JP2003040814A - New liquid crystal compound having 1,2-propanediyl group as coupling group and liquid crystal composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new liquid crystal compound excellent in compatibility and having an effect of decreasing anisotropy of refractive index (Δn) when added to mother liquid crystals, to provide a liquid crystal composition containing the liquid crystal compound, and to provide a liquid crystal displaying element using the liquid crystal composition. SOLUTION: This new liquid crystal compound having a 1,2-dipropanediyl group is expressed by general formula (I) (R<1> and R<2> are each a 1-20C strait chain, branched chain or cyclic alkyl, alkoxyl, alkoxylalkyl, alkenyl or alkenyloxy which may be substituted by a 1-20C alkoxyl or 1-30 halogen atoms; X<1> to X<4> are each H, F, Cl or CN; cyclohexane rings have each a 1,4-trans configuration; and m is 0 or 1). The nematic liquid crystal composition contains the liquid crystal compound. The liquid crystal displaying element is given by using the liquid crystal composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel compound useful as an electro-optical liquid crystal display material, having a 1,2-propanediyl group as a linking group, a liquid crystal composition containing the same, and a liquid crystal composition as a constituent element. Liquid crystal element.

[0002]

2. Description of the Related Art Liquid crystal display devices have come to be used in watches, calculators, various measuring instruments, home appliances in general, automobile panels, word processors, electronic notebooks, mobile phones, computers, televisions and the like.

Liquid crystal materials are classified according to the display system and drive system.
Various characteristics are required. In particular, a wide temperature range is very important in most cases, but the nematic phase maximum temperature (T _NI ) is sufficiently high.
Melting point (T _CN ) or smectic-nematic transition temperature
(T _SN ) is low enough.

Compatibility with other liquid crystal compounds and general-purpose liquid crystal compositions is also important. When the compatibility is poor, it is necessary to mix a large number of liquid crystal compounds in order to avoid the risk of precipitation and phase separation, and it takes a lot of time and effort to prepare the composition, and it is possible to avoid cost increase. I couldn't do it.

Further, the refractive index anisotropy (Dn) is also an important characteristic, and various values are required depending on the display method. In the TN type and STN type that are currently in practical use, a reflective liquid crystal display element that does not use a backlight has been in practical use due to recent portability. In a liquid crystal display device, in order to prevent coloring and unevenness due to the generation of interference fringes, the product (Δn ・ d) of the cell thickness (d) and the refractive index anisotropy (Δn) is set to a certain value (0.5, 1.0, 1.6). , 2.2, etc.), but this is when using a backlight, and in the above-mentioned reflective liquid crystal display element, the value of d is Doubled, resulting in 1 as Δn
A value of / 2 is required. By reducing the cell thickness, coloring and unevenness due to the generation of interference fringes can be prevented, but there is a limit, and as a result, a liquid crystal material having a small Δn is required. At present, as a compound having a small Δn, a compound having a trans-1,4-cyclohexylene group is typical. However, Δn cannot be sufficiently reduced only by a compound having this skeleton, and a liquid crystal material having a liquid crystal skeleton having a smaller Δn has been strongly demanded. Further, in recent years, a compound having a negative Δε has been attracting attention, and there is a demand for the development of a compound having a fluorine atom in the minor axis direction of the molecule and exhibiting a large negative absolute Δε.

Further, there is a demand for the development of a liquid crystal material which has a high chemical stability against light, heat, water and the like and which does not cause image sticking which is a major cause of display defects in the display.

To meet these requirements, a great number of liquid crystal compounds have been synthesized so far, but not all the problems have been solved, and liquid crystals having more excellent characteristics for each of the above requirements. At present, there is a demand for compounds.

Generally, a liquid crystal compound is structurally formed of a central skeleton (core) portion and a side group (polar group and / or side chain). Various studies have been conducted on a linking group that connects ring structures. However, the ester or ether bond is weak against acids, bases, heat, etc., and the structure having a double bond such as styrene is easily isomerized by UV and does not satisfy the requirement.

[0009]

The problem to be solved by the present invention is to provide a novel liquid crystalline compound having a 1,2-propanediyl group as a linking group. It is intended to provide a small liquid crystal composition and a liquid crystal element including the liquid crystal composition as a constituent element.

