JP2007291046A - New compound and liquid crystal composition containing the compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound having good compatibility and keeping a liquid crystal phase even at a low temperature and provide a liquid crystal composition containing the compound. <P>SOLUTION: The invention provides a compound expressed by formula (1) (X is alkyl or alkoxy which may be substituted with halogen atom; Y is oxygen atom or alkylene group which may be interrupted with oxygen; Z is -CH<SB>2</SB>-, -CO-, -COO-, -OCO-, single bond or the like; the ring A is a 4-20C cyclic group; n is 1-3; and R<SB>1</SB>is hydrogen, alkyl or phenyl), and a liquid crystal composition containing the compound. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a novel compound useful as a liquid crystal display element and a liquid crystal composition containing the compound.

  Liquid crystals are applied as various electro-optical elements and have been put into practical use for displays such as watches, calculators, and automobile panels. Most of the liquid crystal display devices that are currently in practical use utilize the dielectric alignment effect of twisted nematic liquid crystals. However, recently, other types of display methods have been actively developed, and liquid crystal display elements using a cholesteric-nematic phase transition display method, a polymer dispersion display method, or the like are also used.

  Liquid crystal display elements are required to have various performances such as a wide operating temperature range, low operating voltage, high speed response, high contrast ratio, wide viewing angle, chemical stability, etc. There is no one that satisfies the requirements, and a plurality of liquid crystal materials and non-liquid crystal materials excellent in one or more characteristics are mixed to form a liquid crystal composition. Therefore, it is preferable that the materials are well mixed with each other.

  And since a liquid crystal display element may be used at low temperature, it is preferable to use the liquid-crystal composition which maintains a liquid crystal phase also at low temperature. A compound having a low minimum temperature that exhibits a liquid crystal phase can contribute to widening of the temperature range of the nematic phase in a composition containing the compound.

  Patent Documents 1 to 3 disclose a compound having an alkoxy group having a low viscosity and a branched end in a liquid crystal display device, but it is not satisfactory.

JP 2004-115414 A Japanese Patent No. 2554122 Japanese Patent Publication No. 6-10170

  That is, an object of the present invention is to provide a compound having good compatibility and maintaining a liquid crystal phase even at a low temperature, and a liquid crystal composition containing the compound.

  As a result of intensive studies, the present inventors have found that a novel compound represented by the following general formula (1) is a very suitable compound for achieving the above object, and have reached the present invention. .

  That is, this invention achieves the said objective by providing the compound represented by following General formula (1).

｛式中、Ｘは、分岐を有してもよい炭素原子数１〜１０のアルキル基、又は分岐を有してもよい炭素原子数１〜１０のアルコキシ基を表し、該アルキル基又は該アルコキシ基は不飽和結合を有していてもよく、一部あるいは全部の水素原子がハロゲン原子で置換されていてもよい。Ｙは、一部の炭素原子が酸素原子で置換されてもよい炭素原子数１〜５のアルキレン基、又は酸素原子を表し、Ｚは、−ＣＨ₂−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ₂Ｏ−、−ＯＣＨ₂−、−ＣＨ₂ＣＨ₂−、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−、−ＣＦ₂Ｏ−、−ＯＣＦ₂−、−ＣＨ₂ＣＨ₂ＣＯＯ−、−ＯＣＯ−ＣＨ₂ＣＨ₂−、−ＣＦ₂ＣＦ₂−、−Ｃ≡Ｃ−ＣＯＯ−、−ＯＣＯ−Ｃ≡Ｃ−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＯＣＯ−ＣＨ＝ＣＨ−又は単結合を表し、環Ａは置換基を有してもよい炭素原子数４〜２０の環状基を表し、ｎは１〜３の整数を表し、ｎが２以上の整数のときは、環Ａ及びＺは、それぞれ異なるものであってもよく、Ｒ₁は、水素原子、分岐を有してもよい炭素原子数１〜１０のアルキル基（該アルキル基は、不飽和結合を有してもよく一部あるいは全部の水素原子がハロゲン原子で置換されてもよい）、又は、下記一般式（２）で表される置換基を表す。｝

