JP4887605B2 - Chroman derivative and liquid crystal composition containing the compound - Google Patents

Description

  The present invention relates to a chroman derivative, a liquid crystal composition using the same, and a liquid crystal display device using the same.

  Liquid crystal display elements are currently widely used because of their excellent features such as low voltage operation and thin display. Conventional liquid crystal display elements, especially small and medium-sized displays, include TN (twisted nematic), STN (super twisted nematic), or active matrix (TFT: thin film transistor) based on TN, which have different dielectric constants. A liquid crystal composition having a positive isotropic value is used.

  However, one of the drawbacks of these display methods is the narrow viewing angle, and the improvement of the liquid crystal panel that has been increasing in recent years has become a major issue for improvement. In recent years, display methods such as vertical alignment and IPS (in-plane switching) have been newly put to practical use as a solution. The vertical alignment method is a method in which the viewing angle is improved by utilizing the vertical alignment of liquid crystal molecules, and a liquid crystal composition having a negative dielectric anisotropy value is used. IPS is a method that improves the viewing angle by switching the liquid crystal molecules using a horizontal electric field in the horizontal direction with respect to the glass substrate, and uses a liquid crystal composition with positive or negative dielectric anisotropy. Is done. As described above, the vertical alignment method and the IPS, which are effective display methods for improving the viewing angle, require a liquid crystal compound and a liquid crystal composition having a negative dielectric anisotropy value. It has become. However, as described above, since the conventional display method mainly uses a liquid crystal composition having a positive dielectric anisotropy value, liquid crystal compounds and liquid crystal compositions having a negative dielectric anisotropy value are used. Is not fully developed.

  Examples of the liquid crystal compound having a negative dielectric anisotropy value include a liquid crystal compound having a 2,3-difluorophenylene skeleton (see Patent Document 1) and a 3,4-difluoro-5,6,7,8-tetrahydronaphthalene skeleton. A liquid crystal compound (see Patent Document 2) is disclosed. However, these compounds do not necessarily have a sufficiently large absolute value of dielectric anisotropy, which hinders the development of the liquid crystal display device described above, and the dielectric anisotropy value is negative and the absolute value thereof is Development of a compound having a large size was demanded.

  As a compound having a large absolute value of dielectric anisotropy, a liquid crystal compound having a 1,7,8-trifluoronaphthalene skeleton (see Patent Document 3) is disclosed. However, although this compound has a large absolute value of dielectric anisotropy, since it has a naphthalene skeleton, it has a large refractive index anisotropy and is difficult to apply to a liquid crystal composition having a small refractive index anisotropy. there were.

  On the other hand, the application of a compound having a chroman ring as a liquid crystal material is already known (see Patent Documents 4 and 5). However, since the compounds described in these documents have an unsubstituted chroman ring and an optically active group, they are intended for application to ferroelectric liquid crystal compositions. Further, these documents do not disclose negative dielectric anisotropy, and most of the compounds described have a positive dielectric anisotropy. In view of a normal nematic liquid crystal composition, a chroman compound in which an optically active group is not essential is also known (see Patent Document 6). However, the compound described is a compound having an unsubstituted chroman ring, and is considered to have a ferroelectric liquid crystal composition in mind. Moreover, most of the compounds have positive dielectric anisotropy, and there is no description regarding negative dielectric anisotropy.

  From the above, development of a liquid crystal material having a large absolute value of negative dielectric anisotropy and a small refractive index anisotropy has been demanded.

German Patent Application Publication No. 3,906,019 German Patent Application Publication No. 19522145 German Patent Application Publication No. 19522195 Japanese Patent Laid-Open No. 5-25158 JP-A-6-256337 JP-A-6-256339

  An object of the present invention is to provide a liquid crystal compound having a negative dielectric anisotropy, a large absolute value, and a small refractive index anisotropy. A liquid crystal composition and a liquid crystal display device using the same are provided. Is to provide.

As a result of studying various liquid crystal materials in order to solve the above-mentioned problems, the present inventors have completed the following invention.
In a liquid crystal display element having a structure in which a liquid crystal is sandwiched between a pair of substrates and including at least an alignment control layer (including an alignment film), a transparent electrode, and a polarizing plate, the liquid crystal is at least one type of general formula (A )

(式中、W¹及びW²はそれぞれ独立的にフッ素原子、塩素原子、−CF₃、−CF₂H、−OCF₃又は−OCF₂Hを表す。)で表される部分構造を有する液晶化合物を含有し、誘電率異方性が負であることを特徴とする液晶表示素子及び一般式(１)

(Wherein W ¹ and W ² each independently represent a fluorine atom, a chlorine atom, —CF ₃ , —CF ₂ H, —OCF ₃ or —OCF ₂ H). A liquid crystal display element comprising a compound and having a negative dielectric anisotropy and a general formula (1)

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and one CH ₂ group present in these groups) Alternatively, two or more CH ₂ groups that are not adjacent to each other may be substituted with an oxygen atom or a sulfur atom, and one or more hydrogen atoms present in these groups may be replaced with a fluorine atom or a chlorine atom. May be replaced,
A ^1, A ^2, A ³ and A ⁴ are each independently not one CH ₂ group or adjacent existing in xylene group (in this group the trans-1,4-cyclohexylene two CH ₂ groups May be substituted with an oxygen atom or a sulfur atom), 1,4-phenylene group (one or two or more CH groups present in this group may be substituted with a nitrogen atom), 1 , 4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or Represents a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, the hydrogen atom present in these groups may be substituted with -CN or halogen,
Z ¹ , Z ² , Z ³ and Z ⁴ are each independently -CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-,- CH (CH ₃ ) CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF-, -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-,-(CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -C≡C-, -CF ₂ O-, -OCF _2- , -COO-, -OCO -, - COS -, - SCO- or a single bond, if ^{a 1, a 2, a 3} , a 4, Z 1, Z 2, Z 3 and Z ⁴ there are multiple, they same But it can be different,
a, b, c and d each independently represent 0 or 1,
W ¹ and W ² each independently represent a fluorine atom, a chlorine atom, —CF ₃ , —CF ₂ H, —OCF ₃ or —OCF ₂ H. And a liquid crystal composition using the same.

  The chroman derivative of the present invention has the characteristics that the dielectric anisotropy is negative, the absolute value thereof is large, and the refractive index anisotropy is small. A liquid crystal composition and a liquid crystal display element comprising the compound as a constituent member are useful as a liquid crystal display element such as a vertical alignment method or IPS.

An example of the present invention will be described below.
The liquid crystal display element of the present invention is characterized in that the liquid crystal layer sandwiched between a pair of substrates contains a liquid crystal compound having a structure represented by the general formula (A). In the general formula (A), W ¹ and W ² preferably contain a liquid crystal compound having a structure representing a fluorine atom.

  The liquid crystal display element of the present invention is particularly preferably used as an active matrix liquid crystal display element. In order to obtain a wider viewing angle as a display mode, a VA (Vertically aligned) mode, an IPS (In-Plane Switching) mode, an ECB ( Electrically controlled birefringence) mode is preferred.

Although the compound represented by General formula (1) includes many compounds, the following compound is preferable.
In general formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. It preferably represents an alkyl group having 1 to 7 carbon atoms substituted by an alkoxyl group or an alkenyl group having 2 to 7 carbon atoms substituted by an alkoxyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 12 carbon atoms, carbon An alkenyl group having a number of 2 to 12 is more preferable, specifically, —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ , — (CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E-form),-(CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E-form), -OCH _{3 , -OCH 2 CH 3, -O (} CH 2) 2 CH 3, -O (CH 2) it is particularly preferably represents ₃ CH ₃ or _{-O (CH 2) 4 CH 3} , location If rings are aromatic _{rings, -CH 3, -CH 2 CH 3} , - (CH 2) 2 CH 3, - (CH 2) 3 CH 3, - (CH 2) 4 CH 3, - (CH 2) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ ,-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form),-( CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form), -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ ) It is particularly preferred to represent ₃ CH ₃ or —O (CH ₂ ) ₄ CH ₃ .

Among these, when R ¹ or R ² substituted at the 6-position of the chroman ring represents an alkoxy group, the dielectric anisotropy is preferably increased.

A ^1, A ^2, A ³ and A ⁴ each independently is not one CH ₂ group or adjacent existing in xylene group (in this group the trans-1,4-cyclohexylene two CH ₂ Including those in which the group is substituted with an oxygen atom), 1,4-phenylene groups (including those in which one or two CH groups present in this group are substituted with nitrogen atoms), 1,4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group Or a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group or a substituent in which these hydrogen atoms are substituted with fluorine atoms, preferably a trans-1,4-cyclohexylene group, 1 , 4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3-difluoro-1,4-phenylene group or 1,4-bicyclo [2.2.2 ] Octylene group More preferably, trans-1,4-cyclohexylene group, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group or 2,3-difluoro-1 1,4-phenylene group is more preferable, and trans-1,4-cyclohexylene group or 1,4-phenylene group is particularly preferable.

Z ¹ , Z ² , Z ³ and Z ⁴ are each independently --CH ₂ CH _2- , --CH = CH-(E form), --CH (CH ₃ ) CH _2- , --CH ₂ CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF- (E form), -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-,- (CH ₂ ) ₄ —, —C≡C—, —CF ₂ O—, —OCF ₂ —, —COO—, —OCO—, or a single bond is preferred, but —CH ₂ CH ₂ —, — CH = CH- (E isomer), -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF- (E isomer), -CH ₂ O -, -OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-, -C≡C-, -CF ₂ O-, -OCF ₂ -or a single bond is more preferred, and -CH ₂ CH ₂ −, —CH ₂ O—, —OCH ₂ , —CF ₂ O—, —OCF ₂ —, —CH═CH— (E form) or a single bond is more preferable, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ — or a single bond is particularly preferred.

Among them, a compound in which Z ¹ or Z ² substituted at the 6-position of the chroman ring is —CH ₂ O— or —CF ₂ O— and the oxygen atom in the group is bonded to the chroman ring is a very large negative dielectric. Has a rate anisotropy value.
W ¹ and W ² each independently preferably represent a fluorine atom, a chlorine atom, -CF ₃ , -CF ₂ H, -OCF ₃ or -OCF ₂ H, more preferably a fluorine atom or a chlorine atom, A fluorine atom is particularly preferred.

  a, b, c and d each independently represent 0 or 1, preferably satisfying 1 ≦ a + b + c + d ≦ 3, more preferably satisfying 1 ≦ a + b + c + d ≦ 2.

  More specifically, among the compounds of the general formula (1), the compounds described in the formula group 1 can be mentioned as particularly preferred compounds.