[0010]

In order to solve the above-mentioned problems, the present invention has the general formula (I)

[Chemical 2] (In the formula, each of R ¹ and R ² independently has 1 to 20 carbon atoms.
Represents an alkyl group, an alkoxyl group, an alkoxyl alkyl group, an alkenyl group or an alkenyloxy group, which may contain a straight chain, branched chain or cyclic moiety, and has 1 to 1 carbon atoms.
Optionally substituted by an alkoxyl group of 0 or 1 to 30 halogen atoms, m represents 0 or 1, and X ^{1 to} X ⁴
Each independently represent a hydrogen atom, a fluorine atom, a chlorine atom or a cyano group. The 1,4-position of the cyclohexane ring is in the trans configuration. ), A liquid crystal compound having a 1,2-propanediyl group is synthesized, and a liquid crystal device containing the compound represented by the general formula (I) and a liquid crystal device having the liquid crystal composition as a constituent element, Found as a means to solve.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
To do. Having a 1,2-propanediyl group represented by the general formula (I)
In the liquid crystal compound that ¹, R²Each independently
Includes linear, branched or cyclic moieties containing 1 to 7 carbon atoms
Good alkyl group, alkoxyl group, alkoxyl alkyl
Group, alkenyl group or alkenyloxy group is preferred.
In addition, straight chain alkyl groups having 1 to 7 carbon atoms,
Syl group, alkoxyl alkyl group, alkenyl group or
Alkenyloxy groups are preferred, straight-chain with 1 to 7 carbon atoms
Alkyl or alkenyl groups are particularly preferred. m is low
When viscosity is required, 0 is preferable and it can be used at high temperatures.
When a large liquid crystal temperature range is required, 1 is preferable. X¹~ X
^FourIs preferably a hydrogen atom or a fluorine atom, all hydrogen
Atoms or one or more are fluorine atoms and the others are hydrogen atoms
More preferably. Especially the phase with other liquid crystal compounds
In order to improve solubility, one is a fluorine atom
The other is more preferably a hydrogen atom, and Δε is large.
X for negative negative absolute value¹ And X² Is fluorine
Atom and X³ And X^Four Is preferably a hydrogen atom
Yes.

In the general formula (I), various compound groups are included depending on the selection of R ¹ , R ² , m, and X ^{1 to} X ⁴ ,
The compounds shown below are particularly preferred.

[Chemical 3]

[0013]

[Chemical 4] (In the formula, R ¹ and R ² have the same meanings as in the general formula (I).) Furthermore, in the above formulas, the general formulas (Iaa), (Iaf), (Iba)
And each compound of (Ibf) are more preferred and represented by the general formula (Ia
The compounds of f) and (Ibf) are particularly preferred. In the general formulas (Iaa) to (Ibf), R ¹ and R ² preferably represent a linear alkyl group having 1 to 7 carbon atoms, an alkoxyl group, an alkoxylalkyl group, an alkenyl group or an alkenyloxy group, It is particularly preferred to represent a straight-chain alkyl or alkenyl radical having 1 to 7 carbon atoms.

The compounds of the general formula (I) according to the invention are those whose R ¹ ,
It can be produced as follows depending on R ² , m, and X ^{1 to} X ⁴ . For compounds represented by general formula (Iaa)

(I) General formula (IIa)

[Chemical 5]

(Wherein R ¹ has the same meaning as in formula (I), and X represents a halogen atom such as chlorine, bromine or iodine, preferably a bromine atom). Is reacted with magnesium to give a Grignard reagent, or lithiated with an alkyllithium such as butyllithium to give an organometallic reagent.
(IIIa)

[0017]

[Chemical 6] (In the formula, R ² has the same meaning as in the general formula (I).), And the obtained general formula (IVa) is obtained.

[0018]

[Chemical 7] (In the formula, R ¹ and R ² have the same meaning as in the general formula (I).) The alcohol represented by the general formula (Va) to (Vc) is dehydrated in the presence of an acid catalyst.

[0019]

[Chemical 8] (Wherein R ¹ and R ² have the same meanings as in formula (I)). The compound represented by the general formula (Iaa) is produced by catalytically reducing this, isomerizing 1,4-cyclohexylene ring to trans as necessary, and separating the target product by column chromatography, recrystallization, etc. can do.

(Ii) The general formula (IIa) is reacted with magnesium to give a Grignard reagent, or lithiated with an alkyllithium such as butyllithium to give an organometallic reagent, which is the general formula (VIa)

[Chemical 9] (In the formula, R ² has the same meaning as in the general formula (I).) Then, the obtained alcohol is oxidized or the general formula (VIb) is used.