（式中、Ｒ₂、Ｒ₃及びＲ₄は、各々独立して水素原子、シアノ基、ハロゲン原子、分岐を有してもよい炭素原子数１〜１０のアルキル基、又は分岐を有してもよい炭素原子数１〜１０のアルコキシ基を表し、該アルキル基又は該アルコキシ基は、不飽和結合を有していてもよく、一部あるいは全部の水素原子がハロゲン原子で置換されていてもよい。）

{Wherein X represents an alkyl group having 1 to 10 carbon atoms which may have a branch, or an alkoxy group having 1 to 10 carbon atoms which may have a branch, and the alkyl group or the alkoxy The group may have an unsaturated bond, and some or all of the hydrogen atoms may be substituted with halogen atoms. Y represents an alkylene group having 1 to 5 carbon atoms in which some carbon atoms may be substituted with oxygen atoms, or an oxygen atom, and Z represents —CH ₂ —, —CO—, —COO—, — OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—, —CF ₂ O—, —OCF ₂ —, —CH ₂ CH ₂ COO _{-, - OCO-CH 2 CH} 2 -, - CF 2 CF 2 -, - C≡C-COO -, - OCO-C≡C -, - CH = CH-COO -, - OCO-CH = CH- or Represents a single bond, ring A represents an optionally substituted cyclic group having 4 to 20 carbon atoms, n represents an integer of 1 to 3, and when n is an integer of 2 or more, ring A and Z may be different from each other, R ₁ is a hydrogen atom, an alkyl group (the alkyl group optionally carbon atoms 1 to 10 have a branch Some may have an unsaturated bond or all of the hydrogen atoms may be substituted with halogen atom), or a substituted group represented by the following general formula (2). }

(Wherein R ₂ , R ₃ and R ₄ each independently have a hydrogen atom, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may have a branch, or a branch. Represents an alkoxy group having 1 to 10 carbon atoms, the alkyl group or the alkoxy group may have an unsaturated bond, and a part or all of the hydrogen atoms may be substituted with a halogen atom. Good.)

  Moreover, this invention achieves the said objective by providing the compound represented by following General formula (3).

（式中、Ｘ、Ｙ、Ｒ₁、環Ａ及びｎは上記一般式（１）と同じものを表す。）

(In the formula, X, Y, R ₁ , ring A and n represent the same as in the general formula (1).)

  Moreover, this invention achieves the said objective by providing the compound represented by following General formula (4).

（式中、Ｘ及びＲ₁は上記一般式（１）と同じものを表し、Ｒ₅は水素原子又はメチル基を表し、ｍは１又は２の整数を表す。）

(In the formula, X and R ₁ represent the same as those in the general formula (1), R ₅ represents a hydrogen atom or a methyl group, and m represents an integer of 1 or 2.)

Furthermore, the present invention provides a compound in which, in the general formula (4), X is a methyl group, R ₁ is a 3-fluoro-4-cyanophenyl group, R ₅ is a methyl group, and m is 2. The above objective has been achieved.

In addition, the present invention provides a compound in which, in the general formula (4), X is a methyl group, R ₁ is a 3,4-difluorophenyl group, R ₅ is a methyl group, and m is 2. The goal has been achieved.

Moreover, this invention achieves the said objective by providing the compound whose X, R < ₁ >, and R < ₅ > are methyl groups and m is 2 in the said General formula (4).

  Moreover, this invention achieves the said objective by providing the liquid crystal composition containing the said compound.

  According to the compound of the present invention, the solubility is excellent, the compound can be well mixed with other compounds, and the effect of widening the liquid crystal phase expression temperature range is obtained.

Hereinafter, preferred embodiments of the compound of the present invention and a liquid crystal composition containing the compound will be described in detail.
In the general formula (1), the alkyl group having 1 to 10 carbon atoms which may have a branch represented by X, R ₁ , R ₂ , R ₃ or R ₄ has an unsaturated bond. Alternatively, all or some of the hydrogen atoms may be substituted with halogen atoms. For example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, 1-methylpropyl, 2-methylpropyl, pentyl, 3-methylbutyl, hexyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, heptyl, octyl , Isooctyl, 2-ethylhexyl, 2-propylpentyl, nonyl, decyl, vinyl, allyl, prop-2-en-1-yl, hexa-2-en-1-yl, 4-methyl-hex-2-ene- Examples of the group include 1-yl, hepta-5-en-4-yl, and octenyl, and methyl, propyl, 2-methylpropyl, pentyl, and 2-methylpentyl are particularly preferable.

