-enyl, but-1-,-2- or but-3-enyl, penta-1-,-2-,-3- or penta-4-enyl. , Hexa-1-,-2-,-3-,-4- or hexa-5-enyl, hepta-1-,-2-,-3-,-4-,-5- or hepta-6-enyl Is. If both C atoms of the C—C double bond are substituted, the alkenyl group can be present as the E isomer and / or the Z isomer (trans / cis). Generally, the respective E isomer is preferred. Of the alkenyl groups, prop-2-enyl, but-2- or but-3-enyl, penta-3- or penta-4-enyl are particularly preferred.

R ¹ and R ^{2 in} formula I are, independently of one another, an alkynyl group which is straight-chain or branched and has 2 to 15 C atoms with at least one C—C triple bond. Good. Preferably, the alkyne group is 1- or 2-propynyl and 1-, 2- or 3-propynyl.

から選択される１つの二置換の環状基、ことに式

を表す。 The group A ¹ is preferably independently of the formula

One disubstituted cyclic group selected from

Represents.

から選択される二置換の環状基、特に好ましくは、式

の基を表す。 The groups A ² are preferably, independently of one another, of the formula

A disubstituted cyclic group selected from

Represents a group of.

Group L preferably represents an alkyl group or an alkoxy group having F, Cl, carbon atoms -CF ₃ or 1, 2 or 3,.

  Halogen in the context of the invention represents fluorine, chlorine, bromine and iodine, in particular fluorine or chlorine.

  In the context of the present invention, the term "alkyl", unless defined differently elsewhere in this specification or in the claims, is from 1 to 15 (ie 1, 2, 3, 4, 5,6,7,8,9,10,11,12,13,14 or 15) represents a linear or branched saturated aliphatic hydrocarbon group having carbon atoms.

［式中、Ｒ¹、Ｒ²、Ａ¹およびＡ²は、式Ｉについて上記に定義されたものと同じ意味を有する］から選択される。 Particularly preferably, the compounds according to the invention of the formula I have the subformulae IA, IB, IC and ID

Where R ¹ , R ² , A ¹ and A ² have the same meaning as defined above for formula I.

の化合物であり、式中、「アルキル」および「アルキル^*」は、それぞれ互いに無関係に、１〜７のＣ原子を有する直鎖のアルキル基を表す。「アルキル」は、特に好ましくは、２、３、４、５または６の、ことに３または５のＣ原子を有するアルキル基を表す。「アルキル^*」は、好ましくは、１、２、３または４のＣ原子を有するアルキル基を表す。 Preferred compounds of formulas IA, IB, IC and ID have the formula:

In the formula, "alkyl" and "alkyl ^* " each independently of one another represent a straight-chain alkyl group having 1 to 7 C atoms. "Alkyl" particularly preferably represents an alkyl group having 2, 3, 4, 5 or 6, especially 3 or 5 C atoms. "Alkyl ^* " preferably represents an alkyl group having 1, 2, 3 or 4 C atoms.

の化合物から選択され、式中、「アルキル」は、ＩＡ−１、ＩＢ−１などについての上記に定義されたものと同じである。この中で式ＩＢ−１−１およびＩＢ−２−１の化合物が特に好ましく、ことに、「アルキル」は、ｎ−プロピル基を意味する。 Particularly preferred compounds of formula I have the formula:

Wherein "alkyl" is the same as defined above for IA-1, IB-1 and the like. Of these, the compounds of the formulas IB-1-1 and IB-2-1 are particularly preferred, in particular “alkyl” means the n-propyl group.

  As long as the group or substituent of the compound according to the present invention, or the compound itself according to the present invention has an asymmetric center and therefore exists as an optically active or stereoisomeric group, substituent or compound, these are also included in the present invention. Be done. In this case, the compounds according to the invention of the general formula I are in the form of the isomers pure, for example as the pure enantiomers, diastereomers, E isomers or Z isomers, trans isomers or cis isomers or in any ratio. It is self-evident that it may exist as a mixture of a plurality of isomers in, for example, a racemate, an E / Z isomer mixture, or a cis / trans isomer mixture.