(In the formula, R ¹ and R ² are each independently —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ , — (CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) _{2 CH = CH 2, - (CH} 2) 2 CH = CHCH 3 (E _{bodies), - (CH 2) 4} CH = CH 2, - (CH 2) 4 CH = CHCH 3 (E bodies), - OCH _{3, -OCH 2 CH 3, -O (CH} 2) 2 CH 3, -O (CH 2) 3 CH 3 or -O (CH ₂₎ represents a ₄ CH _3.)
The compound represented by the general formula (1) can be obtained by the following production method.

  (Manufacturing method 1) General formula (12)

(式中、R¹、A¹、A²、Z¹、Z²、a及びbはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるベンゼン誘導体に対し、ハロゲン基を導入して一般式(13)

(Wherein R ¹ , A ¹ , A ² , Z ¹ , Z ² , a and b each independently represent the same meaning as in formula (1)), a halogen group General formula (13)

(式中、R¹、A¹、A²、Z¹、Z²、a及びbはそれぞれ独立的に一般式(１)と同じ意味を表し、W³はハロゲンを表す。)で表されるベンゼン誘導体を得る。このときW³は塩素、臭素及びよう素が好例として挙げられるが、よう素がより好ましい。
得られた一般式(13)の化合物に、一般式(14)

(Wherein R ¹ , A ¹ , A ² , Z ¹ , Z ² , a and b each independently represent the same meaning as in general formula (1), and W ³ represents halogen). A benzene derivative is obtained. In this case, W ³ is preferably exemplified by chlorine, bromine and iodine, but iodine is more preferable.
The compound of the general formula (13) obtained was added to the general formula (14).

(式中、R²、A³、A⁴、Z³、Z⁴、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるアセチレン誘導体をカップリング反応させ、一般式(15)

(Wherein R ² , A ³ , A ⁴ , Z ³ , Z ⁴ , c and d each independently represent the same meaning as in general formula (1)), a coupling reaction of the acetylene derivative represented by General formula (15)

(式中、R¹、R²、A¹、A²、A³、A⁴、Z¹、Z²、Z³、Z⁴、a、b、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるアセチレン誘導体を得る。
得られた一般式(15)の化合物を水素添加して、一般式(16)

(In the formula, R ¹ , R ² , A ¹ , A ² , A ³ , A ⁴ , Z ¹ , Z ² , Z ³ , Z ⁴ , a, b, c and d are each independently represented by the general formula (1 The acetylene derivative represented by the same meaning as) is obtained.
The obtained compound of the general formula (15) is hydrogenated to obtain a compound of the general formula (16)

(式中、R¹、R²、A¹、A²、A³、A⁴、Z¹、Z²、Z³、Z⁴、a、b、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるアルコール誘導体を得る。
得られた一般式(16)の化合物に塩基を反応させ、一般式(17)

(In the formula, R ¹ , R ² , A ¹ , A ² , A ³ , A ⁴ , Z ¹ , Z ² , Z ³ , Z ⁴ , a, b, c and d are each independently represented by the general formula (1 The alcohol derivative represented by the same meaning as) is obtained.
A base is reacted with the obtained compound of the general formula (16), and the general formula (17)

(式中、R¹、R²、A¹、A²、A³、A⁴、Z¹、Z²、Z³、Z⁴、a、b、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表し、M^aはリチウム、ナトリウム、カリウム等のアルカリ金属、マグネシウム、カルシウム等のアルカリ土類金属等の金属を表す。)で表されるアルコラートを得る。好ましい塩基の例として金属水素化物、金属炭酸塩、金属水酸化物、金属カルボン酸塩、金属アミド、金属等を挙げることができ、中でもアルカリ金属水素化物、アルカリ金属炭酸塩、アルカリ金属水酸化物、アルカリ金属アミド、アルカリ金属が好ましく、アルカリ金属水素化物、アルカリ金属炭酸塩は更に好ましい。アルカリ金属水素化物としては水素化リチウム、水素化ナトリウム、水素化カリウムを、アルカリ金属炭酸塩としては炭酸ナトリウム、炭酸水素ナトリウム、炭酸カリウム、炭酸水素カリウムをそれぞれ好ましく挙げることができる。

(In the formula, R ¹ , R ² , A ¹ , A ² , A ³ , A ⁴ , Z ¹ , Z ² , Z ³ , Z ⁴ , a, b, c and d are each independently represented by the general formula (1 M ^a represents an alkali metal such as lithium, sodium and potassium, and an alkaline earth metal such as magnesium and calcium. Examples of preferred bases include metal hydrides, metal carbonates, metal hydroxides, metal carboxylates, metal amides, metals and the like, among them alkali metal hydrides, alkali metal carbonates, alkali metal hydroxides. Alkali metal amides and alkali metals are preferred, and alkali metal hydrides and alkali metal carbonates are more preferred. Preferred examples of the alkali metal hydride include lithium hydride, sodium hydride, and potassium hydride, and preferred examples of the alkali metal carbonate include sodium carbonate, sodium hydrogen carbonate, potassium carbonate, and potassium hydrogen carbonate.

  At this time, any solvent can be used as long as it allows the reaction to proceed appropriately, but ether solvents, hydrocarbon solvents, aromatic solvents, polar solvents, and the like can be preferably used. As ether solvents, 1,4-dioxane, 1,3-dioxane, tetrahydrofuran, diethyl ether, t-butyl methyl ether and the like, and as chlorine solvents, dichloromethane, 1,2-dichloroethane, carbon tetrachloride and the like, The hydrocarbon solvent is pentane, hexane, cyclohexane, heptane, octane, etc., the aromatic solvent is benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, etc., the polar solvent is N, N-dimethylformamide, Preferable examples include N-methylpyrrolidone, dimethyl sulfoxide, sulfolane and the like. Among these, ether solvents such as tetrahydrofuran and dimethyl ether and polar solvents such as N, N-dimethylformamide are more preferable. Each of the above solvents may be used alone, or two or more solvents may be mixed and used.

  The reaction temperature can be in the range from the freezing point of the solvent to the reflux temperature, but is preferably from -20 ° C to 60 ° C.

  By subjecting the resulting compound of the general formula (17) to a substitution reaction in the molecule, the general formula (18)

(式中、R¹、R²、A¹、A²、A³、A⁴、Z¹、Z²、Z³、Z⁴、a、b、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるクロマン誘導体を得ることができる。本反応は一般式(17)で表されるアルコラートの生成反応と同一系内で行なうことが好ましい。

(In the formula, R ¹ , R ² , A ¹ , A ² , A ³ , A ⁴ , Z ¹ , Z ² , Z ³ , Z ⁴ , a, b, c and d are each independently represented by the general formula (1 The chroman derivative represented by the same meaning as) can be obtained. This reaction is preferably carried out in the same system as the alcoholate production reaction represented by the general formula (17).

(Manufacturing method 2)
By using 1,2,3-trifluorobenzene as a starting material and performing the same reaction as in Production Method 1,

(式中、R²、A³、A⁴、Z³、Z⁴、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるクロマン誘導体を得る。
得られた一般式(19)の化合物をリチオ化することで、一般式(20)

(Wherein R ² , A ³ , A ⁴ , Z ³ , Z ⁴ , c and d each independently represent the same meaning as in general formula (1)).
By lithiation of the obtained compound of the general formula (19), the general formula (20)

(式中、R²、A³、A⁴、Z³、Z⁴、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるリチウム化合物を得る。

(Wherein R ² , A ³ , A ⁴ , Z ³ , Z ⁴ , c and d each independently represent the same meaning as in general formula (1)).

  The obtained compound of the general formula (20) is represented by the general formula (21)

(式中、R¹、A¹、Z¹及びaはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるシクロヘキサノン誘導体と反応させることにより、一般式(22)

(Wherein R ¹ , A ¹ , Z ¹ and a each independently represent the same meaning as in general formula (1)), by reacting with a cyclohexanone derivative represented by general formula (22)

(式中、R¹、R²、A¹、A³、A⁴、Z¹、Z³、Z⁴、a、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるアルコールを得る。

(In the formula, R ¹ , R ² , A ¹ , A ³ , A ⁴ , Z ¹ , Z ³ , Z ⁴ , a, c and d each independently represent the same meaning as in the general formula (1).) The alcohol represented by is obtained.

  By dehydrating the obtained compound of the general formula (22) general formula (23)

(式中、R¹、R²、A¹、A³、A⁴、Z¹、Z³、Z⁴、a、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるオレフィンを得る。
得られた一般式(23)の化合物を水素添加することで一般式(24)

(In the formula, R ¹ , R ² , A ¹ , A ³ , A ⁴ , Z ¹ , Z ³ , Z ⁴ , a, c and d each independently represent the same meaning as in the general formula (1).) Is obtained.
By hydrogenating the obtained compound of the general formula (23), the general formula (24)

(式中、R¹、R²、A¹、A³、A⁴、Z¹、Z³、Z⁴、a、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるクロマン誘導体を得ることができる。

(In the formula, R ¹ , R ² , A ¹ , A ³ , A ⁴ , Z ¹ , Z ³ , Z ⁴ , a, c and d each independently represent the same meaning as in the general formula (1).) The chroman derivative represented by this can be obtained.

(Manufacturing method 3)
By oxidizing the compound of the general formula (19), the general formula (25)

(式中、R²、A³、A⁴、Z³、Z⁴、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるクロマン誘導体を得る。
得られた一般式(25) の化合物に塩基を反応させ、一般式(26)

(Wherein R ² , A ³ , A ⁴ , Z ³ , Z ⁴ , c and d each independently represent the same meaning as in general formula (1)).
A base is reacted with the obtained compound of the general formula (25) to give a general formula (26)

(式中、M^a、R²、A³、A⁴、Z³、Z⁴、c及びdはそれぞれ独立的に一般式(17)と同じ意味を表す。) で表されるクロマン誘導体を得る。
得られた一般式(26) の化合物に一般式(27)

(Wherein, M ^a , R ² , A ³ , A ⁴ , Z ³ , Z ⁴ , c and d each independently represent the same meaning as in general formula (17)). .
The compound of the general formula (26) obtained was added to the general formula (27)

(式中、R¹、A¹、A²、Z¹及びaはそれぞれ独立的に一般式(１)と同じ意味を表し、X^aは塩素、臭素、よう素、ベンゼンスルホニル機、p-トルエンスルホニル基、メタンスルホニル基又はトリフルオロメタンスルホニル基を表す。)で表される化合物を反応させることで、一般式(28)

(Wherein R ¹ , A ¹ , A ² , Z ¹ and a each independently represent the same meaning as in general formula (1), X ^a is chlorine, bromine, iodine, benzenesulfonyl machine, p-toluene A sulfonyl group, a methanesulfonyl group or a trifluoromethanesulfonyl group) is reacted with a compound represented by the general formula (28)

(式中、R¹、R²、A¹、A²、A³、A⁴、Z¹、Z³、Z⁴、a、c及びdはそれぞれ独立的に一般式(17)と同じ意味を表す。) で表されるクロマン誘導体を得ることができる。

(Wherein R ¹ , R ² , A ¹ , A ² , A ³ , A ⁴ , Z ¹ , Z ³ , Z ⁴ , a, c and d each independently have the same meaning as in general formula (17) A chroman derivative represented by the following formula:

  The compound represented by the general formula (15) can also be synthesized by the following method.