[Chemical 10] (In the formula, R ² has the same meaning as in the general formula (I).) And is reacted with an acid chloride or the like,

General formula (VIIa)

[Chemical 11] (In the formula, R ¹ and R ² have the same meaning as in the general formula (I).) After the ketone represented by the formula (VIII)

[0022]

[Chemical 12] The compound represented by the general formula (Iaa) can be produced by reacting with a Wittig reaction agent represented by and further reducing.

(Iii) the general formula (IVa) is replaced by the general formula (IXa)

[Chemical 13] (In the formula, R ¹ and R ² have the same meanings as in formula (I), and Y represents C (= S) C ₆ H ₅ , C (= S) SCH ₃ , C (= S) OC ₆ H. (Represents ₅ mag.)
After being converted into an ester represented by (n-Bu) ₃ SnH or the like, or by reducing the alcohol represented by the formula (IXa) with hydrosilane such as triethylsilane general formula (Iaa)
A compound represented by can be produced.

(Iv) Instead of the general formula (IIa) in (i), the general formula (Xa)

[Chemical 14] (In the formula, X represents the same meaning as in the general formula (IIa).), Instead of the general formula (IIIa), the general formula (X
I)

[0025]

[Chemical 15] The compound represented by the formula (XIIa) is dehydrated in the presence of an acid catalyst, reacetalized if necessary, catalytically reduced, and then deacetalized.

[0026]

[Chemical 16] A cyclohexanone derivative represented by The expression (X
IIIa)

[0027]

[Chemical 17] After reacting with a Wittig reaction agent represented by the formula (XIVa) by deprotection and isomerization

[0028]

[Chemical 18] A cyclohexanecarbaldehyde derivative represented by The formula (XVa)

[0029]

[Chemical 19] A compound having a vinyl group can be produced by reacting a Wittig reaction agent represented by Also,
A compound having a 3-butenyl group can be produced by reacting (XIIa) with the Wittig reagent of (XIIIa) twice more and then with the Wittig reagent of (XVb). Furthermore, in place of the general formula (Xa), the general formula (IIa), (X
b), (Xc)

[0030]

[Chemical 20] (In the formula, X represents the same meaning as in the general formula (IIa).) A compound represented by the general formula (XIa) is used instead of the general formula (XIa).
(IIIa), (XIb), (XIc)

[0031]

[Chemical 21] By using a compound represented by the formula (XVb) instead of the formula (XVa)

[0032]

[Chemical formula 22] A compound having an unsaturated side chain can be synthesized by appropriately using a Wittig reaction agent represented by and combining them.

Compounds other than the above-mentioned compounds represented by the general formula (I) can be produced in the same manner or by application thereof. Here, instead of the general formula (IIa), the general formula (II
b) ~ (IIp)

[0034]

[Chemical formula 23] (In the formula, R ¹ has the same meaning as in the general formula (I), and X has the same meaning as in the general formula (IIa)), or a compound represented by the general formula (Xa) is used. General formula (Xd) ~ (Xu)

[0035]

[Chemical formula 24]

[0036]

[Chemical 25]

[0037]

[Chemical formula 26] (Wherein X represents the same meaning as in general formulas (I) and (II).), Instead of general formula (IIIa), general formula (IIIb)

[0038]

[Chemical 27] (In the formula, R ² has the same meaning as in the general formulas (I) and (II).) Using the compound represented by the general formula (XIa), general formulas (IIIa), (XId), (XIe)

[Chemical 28] The compounds represented by the general formulas (Iab) to (Ibf) can be produced in the same manner by appropriately using the compounds represented by

The composition provided by the present invention contains at least one compound represented by the general formula (I) as its first component, and as other components, in particular from the following second to fourth components: It is preferable to contain at least one kind. That is, the second component is a so-called fluorine-based (halogen-based)
A p-type liquid crystal compound, which is composed of compounds represented by the following general formulas (A1) to (A3).