または−Ｃｙｃ−の１，４−置換シクロヘキシル環は、液晶媒体用の開示された化合物において、好ましくはトランス配置されている、つまり存在するこれらの２つの置換基は熱力学的に好ましいいす型配座で両方ともエクアトリアル位にある。同様のことが、テトラヒドロピランおよびジオキサンの環の好ましい配座についても当てはまる。 formula

Or, the -Cyc- 1,4-substituted cyclohexyl ring is preferably in the trans configuration in the disclosed compounds for liquid crystal media, ie these two substituents present are thermodynamically favored chair-shaped configurations. Both are in equatorial position. The same applies for the preferred conformations of the tetrahydropyran and dioxane rings.

の１，４−置換１−フルオロシクロヘキシル環は、式

の環を表し、つまり熱力学的に好ましい配座で、アキシャル位でＦで置換された１，４−トランス配座のシクロヘキサン環を表す。 formula

The 1,4-substituted 1-fluorocyclohexyl ring of

Of the cyclohexane ring in the 1,4-trans conformation, which is a thermodynamically favored conformation and is substituted with F at the axial position.

  The compounds of the general formula I can be prepared by methods known per se as described in the literature (e.g. basic literature such as Houben-Weyl, Methoden der organischen Chemie, Georg-Thieme-Verlag, Stuttgart) and the reactions mentioned. Can be prepared under reaction conditions known and suitable for. In this case, it is also possible to use variants which are known per se, but are not mentioned here in greater detail.

  The starting materials may optionally be generated in situ so that they are not isolated from the reaction mixture but react immediately with the compounds of general formula I.

  The synthesis of the compounds according to the invention of the general formula I is exemplarily described in the examples. The starting materials can be obtained by publicly available literature methods or by purchasing.

A particularly suitable synthetic route to the compounds according to the invention is illustrated in the following reaction scheme. The substituents R ¹ , R ² and the counters m and n have the same meanings as indicated for formula I in the following reaction schemes.

  The synthesis of compounds of formula I is preferably epoxidation of cyclohexanone 5 with a sulfur ylide nucleophile (Corey), ring opening of epoxide 6 with HF, followed by etherification of a phenolic compound of alcohol 7 ( This is carried out by converting the target compound 8 (see Formula I) according to Reaction Scheme 1).

反応式１、式Ｉの化合物の例示的合成。Ｒは、基Ｒ¹−［Ａ¹］_n−に相当する。

Exemplary Synthesis of Compounds of Scheme 1, Formula I. R is a group _{^{R 1 - [A 1] n}} - corresponds to.

The reactions shown should be construed as exemplary. These partial reactions are basically well known to the person skilled in the art. Compounds with different rings and substituents are prepared according to the outlined synthesis. The group R in the reaction formula 1 represents a general group represented by — [A ¹ ] _n —R ^{1 in} the general formula I. One of ordinary skill in the art can make corresponding modifications of the proposed synthesis to obtain the compounds of formula I, and can also take other suitable synthetic routes.

  By virtue of the synthesis described above, the present invention also comprises, in one embodiment, one or more processes for the preparation of compounds of formula I.

［式中、ｍ、Ａ¹、Ｒ¹は、無関係に、式Ｉで定義されたものと同じである］の化合物を、式（Ｂ）

［式中、無関係に、Ａ²、ｎおよびＲ²は、式Ｉで定義されたものと同じである］の化合物と反応させる方法段階を含むことを特徴とする、式Ｉの化合物の製造方法を含む。 Therefore, the present invention provides formula (A)

[Wherein m, A ¹ and R ¹ are independently the same as defined in formula I]

A process for the preparation of a compound of formula I, characterized in that it comprises a method step of reacting with a compound of the formula: wherein A ² , n and R ² are the same as defined in formula I. including.