In the general formula (1), the alkoxy group that may have 1 to 10 carbon atoms represented by X, R ₂ , R _3, or R ₄ may have an unsaturated bond. All or some of the hydrogen atoms may be substituted with halogen atoms. Examples include methoxy, ethoxy, propoxy, butoxy, pentoxy, heptoxy, octoxy, nonyloxy, decyloxy and the like, and methoxy, propoxy and pentoxy are particularly preferable.

  In the general formula (1), examples of the alkylene group having 1 to 5 carbon atoms represented by Y include methylene, ethylene, propylene, butylene, and pentylene, and the alkylene group is a part of the carbon chain. The carbon atom may be substituted with an oxygen atom.

In the general formula (1), the cyclic group having 4 to 20 carbon atoms represented by ring A may be a monocyclic, polycyclic, condensed ring, or aggregate ring composed of an aromatic group, and a saturated aliphatic group. It may be a monocyclic, polycyclic or condensed ring condensed ring, or a condensed ring composed of a combination of a cyclic group of an aromatic group and a saturated aliphatic group. Examples of the cyclic group having 4 to 20 carbon atoms include 1,4-phenylene, 1,4-cyclohexylene, 2,6-naphthylene, 4-cyclohexylbenzene, biphenyl, 2,7-anthracene or 2,7- Examples include phenanthrene, and any hydrogen atom in ring A may be substituted with a halogen atom such as fluorine, chlorine, bromine or iodine, a cyano group, an alkyl group or an alkoxy group. Preferred examples of the alkyl group include those having 1 to 3 carbon atoms such as methyl, ethyl and propyl, and examples of the alkoxy group include those having 1 to 3 carbon atoms such as methoxy, ethoxy and propoxy. Is preferred.
Specific examples of ring A include cyclic groups as exemplified below, but the present invention is not limited to these cyclic groups.

Examples of the substituent represented by the general formula (2) as R _{1 in the} general formula (1) include 4-cyanophenyl, 3,5-difluorophenyl, 3,4-difluorophenyl, and 3-fluoro. -4-propoxyphenyl, 3-fluoro-4-cyanophenyl and the like can be preferably used.

  Among these compounds represented by the general formula (1), a compound represented by the general formula (3) and a compound represented by the general formula (4) are preferable.

Further, in the compound represented by the general formula (4), a compound in which X is a methyl group, R ₁ is a 3-fluoro-4-cyanophenyl group, R ₅ is a methyl group, and m is 2, X is a methyl group R ₁ is a 3,4-difluorophenyl group, R ₅ is a methyl group, and m is 2, and X, R ₁ and R ₅ are methyl groups, and m is 2.

  Specific examples of the compound of the present invention represented by the general formula (1) include the following compound No. 1-No. 15 is mentioned. However, the present invention is not limited by the following compounds.

The compound of the present invention can be specifically obtained as in the synthesis examples described later, but can be generally obtained as in the reaction formula shown in [Chemical Formula 21].
That is, it is easy to react a carboxylic acid compound (4) having a branched alkoxy group with a phenol having a specific substituent in the presence of dicyclohexylcarbodiimide (DCC) in a solvent such as dichloromethane as necessary. Can be manufactured. Since this reaction is exothermic, it is carried out at room temperature or under water cooling.

The compound of the present invention is useful as a liquid crystal compound, and constitutes the liquid crystal composition of the present invention by blending a conventionally known liquid crystal compound, a liquid crystal similar compound, or a mixture thereof (mother liquid crystal).
Moreover, the liquid crystal composition of the present invention preferably contains 1 to 50% by mass, and particularly preferably 1 to 10% by mass of the compound of the present invention.

  Examples of the mother liquid crystal include a compound represented by the following general formula (5) or a mixture thereof.