[Chemical 29]

In the above formula, R ^b represents an alkyl group having 1 to 12 carbon atoms, which may be linear or may have a methyl or ethyl branch, and is a 3- to 6-membered cyclic group. Any --CH _2- , which may have a structure and is present in the group, is --O--, --CH
= CH-, -CH = CF-, -CF = CH-, -CF = CF- or -C≡C-, and any hydrogen atom present in the group is a fluorine atom or trifluoro. It may be substituted with a methoxy group, but is a linear alkyl group having 2 to 7 carbon atoms, a linear 1-alkenyl group having 2 to 7 carbon atoms, or a linear 3 group having 4 to 7 carbon atoms. -Alkenyl groups, terminal carbon atoms
1-5 carbon atoms substituted with 1-3 alkoxyl groups
Alkyl groups of are preferred. Further, when asymmetric carbon is generated by branching, the compound may be optically active or racemic.

Ring A, Ring B and Ring C are each independently substituted with a trans-1,4-cyclohexylene group, a transdecahydronaphthalene-trans-2,6-diyl group, and one or more fluorine atoms. May be 1,4-phenylene group, 1
Naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, tetrahydronaphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, substituted by a fluorine atom 1,4-cyclohexenylene group, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group or pyridine-2,5-diyl group may be represented by trans- 1,4-cyclohexylene group, transdecahydronaphthalene-trans-2,6-diyl group,
Naphthalene-2,6 optionally substituted by fluorine atom
A -diyl group or a 1,4-phenylene group optionally substituted by 1 to 2 fluorine atoms is preferable. Particularly when Ring B is a trans-1,4-cyclohexylene group or a trans decahydronaphthalene-trans-2,6-diyl group,
Ring A is preferably a trans-1,4-cyclohexylene group, and Ring B is a ring B when Ring C is a trans-1,4-cyclohexylene group or a transdecahydronaphthalene-trans-2,6-diyl group. And ring A is preferably a trans-1,4-cyclohexylene group. Also, in (A3)
A is preferably a trans-1,4-cyclohexylene group. L ^a , L ^b and L ^c are linking groups, each independently a single bond, an ethylene group (-CH ₂ CH _2- ), a 1,2-propylene group.
_{(-CH (CH 3) CH 2} - and _{-CH 2 CH (CH 3) -} ), 1,4- butylene group,
-COO-, -OCO-, -OCF _2- , -CF ₂ O-, -CH = CH-, -CH = CF-,
-CF = CH-, -CF = CF-, -C≡C- or -CH = NN = CH-, but a single bond, ethylene group, 1,4-butylene group, -COO-, -OC
F _2- , -CF ₂ O-, -CF = CF- or -C≡C- is preferable, and a single bond or an ethylene group is particularly preferable. Further, it is preferable that at least one of them in (A2) and at least two of them in (A3) represent a single bond.

Ring Z is an aromatic ring and has the following general formulas (IXa) to (I
Xc).

[Chemical 30] Wherein represents a Y ^a to Y ^j are each independently a hydrogen atom or fluorine atom, in (IXa), at least one of Y ^a and Y ^b is preferably a fluorine atom, in (IXb), At least one of Y ^{d to} Y ^f is preferably a fluorine atom, and particularly preferably Y ^d is a fluorine atom.

The terminal group P ^a represents a fluorine atom, a chlorine atom, trifluoromethoxy group, difluoromethoxy group, trifluoromethyl group or difluoromethyl group or 2 or more carbon atoms substituted by fluorine atoms 2 or 3 of alkoxylation It represents a group, an alkyl group, an alkenyl group or an alkenyloxy group, but a fluorine atom, a trifluoromethoxy group or a difluoromethoxy group is preferable, and a fluorine atom is particularly preferable. Further, in (A2), the compound of the general formula (I) of the present invention is excluded.

The third component is a so-called cyano-based p-type liquid crystal compound, and is composed of compounds represented by the following general formulas (B1) to (B3).

[Chemical 31]

In the above formula, R ^c represents an alkyl group having 1 to 12 carbon atoms, which may be linear or may have a methyl or ethyl branch, and is a 3- to 6-membered cyclic group. Any --CH _2- , which may have a structure and is present in the group, is --O--, --CH
= CH-, -CH = CF-, -CF = CH-, -CF = CF- or -C≡C-, and any hydrogen atom present in the group is a fluorine atom or trifluoro. It may be substituted with a methoxy group, but is a linear alkyl group having 2 to 7 carbon atoms, a linear 1-alkenyl group having 2 to 7 carbon atoms, or a linear 3 group having 4 to 7 carbon atoms. -Alkenyl groups, terminal carbon atoms
1-5 carbon atoms substituted with 1-3 alkoxyl groups
Alkyl groups of are preferred. Further, when asymmetric carbon is generated by branching, the compound may be optically active or racemic.