  The reaction of A with B optionally follows other process steps which ultimately give compounds of formula I. This reaction preferably gives the compound of formula I directly.

  One aspect of the present invention is also an intermediate of formula (A). A preferred class of this compound is obtained analogously to the preferred embodiments of the compounds of formula I disclosed herein above or below.

  The compounds of formula (A) can preferably be prepared by epoxide ring opening with HF from the corresponding oxirane, which is also directly available from cyclohexanone. Intermediates of formula (A) can be converted directly to final compounds of formula I. Therefore, this is a valuable intermediate.

The process according to the invention allows a simple and independent modification of the substituents and parameters A ¹ , A ² , m, n, R ¹ and R ² since both rings A ¹ and A ² Because it is only integrated into the compound of formula I at the end of the convergent synthesis.

  This process, the preceding reaction steps and the subsequent work-up of the reaction mixture can be carried out essentially as a batch reaction or in a continuous reaction mode. Continuous reaction modes include, for example, reactions in continuous stirred tank reactors, stirred tank cascades, loop or cross flow reactors, flow tubes, or microreactors. Work-up of the reaction mixture may optionally include solid phase filtration, chromatography, separation between immiscible phases (eg extraction), adsorption on a solid support, distillation of solvent and / or azeotrope, It is carried out selectively by selective distillation, sublimation, crystallization, co-crystallization or nanofiltration with a membrane.

  As already mentioned, the compounds of general formula I can be used in liquid-crystalline media. The subject of the invention is therefore also liquid-crystalline media having at least two liquid-crystalline compounds, which comprise at least one compound of the general formula I.

  The subject of the present invention is also liquid-crystalline media which, in addition to one or more compounds according to the invention of the formula I, comprise 2-40, preferably 4-30, components as further constituents. Particularly preferably, this medium comprises, in addition to one or more compounds according to the invention, 7 to 25 components. These other constituents preferably consist of nematic or nematogen (mono- or isotropic) substances, in particular azoxybenzene, benzylideneaniline, biphenyl, terphenyl, 1,3-dioxane, 2,5-tetrahydro. Pyran, phenylbenzoate or cyclohexylbenzoate, cyclohexanecarboxylic acid phenyl ester or cyclohexanecarboxylic acid cyclohexyl ester, cyclohexylbenzoic acid phenyl ester or cyclohexyl ester, cyclohexylcyclohexanecarboxylic acid phenyl ester or cyclohexyl ester, benzoic acid, cyclohexanecarboxylic acid Or cyclohexyl cyclohexane carboxylic acid cyclohexyl phenyl ester, phenyl cyclohexane, cyclo Hexylbiphenyl, phenylcyclohexylcyclohexane, cyclohexylcyclohexane, cyclohexylcyclohexylcyclohexene, 1,4-biscyclohexylbenzene, 4 ', 4'-bicyclohexylbiphenyl, phenylpyrimidine or cyclohexylpyrimidine, phenylpyridine or cyclohexylpyridine, phenyldioxane or cyclohexyldioxane, Phenyl-1,3-dithiane or cyclohexyl-1,3-dithiane, 1,2-diphenylethane, 1,2-dicyclohexylethane, 1-phenyl-2-cyclohexylethane, 1-cyclohexyl-2- (4-phenylcyclohexyl) ) Ethane, 1-cyclohexyl-2-biphenylethane, 1-phenyl-2-cyclohexylphenylene Emissions, optionally halogenated stilbenes, benzyl phenyl ether, is selected from Trang and type of material of substituted cinnamic acids. The 1,4-phenyl group in this compound may be fluorinated at one or more sites.