（式中、Ｒ₆は、水素原子、又は炭素原子数１〜８のアルキル基、アルコキシ基、アルケニル基、アルケニルオキシ基、アルキニル基、アルキニルオキシ基、アルコキシアルキル基、アルカノイルオキシ基若しくはアルコキシカルボニル基を示し、これらはハロゲン原子、シアノ基等で置換されていてもよい。Ｗ₂は、シアノ基若しくはハロゲン原子、又はＲ₆で表される基と同様の基を示す。Ｗ₁、Ｗ₃及びＷ₄は、水素原子、ハロゲン原子又はシアノ基を示す。Ｚ₁及びＺ₂は、各々独立に、直接結合手、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ₂Ｏ−、−ＯＣＨ₂−、−ＣＨ₂ＣＨ₂−、−ＣＨ＝ＣＨＣＨ₂Ｏ−、−ＣＦ₂Ｏ−、−ＯＣＦ₂−、−ＣＨ₂ＣＨ₂−ＣＯＯ−、−ＣＯＯ−ＣＨ₂ＣＨ₂−、−ＣＨ＝ＣＨ−、又は−Ｃ≡Ｃ−を示す。ｐは、０、１又は２を示す。環Ｂ、環Ｃ及び環Ｄは、各々独立に、ベンゼン環、シクロヘキサン環、シクロヘキセン環、ピリミジン環又はジオキサン環を示す。）

(In the formula, R ₆ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, an alkoxy group, an alkenyl group, an alkenyloxy group, an alkynyl group, an alkynyloxy group, an alkoxyalkyl group, an alkanoyloxy group or an alkoxycarbonyl group. These may be substituted with a halogen atom, a cyano group, etc. W ₂ represents a cyano group, a halogen atom, or a group similar to the group represented by R ₆ , W ₁ , W ₃ and W ₄ represents a hydrogen atom, a halogen atom or a cyano group, and Z ₁ and Z ₂ are each independently a direct bond, —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, — CH ₂ CH ₂ —, —CH═CHCH ₂ O—, —CF ₂ O—, —OCF ₂ —, —CH ₂ CH ₂ —COO—, —COO—CH ₂ CH ₂ —, —CH═CH—, or -C≡C- is shown. Is. Ring B indicating 0, 1 or 2, ring C and ring D, each independently represents a benzene ring, cyclohexane ring, cyclohexene ring, a pyrimidine ring or a dioxane ring.)

Specific examples of the compound represented by the general formula (5) include compounds represented by the following [Chemical Formula 23]. In the following compounds, R ₆ , W ₁ , W ₂ , W ₃ and W ₄ have the same meaning as in the general formula (5).

  In addition, a known chiral agent can be used in combination with the liquid crystal composition of the present invention. Examples of the chiral agent include compounds shown in [Chemical Formula 24] and [Chemical Formula 25].

（式中、Ｒ₇及びＲ₈は、それぞれ独立して、アルキル基、アルコキシ基、アルキルカルボニルアルコキシ基又はアルコキシカルボニル基を表し、これらはエーテル基によって中断されていてもよく、ハロゲン原子及び／又はシアノ基により置換されていても良く、あるいは不飽和結合を有していても良い。環Ｅ、環Ｆ及び環Ｇは、それぞれ独立して、１，４−フェニレン、ｔｒａｎｓ−１，４−シクロヘキシレン、又は２−若しくは３−フルオロ−１，４−フェニレン若しくは１，４−シクロヘキセニレンを表し、これらはハロゲン原子及び／又はシアノ基により置換されていても良い。Ｚ₃及びＺ₄は、それぞれ独立して、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ₂ＣＨ₂−、−ＣＨ＝ＣＨ−、−（ＣＨ₂）₄−、−ＣＨ₂Ｏ−、−ＯＣＨ₂−、−（ＣＨ₂）₃Ｏ−、−Ｏ（ＣＨ₂）₃−、ＣＨ＝ＣＨＣＨ₂Ｏ−、−ＯＣＨ₂ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−、−ＣＦ₂Ｏ−、−ＯＣＦ₂−、−ＣＦＨＣＦＨ−、−ＣＨ₂ＣＨ₂−ＣＯＯ−、−ＯＣＯ−ＣＨ₂ＣＨ₂−、−ＣＦ₂−ＣＦ₂−又は単結合を表す。ｑは、０、１又は２を表す。ただし、式中には少なくとも１個以上の不斉炭素原子を有する。）