Ring D, ring e and ring F are each independently substituted with a trans-1,4-cyclohexylene group, a transdecahydronaphthalene-trans-2,6-diyl group, and one or more fluorine atoms. May be 1,4-phenylene group, 1
Naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, tetrahydronaphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, substituted by a fluorine atom 1,4-cyclohexenylene group, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group or pyridine-2,5-diyl group may be represented by trans- 1,4-cyclohexylene group, transdecahydronaphthalene-trans-2,6-diyl group,
Naphthalene-2,6 optionally substituted by fluorine atom
A -diyl group or a 1,4-phenylene group optionally substituted by 1 to 2 fluorine atoms is preferable. Especially when the ring e is a trans-1,4-cyclohexylene group or a trans decahydronaphthalene-trans-2,6-diyl group,
Ring D is preferably a trans-1,4-cyclohexylene group, and when ring F is a trans-1,4-cyclohexylene group or a trans decahydronaphthalene-trans-2,6-diyl group, ring D And ring e is preferably a trans-1,4-cyclohexylene group. Also, in (B3)
D is preferably a trans-1,4-cyclohexylene group.

L^d, L^eAnd L^fIs a linking group,
Independently, a single bond, ethylene group (-CH ₂CH₂-), 1,2-propy
Ren group (-CH (CH₃) CH₂-And-CH₂CH (CH₃)-), 1,4-butyre
Group, -COO-, -OCO-, -OCF₂-,-CF₂O-, -CH = CH-, -CH
= CF-, -CF = CH-, -CF = CF-, -C≡C-, -OCH₂-, -CH₂O
-Or-represents CH = NN = CH-, but a single bond, ethylene
Group, -COO-, -OCF₂-,-CF₂O-, -CF = CF- or -C≡C-
A single bond, an ethylene group or -COO- is particularly preferable.
Good Further, in (B2), at least one of them is
In 3), at least two of them may represent a single bond.
preferable.

Ring Y is an aromatic ring and has the following general formulas (IXd) to (I
Xf).

[Chemical 32] In the formula, Y ^{h to} Y ⁿ each independently represent a hydrogen atom or a fluorine atom, but in (IXe), Y ⁿ and Y ^o are preferably hydrogen atoms. Terminal group P ^a represents a cyano group (-CN),
It represents a cyanato group (—OCN) or —C≡CCN, but a cyano group is preferred. Further, in (B2), the compound of the general formula (I) of the present invention is excluded.

The fourth component is a so-called n-type liquid crystal having a dielectric anisotropy of 0 or negative and has the following general formulas (C1) to (C
It is composed of the compound represented by 3).

[Chemical 33]

In the above formula, R ^d and R ^e each independently represents an alkyl group having 1 to 12 carbon atoms, which may be linear or may have a methyl or ethyl branch,
May have a cyclic structure having 3 to 6-membered ring, any -CH ₂ present in the group - is -O -, - CH = CH - , - CH = CF -, - CF = CH-,
-CF = CF- or -C≡C- may be exchanged, and any hydrogen atom present in the group may be replaced by a fluorine atom or a trifluoromethoxy group, but the number of carbon atoms is 1 to 7 linear alkyl group, 2 to 7 carbon linear 1-alkenyl group, 4 to 7 carbon linear 3-alkenyl group, 1 to 3 carbon linear alkoxyl group Alternatively, a linear alkyl group having 1 to 5 carbon atoms whose terminal is substituted with an alkoxyl group having 1 to 3 carbon atoms is preferable, and at least one is a linear alkyl group having 1 to 7 carbon atoms, the number of carbon atoms. 2 to 7 linear 1-alkenyl groups or carbon atoms
Particularly preferably, it is a linear 3-alkenyl group having 4 to 7.

Ring G, ring H, ring I and ring J are each independently a trans-1,4-cyclohexylene group, trans decahydronaphthalene-trans-2,6-diyl group, 1 to 2 fluorines. May be substituted by atoms or methyl groups
1,4-phenylene group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, tetrahydronaphthalene-2,6-optionally substituted by 1 to 2 fluorine atoms Diyl group, 1,4-cyclohexenylene group optionally substituted by 1 to 2 fluorine atoms, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group or Represents a pyridine-2,5-diyl group, but in each compound, transdecahydronaphthalene-trans-2,
6-diyl group, naphthalene optionally substituted by one or more fluorine atoms-2,6-diyl group, tetrahydronaphthalene optionally substituted by 1 to 2 fluorine atoms
-2,6-diyl group, 1,4-cyclohexenylene group optionally substituted by a fluorine atom, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group or The number of pyridine-2,5-diyl groups is preferably 1 or less, and the other rings are trans-1,4-cyclohexylene groups or 1 to 2
It is preferably a 1,4-phenylene group which may be substituted with one fluorine atom or a methyl group.