The most important compounds mentioned as other constituents of the medium according to the invention can be characterized by the formulas (II), (III), (IV), (V) and (VI):
R'-LE-R "(II)
R'-L-COO-ER "(III)
R'-L-OOC-E-R "(IV)
_{R'-L-CH 2 CH 2} -E-R "(V)
_{R'-L-CF 2 O-} E-R "(VI)

  In formulas (II), (III), (IV), (V) and (VI), L and E may be the same or different and each independently of the other, -Phe-, -Cyc-,- Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -Pyr-, -Dio-, -Thp-, -G-Phe- and -G-Cyc- and groups formed from their enantiomers. Represents a divalent group consisting of, where Phe represents 1,4-phenylene, which is unsubstituted or substituted with fluorine, and Cyc is trans-1,4-cyclohexylene or 1,4-cyclohexylene. Represents cenylene, Pyr represents pyrimidine-2,5-diyl or pyridine-2,5-diyl, Dio represents 1,3-dioxane-2,5-diyl, and Thp is tetrahydropyra. Represents -2,5-diyl, G represents 2- (trans-1,4-cyclohexyl) -ethyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, 1,3-dioxane-2, Represents 5-diyl or tetrahydropyran-2,5-diyl.

  Preferably one of the groups L and E is Cyc or Phe. E is preferably Cyc, Phe or Phe-Cyc. Preferably, the medium according to the invention is such that L and E are selected from compounds of formula (II), (III), (IV), (V) and (VI), wherein L and E are selected from the group of Cyc and Phe. One or more components, and at the same time, one of the groups L and E is selected from the group of Cyc and Phe and the other group is -Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -G-Phe. One or more components selected from the compounds of formula (II), (III), (IV), (V) and (VI) selected from the group of-and-G-Cyc-, and optionally a group L and E are formulas (II), (III), (IV), (V) selected from the group of -Phe-Cyc-, -Cyc-Cyc-, -G-Phe- and -G-Cyc-. And one selected from the compounds of (VI) Including the components of the above.

  R ′ and R ″ are each independently of one another in a smaller subgroup of compounds of the formulas (II), (III), (IV), (V) and (VI) alkyl having up to 8 C atoms, Represents alkenyl, alkoxy, alkoxyalkyl (oxaalkyl), alkenyloxy or alkanoyloxy.Hereinafter, these smaller subgroups are referred to as group A, and these compounds are represented by the partial formulas (IIa), (IIIa), ( IVa), (Va) and (VIa) In most of these compounds R'and R "are different from each other, wherein one of these groups is usually alkyl, alkenyl , Alkoxy or alkoxyalkyl (oxaalkyl).

を表す。 In another smaller group of compounds of formulas (II), (III), (IV), (V) and (VI), represented as another group B, E is

Represents.

  In the compounds of group B represented by the partial formulas (IIb), (IIIb), (IVb), (Vb) and (VIb), R ′ and R ″ are the compounds of the partial formulas (IIa) to (VIa). It has the indicated meaning and is preferably alkyl, alkenyl, alkoxy or alkoxyalkyl (oxaalkyl).

  In other smaller subgroups of compounds of formulas (II), (III), (IV), (V) and (VI), R "represents -CN. This subgroup is hereinafter referred to as group C. And compounds of this subgroup are correspondingly represented by sub-formulae (IIc), (IIIc), (IVc), (Vc) and (VIc): sub-formulas (IIc), (IIIc), ( In compounds IVc), (Vc) and (VIc) R ′ has the meaning indicated in the compounds of sub-formulae (IIa) to (VIa) and is preferably alkyl, alkenyl, alkoxy or alkoxyalkyl ( Oxaalkyl).

  Besides the preferred compounds of groups A, B and C, other compounds of formula (II), (III), (IV), (V) and (VI) with other modifications of the given substituents are also conventional. is there. All these substances can be obtained by methods known in the literature or methods similar thereto.

The medium according to the invention comprises, besides the compounds according to the invention of the general formula I, preferably also one or more compounds from the groups A, B and / or C. The mass proportions of compounds from these groups, based on the medium according to the invention, are as follows:
Group A:
0-90%, preferably 20-90%, especially 30-90%.
Group B:
0-80%, preferably 10-80%, especially 10-70%.
Group C:
0-80%, preferably 5-80%, especially 5-50%.