(Manufacturing method 4)
A compound represented by the general formula (13) and 3-methyl-1-butyn-3-ol are subjected to a coupling reaction to give a general formula (29)

(式中、R¹、A¹、A²、Z¹、Z²、a及びbはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表される化合物を得る。
得られた一般式(29)で表される化合物に塩基を作用させて一般式(30)

(Wherein R ¹ , A ¹ , A ² , Z ¹ , Z ² , a and b each independently represent the same meaning as in general formula (1)).
A base is allowed to act on the resulting compound represented by the general formula (29) to give a general formula (30)

(式中、R¹、A¹、A²、Z¹、Z²、a及びbはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表される化合物を得る。
得られた一般式(30)で表される化合物のアセチリドを調製した後一般式(31)

(Wherein R ¹ , A ¹ , A ² , Z ¹ , Z ² , a and b each independently represent the same meaning as in general formula (1)).
After preparing acetylide of the compound represented by the general formula (30) obtained, the general formula (31)

(式中、R²、A³、A⁴、Z³、Z⁴、c及びdはそれぞれ独立的に一般式(１)と同じ意味を表す。)で表されるアルデヒド化合物と反応させることにより、一般式(15)で表される化合物を得ることができる。

(Wherein R ² , A ³ , A ⁴ , Z ³ , Z ⁴ , c and d each independently represent the same meaning as in general formula (1)), by reacting with the aldehyde compound represented by A compound represented by the general formula (15) can be obtained.

  In this invention, the liquid crystal composition containing the compound represented by General formula (1) is provided. In this case, only 1 type of compound represented by General formula (1) may be contained, and it is also preferable to contain 2 or more types. The content of the compound represented by the general formula (1) is preferably 2 to 40% by mass, and more preferably 2 to 30% by mass.

  The liquid crystal composition of the present invention has the general formula (2) in addition to the compound represented by the general formula (1).

(式中、R³及びR⁴はそれぞれ独立的に水素原子、炭素数1から12のアルキル基又は炭素数2から12のアルケニル基を表し、これらの基中に存在する1個のCH₂基又は隣接していない2個以上のCH₂基は酸素原子又は硫黄原子に置換されても良く、又、これらの基中に存在する1個又は2個以上の水素原子はフッ素原子又は塩素原子に置換されても良く、
B¹及びB²はそれぞれ独立的にトランス-1,4-シクロへキシレン基(この基中に存在する1個のCH₂基又は隣接していない2個のCH₂基は酸素原子又は硫黄原子に置換されても良い。)、1,4-フェニレン基(この基中に存在する1個又は2個以上のCH基は窒素原子に置換されても良い。)、1,4-シクロヘキセニレン基、1,4-ビシクロ[2.2.2]オクチレン基、ピペリジン-1,4-ジイル基、ナフタレン-2,6-ジイル基、デカヒドロナフタレン-2,6-ジイル基又は1,2,3,4-テトラヒドロナフタレン-2,6-ジイル基を表し、これらの基中に存在する水素原子は−CN又はハロゲンで置換されていても良く、
Y¹及びY²はそれぞれ独立的に、−CH₂CH₂−、−CH=CH−、−CH(CH₃)CH₂−、−CH₂CH(CH₃)−、−CH(CH₃)CH(CH₃)−、−CF₂CF₂−、−CF=CF−、−CH₂O−、−OCH₂−、−OCH(CH₃)−、−CH(CH₃)O−、−(CH₂)₄−、−(CH₂)₃O−、−O(CH₂)₃−、−C≡C−、−CF₂O−、−OCF₂−、−COO−、−OCO−、−COS−、−SCO−又は単結合を表し、
Y²及びB²が複数存在する場合は、それらは同一でも良く異なっていても良く、
pは０、１又は２を表す。)で表される化合物を化合物を含有することが好ましい。

(In the formula, R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and one CH ₂ group present in these groups. Alternatively, two or more CH ₂ groups that are not adjacent to each other may be substituted with an oxygen atom or a sulfur atom, and one or more hydrogen atoms present in these groups may be replaced with a fluorine atom or a chlorine atom. May be replaced,
B ¹ and B ² are each independently a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or _two non-adjacent CH ₂ groups are oxygen atoms or sulfur atoms) 1,4-phenylene group (one or more CH groups present in this group may be substituted with a nitrogen atom), 1,4-cyclohexenylene 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, or 1,2,3, 4-tetrahydronaphthalene-2,6-diyl group, a hydrogen atom present in these groups may be substituted with -CN or halogen,
Y ¹ and Y ² are each independently -CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH (CH ₃ ) CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF-, -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-,-( CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -C≡C-, -CF ₂ O-, -OCF _2- , -COO-, -OCO-,- COS-, -SCO- or single bond
When there are a plurality of Y ² and B ² , they may be the same or different,
p represents 0, 1 or 2. It is preferable to contain a compound represented by

In the general formula (2), R ³ and R ⁴ are each independently an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, or 1 to 5 carbon atoms. Preferably represents an alkyl group having 1 to 7 primes substituted by an alkoxyl group or an alkenyl group having 2 to 7 carbons substituted by an alkoxyl group having 1 to 5 carbons, an alkyl group having 1 to 12 carbons, An alkenyl group having 2 to 12 carbon atoms is more preferable, specifically, —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ , — (CH ₂ ) _{4 CH 3, - (CH 2)} 5 CH 3, - (CH 2) 6 CH 3, - (CH 2) 7 CH 3, -CH = CH 2, -CH = CHCH 3 (E bodies), - (CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form),-(CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form), -OCH _{3, -OCH 2 CH 3, -O} (CH 2) 2 CH 3, -O (CH 2) it is particularly preferably represents ₃ CH ₃ or _{-O (CH 2) 4 CH 3} , When rings conversion of the aromatic _{ring, -CH 3, -CH 2 CH 3} , - (CH 2) 2 CH 3, - (CH 2) 3 CH 3, - (CH 2) 4 CH 3, - (CH 2 ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ ,-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form),- (CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form), -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ It is particularly preferred that it represents ₃ CH ₃ or —O (CH ₂ ) ₄ CH ₃ .

B ¹ and B ² are each independently a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or _two non-adjacent CH ₂ groups are replaced by oxygen atoms) 1,4-phenylene group (including those in which one or two CH groups present in this group are substituted with nitrogen atoms), 1,4-cyclohexeni Len group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or 1,2,3 , 4-tetrahydronaphthalene-2,6-diyl group or a hydrogen atom substituted with a fluorine atom, preferably trans-1,4-cyclohexylene group, 1,4-cyclohexenylene Group, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3-difluoro-1,4-phenylene group or 1,4-bicyclo [ 2.2.2] More preferred is a cutylene group, trans-1,4-cyclohexylene group, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group or 2,3- A difluoro-1,4-phenylene group is more preferable, and a trans-1,4-cyclohexylene group or a 1,4-phenylene group is particularly preferable.

Y ¹ and Y ² are each independently -CH ₂ CH _2- , -CH = CH- (E form), -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CF _{2 CF 2 -, - CF =} CF- (E _{bodies), - CH 2 O -,} - OCH 2 -, - OCH (CH 3) -, - CH (CH 3) O -, - (CH 2) 4 - , —C≡C—, —CF ₂ O—, —OCF ₂ —, —COO—, —OCO—, or a single bond,
_{, - - -CH 2 CH 2 CH} = CH- (E _{bodies), - CH 2 O -,} - OCH 2 -, - C≡C -, - CF 2 O -, - OCF 2 -, - COO -, - OCO-, or more preferably a single _{bond, -CH 2 CH 2 -, -} CH = CH- (E bodies), - C≡C -, - COO -, - OCO-, or a single bond Is more preferable, and it is particularly preferable to represent —CH ₂ CH ₂ — or a single bond.

p preferably represents 1 or 2.
Specifically, the compound represented by the general formula (2) preferably has a structure represented by the following general formula (2-1) to general formula (2-22).

(In the formula, R ¹³ and R ¹⁴ are each independently —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ , — (CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form), -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ ) ₃ CH ₃ or -O (CH ₂ ) ₄ CH ₃ Represents.)
The liquid crystal composition of the present invention comprises the group consisting of general formula (3a), general formula (3b) and general formula (3c) in addition to the compound represented by general formula (1).

(In the formula, R ⁵ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and one CH ₂ group present in these groups or _two not adjacent to each other. The above CH ₂ group may be substituted with an oxygen atom or a sulfur atom, and one or two or more hydrogen atoms present in these groups may be substituted with a fluorine atom or a chlorine atom,
B ³ , B ⁴ and B ⁵ are each independently a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or _two non-adjacent CH ₂ groups are oxygen atoms) Or a 1,4-phenylene group (one or more CH groups present in this group may be substituted with a nitrogen atom), 1,4- Cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or 1,2 , 3,4-tetrahydronaphthalene-2,6-diyl group, a hydrogen atom present in these groups may be substituted with -CN or halogen,
Y ³ , Y ⁴ and Y ⁵ are each independently -CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH ( _{CH 3) CH (CH 3)} -, - CF 2 CF 2 -, - CF = CF -, - CH 2 O -, - OCH 2 -, - OCH (CH 3) -, - CH (CH 3) O- ,-(CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -C≡C-, -CF ₂ O-, -OCF _2- , -COO-, -OCO -, -COS-, -SCO- or a single bond,
L ¹ , L ² , L ⁴ , L ⁵ , L ⁶ , L ⁷ , L ⁸ , L ¹⁰ , L ¹¹ and L ¹² each independently represent a hydrogen atom or a fluorine atom,
q and r each independently represent 0, 1 or 2, but the sum of q and r is 2 or less,
L ³ and L ⁹ each independently represent the same meaning as a hydrogen atom, a fluorine atom, a chlorine atom, -CN, -CF ₃ , -OCH ₂ F, -OCHF ₂ , -OCF ₃ , -CH ₂ CF ₃ or R ⁵ Represents. It is preferable to contain one or more compounds selected from

In general formula (3a), general formula (3b) and general formula (3c), R ⁵ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, carbon It preferably represents an alkyl group having 1 to 7 primes substituted by an alkoxyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 7 carbon atoms substituted by an alkoxyl group having 1 to 5 carbon atoms. More preferred are alkenyl groups having 2 to 12 carbon atoms, specifically, -CH ₃ , -CH ₂ CH ₃ ,-(CH ₂ ) ₂ CH ₃ ,-(CH ₂ ) ₃ CH ₃ ,-( CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form), -(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form),-(CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form) _{), - OCH 3, -OCH 2} CH 3, -O (CH 2) 2 CH 3, -O (CH 2) it is particularly preferably represents ₃ CH ₃ or _{-O (CH 2) 4 CH 3} , When rings conversion of the aromatic _{ring, -CH 3, -CH 2 CH 3} , - (CH 2) 2 CH 3, - (CH 2) 3 CH 3, - (CH 2) 4 CH 3, - (CH 2 ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ ,-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form),- (CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form), -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ It is particularly preferred that it represents ₃ CH ₃ or —O (CH ₂ ) ₄ CH ₃ .