L^g, L^hAnd LⁱIs a linking group,
Independently, a single bond, ethylene group (-CH ₂CH₂-), 1,2-propy
Ren group (-CH (CH₃) CH₂-And-CH₂CH (CH₃)-), 1,4-butyre
Group, -COO-, -OCO-, -OCF₂-,-CF₂O-, -CH = CH-, -CH
= CF-, -CF = CH-, -CF = CF-, -C≡C- or -CH = NN = CH
-Represents a single bond, ethylene group, 1,4-butylene group, -CO
O-, -OCO-, -OCF₂-,-CF₂O-, -CF = CF-, -C≡C- or-
CH = NN = CH- is preferred, and at least in (C2)
Also at least one of them has a single bond in (C3).
It is preferable to represent. In addition, in (C2),
Compounds of general formula (I) are excluded.

A more preferable form of (C1) can be represented by the following general formulas (C1a) to (C1h).

[Chemical 34]

In the above formulas, R ^f and R ^g are each independently a straight-chain alkyl group having 1 to 7 carbon atoms and 2 to 7 carbon atoms.
A straight-chain 1-alkenyl group, a straight-chain 3-alkenyl group having 4 to 7 carbon atoms, a straight-chain alkoxyl group having 1 to 3 carbon atoms, or a terminal substituted with an alkoxyl group having 1 to 3 carbon atoms. Represents a straight-chain alkyl group having 1 to 5 carbon atoms, at least one of which is a straight-chain alkyl group having 1 to 7 carbon atoms, a straight-chain 1-alkenyl group having 2 to 7 carbon atoms, or a carbon atom. Number of atoms
It represents a linear 3-alkenyl group of 4 to 7. However, ring G1 ~ ring
When G8 is an aromatic ring, the corresponding R ^f excludes a 1-alkenyl group and an alkoxyl group, and when ring H1 to ring H8 are an aromatic ring, the corresponding R ^g excludes a 1-alkenyl group and an alkoxyl group.

Ring G1 and ring H1 are each independently substituted with a trans-1,4-cyclohexylene group, a transdecahydronaphthalene-trans-2,6-diyl group, 1 to 2 fluorine atoms or a methyl group. Optionally 1,4-phenylene group, naphthalene which may be substituted by one or more fluorine atoms-2,6-diyl group, tetrahydronaphthalene which may be substituted by 1 to 2 fluorine atoms- 2,6
-Diyl group, 1,4-cyclohexenylene group optionally substituted by 1 to 2 fluorine atoms, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group Or represents a pyridine-2,5-diyl group, in each compound,
Transdecahydronaphthalene-trans-2,6-diyl group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, optionally substituted by 1-2 fluorine atoms Tetrahydronaphthalene-2,6-diyl group, 1,4-cyclohexenylene group optionally substituted by a fluorine atom, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl Group or pyridine-2,5-
The number of diyl groups is preferably 1 or less, in which case the other ring is trans-1,4-cyclohexylene group or 1
~ 1,4-phenylene group optionally substituted by 2 fluorine atoms or a methyl group. Ring G2 and ring H2 are each independently a trans-1,4-cyclohexylene group, trans decahydronaphthalene-trans-2,6-diyl group,
1,4-phenylene group optionally substituted by 1 to 2 fluorine atoms or methyl group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, 1
~ Represents a tetrahydronaphthalene-2,6-diyl group optionally substituted by two fluorine atoms, in each compound trans decahydronaphthalene-trans-2,6-
Diyl group, naphthalene optionally substituted by one or more fluorine atoms-2,6-diyl group, tetrahydronaphthalene optionally substituted by 1-2 fluorine atoms-
The number of 2,6-diyl groups is preferably 1 or less, in which case the other ring may be substituted with a trans-1,4-cyclohexylene group or 1 to 2 fluorine atoms or a methyl group. It is a 1,4-phenylene group. Ring G3 and Ring H3
Are each independently 1,2-phenylene group optionally substituted by 1 to 2 fluorine atoms or a methyl group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms Represents a tetrahydronaphthalene-2,6-diyl group which may be substituted by 1 to 2 fluorine atoms, and naphthalene-2,6-which may be substituted by one or more fluorine atoms in each compound. Diyl group, 1-2
It is preferable that the number of tetrahydronaphthalene-2,6-diyl groups which may be substituted by 4 fluorine atoms is 1 or less.