(Wherein R ₇ and R ₈ each independently represents an alkyl group, an alkoxy group, an alkylcarbonylalkoxy group or an alkoxycarbonyl group, which may be interrupted by an ether group, and may be a halogen atom and / or It may be substituted with a cyano group or may have an unsaturated bond, and ring E, ring F and ring G are each independently 1,4-phenylene, trans-1,4-cyclohexyl. cyclohexylene, or 2- or 3-fluoro-1,4-phenylene or 1,4-cyclohexenylene, these good .Z ₃ and Z ₄ may be substituted by a halogen atom and / or a cyano group, independently, -COO -, - OCO -, - CH 2 CH 2 -, - CH = CH -, - (CH 2) 4 -, - CH 2 O -, - OCH 2 -, _{(CH 2) 3 O -,} - O (CH 2) 3 -, CH = CHCH 2 O -, - OCH 2 CH = CH -, - C≡C -, - CF 2 O -, - OCF 2 -, - _{CFHCFH -, - CH 2 CH 2} -COO -, - OCO-CH 2 CH 2 -, - CF 2 -CF 2 -. or .q represents a single bond, represents 0, 1 or 2 provided that, in the formula Has at least one asymmetric carbon atom.)

（式中、Ｒ₉は、水素原子、ハロゲン原子、アルキル基、アルコキシ基、アルキルカルボニルオキシ基、アルコキシカルボニル基、置換基を有することのできるアリール基、アリールオキシ基、アリールカルボニルオキシ基又はアリールオキシカルボニル基等を表し、これらの基中の水素原子はハロゲン原子に置き換えられていても良く、エチレン基はエテニレン基又はエチニレン基により置き換えられても良い。Ｒ₁₀は、アルキル基又はアルケニル基を表す。環Ｈは、唯一つの二重結合を他の環とは共有することなく有する縮合環を表し、アルキル基及び／又はアルコキシ基で置換されていても良い。）

(In the formula, R ₉ represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkoxycarbonyl group, an aryl group that can have a substituent, an aryloxy group, an arylcarbonyloxy group, or an aryloxy group. Represents a carbonyl group, etc., a hydrogen atom in these groups may be replaced by a halogen atom, and an ethylene group may be replaced by an ethenylene group or an ethynylene group, and R ₁₀ represents an alkyl group or an alkenyl group. Ring H represents a condensed ring having a single double bond without sharing with other rings, and may be substituted with an alkyl group and / or an alkoxy group.

  Specific examples of the chiral agent include compounds represented by [Chemical Formula 26].

  Further, for example, it has been proposed in JP-A-63-175095, JP-A-1-242542, JP-A-1-258635, JP-A-6-200251, and JP-A-2002-308833. Chiral agents can also be used.

These chiral agents can be used alone or in combination of two or more. In that case, a combination of spirals having different twist directions or a combination of spirals having the same twist direction may be used. Further, for example, as proposed in Japanese Patent Application Laid-Open No. 7-258641, the temperature dependence of the turning ability of the cholesteric phase is positive, and the temperature dependence of the turning ability of the cholesteric phase is negative. Can be combined.
The pitch of the liquid crystal composition can be adjusted by changing the type and concentration of the chiral agent used. Preferably, the pitch is adjusted to be in the range of 0.2 μm to 300 μm.

  The liquid crystal composition of the present invention has a benzotriazole-based, benzophenone-based, triazine-based, benzoate-based, oxanilide-based, cyanoacrylate-based for the purpose of imparting excellent stability to light and heat over a long period of time. UV absorbers such as hindered amine light stabilizers, phenol-based, phosphorus-based, sulfur-based antioxidants, and the like can also be added.

  In addition, a compound such as a surfactant can be added to the liquid crystal composition of the present invention in order to obtain an antistatic effect. Examples of the compound include JP-A-59-4676, JP-A-4-36384, JP-A-4-180993, JP-A-11-212070, JP-A-8-337779, JP-A-8-337779. Examples thereof include compounds proposed in 9-67577 and JP-A 2003-342580.

Next, preferable examples of the liquid crystal composition of the present invention are shown in [Table 1] to [Table 6], but the liquid crystal composition of the present invention is not limited to these examples.
<Formulation example>

Hereinafter, the present invention will be further described with synthesis examples and examples. However, the present invention is not limited by the following synthesis examples and examples.
In addition, the following synthesis examples 1-3 show the Example of the compound of this invention, and the following Example 1 of the liquid crystal composition of this invention using the compound of this invention obtained by the synthesis example 3 is shown. An example is shown.