B ³ , B ⁴ and B ⁵ are each independently a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or _two non-adjacent CH ₂ groups are oxygen Including those substituted by atoms), 1,4-phenylene groups (including those in which one or two CH groups present in this group are substituted by nitrogen atoms), 1,4- Cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or 1,2 , 3,4-tetrahydronaphthalene-2,6-diyl group or a hydrogen atom substituted by a fluorine atom, preferably a trans-1,4-cyclohexylene group, 1,4-phenylene Group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,3-difluoro-1,4-phenylene group or 1,4-bicyclo [2.2.2] octylene group More preferred Trans-1,4-cyclohexylene group, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group or 2,3-difluoro-1, A 4-phenylene group is more preferable, and a trans-1,4-cyclohexylene group or a 1,4-phenylene group is particularly preferable.

Y ³ , Y ⁴ and Y ⁵ are each independently -CH ₂ CH _2- , -CH = CH- (E form), -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )- , -CF ₂ CF _2- , -CF = CF- (E form), -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-,-(CH ₂ ) ₄ −, —C≡C—, —CF ₂ O—, —OCF ₂ —, —COO—, —OCO—, or a single bond, preferably —CH ₂ CH ₂ —, —CH═CH - (E _{bodies), - CH (CH 3)} CH 2 -, - CH 2 CH (CH 3) -, - CF 2 CF 2 -, - CF = CF- (E _{bodies), - CH 2 O -,} - OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-, -C≡C-, -CF ₂ O-, -OCF ₂ -or a single bond is more preferred, -CH ₂ CH _2- , -CH ₂ O-, -OCH ₂ , -CF ₂ O-, -OCF _2- , -CH = CH- (E form) or a single bond is more preferable, -CH ₂ CH _2- , -CH ₂ O- , —OCH ₂ — or a single bond is particularly preferred.

L ¹ , L ² , L ⁴ , L ⁵ , L ⁶ , L ⁷ , L ⁸ , L ¹⁰ , L ¹¹ and L ¹² each independently represent a hydrogen atom or a fluorine atom, but at least one of them represents a fluorine atom. It is preferable to represent, and it is also preferable to have two or three fluorine atoms. In the general formula (3a), L ¹ and L ² represents a hydrogen atom, L ⁴ and L ⁵ preferably represent a fluorine atom. In the general formula (3b), when at least one fluorine atom is substituted on the substituent group consisting of L ⁶ , L ⁷ and L ⁸ , L ¹⁰ , L ¹¹ and L ¹² are all hydrogen atoms. Preferably, when at least one fluorine atom is substituted on the substituent group consisting of L ¹⁰ , L ¹¹ and L ¹² , L ⁶ , L ⁷ and L ⁸ are all preferably hydrogen atoms. In general formula (3c), when at least one fluorine atom is substituted on the substituent group consisting of L ¹⁰ and L ¹¹ , L ⁸ is preferably a hydrogen atom, and L ⁸ represents a fluorine atom. , L ¹⁰ and L ¹¹ preferably represent a hydrogen atom.

  Specifically, the compound represented by the general formula (3a) preferably has a structure represented by the following general formula (3a-1) to general formula (3a-10).

(In the formula, R ⁵ and R ¹⁵ are each independently —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ , — (CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) ₂ CH = CH ₂ or-(CH ₂ ) ₂ CH = CHCH ₃ (E form))
Specifically, the compound represented by the general formula (3c) preferably has a structure represented by the following general formula (3b-1) to general formula (3b-8).

(In the formula, R ⁵ and R ¹⁵ are each independently —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ , — (CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form), -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ ) ₃ CH ₃ or -O (CH ₂ ) ₄ CH ₃ Represents.)
Specifically, the compound represented by the general formula (3c) preferably has a structure represented by the following general formula (3c-1) to general formula (3c-3).

(In the formula, R ⁵ and R ¹⁵ are each independently —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ , — (CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form), -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ ) ₃ CH ₃ or -O (CH ₂ ) ₄ CH ₃ Represents.)
In the liquid crystal composition of the present invention, a compound selected from the group consisting of the compound represented by the general formula (1), the compound represented by the general formula (2), and the general formula (3a) to the general formula (3c). It is more preferable to contain.
The dielectric anisotropy of the liquid crystal composition is preferably −0.2, more preferably −0.4 or less.

  EXAMPLES Hereinafter, although an Example is given and this invention is further explained in full detail, this invention is not limited to these Examples. Further, “%” in the compositions of the following Examples and Comparative Examples means “% by mass”.

A liquid crystal display device exhibiting VA mode display characteristics was manufactured as follows (see FIG. 1). A transparent solid electrode is provided on one opposing glass substrate, and a vertical alignment film (trade name JALS-204, manufactured by JSR) is formed on it. The transparent electrode on the other glass substrate has a transparent electrode as shown in FIG. Slits with zigzag bending patterns with a width of 10μm are provided at intervals of 50μm (see Fig. 3). A vertical alignment film (trade name JALS-204 manufactured by JSR) is formed on the slits, and both glass substrates are overlapped. LCD display cell is fabricated (cell thickness 3.5μm). A liquid crystal display device was constructed by injecting a liquid crystal composition into the cell.
In the examples, the measured characteristics are as follows.
T _NI : Nematic phase-isotropic liquid phase transition temperature (° C)
Δε: Dielectric anisotropy (25 ° C and 1kHz)
Δn: birefringence (20 ° C. and 589 nm)
A cell having a cell thickness of 6 μm and vertical alignment (homeotropic alignment) (the alignment film uses JALS-204 manufactured by JSR) was used.

The following abbreviations are used in compound descriptions.
THF: tetrahydrofuran
DMF: N, N-dimethylformamide
p-TsOH: p-toluenesulfonic acid
Et: ethyl group
Bu: Butyl group
CN: Cyano group
Ms: Methanesulfonyl group (Example 1) Synthesis of 7,8-difluoro-6- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] -2-propylchroman (Ia)

(1-1) Synthesis of 2,3,4-trifluoro-1- [1-hydroxy-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene Under nitrogen atmosphere, 7.6 g of magnesium and 20 mL of THF were cooled with water. While stirring, a solution of 2,3,4-trifluorobromobenzene 60 g in THF (200 mL) was added dropwise over 2 hours and stirred for 3 hours. Thereto was added dropwise a solution of 70 g of 4- (trans-4-propylcyclohexyl) cyclohexanone in THF (200 mL) over 2 hours, followed by stirring for 2 hours. The reaction solution was poured into 10% hydrochloric acid and stirred for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed successively with water and saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to give 2,3,4-trifluoro-1- [1-hydroxy-4- (trans -4-propylcyclohexyl) cyclohexyl] benzene (110 g, insufficient drying) was obtained.
MS m / z: 354 (M ⁺ ), 55 (100)

(1-2) Synthesis of 2,3,4-trifluoro-1- [4- (trans-4-propylcyclohexyl) -1-cyclohexenyl] benzene
Dissolve 110 g of 2,3,4-trifluoro-1- [1-hydroxy-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene (insufficient drying) in 400 mL of toluene, and p-toluenesulfonic anhydride 10 g of the product was added and heated to reflux for 2 hours. Water was added thereto, followed by stirring for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed successively with water and saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel, hexane) to obtain 93 g of 2,3,4-trifluoro-1- [4- (trans-4-propylcyclohexyl) -1-cyclohexenyl] benzene.
MS m / z: 336 (M ⁺ ), 69 (100)

(1-3) Synthesis of 2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene
Dissolve 93 g of 2,3,4-trifluoro-1- [4- (trans-4-propylcyclohexyl) -1-cyclohexenyl] benzene in 300 mL of ethyl acetate, 5% palladium on carbon (containing 50% water) 9 g was added and stirred at a hydrogen pressure of 0.5 MPa for 5 hours. Palladium carbon was removed by filtration, and the solvent was distilled off under reduced pressure to obtain 90 g of a mixture of a pale yellow oily substance and a pale yellow solid. Of this, 80 g was purified by recrystallization (ethanol / methanol / hexane) to obtain 17 g of 2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene. .
MS m / z: 338 (M ⁺ ), 69 (100)

(1-4) Synthesis of 5-iodo-2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene 2,3,4-trifluoro under nitrogen atmosphere 17 g of 1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene was dissolved in 300 mL of THF and cooled to -60 ° C. Thereto, 39 mL of butyl lithium (1.56 M hexane solution) was added dropwise over 30 minutes and stirred for 2 hours. A solution of iodine 14 g in THF (50 mL) was added dropwise over 1 hour, and the temperature was raised to room temperature. The reaction solution was poured into an aqueous sodium thiosulfate solution and stirred for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed sequentially with water and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure to remove 5-iodo-2,3,4-trifluoro-1- [trans-4- 25 g of (trans-4-propylcyclohexyl) cyclohexyl] benzene was obtained.
MS m / z: 464 (M ⁺ ), 69 (100)

(1-5) Synthesis of 5- (3-hydroxy-1-hexynyl) -2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene Under a nitrogen atmosphere, 5-Iodo-2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene (25 g) was dissolved in DMF (300 mL), triethylamine (21 mL), copper iodide (I 0.19 g) and tetrakistriphenylphosphine palladium (0) 0.58 g were added and heated to 55 ° C. A solution of 1-hexyn-3-ol 5.9 g in DMF (30 mL) was added dropwise over 20 minutes, and the mixture was stirred for 3 hours. The reaction mixture was poured into an aqueous sodium thiosulfate solution and stirred for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed with water, 10% hydrochloric acid twice, water, saturated aqueous sodium hydrogen carbonate solution and saturated brine in that order, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel, toluene) twice, activated carbon treatment (acetone), column chromatography (silica gel, hexane / acetone) in this order, and 5- (3-hydroxy-1-hexynyl) -2,3 Thus, 20 g of 4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene was obtained.
MS m / z: 434 (M ⁺ ), 69 (100)

(1-6) Synthesis of 5- (3-hydroxy-1-hexyl) -2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene
5- (3-hydroxy-1-hexynyl) -2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene (20 g) was dissolved in ethanol (80 mL). 2 g of palladium on carbon (containing 50% water) was added and stirred at a hydrogen pressure of 0.5 MPa for 6 hours, and then left overnight. Palladium carbon was removed by filtration, and the solvent was distilled off under reduced pressure to remove 5- (3-hydroxy-1-hexyl) -2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) Cyclohexyl] benzene 10 g was obtained.
MS m / z: 438 (M ⁺ ), 420 (100)