A more preferable form of (C2) can be represented by the following general formulas (C2a) to (C2m).

[Chemical 35]

In the above formula, ring G1, ring G2, ring G3, ring H1, ring H2 and ring H3 have the above-mentioned meanings, ring I1 is ring G1 and ring I2 is ring.
G2 and ring I3 have the same meanings as ring G3. Also,
In each of the above compounds, transdecahydronaphthalene
-Trans-2,6-diyl group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, 1-2
Tetrahydronaphthalene-2,6-diyl group optionally substituted by fluorine atoms, 1,4-cyclohexenylene group optionally substituted by fluorine atoms, 1,3-dioxane-trans-2,5 -Diyl group, pyrimidine-2,5-diyl group or pyridine-2,5-diyl group is preferably 1 or less, in which case the other ring is trans-1,4-cyclohexylene group or 1 ~ It is a 1,4-phenylene group which may be substituted with two fluorine atoms or a methyl group.

Next, a more preferable form of (C3) can be represented by the following general formulas (C3a) to (C3f).

[Chemical 36]

In the above formula, ring G1, ring G2, ring H1, ring H2, ring I1 and ring I2 have the above-mentioned meanings, ring J1 is ring G1 and ring J2 is ring.
Represents the same meaning as G2. In each of the above compounds, transdecahydronaphthalene-trans-2,6-
Diyl group, naphthalene optionally substituted by one or more fluorine atoms-2,6-diyl group, tetrahydronaphthalene optionally substituted by 1-2 fluorine atoms-
2,6-diyl group, optionally substituted by fluorine atom
1,4-cyclohexenylene group, 1,3-dioxane-trans-
The number of 2,5-diyl group, pyrimidine-2,5-diyl group or pyridine-2,5-diyl group is preferably within 1, and the other ring in that case is trans-1,4-cyclohexylene group. Alternatively, it is a 1,4-phenylene group which may be substituted with 1 to 2 fluorine atoms or a methyl group.

[0060]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Here, the following abbreviations are used in the description of compounds. Terminal n (number) C _n H _{2n + 1-} , -C _n H _{2n + 1} -mdn-(CH ₂ ) mC = C-CnH _{n + 1} ndm- CnH _{n + 1} -C = C-(CH ₂ ) m-

[0061]

[Chemical 37] -G- -CH ₂ CH (CH ₃ )-

Example 1 4- [1-Methyl-2- (trans-4-propylcyclohexyl) ethyl] -4- (trans-4′-propylcyclohexyl) -2,3-difluorobenzene (Iaf-1 ) Synthesis

[Chemical 38]

8 g of magnesium in a 3 L reaction vessel (N ₂ displacement, mechanical stirrer, thermometer, Dimroth condenser)
And 20 mL of tetrahydrofuran (THF) are added, and 100 g of trans-1- (bromomethyl) -trans-4-propylcyclohexylbenzene in tetrahydrofuran (T
HF) 400 mL solution was added dropwise. After completion of the dropwise addition, the mixture was stirred for 1 hour, and then a solution of trans-4-propylcyclohexylcarbaldehyde 51.2 g in THF 200 mL was added dropwise. The reaction was stopped by adding 100 mL of water, 100 mL of hexane was added, the organic phase was separated, and the organic phase was further washed with 200 mL of water twice, further with 200 mL of saturated saline, and then with anhydrous sodium sulfate. It was dehydrated and dried. After distilling off the solvent, 115.6 g of alcohol was obtained. To a 3 L reaction vessel (N ₂ displacement, mechanical stirrer, thermometer, Dimroth condenser) was added the total amount of the obtained alcohol and acetic acid (500 mL), and 185 g of an aqueous sodium hypochlorite solution was added dropwise under ice cooling. After the addition was complete, after stirring for an additional 1 hour, 300 mL of water and 500 mL of toluene were added, the organic phase was separated, and the organic phase was washed twice with 200 mL of water and then with 200 mL of saturated saline. , Dehydrated and dried over anhydrous sodium sulfate. After distilling off the solvent, 118 g of a ketone body was obtained.