[Synthesis Example 1] (Production of Compound No. 1)
Compound No. 1 was synthesized according to the following steps according to the reaction formula shown in [Chemical Formula 27].

<Step 1> Synthesis of intermediate 1 (methylation)
4-Hydroxy-4′-biphenylcarboxylic acid (1) 92.5 g (0.43 mol) and methanol (MeOH) 1500 ml were charged, and 18.5 ml of sulfuric acid was added dropwise at room temperature. After completion of the dropwise addition, the temperature was raised to 65 degrees and the reaction was carried out with stirring. After completion of the reaction, the precipitate obtained by cooling with ice water cooling was filtered off, and the precipitate was washed with methanol and dried to obtain white crystals (yield 89.0 g, yield 90.3%).
As a result of analysis by infrared absorption spectrum (IR) and 1H-NMR, the obtained white crystal was confirmed to be methyl 4-hydroxy-4′-biphenylcarboxylate (2).

<Step 2> Compound No. Synthesis of 1 methyl 4-hydroxy-4′-biphenylcarboxylate (2) obtained in step 1 10.0 g (0.044 mol), 4-methyl-2-pentanol 4.9 g (0.048 mol), triphenyl Phosphine 12.9 g (0.049 mol) and ethyl acetate 30 g were charged, and after stirring, 9.7 g (0.048 mol) of diisopropyl azodicarboxylate (DIPAD) was added dropwise while cooling with water. It stirred for 2 hours after completion | finish of dripping. After removing the solvent by filtration, purification on a silica gel column (developing solution: toluene) was performed. Further, the purified solution was recrystallized (solvent: ethanol) to obtain 8.4 g of white crystals (yield 61.4%).
As a result of analysis by infrared absorption spectrum (IR) and 1H-NMR, the obtained white crystals were compound No. 1 as the target product. Identified as one compound. The analysis results, measurement results of phase transition temperature and optical (refractive index) anisotropy are shown below.

(result of analysis)
(1) IR (cm ^-1 )
2955, 2870, 1717, 1605, 1562, 1528, 1497, 1439, 1389, 1288, 1254, 1200, 1111, 1049, 964, 941, 833, 772, 721, 698, 629, 486
(2) ¹ H-NMR (ppm)
0.9-1.0 (m; 6H), 1.3 (d; 3H), 1.5-1.9 (m; 3H), 3.9 (s; 3H), 4.3-4. 6 (m; 1H), 6.9-7.0 (d; 2H), 7.5-7.6 (m; 4H), 8.0-8.1 (d; 2H)
(3) Phase transition temperature As a result of sandwiching this compound between two glass plates and observing the phase morphology with a polarizing microscope, the following phase transition was confirmed. Incidentally, the transition temperature from the isotropic liquid phase to the crystal phase could not be specified.

(4) Optical (refractive index) anisotropy 1 is extrapolated from the physical properties of the composition added at 10% by mass to the ester-based nematic liquid crystal having an optical (refractive index) anisotropy (Δn) of 0.0979, and the optical (refractive index) anisotropy ( When Δn) was calculated, a value of Δn = 0.152 was obtained.
The ester-based nematic liquid crystal used was a 4-n-alkylcyclohexanecarboxylic acid alkoxyphenyl ester-based composition having the composition shown below.

[Synthesis Example 2] (Production of Compound No. 2)
Compound No. 2 was synthesized according to the following steps according to the reaction formula shown in [Chemical Formula 30].

<Step 1> (Hydrolysis)
7.0 g (0.022 mol) of methyl 4- (2,4-dimethylbutoxy) -4′-biphenylcarboxylate (3) and 21 g of ethanol (EtOH) were added, and further 2.0 g of potassium hydroxide (KOH) ( 0.034 mol) and an aqueous solution of 10.5 g of water were added, heated to 80 degrees and stirred for 3 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, mixed water of 3.9 g of 35% hydrochloric acid and 100 g of water was added to obtain a precipitate. The obtained precipitate was filtered off, washed with water and dried to obtain white crystals (4) (yield 6.6 g, yield 98.5%).
As a result of analysis, the white crystal (4) was confirmed to be 4- (2,4-dimethylbutoxy) -4′-biphenylcarboxylic acid.