(1-7) Synthesis of 7,8-difluoro-6- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] -2-propylchroman Sodium hydride (60% in oil) 1.23 g under nitrogen substitution Was suspended in 18 mL of DMF. 5- (3-hydroxy-1-hexyl) -2,3,4-trifluoro-1- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] benzene 9 g in THF (36 mL) Was added dropwise over 30 minutes and stirred at 40 ° C. for 3 hours and at 50 ° C. for 3 hours. After adding toluene and stirring for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed successively with water and saturated brine, dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel, hexane), recrystallization (hexane), and recrystallization (hexane / ethanol) to give 7,8-difluoro-6- [trans-4- (trans-4 -Propylcyclohexyl) cyclohexyl] -2-propylchroman 2.5 g was obtained.
MS m / z: 418 (M ⁺ , 100)
¹ H-NMR (400 MHz, CDCl ₃ )
δ (ppm): 0.87 (t, J = 7.6 Hz, 3 H), 0.97 (t, J = 7.2 Hz, 3 H), 1.1 1.2 (m, 6 H), 1.25 1.65 (m, 10 H), 1.65 1.9 (m, 12 H), 1.95 2.05 (m, 1 H), 2.6 2.85 (m, 3 H), 3.9 4.05 (m, 1H), 6.58 (d, J = 6.4 Hz, 1 H)
Example 2 Synthesis of 6- [4- (trans-4-propylcyclohexyl) phenyl] -7,8-difluoro-2-propylchroman (Ib)

(2-1) Synthesis of 4-iodo-1,2,3-trifluorobenzene Under a nitrogen atmosphere, 1,2,3-trifluorobenzene was dissolved in THF and cooled to -60 ° C. Butyl lithium (1.56 M hexane solution) was added dropwise thereto over 30 minutes, and the mixture was stirred for 2 hours. Thereto was added dropwise a solution of iodine in THF over 1 hour, and the temperature was raised to room temperature. The reaction solution was poured into an aqueous sodium thiosulfate solution and stirred for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed in order with water and saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to give 4-iodo-1,2,3-trifluorobenzene.

(2-2) Synthesis of 1- (3-hydroxy-1-hexynyl) -2,3,4-trifluorobenzene Dissolve 4-iodo-1,2,3-trifluorobenzene in DMF under nitrogen atmosphere. , Triethylamine, copper (I) iodide, and tetrakistriphenylphosphine palladium (0) were added and heated to 55 ° C. Thereto was added dropwise a DMF solution of 1-hexyn-3-ol over 20 minutes, and the mixture was stirred for 3 hours. The reaction mixture was poured into an aqueous sodium thiosulfate solution and stirred for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed with water, 10% hydrochloric acid twice, water, saturated aqueous sodium hydrogen carbonate solution and saturated brine in that order, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel, toluene / hexane) to obtain 1- (3-hydroxy-1-hexynyl) -2,3,4-trifluorobenzene.

(2-3) Synthesis of 1- (3-hydroxyhexyl) -2,3,4-trifluorobenzene
1- (3-Hydroxy-1-hexynyl) -2,3,4-trifluorobenzene is dissolved in ethanol, 5% palladium on carbon (containing 50% water) is added, and the mixture is stirred for 6 hours at 0.5 MPa hydrogen pressure. Left overnight. Palladium carbon was removed by filtration, and the solvent was distilled off under reduced pressure to obtain 1- (3-hydroxy-1-hexyl) -2,3,4-trifluorobenzene.

(2-4) Synthesis of 7,8-difluoro-2-propylchroman Sodium hydride (60% in oil) was suspended in DMF under nitrogen substitution. A THF solution of 1- (3-hydroxy-1-hexyl) -2,3,4-trifluorobenzene was added dropwise thereto over 30 minutes, and the mixture was stirred at 50 ° C. for 3 hours. After adding toluene and stirring for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed successively with water and saturated brine, dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel, hexane) to obtain 7,8-difluoro-2-propylchroman.

(2-5) Synthesis of 7,8-difluoro-2-propylchroman-6-boric acid Under a nitrogen atmosphere, 7,8-difluoro-2-propylchroman was dissolved in THF and cooled to -60 ° C. Butyl lithium (1.56 M hexane solution) was added dropwise thereto over 30 minutes, and the mixture was stirred for 2 hours. Thereto, a THF solution of trimethyl borate was added dropwise over 1 hour, and the temperature was raised to room temperature. The reaction solution was poured into 10% hydrochloric acid and stirred for 2 hours. The organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed sequentially with water and saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to obtain 7,8-difluoro-2-propylchroman-6-borate.

(2-6) Synthesis of 6- [4- (trans-4-propylcyclohexyl) phenyl] -7,8-difluoro-2-propylchroman In a nitrogen atmosphere, 4- (trans-4-propylcyclohexyl) bromobenzene was synthesized. Dissolved in toluene, 7,8-difluoro-2-propylchroman-6-boric acid, potassium carbonate, water and tetrakistriphenylphosphine palladium (0) were added. This was stirred under pressure at 90 ° C. for 5 hours. The reaction mixture was poured into water and stirred for a while, then the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed successively with water, 10% hydrochloric acid and saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography (silica gel, toluene) and recrystallization (toluene / hexane) to give 6- [4- (trans-4-propylcyclohexyl) phenyl] -7,8-difluoro-2-propylchroman. It was.
¹ H-NMR (400 MHz, CDCl ₃ )
δ (ppm): 0.92 (t, J = 7.2 Hz, 3 H), 0.97 (t, J = 7.2 Hz, 3 H), 1.1 1.5 (m, 11 H), 1.5 2.1 (m, 8 H), 2.5 2.9 (m, 3 H), 3.9 4.1 (m, 1H), 6.6 7.0 (m, 1 H), 7.1 7.6 (m, 4 H)
(Example 3) Preparation of liquid crystal composition (1)
Host liquid crystal composition (H) having the following composition

Was prepared. Here, the physical properties of (H) are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 103.2 ° C
Dielectric anisotropy (Δε): 0.03
Refractive index anisotropy (Δn): 0.099
A liquid crystal composition (M-1) comprising 90% of the host liquid crystal (H) and 10% of (Ia) obtained in Example 1 was prepared. The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (TN-I): 109.0 ° C
Dielectric anisotropy (Δε): −0.52
Refractive index anisotropy (Δn): 0.098
The liquid crystal composition (M-1) containing the compound (Ia) of the present invention has an increase in nematic phase-isotropic liquid phase transition temperature (T _NI ) and anisotropy of dielectric constant as compared with the host liquid crystal (H). The sex (Δε) decreased to a negative value. This shows that the compound (Ia) of the present invention stably exhibits a nematic phase even at a high temperature, has a negative dielectric anisotropy, and has an extremely large absolute value.
Comparative Example 1 Preparation of Liquid Crystal Composition 90% of the host liquid crystal (H) prepared in Example 3 and the formula (R-1)

で表される化合物１０％からなる液晶組成物（Ｎ−１）を調製した。この組成物の物性値は以下の通りである。

A liquid crystal composition (N-1) consisting of 10% of the compound represented by the formula: The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 109.6 ° C
Dielectric anisotropy (Δε): −0.42
Refractive index anisotropy (Δn): 0.100
The liquid crystal composition (N-1) containing the compound represented by the formula (R-1) described in Patent Document 1 has an absolute value of dielectric anisotropy as compared with (M-1) described in Example 1. Is small and the refractive index anisotropy is slightly large.
Comparative Example 2 Preparation of Liquid Crystal Composition 90% of host liquid crystal (H) prepared in Example 3 and formula (R-2)

で表される化合物１０％からなる液晶組成物（Ｎ−２）を調製した。この組成物の物性値は以下の通りである。

A liquid crystal composition (N-2) comprising 10% of the compound represented by the formula: The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 109.4 ° C
Dielectric anisotropy (Δε): −0.22
Refractive index anisotropy (Δn): 0.099
The liquid crystal composition (N-2) containing the compound represented by the formula (R-2) described in Patent Document 2 has an absolute value of dielectric anisotropy as compared with (M-1) described in Example 3. Is small.
(Comparative Example 3) Preparation of liquid crystal composition 90% of host liquid crystal (H) prepared in Example 3 and formula (R-3)

で表される化合物１０％からなる液晶組成物（Ｎ−３）を調製した。この組成物の物性値は以下の通りである。

A liquid crystal composition (N-3) comprising 10% of the compound represented by the formula: The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 114.5 ° C
Dielectric anisotropy (Δε): −0.60
Refractive index anisotropy (Δn): 0.105
The liquid crystal composition (N-3) containing the compound represented by the formula (R-3) described in Patent Document 3 has an absolute value of dielectric anisotropy as compared with (M-1) described in Example 3. However, the refractive index anisotropy has increased considerably. A liquid crystal display element having excellent display quality could be produced using the liquid crystal composition.
Example 4 Synthesis of 2-butyl-7,8-difluoro-6- (trans-4-pentylcyclohexylmethoxy) chroman (Ie)

(4-1) Synthesis of 1- (3-methyl-3-hydroxy-1-butynyl) -2,3,4-trifluorobenzene Under nitrogen substitution, 247 g of 2,3,4-trifluorobromobenzene was DMF It melt | dissolved in 740 mL, Triethylamine 247 mL, tetrakis triphenylphosphine palladium (0) 3.7 g and copper iodide (I) 4.4 g were added, and it heated at 70 degreeC. 108 g of 3-methyl-1-butyn-3-ol was added over 1 hour, and the mixture was stirred at room temperature for 2 hours, at 50 ° C for 1 hour, at 60 ° C for 30 minutes, and at 80 ° C for 2 hours. 500 mL of water was added and the mixture was allowed to cool to room temperature, and 200 mL of concentrated hydrochloric acid was added. This was extracted twice with ethyl acetate, and the organic layers were combined, washed with water and then saturated brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by distillation under reduced pressure (78 84 ° C / 0.65 0.70 mmHg) to give 1- (3-methyl-3-hydroxy-1-butynyl) -2,3,4-trimethyl as a yellow solid. 229 g of fluorobenzene was obtained.

(4-2) Synthesis of 1-ethynyl-2,3,4-trifluorobenzene
1- (3-Methyl-3-hydroxy-1-butynyl) -2,3,4-trifluorobenzene 229 g added with 23 g sodium hydroxide and stirred at 120 ° C for 1 hour, produced by atmospheric distillation Acetone was distilled off. This was purified by distillation under reduced pressure (101 108 ° C./34 kPa (256 mmHg)) to obtain 110 g of 1-ethynyl-2,3,4-trifluorobenzene as an almost colorless oily substance.