  The medium according to the invention comprises preferably 1 to 40%, particularly preferably 5 to 30% of the compound of the invention of the formula I. This medium preferably comprises 1, 2, 3, 4 or 5 of the compounds of the invention of the formula I.

  The production of the medium according to the invention takes place in the usual manner in itself. In principle, these components dissolve in one another, preferably at elevated temperature. With suitable additives, the liquid crystal phases of the present invention can be modified for use in all types of liquid crystal display elements known to date. Additives of this kind are known to the person skilled in the art and are explained in detail in the literature (H. Kelker / R. Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, 1980). For example, pleochroic dyes or substances for modifying the dielectric anisotropy, viscosity and / or orientation of the nematic phase can be added for the production of colored guest-host systems.

  The compounds of formula I are particularly suitable for use in VA-TFT displays or passive VA displays due to their negative Δε.

  The subject of the invention is therefore also an electro-optical display element comprising a liquid crystal medium according to the invention. Preferably, the display element is a VA-TFT display element (VA: vertical alignment; TFT: thin film transistor).

  Other combinations of the embodiments and variants of the invention according to the description will be apparent from the claims and from combinations of two or more of these claims.

  The invention will now be described in greater detail on the basis of an example, but the invention is not limited to this example. The person skilled in the art can derive the details for the implementation from the examples which are not explained in detail in the general description, and the person skilled in the art can generalize to the general expertise and apply to the special task setting. You can also

  In addition to the usual and well-known abbreviations, the following abbreviations are used: Schmp. : Melting point; K: crystalline phase; N: nematic phase; Sm: smectic phase (described in detail in some cases); I: isotropic phase. The numbers between these symbols represent the transition temperature of the substance in question.

  Temperatures are expressed in degrees Celsius unless otherwise noted.

  The determination of physical, physicochemical or electro-optical parameters is described inter alia in the brochure "Merck Liquid Crystals-Licristal ® -Physical Properties of Liquid Crystals-Description of the Measurements Methods", 1998, Merck KGaA, Darmstadt. It is carried out by a generally known method as described above.

  As mentioned above and below, Δn represents the optical anisotropy (589 nm, 20 ° C.) and Δε represents the dielectric anisotropy (1 kHz, 20 ° C.). The dielectric anisotropy Δε is determined at 20 ° C. and 1 kHz. The optical anisotropy Δn is determined at 20 ° C. and a wavelength of 589.3 nm.

The Δε value and Δn value, the extrapolated clearing point (Klp.) And the rotational viscosity (γ ₁ ) of the compound according to the present invention are 5 to 10% of the respective compounds of the present invention, and 90 to 95%. Obtained by linear extrapolation from a liquid crystal mixture consisting of the commercially available liquid crystal mixture ZLI-2857 (for Δε, Klp.) Or ZLI-4792 (for Δn, γ ₁ ) (mixture, Merk KGaA, Darmstadt).

Examples Starting materials can be obtained by publicly available literature or by purchase.

ケトン９（２９．０ｇ、１３０．４ｍｍｏｌ）とトリメチルスルホキソニウムヨージド（４３．０ｇ、１９５．６ｍｍｏｌ）とのジメチルスルホキシド（２１０ｍｌ）中の混合物に、室温で、カリウム−ｔｅｒｔ−ブトキシド（２１．９ｇ、１９５．６ｍｍｏｌ）のジメチルスルホキシド（９０ｍｌ）中の溶液を滴下する。生じる混合物を３６ｈ攪拌し、引き続きヘプタン（５００ｍｌ）を加え、さらに０．５ｈ攪拌する。ヘプタン相を分離し、Celite（登録商標）で濾過し、水で洗浄し、Ｎａ₂ＳＯ₄で乾燥し、真空中で濃縮する。残留物（１６．７ｇ）を、Puriflash（ＳｉＯ₂ ３００ｇ、ヘプタン／メチル−ｔｅｒｔ−ブチルエーテル９：１）で精製する。エポキシド１０（９５．８％ＨＰＬＣ）が無色の結晶体として得られる。 Example 1:
Stage 1