<Step 2> Compound No. Synthesis of 2 4- (2,4-dimethylbutoxy) -4′-biphenylcarboxylic acid (4) obtained in Step 1 3.0 g (0.010 mol), 3,4-difluorophenol 1.4 g (0.011 mol) ), 0.06 g (0.0005 mol) of dimethylaminopyridine (DMAP) and 30 g of dichloromethane were added, and a mixed solution of 2.2 g (0.011 mol) of dicyclohexylcarbodiimide (DCC) and 2.5 g of dichloromethane was added dropwise while cooling with water. After stirring for 1 hour, the precipitate was filtered off and the solvent was removed. The obtained precipitate was subjected to silica gel column purification (developing solution: toluene), and the resulting purified solution was recrystallized (solvent ethanol / toluene) and dried to give white crystals (5) (yield 3.4 g, yield). 83%).
As a result of analysis by infrared absorption spectrum (IR) and 1H-NMR, the obtained white crystal (5) was compound No. 1 as the target product. Two compounds were identified. Measurement results of these analysis results, phase transition temperature and optical (refractive index) anisotropy are shown below.

(result of analysis)
(1) IR (cm ^-1 )
2955, 2932, 2870, 1732, 1605, 1516, 1497, 1439, 1400, 1277, 1250, 1184, 1146, 1107, 1065, 1030, 1015, 953, 930, 887, 810, 764, 721, 694, 640, 605, 579, 513
(2) ¹ H-NMR (ppm)
0.9-1.0 (m; 6H), 1.3 (d; 3H), 1.5-1.9 (m; 3H), 4.3-4.6 (m; 1H), 6. 9-7.4 (m; 5H), 7.5-7.7 (m; 4H), 8.1-8.2 (d; 2H)
(3) Phase transition temperature As a result of sandwiching this compound between two glass plates and observing the phase morphology with a polarizing microscope, the following phase transition was confirmed.

（４）光学（屈折率）異方性
得られた化合物Ｎｏ．２について、光学（屈折率）異方性（Δｎ）が０．０９７９であるエステル系ネマチック液晶に対して１０質量％添加した組成物の物性から外挿して、光学（屈折率）異方性（Δｎ）を算出したところ、Δｎ＝０．１９６の値が得られた。

(4) Optical (refractive index) anisotropy 2 is extrapolated from the physical properties of the composition added by 10% by mass to the ester-based nematic liquid crystal having an optical (refractive index) anisotropy (Δn) of 0.0979, and optical (refractive index) anisotropy ( When Δn) was calculated, a value of Δn = 0.196 was obtained.

[Synthesis Example 3] (Production of Compound No. 3)
Compound No. 3 was synthesized according to the reaction formula shown in the following [Chemical Formula 31].

<Compound No. Production of 3>
4- (2,4-Dimethylbutoxy) -4′-biphenylcarboxylic acid (4) 3.0 g (0.01 mol) obtained in Step 1 of Synthesis Example 2 and 4-cyano-3-fluorophenol 1.4 g (0.011 mol), 0.06 g (0.0005 mol) of dimethylaminopyridine, and 30 g of dichloromethane were added, and a mixed solution of 2.2 g (0.011 mol) of dicyclohexylcarbodiimide and 2.5 g of dichloromethane was added dropwise while cooling with water. After stirring for 1 hour, the precipitate was filtered off and the solvent was removed. The obtained precipitate is subjected to silica gel column purification (developing solution: toluene), and the purified solution is recrystallized (solvent: ethanol / toluene) and dried to give white crystals (6) (yield 2.8 g, yield). 66.7%).
As a result of analysis by infrared absorption spectrum (IR) and 1H-NMR, the obtained white crystal (6) was compound No. 1 as the target product. 3 compounds were identified. Measurement results of these analysis results, phase transition temperature and optical (refractive index) anisotropy are shown below.

(result of analysis)
(1) IR (cm ^-1 )
2936, 2870, 2237, 1740, 1601, 1497, 1431, 1381, 1254, 1192, 1150, 1107, 1057, 1015, 961, 930, 887, 829, 764, 694, 621, 505
(2) ¹ H-NMR (ppm)
0.9-1.0 (m; 6H), 1.3 (d; 3H), 1.5-1.9 (m; 3H), 4.3-4.6 (m; 1H), 6. 9-7.4 (m; 5H), 7.5-7.7 (m; 4H), 8.1-8.2 (d; 2H)
(3) Phase transition temperature As a result of sandwiching this compound between two glass plates and observing the phase morphology with a polarizing microscope, the following phase transition was confirmed. Note that the transition temperature from the smectic phase to the crystal phase could not be specified.