(4-3) Synthesis of 1- (3-hydroxy-1-heptynyl) -2,3,4-trifluorobenzene Under nitrogen substitution, 110 g of 1-ethynyl-2,3,4-trifluorobenzene was converted to THF 440. Dissolved in mL. Under ice cooling, 846 mL of methylmagnesium bromide (1.0 M in Toluene / THF = 4/1) was added dropwise over 1 hour, and the mixture was stirred as it was for 30 minutes. 72.8 g of pentanal was added dropwise over 1 hour, and the mixture was warmed to room temperature and stirred for 1 hour. The reaction solution was poured into 300 g of ice / 300 mL of concentrated hydrochloric acid and stirred for a while, the organic layer was separated, and the aqueous layer was extracted with toluene. The organic layers were combined, washed with water and saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to give a brown oily substance. This was purified by column chromatography (silica gel, toluene) to obtain 183 g of 1- (3-hydroxy-1-heptynyl) -2,3,4-trifluorobenzene as a reddish brown oily substance.

(4-4) Synthesis of 1- (3-hydroxyheptyl) -2,3,4-trifluorobenzene
Dissolve 183 g of 1- (3-hydroxy-1-heptynyl) -2,3,4-trifluorobenzene in 730 mL of ethyl acetate, add 9 g of 5% palladium on carbon (containing 50% water) and add 0.4 hydrogen pressure. Stir at MPa for 6 hours. The catalyst was removed by filtration (using cellulose), and the solvent was distilled off under reduced pressure to obtain 170 g of 1- (3-hydroxyheptyl) -2,3,4-trifluorobenzene as a pale yellow solid.

(4-5) Synthesis of 2-butyl-7,8-difluorochroman Under nitrogen replacement, 28.6 g of sodium hydride was suspended in 160 mL of THF and 160 mL of DMF. A small amount of a THF (160 mL) solution of 170 g of 1- (3-hydroxyheptyl) -2,3,4-trifluorobenzene was added dropwise, 160 mL of DMF was added, and the mixture was heated to 55 ° C. After confirming the start of self-heating, the remaining solution was added dropwise over 1 hour and stirred at 50 ° C. for 30 minutes. The reaction solution was poured into water, concentrated hydrochloric acid was added, and the organic layer was separated. The aqueous layer was extracted with hexane, and the organic layers were combined, washed with water, saturated aqueous sodium hydrogen carbonate solution and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure to obtain 170 g of a light brown oily substance. This was purified by column chromatography (silica gel, hexane), distillation under reduced pressure (70 126 ° C / 3 mmHg), and column chromatography (silica gel, hexane) to give 2-butyl-7,8-difluorochroman85 as an almost colorless oily substance. g was obtained.

(4-6) Synthesis of 2-butyl-7,8-difluorochroman-2-ol Under nitrogen substitution, 85 g of 2-butyl-7,8-difluorochroman was dissolved in 340 mL of THF. After cooling to -70 ° C, 236 mL of butyllithium (1.59 M in hexane) was added dropwise over 30 minutes, and then stirred at -50 ° C to -60 ° C for 30 minutes. Trimethyl borate (43 g) was added dropwise over 30 minutes, and the temperature was slowly raised to 0 ° C. Acetic acid (32 mL) was added dropwise over 10 minutes. After stirring for 10 minutes, a 30% aqueous hydrogen peroxide solution was added dropwise over 30 minutes, and the mixture was stirred as it was for 1 hour. 200 mL of water was added, the organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The organic layers were combined, washed with water and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure to obtain 101 g of a pale yellow oily substance. This was purified by column chromatography (silica gel, hexane → hexane / ethyl acetate) to obtain 40 g of 2-butyl-7,8-difluorochroman-2-ol as a pale yellow oily substance.

(4-7) Synthesis of 2-butyl-7,8-difluoro-6- (trans-4-pentylcyclohexylmethoxy) chroman (Ie)
20.5 g of 2-butyl-7,8-difluorochroman-2-ol was dissolved in 70 mL of DMF, 25.1 g of bromo-trans-4-pentylcyclohexylmethane and 11.7 g of anhydrous potassium carbonate were added, and the mixture was heated to reflux for 1 hour. The reaction solution was poured into 10% hydrochloric acid, stirred for a while, and extracted with toluene. The organic layer was washed with 10% hydrochloric acid twice, water, 5% aqueous sodium hydroxide solution twice, water, saturated aqueous sodium hydrogen carbonate solution twice and saturated brine in that order, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting brown oily substance was subjected to column chromatography (silica gel, hexane), recrystallization (acetone / methanol), distillation under reduced pressure (227 ° C / 0.6 mmHg), column chromatography (silica gel, hexane / toluene). ), Recrystallization (acetone / methanol), and recrystallization (acetone / methanol) to give 2-butyl-7,8-difluoro-6- (trans-4-pentylcyclohexylmethoxy) chroman (Ie) 8.8 as colorless crystals g was obtained.
MS m / z: 408 (M ⁺ ), 55 (100)
¹ H-NMR (400 MHz, CDCl ₃ )
δ (ppm): 0.88 (t, J = 6.8 Hz, 3 H), 0.93 (t, J = 6.8 Hz, 3 H), 0.9 2.1 (m, 26 H), 2.6 2.8 (m, 2 H), 3.73 (d, J = 6.4 Hz, 2 H), 3.9 4.0 (m, 1 H), 6.38 (d, J = 7.6 Hz, 1 H)
Example 5 Synthesis of 2-butoxy-7,8-difluoro-6- (trans-4- (trans-4-ethylcyclohexyl) cyclohexylmethoxy) chroman (If)

Dissolve 20.5 g of 2-butyl-7,8-difluorochroman-2-ol in 70 mL of DMF and add 25 g of 4- (trans-4-ethylcyclohexyl) cyclohexylmethyl methanesulfonate and 11.4 g of anhydrous potassium carbonate. Heated to reflux for 3 hours. The reaction solution was poured into 10% hydrochloric acid, stirred for a while, and extracted with toluene. The organic layer was washed with 10% hydrochloric acid twice, water, 5% aqueous sodium hydroxide solution twice, water, saturated aqueous sodium hydrogen carbonate solution twice and saturated brine in that order, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting brown solid was purified by column chromatography (silica gel, hexane / toluene), recrystallization (hexane), recrystallization (acetone), recrystallization (acetone) to give 2- 14.7 g of butoxy-7,8-difluoro-6- (trans-4- (trans-4-ethylcyclohexyl) cyclohexylmethoxy) chroman (If) was obtained.
MS m / z: 448 (M ⁺ ), 242 (100)
¹ H-NMR (400 MHz, CDCl ₃ )
δ (ppm): 0.86 (t, J = 7.2 Hz, 3 H), 0.93 (t, J = 6.8 Hz, 3 H), 0.8 2.1 (m, 30 H), 2.6 2.8 (m, 2 H), 3.72 (d, J = 6.4 Hz, 2 H), 3.9 4.0 (m, 1 H), 6.38 (d, J = 8.0 Hz, 1 H)
Example 6 Synthesis of 6- [2- (trans-4′-ethylbicyclohexyl-trans-4-yl) ethyl] -7,8-difluoro-2-pentylchroman (Ig)

(6-1) Synthesis of 6- [2- (trans-4'-ethylbicyclohexyl-trans-4-yl) vinyl] -7,8-difluoro-2-pentylchroman
A butyllithium / hexane solution (90 ml, 0.14 mol) was added dropwise to a THF (120 ml) solution of 30 g of 7,8-difluoro-2-pentylchroman at −78 ° C. The mixture was stirred at −50 ° C. for 5 hours, and a solution of 35 g of trans-4-ethylbicyclohexyl-4-ylacetaldehyde in THF (70 ml) was added dropwise. The temperature was raised to 0 ° C. over 2 hours, and 3M hydrochloric acid was added. Extracted with ethyl acetate (twice). The organic layers were combined, washed sequentially with a saturated aqueous sodium hydrogen carbonate solution and saturated brine, and dried over anhydrous sodium sulfate to obtain 77 g of a yellow solid. The crude product was used in the next reaction without purification.
To a toluene (150 ml) solution of the crude product (77 g), 3.5 g of p-toluenesulfonic acid monohydrate was added. The mixture was heated to reflux until there was no water distilled from the water separator (about 3 hours). The reaction solution was allowed to cool and a saturated aqueous sodium hydrogen carbonate solution was added. The aqueous layer was extracted with toluene. The extract was washed with saturated brine and dried over anhydrous magnesium sulfate. Concentration gave a brown powder. Purify by column chromatography (alumina, hexane), and add 55 g of 6- [2- (trans-4'-ethylbicyclohexyl-trans-4-yl) vinyl] -7,8-difluoro-2-pentylchroman. Obtained as a yellow powder.

(6-1) Synthesis of 6- [2- (trans-4'-ethylbicyclohexyl-trans-4-yl) ethyl] -7,8-difluoro-2-pentylchroman (Ig)
6- [2- (trans-4′-ethylbicyclohexyl-trans-4-yl) vinyl] -7,8-difluoro-2-pentylchroman in 75 g THF / ethanol solution (350 ml / 350 ml) 3.5 g of 5% palladium carbon (50% water-containing product) was added, and the mixture was stirred at room temperature for 5 hours under hydrogen pressure (0.5 MPa). The reaction solution was filtered (using celite), the solvent was distilled off, and the resulting pale yellow powder was purified by column chromatography (silica gel, hexane) and recrystallized twice (acetone), and 6- [2- 30 g of (trans-4′-ethylbicyclohexyl-trans-4-yl) ethyl] -7,8-difluoro-2-pentylchroman (Ig) was obtained as a white powder.
MS m / z: 389 (M ⁺ )
¹ H-NMR (400 MHz, CDCl ₃ )
δ (ppm): 0.77-1.08 (m, 10H), 0.86 (t, J = 7.2 Hz, 3H), 0.91 (t, J = 7.0 Hz, 3H), 1.14-1.22 (m, 3H), 1.26 (s , 1H), 1.30-1.37 (m, 4H), 1.39-1.46 (m, 3H), 1.51-1.83 (m, 12H), 1.96-2.10 (m, 1H), 2.53 (t, J = 7.8 Hz, 2H ), 2.66-2.82 (m, 2H), 3.98-4.01 (m, 1H), 6.55 (d, J = 6.8 Hz, 1H)
(Example 7) Preparation of liquid crystal composition (2)
A liquid crystal composition (M-2) comprising 90% of the host liquid crystal (H) prepared in Example 3 and 10% of the compound represented by the formula (Ie) obtained in Example 4 was prepared. The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 93.4 ° C
Dielectric anisotropy (Δε): −0.63
Refractive index anisotropy (Δn): 0.095
(Example 8) Preparation of liquid crystal composition (3)
A liquid crystal composition (M-3) comprising 90% of the host liquid crystal (H) prepared in Example 3 and 10% of the compound represented by the formula (If) obtained in Example 5 was prepared. The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 104.2 ° C
Dielectric anisotropy (Δε): −0.60
Refractive index anisotropy (Δn): 0.097
(Example 9) Preparation of liquid crystal composition (4)
A liquid crystal composition (M-4) comprising 90% of the host liquid crystal (H) prepared in Example 3 and 10% of the compound represented by the formula (Ig) obtained in Example 6 was prepared. The physical properties of this composition are as follows.