To a mixture of ketone 9 (29.0 g, 130.4 mmol) and trimethylsulfoxonium iodide (43.0 g, 195.6 mmol) in dimethylsulfoxide (210 ml) at room temperature potassium-tert-butoxide (21. A solution of 9 g, 195.6 mmol) in dimethylsulfoxide (90 ml) is added dropwise. The resulting mixture is stirred for 36 h, then heptane (500 ml) is added and stirred for another 0.5 h. The heptane phase is separated, filtered through Celite®, washed with water, dried over Na ₂ SO ₄ and concentrated in vacuo. The residue (16.7 g) is purified on Puriflash (300 g SiO ₂ , heptane / methyl-tert-butyl ether 9: 1). Epoxide 10 (95.8% HPLC) is obtained as colorless crystals.

エポキシド１０（１５．６ｇ、６１．８ｍｍｏｌ、ＨＰＬＣ：９３．７％）のジクロロメタン（２７５ｍｌ）中の溶液に、−５℃で、ＨＦのピリジン中の溶液（６５％、５．０ｍｌ、１８５．５ｍｍｏｌ）を滴下する。生じる混合物を、−５℃で１ｈ攪拌し、引き続きＳｉＯ₂層で濾過する（１Ｌ、ジクロロメタンで洗浄）。アルコール１１（ＨＰＬＣ：３１．９％）が無色の油状物として得られる。 Stage 2

A solution of epoxide 10 (15.6 g, 61.8 mmol, HPLC: 93.7%) in dichloromethane (275 ml) was added at -5 ° C to a solution of HF in pyridine (65%, 5.0 ml, 185.5 mmol). ) Is dropped. The resulting mixture is stirred at −5 ° C. for 1 h, then filtered through a layer of SiO ₂ (1 L, washed with dichloromethane). Alcohol 11 (HPLC: 31.9%) is obtained as a colorless oil.

ジイソプロピルアゾジカルボキシラート（ＤＩＡＤ、１０．９ｍｌ、５５．５ｍｍｏｌ）を、１０℃で、アルコール１１（１０．２ｇ、１２．６ｍｍｏｌ、ＨＰＬＣ：３１．９％）と、フェノール１２（６．９ｇ、４７．８ｍｍｏｌ）と、トリフェニルホスフィン（１２．５ｇ、４７．６ｍｍｏｌ）とのテトラヒドロフラン（ＴＨＦ、１６１ｍｌ）中の攪拌溶液に滴加する。生じる混合物を、室温で７日間および４５℃で１日間攪拌し、引き続きＳｉＯ₂層（１００ｇ）で濾過し、フラッシュクロマトグラフィーで２回精製する（ヘプタン／メチル−ｔｅｒｔ−ブチルエーテル）。イソプロパノールから２回再結晶させた後に、最終化合物２（１．２ｇ、２５％、ＨＰＬＣ：９９．７％）が無色の結晶体として得られる。
¹Ｈ ＮＭＲ：０．８１〜１．８７（ｍ、２４Ｈ）、２．０３〜２．１５（ｍ、２Ｈ）、２．２５（ｄ、Ｊ＝２．１Ｈｚ、３Ｈ）、３．９８（ｄ、Ｊ＝１６．４Ｈｚ、２Ｈ）、６．６８（ｄｄｄ、Ｊ＝８．７、８．１、１．９Ｈｚ、１Ｈ）、６．８２（ｄｄｄ、Ｊ＝８．２、８，２、２．１Ｈｚ、１Ｈ）；¹⁹Ｆ ＮＭＲ：−１４０．６（ｄｄｔ、Ｊ＝１９．３、７．８、１．８Ｈｚ、１Ｆ）、−１５９．０（ｄｄｄ、Ｊ＝１９．４、７．４、２．４Ｈｚ、１Ｆ）、−１６５．８（ｑｔ、Ｊ＝２４．３、９．３Ｈｚ、１Ｆ）；ＥＩ−ＭＳ：３８２．３
相：Ｋ ９１ Ｎ １１８ Ｉ（Ｓｃｈｍｐ．９１℃）、
Δε＝−６．７３、Δｎ＝０．０７９２、γ₁＝４５４ｍＰａ・ｓ。 Stage 3