（４）光学（屈折率）異方性
得られた化合物Ｎｏ．３について、光学（屈折率）異方性（Δｎ）が０．０９７９であるエステル系ネマチック液晶に対して１０質量％添加した組成物の物性から外挿して、光学（屈折率）異方性（Δｎ）を算出したところ、Δｎ＝０．２３８の値が得られた。

(4) Optical (refractive index) anisotropy 3, the optical (refractive index) anisotropy (Δn) is extrapolated from the physical properties of the composition added at 10% by mass to the ester nematic liquid crystal having 0.0979. When Δn) was calculated, a value of Δn = 0.238 was obtained.

[Example 1] (Solubility)
In the liquid crystal composition in which 10% by mass of the compound shown in Table 7 is added to the nematic liquid crystal having an optical (refractive index) anisotropy (Δn) of 0.0979, each of 0 ° C. and room temperature (25 ° C.) When the liquid crystal composition solidified when left at a temperature of 1 day and night, it was evaluated as x, and when it was in a liquid state, it was evaluated as ◯. The results are shown in Table 7.

  From Table 7, the compound of the present invention has excellent solubility at low temperatures, can be well mixed with other compounds, and can meet the demand for widening the liquid crystal phase expression temperature range. In addition, since the compound has a high value of optical (refractive index) anisotropy Δn, a liquid crystal composition using the compound can make a liquid crystal display element thin, and the selection wavelength range of liquid crystal becomes wide. The effect performed can also be produced.

Claims (7)

A compound represented by the following general formula (1).

{Wherein X represents an alkyl group having 1 to 10 carbon atoms which may have a branch, or an alkoxy group having 1 to 10 carbon atoms which may have a branch, and the alkyl group or the alkoxy The group may have an unsaturated bond, and some or all of the hydrogen atoms may be substituted with halogen atoms. Y represents an alkylene group having 1 to 5 carbon atoms in which some carbon atoms may be substituted with oxygen atoms, or an oxygen atom, and Z represents —CH ₂ —, —CO—, —COO—, — OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—, —CF ₂ O—, —OCF ₂ —, —CH ₂ CH ₂ COO _{-, - OCO-CH 2 CH} 2 -, - CF 2 CF 2 -, - C≡C-COO -, - OCO-C≡C -, - CH = CH-COO -, - OCO-CH = CH- or Represents a single bond, ring A represents an optionally substituted cyclic group having 4 to 20 carbon atoms, n represents an integer of 1 to 3, and when n is an integer of 2 or more, ring A and Z may be different from each other, R ₁ is a hydrogen atom, an alkyl group (the alkyl group optionally carbon atoms 1 to 10 have a branch Some may have an unsaturated bond or all of the hydrogen atoms may be substituted with halogen atom), or a substituted group represented by the following general formula (2). }

(Wherein R ₂ , R ₃ and R ₄ each independently have a hydrogen atom, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms which may have a branch, or a branch. Represents an alkoxy group having 1 to 10 carbon atoms, the alkyl group or the alkoxy group may have an unsaturated bond, and a part or all of the hydrogen atoms may be substituted with a halogen atom. Good.) A compound represented by the following general formula (3).

(In the formula, X, Y, R ₁ , ring A and n represent the same as in the general formula (1)). A compound represented by the following general formula (4).

(In the formula, X and R ₁ represent the same as those in the general formula (1), R ₅ represents a hydrogen atom or a methyl group, and m represents an integer of 1 or 2.) The compound according to claim 3, wherein, in the general formula (4), X is a methyl group, R ₁ is a 3-fluoro-4-cyanophenyl group, R ₅ is a methyl group, and m is 2. The compound according to claim 3, wherein, in the general formula (4), X is a methyl group, R ₁ is a 3,4-difluorophenyl group, R ₅ is a methyl group, and m is 2. In the general formula (4), X, R ₁ and R ₅ is a methyl group, and compound of claim 3 wherein m is 2. A liquid crystal composition comprising the compound according to claim 1.