Nematic to isotropic liquid phase transition temperature (T _NI ): 104.8 ° C
Dielectric anisotropy (Δε): −0.43
Refractive index anisotropy (Δn): 0.097
Example 10 Synthesis of 6-ethoxy-2- (trans-4-ethylcyclohexyl) -7,8-difluorochroman

  To a solution of 2,3,4-trifluorophenylacetylene (20 g) in tetrahydrofuran (THF) (100 ml) at 0 ° C., 1.5 M methylmagnesium bromide-THF solution (93 ml) was added dropwise and stirred for 1 hour. did. To this was added dropwise a solution of trans-4-ethylcyclohexanecarbaldehyde (18 g) in THF (50 ml), and the mixture was stirred for 1 hour. The reaction mixture was poured into 5% hydrochloric acid, extracted with ethyl acetate, and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate = 9: 1) to give 1- (trans-4-ethylcyclohexyl) -3- (2,3,4-trifluorophenyl) -2-propyne-1 -Oral (38 g) was obtained.

  1- (trans-4-ethylcyclohexyl) -3- (2,3,4-trifluorophenyl) -2-propyn-1-ol (38 g), 5% palladium-carbon (50% water content, 2 g) 200 ml of ethyl acetate was stirred at room temperature for 4 hours under 4 atmospheres of hydrogen. Palladium-carbon was filtered through Celite, and the filtrate was concentrated to give 1- (trans-4-ethylcyclohexyl) -3- (2,3,4-trifluorophenyl) -1-propanol (38 g). It was.

  Sodium hydride (40% oily, 7 g) was washed with hexane, and dimethylformamide (DMF) (200 ml) was added. To this, at 40 ° C., 1- (trans-4-ethylcyclohexyl) -3- (2,3,4-trifluorophenyl) -1-propanol (38 g) in DMF (50 ml) was added over 1 hour. Then, the mixture was further stirred for 3 hours. The reaction mixture was poured into 5% hydrochloric acid, extracted with hexane, and concentrated. The residue was purified by silica gel column chromatography (hexane) to obtain 2- (trans-4-ethylcyclohexyl) -7,8-difluorochroman (28 g).

  To a solution of 2- (trans-4-ethylcyclohexyl) -7,8-difluorochroman (28 g) in THF (150 ml), 1.6 M butyllithium-hexane solution (65 ml) was added dropwise at −60 ° C., − Stir at 50 ° C. for 2 hours. Trimethyl borate (15 g) was added dropwise thereto, and after stirring for 30 minutes, the temperature was raised to 0 ° C. over 2 hours. Acetic acid (10 ml) was added thereto, and after stirring for 20 minutes, 30% aqueous hydrogen peroxide solution (20 ml) was slowly added and stirred for 1 hour. Water (100 ml) was added, extracted with ethyl acetate, and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate = 4: 1) to obtain 2- (trans-4-ethylcyclohexyl) -7,8-difluoro-6-hydroxychroman (28 g).

2 suspensions of DMF (100 ml) in 2- (trans-4-ethylcyclohexyl) -7,8-difluoro-6-hydroxychroman (28 g), iodoethane (25 g), anhydrous potassium carbonate (15 g) Heated to reflux for hours. The reaction mixture was poured into 5% hydrochloric acid, extracted with toluene, and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate = 9: 1) to obtain 6-ethoxy-2- (trans-4-ethylcyclohexyl) -7,8-difluorochroman (30 g). Further, recrystallization from acetone gave 26 g of pure product.
Melting point 90 ° C
¹ H NMR (CDCl ₃ ) δ 6.37 (dd, J = 8.3 and 2.0 Hz, 1 H), 3.99 (q, J = 7.1 Hz, 2 H), 3.70 (ddd, J = 10.0, 6.5 and 2.2 Hz, 1 H), 2.6-2.8 (m, 2 H), 1.93-2.05 (m, 2 H), 1.65-1.85 (m, 4 H), 1.5-1.65 (m, 1 H), 1.38 (t, J = 7.1 Hz, 3 H), 1.05-1.24 (m, 5 H), 0.82-0.95 (m, 2 H), 0.85 (t, J = 7.6 Hz, 3 H)
Example 11 Synthesis of 6-ethoxy-2- [trans-4- (trans-4-ethylcyclohexyl) cyclohexyl] -7,8-difluorochroman

Similar to the synthesis of 6-ethoxy-2- (trans-4-ethylcyclohexyl) -7,8-difluorochroman, instead of trans-4-ethylcyclohexanecarbaldehyde, trans, trans-4'-ethylbicyclohexyl 6-Ethoxy-2- [trans-4- (trans-4-ethylcyclohexyl) cyclohexyl] -7,8-difluorochroman was synthesized using -4-carbaldehyde.
Phase transition temperature Cr 147 N 162 I
¹ H NMR (CDCl ₃ ) δ 6.37 (broad dd, J = 8.3 and 1.7 Hz, 1 H), 3.99 (q, J = 7.1 Hz, 2 H), 3.69 (ddd, J = 9.8, 6.6 and 2.0 Hz, 1 H), 2.6-2.8 (m, 2 H), 1.9-2.1 (m, 2 H), 1.65-1.85 (m, 6 H), 1.48-1.60 (m, 1 H), 1.37 (t, J = 7.1 Hz, 3 H), 0.75-1.25 (m, 15 H), 0.84 (t, J = 7.3 Hz, 3 H)
Example 12 Synthesis of 6-ethoxy-7,8-difluoro-2- [2- (trans-4-propylcyclohexyl) ethyl] chroman

Similar to the synthesis of 6-ethoxy-2- (trans-4-ethylcyclohexyl) -7,8-difluorochroman, instead of trans-4-ethylcyclohexanecarbaldehyde, 3- (trans-4-propylcyclohexyl) 6-Ethoxy-7,8-difluoro-2- [2- (trans-4-propylcyclohexyl) ethyl] chroman was synthesized using propanal.
Melting point 77 ℃
¹ H NMR (CDCl ₃ ) δ 6.38 (dd, J = 8.4 and 2.0 Hz, 1 H), 3.99 (q, J = 7.1 Hz, 2 H), 3.88-3.96 (m, 1 H), 2.6-2.8 ( m, 2 H), 1.94-2.02 (m, 1 H), 1.55-1.85 (m, 7 H), 1.38 (t, J = 7.1 Hz, 3 H), 1.00-1.45 (m, 8 H), 0.85 (t, J = 7.3 Hz, 3 H), 0.8-0.95 (m, 4 H)
Example 13 Synthesis of 6-ethoxy-7,8-difluoro-2- [2- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] ethyl] chroman

Similar to the synthesis of 6-ethoxy-2- (trans-4-ethylcyclohexyl) -7,8-difluorochroman, instead of trans-4-ethylcyclohexanecarbaldehyde, 3- (trans, trans-4'- 6-Ethoxy-7,8-difluoro-2- [2- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] ethyl] chroman was synthesized using propylbicyclohexane-4-yl) propanal .
Phase transition temperature Cr 126 N 160 I
¹ H NMR (CDCl ₃ ) δ 6.37 (broad dd, J = 8.3 and 1.8 Hz, 1 H), 3.99 (q, J = 6.9 Hz, 2 H), 3.88-3.96 (m, 1 H), 2.6-2.8 (m, 2 H), 1.93-2.03 (m, 1 H), 1.55-1.85 (m, 11 H), 1.78 (t, J = 6.9 Hz, 3 H), 1.2-1.45 (m, 8 H), 0.84 (t, J = 7.3 Hz, 3 H), 0.75-1.05 (m, 10 H)
(Example 14) Preparation of liquid crystal composition (5)
A liquid crystal composition (M-5) comprising 90% of the host liquid crystal (H) prepared in Example 3 and 10% of the compound represented by the formula (Ie) obtained in Example 4 was prepared. The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 93.4 ° C
Dielectric anisotropy (Δε): −0.63
Refractive index anisotropy (Δn): 0.095
(Example 15) Preparation of liquid crystal composition (6)
A liquid crystal composition (M-6) comprising 90% of the host liquid crystal (H) prepared in Example 3 and 10% of the compound represented by the formula (If) obtained in Example 5 was prepared. The physical properties of this composition are as follows.

Nematic phase-isotropic liquid phase transition temperature (T _NI ): 104.2 ° C
Dielectric anisotropy (Δε): −0.60
Refractive index anisotropy (Δn): 0.097
(Example 16) Preparation of liquid crystal composition (7)
A liquid crystal composition (M-7) comprising 90% of the host liquid crystal (H) prepared in Example 3 and 10% of the compound represented by the formula (Ig) obtained in Example 6 was prepared. The physical properties of this composition are as follows.

Nematic to isotropic liquid phase transition temperature (T _NI ): 104.8 ° C
Dielectric anisotropy (Δε): −0.43
Refractive index anisotropy (Δn): 0.097
(Example 17) Preparation of liquid crystal composition (8)
A liquid crystal composition (M-8) comprising 90% of the host liquid crystal (H) prepared in Example 3 and 10% of (Ig) obtained in Example 6 was prepared. The physical properties of this composition are as follows.

Nematic to isotropic liquid phase transition temperature (T _NI ): 104.8 ° C
Dielectric anisotropy (Δε): −0.43
Refractive index anisotropy (Δn): 0.097
The physical properties of the liquid crystal composition of the present invention are described in the following table.

From this table, (M-1) to (M-8), which are liquid crystal compositions using the chroman compound of the present invention, have a large negative anisotropy and a dielectric anisotropy. It turns out that the nature is also small. In contrast, the liquid crystal composition (N-1) of Comparative Example 1 having a 2,3-difluorophenylene group has a small absolute value of dielectric anisotropy and a slightly small refractive index anisotropy. . Further, the liquid crystal composition (N-2) of Comparative Example 2 using a 7,8-difluorotetrahydronaphthalene-based compound has a small absolute value of dielectric anisotropy, and a 1,7,8-trifluoronaphthalene-based compound. Although the liquid crystal composition (N-3) of Comparative Example 3 using a compound had a relatively large absolute value of dielectric anisotropy, the refractive index anisotropy was considerably large.
(Example 18) Preparation of liquid crystal composition (9)
A liquid crystal composition represented by the following formula was prepared as a liquid crystal composition using a compound represented by a plurality of general formulas (1).