Diisopropyl azodicarboxylate (DIAD, 10.9 ml, 55.5 mmol) was added with alcohol 11 (10.2 g, 12.6 mmol, HPLC: 31.9%) and phenol 12 (6.9 g, 47) at 10 ° C. 0.8 mmol) and triphenylphosphine (12.5 g, 47.6 mmol) in tetrahydrofuran (THF, 161 ml) is added dropwise to a stirred solution. The resulting mixture is stirred for 7 days at room temperature and 1 day at 45 ° C., then filtered through a layer of SiO ₂ (100 g) and purified twice by flash chromatography (heptane / methyl-tert-butyl ether). After recrystallizing twice from isopropanol, the final compound 2 (1.2 g, 25%, HPLC: 99.7%) is obtained as colorless crystals.
¹ H NMR: 0.81 to 1.87 (m, 24H), 2.03 to 2.15 (m, 2H), 2.25 (d, J = 2.1 Hz, 3H), 3.98 (d. , J = 16.4 Hz, 2H), 6.68 (ddd, J = 8.7, 8.1, 1.9 Hz, 1H), 6.82 (ddd, J = 8.2, 8, 2, 2) .Sup.1 Hz, 1 H); ¹⁹ F NMR: -140.6 (ddt, J = 19.3, 7.8, 1.8 Hz, 1 F), -159.0 (ddd, J = 19.4, 7.4). 2.4 Hz, 1F), -165.8 (qt, J = 24.3, 9.3 Hz, 1F); EI-MS: 382.3.
Phase: K 91 N 118 I (Schmp. 91 ° C.),
Δε = -6.73, Δn = 0.0792, γ 1 = 454mPa · s.

相：Ｋ ７２ ＳｍＢ（６１） Ｎ １０１ Ｉ（Ｓｃｈｍｐ．７２℃）
Δε＝−６．２５、Δｎ＝０．０７６２、γ₁＝４３３ｍＰａ・ｓ。

相：Ｋ ７２ Ｎ １４４ Ｉ（Ｓｃｈｍｐ．７２℃）
Δε＝−８．２３、Δｎ＝０．０８３２、γ₁＝７０６ｍＰａ・ｓ。

相：Ｋ ４８ Ｎ（４） Ｉ（Ｓｃｈｍｐ．４８℃）
Δε＝−８．２５、Δｎ＝０．０５７２、γ₁＝７１ｍＰａ・ｓ。 The following compounds are prepared analogously to Example 1:

Phase: K 72 SmB (61) N 101 I (Schmp. 72 ° C.)
Δε = -6.25, Δn = 0.0762, γ 1 = 433mPa · s.

Phase: K 72 N 144 I (Schmp. 72 ° C.)
Δε = -8.23, Δn = 0.0832, γ 1 = 706mPa · s.

Phase: K 48 N (4) I (Schmp. 48 ° C.)
Δε = -8.25, Δn = 0.0572, γ 1 = 71mPa · s.

Other exemplified compounds are similarly prepared:

The radical R ^1/2 is straight-chain, ie unbranched, unless stated otherwise. The structures of the individual compounds are apparent from Table 1.

The alkyl group of formula C _n H _{2n + 1} is an unbranched alkyl group.