The properties of Example 18 were T _NI : 84 ° C., Δn: 0.068, Δε: -3.2.
Further, as a comparative example, a comparative example 4 in which a compound not containing the general formula (1) was substituted was prepared.
(Comparative Example 4)

The characteristics of Comparative Example 4 were T _NI : 59 ° C., Δn: 0.076, Δε: -2.8.
It can be seen that the liquid crystal composition of Example 18 has a small Δn and a large absolute ΔΔε. A liquid crystal display device having excellent display quality could be produced using this liquid crystal composition.
(Example 19) Preparation of liquid crystal composition (10)
A liquid crystal composition represented by the following formula was prepared.

The properties of Example 19 were T _NI : 80 ° C., Δn: 0.087, Δε: −4.0.
(Comparative Example 5)
Comparative Example 5 was prepared by replacing the compound represented by formula (1) with a similar compound in the liquid crystal composition of Example 19.

The characteristics of Comparative Example 5 are T _NI : 82 ° C., Δn: 0.090, Δε: −3.7, and Δn increases and the absolute value of Δε decreases from the liquid crystal composition of Example 19. It was.
(Comparative Example 6)
Further, Comparative Example 6 was prepared in which the compound represented by the general formula (1) in the liquid crystal composition of Example 19 was substituted with a similar compound having a tetrahydronaphthalene ring.

The characteristics of Comparative Example 6 were T _NI : 81 ° C., Δn: 0.089, Δε: -3.1.
In the liquid crystal composition of Comparative Example 6, the absolute value of Δε further decreased.
(Example 20) Preparation of liquid crystal composition (11)
A liquid crystal composition represented by the following formula was prepared.

The properties of Example 20 were T _NI : 82 ° C., Δn: 0.081, and Δε: -3.3.
(Comparative Example 7)
As a comparative example, comparative example 7 was prepared by replacing the compound represented by general formula (1) in the liquid crystal composition of example 20 with a similar compound having a tetrahydronaphthalene ring.

Was prepared. The characteristics of Comparative Example 7 were T _NI : 79 ° C., Δn: 0.084, Δε: -2.8.
It can be seen that the absolute value of Δε is considerably reduced as compared with Example 20.
(Example 21) Preparation of liquid crystal composition (12)
A liquid crystal composition represented by the following formula was prepared.

The characteristics of the liquid crystal composition of Example 21 were T _NI : 80 ° C., Δn: 0.081, Δε: -3.3.
(Example 22) Preparation of liquid crystal composition (13)
A liquid crystal composition represented by the following formula was prepared.

The properties of Example 22 were T _NI : 92 ° C., Δn: 0.083, and Δε: -3.7.

  Using the liquid crystal compositions described in Examples 19 to 22, liquid crystal display elements having excellent display quality could be produced.

It is a figure explaining the cross section of the liquid crystal display device which shows VA mode display characteristic. It is a figure explaining the transparent electrode provided with the slit which has a zigzag bending pattern. It is a figure explaining the slit which has a zigzag bending pattern. (Unit: μm)

Explanation of symbols

1 ... Glass substrate
2 ... Transparent solid electrode
3 ... Vertical alignment film
4 ... Liquid crystal phase
5 ... Transparent electrode with slits
6 ... Zigzag slit

Claims (17)

General formula (1)

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and one CH ₂ group present in these groups) Alternatively, two or more CH ₂ groups that are not adjacent to each other may be substituted with an oxygen atom or a sulfur atom, and one or more hydrogen atoms present in these groups may be replaced with a fluorine atom or a chlorine atom. May be replaced,
A ^1, A ^2, A ³ and A ⁴ are each independently not one CH ₂ group or adjacent existing in xylene group (in this group the trans-1,4-cyclohexylene two CH ₂ groups May be substituted with an oxygen atom or a sulfur atom), 1,4-phenylene group (one or two or more CH groups present in this group may be substituted with a nitrogen atom), 1 , 4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or Represents a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, the hydrogen atom present in these groups may be substituted with -CN or halogen,
Z ¹ , Z ³ and Z ⁴ are each independently -CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH (CH _{3) CH (CH 3) -} , - CF 2 CF 2 -, - CF = CF -, - CH 2 O -, - OCH 2 -, - OCH (CH 3) -, - CH (CH 3) O-, -(CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -C≡C-, -CF ₂ O-, -OCF _2- , -COO-, -OCO- , -COS-, -SCO- or a single bond, Z ² represents -CH ₂ O- or -CF ₂ O-, and A ¹ , A ² , A ³ , A ⁴ , Z ¹ , Z ² , Z ^When there are a plurality of ³ and Z ⁴ , they may be the same or different,
a, c and d each independently represents 0 or 1, b represents 1,
W ¹ and W ² each independently represent a fluorine atom, a chlorine atom, —CF ₃ , —CF ₂ H, —OCF ₃ or —OCF ₂ H. ) A compound represented by In the general formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms (one CH ₂ group present in these groups is oxygen The compound according to claim ¹ , wherein W ¹ and W ² each represents a fluorine atom. In the general formula (1), A ¹ , A ² , A ³ and A ⁴ may be each independently substituted with a trans-1,4-cyclohexylene group, one or more fluorine atoms. The compound according to claim 1, which represents a 1,4-phenylene group or a 1,4-bicyclo [2.2.2] octylene group. In the general formula (1), Z ¹ , Z ² , Z ³ and Z ⁴ are each independently —CH ₂ CH ₂ —, —CH═CH—, —CF ₂ CF ₂ —, —CF═CF—, — _{CH 2 O -, - OCH 2} -, - C≡C -, - CF 2 O -, - OCF 2 - or a compound according to claim 1 which represents a single bond. The compound according to claim 1, wherein in the general formula (1), the sum of a, b, c and d represents 1 or 2. In the general formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms (one CH ₂ group present in these groups is oxygen And W ¹ and W ² each represents a fluorine atom, and A ¹ , A ² , A ³ and A ⁴ are each independently a trans-1,4-cyclohexylene group, Represents a 1,4-phenylene group or a 1,4-bicyclo [2.2.2] octylene group which may be substituted with one or more fluorine atoms, and Z ¹ , Z ² , Z ³ and Z ⁴ each represents independently _{-CH 2 CH 2 -, - CH} = CH -, - CF 2 CF 2 -, - CF = CF -, - CH 2 O -, - OCH 2 -, - C≡C -, - CF 2 O The compound according to claim 1, which represents-, -OCF ₂ -or a single bond, and the sum of a, b, c and d represents 1 or 2. In the general formula (1), R ¹ and R ² each independently represents an alkyl group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, or an alkoxy group having 1 to 7 carbon atoms, and A ¹ , A ² , A ³ and A ⁴ are each independently trans-1,4-cyclohexylene group, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene Group, or a 2,3-difluoro-1,4-phenylene group, Z ¹ , Z ² , Z ³ and Z ⁴ are each independently —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ — or a single bond, W ¹ and W ² represents a fluorine atom, a, b, a compound according to claim 1 in which the sum of c and d is 1 or 2. The compound according to claim 1, wherein in the general formula (1), A ¹ , A ² , A ³ and A ⁴ each independently represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group. A liquid crystal composition containing one or more compounds according to any one of claims 1 to 8. General formula (2)

(In the formula, R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and one CH ₂ group present in these groups. Alternatively, two or more CH ₂ groups that are not adjacent to each other may be substituted with an oxygen atom or a sulfur atom, and one or more hydrogen atoms present in these groups may be replaced with a fluorine atom or a chlorine atom. May be replaced,
B ¹ and B ² are each independently a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or _two non-adjacent CH ₂ groups are oxygen atoms or sulfur atoms) 1,4-phenylene group (one or more CH groups present in this group may be substituted with a nitrogen atom), 1,4-cyclohexenylene 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, or 1,2,3, 4-tetrahydronaphthalene-2,6-diyl group, a hydrogen atom present in these groups may be substituted with -CN or halogen,
Y ¹ and Y ² are each independently -CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH (CH ₃ ) CH _{(CH 3) -, - CF} 2 CF 2 -, - CF = CF -, - CH 2 O -, - OCH 2 -, - OCH (CH 3) -, - CH (CH 3) O -, - (CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -C≡C-, -CF ₂ O-, -OCF _2- , -COO-, -OCO-, -COS -, -SCO- or a single bond,
When there are a plurality of Y ² and B ² , they may be the same or different,
p represents 0, 1 or 2. The liquid crystal composition according to claim 9, comprising at least one compound represented by the formula: Group consisting of general formula (3a), general formula (3b) and general formula (3c)

(In the formula, R ⁵ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms, and one CH ₂ group present in these groups or _two not adjacent to each other. The above CH ₂ group may be substituted with an oxygen atom or a sulfur atom, and one or two or more hydrogen atoms present in these groups may be substituted with a fluorine atom or a chlorine atom,
B ³ , B ⁴ and B ⁵ are each independently a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or _two non-adjacent CH ₂ groups are oxygen atoms) Or a 1,4-phenylene group (one or more CH groups present in this group may be substituted with a nitrogen atom), 1,4- Cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or 1,2 , 3,4-tetrahydronaphthalene-2,6-diyl group, a hydrogen atom present in these groups may be substituted with -CN or halogen,
Y ³ , Y ⁴ and Y ⁵ are each independently -CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH (CH _{3) CH (CH 3) -} , - CF 2 CF 2 -, - CF = CF -, - CH 2 O -, - OCH 2 -, - OCH (CH 3) -, - CH (CH 3) O-, -(CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -C≡C-, -CF ₂ O-, -OCF _2- , -COO-, -OCO- , -COS-, -SCO- or a single bond,
L ¹ , L ² , L ⁴ , L ⁵ , L ⁶ , L ⁷ , L ⁸ , L ¹⁰ , L ¹¹ and L ¹² each independently represent a hydrogen atom or a fluorine atom,
q and r each independently represent 0, 1 or 2, but the sum of q and r is 2 or less,
L ³ and L ⁹ each independently represent the same meaning as a hydrogen atom, a fluorine atom, a chlorine atom, -CN, -CF ₃ , -OCH ₂ F, -OCHF ₂ , -OCF ₃ , -CH ₂ CF ₃ or R ⁵ Represents. The liquid crystal composition according to claim 9, which contains one or more compounds selected from the group consisting of: The liquid crystal composition according to claim 11, comprising at least one compound represented by the general formula (2) according to claim 10 . The liquid crystal composition according to claim 9, wherein the content of the compound represented by the general formula (1) is in the range of 2 to 30% by mass. The liquid crystal composition according to claim 9, which has a dielectric anisotropy value of −0.2 or less. The liquid crystal display element using the liquid-crystal composition of any one of Claim 9 to 14. The liquid crystal display element according to claim 15, which is an active matrix system. The liquid crystal display element according to claim 16, wherein an alignment direction of the alignment film is perpendicular to the substrate surface.

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