Table 1. Physical data

Claims (17)

Formula I:

[In the formula,
m is 0, 1 or 2,
n is 1 or 2,
R ¹ and R ² are, independently of one another, an alkyl radical having 1 to 15 C atoms, one or more CH ₂ radicals in said radical being, independently of one another, of which the O and S atoms are directly relative to one another. In order not to bond, -C≡C-, -CH = CH-,

-O-, -S-, -CO-O- or -O-CO-, and one or more H atoms may be replaced by halogen,
A ¹ independently of one another consists of the following groups a) trans-1,4-cyclohexylene and 1,4-cyclohexenylene, wherein one or more non-adjacent CH ₂ groups are —O— and / Or -S- and one or more H atoms are optionally replaced by F or Cl, and b) tetrahydropyran-2,5-diyl, 1,3- Consisting of dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobutane-1,3-diyl, piperidine-1,4-diyl, thiophene-2,5-diyl and selenophene-2,5-diyl, These are groups which may be substituted with a group L at one or more positions,
Represents a group selected from
L independently represents F, Cl, CN, SCN, SF ₅ or a straight-chain or branched, respectively fluorinated, optionally fluorinated C 1 to C 12 alkyl, alkoxy, alkyl, when each occurs. Represents carbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, and A ² is, independently of one another, of the following groups

Represents a group selected from]. In formula I, ring A ² is A ² is

A compound according to claim 1, characterized in that R ² is an unsubstituted alkyl group having 1 to 15 carbon atoms, an S-alkyl group, an S-alkenyl group or an alkoxy group, or an alkenyl group having 2 to 15 C atoms, an alkenyloxy group or an alkynyl group. The compound according to claim 1 or 2, characterized in that each of these is optionally halogenated at one or more positions.   Compound according to any one of claims 1 to 3, characterized in that in said formula I n = 1. In the above formula I, R ² is an alkoxy group having 1 to 7 C atoms, an alkenyloxy group having 2 to 7 C atoms, an S-alkyl group having 1 to 7 C atoms, or 2 to 7 C atoms. 5. A compound according to any one of claims 1 to 4, characterized in that it is an S-alkenyl group having   The compound according to any one of claims 1 to 5, characterized in that m is 0 or 1. A ¹ is independent of each other

7. A compound according to any one of claims 1 to 6, characterized in that it represents a group selected from The compounds of formula I are sub-formulae IA-ID

[In the formula,
R ¹ , R ² , A ¹ and A ² , m and n each independently have the same meaning as in formula I according to claim 1], The compound according to any one of 1. The compound has the formula

1 to 8 characterized in that alkyl and alkyl ^* are each independently of the other meaning a straight-chain alkyl group having 1 to 7 C atoms. The compound according to any one of 1. R ¹ and R ² are, independently of one another, an alkoxy or alkyl radical having 1 to 7 carbon atoms or an alkenyl radical having 2 to 7 carbon atoms. The compound according to any one of claims. The ring system A ¹ is, independently of each other, a partial structure

Compound according to any one of claims 1 to 10, characterized in that it is selected from formula

The compound according to any one of claims 1 to 11, selected from: wherein alkyl represents a straight-chain alkyl group having 1 to 7 C atoms.   Use of one or more compounds according to any one of claims 1 to 12 in a liquid crystal medium.   A liquid crystal medium containing at least two compounds, characterized in that it contains at least one compound according to any one of claims 1 to 12.   An electro-optical display device comprising the liquid crystal medium according to claim 14. A process for preparing a compound of formula I according to any one of claims 1 to 12, wherein the process comprises the formula (A)

[Wherein m, A ¹ and R ¹ are independently the same as defined in formula I]

A process for the preparation of a compound of formula I, characterized in that it comprises a method step of reacting with a compound of the formula: wherein A ² , n and R ² are the same as defined in formula I. .. Formula (A):

A compound of the formula: wherein m, A ¹ and R ¹ are independently the same as defined in formula I of claim 1.