A Wittig reagent was prepared from methyltriphenylphosphonium bromide and potassium t-butoxide in THF under ice-cooling, and the total amount of the ketone body obtained was added to THF300.
It was dissolved in mL and added dropwise at 5 ° C. After reacting for 1 hour, the temperature was returned to room temperature, water was added, and the organic layer was concentrated. Hexane was added and dissolved, and the insoluble triphenylphosphine oxide was filtered off and washed with a mixed solvent of methanol / water = 1/1. 97 g of crude product obtained by concentrating the hexane layer, ethyl acetate
300 mL and 20 g of palladium-carbon (containing 5% by mass of palladium and 50% water content) were added to a 2 L autoclave, and the hydrogen pressure was increased to 0.5 MPa. After stirring for 4 hours, the catalyst was filtered off and the resulting filtrate was dried under reduced pressure to give trans-4- [1-methyl
Crude crystal of -2- (trans-4-propylcyclohexyl) ethyl] -trans-4'-propylbicyclohexane (Iba-1) 78
got g. The total amount obtained was purified by silica gel column chromatography (developing solvent: hexane) and recrystallized from ethanol to obtain 54 g of a purified product. (N 62 I) Similarly, the following compound is obtained. 3CyPhGCy3, 3CyPh1GCy3, 3CyPh2GCy3, 3CyPh3GCy3, 3Cy
PhGCyCy3, 3CyPh1GCyCy3, 3CyPh2GCyCy3, 3CyPh3GCyCy
3, 3CyPh4GCyCy3, 2CyPhGCy3, 2CyPh1GCy3, 2CyPh2GCy
3, 2CyPh3GCy3, 2CyPhGCyCy3, 2CyPh1GCyCy3, 2CyPh2GC
yCy3, 2CyPh3GCyCy3, 2CyPh4GCyCy3, 3CyPhGCy2, 3CyPh
1GCy2, 3CyPh2GCy2, 3CyPh3GCy2, 3CyPhGCyCy2, 3CyPh1
GCyCy2, 3CyPh2GCyCy2, 3CyPh3GCyCy2, 3CyPh4GCyCy2

Example 2 4- [1-Methyl-2- (trans-4-vinylcyclohexyl) ethyl] -4- (trans-4′-propylcyclohexyl) -2,6-difluorobenzene (Iad-1) ) Synthesis

[Chemical Formula 39]

In Example 1, instead of trans-4-propylcyclohexylcarbaldehyde, cyclohexane was used.
After the Grignard reaction, oxidation, Wittig reaction and catalytic reduction were carried out in the same manner except that 4-one monoethylene acetal carbaldehyde was used, formic acid was added and the mixture was heated and stirred. After cooling, water was added, the separated toluene layer was washed, and then the solvent was distilled off. The obtained crude crystals were recrystallized from ethanol to obtain cyclohexanone crystals. This was dissolved in a mixed solvent of toluene and THF and cooled, and a Wittig reaction agent prepared from methoxymethyltriphenylphosphonium chloride and potassium t-butoxide was added. After returning to room temperature, water and hexane were added, the insoluble material was filtered off from the hexane layer, and then washed with a water / methanol mixed solvent. After the solvent was distilled off, the residue was dissolved in THF, diluted hydrochloric acid was added, and the mixture was heated under reflux for 1 hour. After cooling, water was added and the mixture was extracted with ethyl acetate. After the solvent was distilled off, the residue was dissolved in ethanol, 20% aqueous sodium hydroxide solution was added, and the mixture was stirred at room temperature. After adding water, extracting with toluene, washing and drying, the solvent was distilled off to obtain aldehyde crystals. This was dissolved in THF and a Wittig reagent prepared from ethyltriphenylphosphonium iodide and potassium t-butoxide was added. After returning to room temperature, water and hexane were added, the insoluble matter was filtered off from the hexane layer, and then water / hexane was added.
It was washed with a mixed solvent of methanol. After drying, the solvent was distilled off, the residue was purified by silica gel column chromatography (toluene), and recrystallized to give 4- [1-methyl-2- (trans-4-vinylcyclohexyl) ethyl] -4- (trans-4. Crystals of'-propylcyclohexyl) -2,6-difluorobenzene were obtained.
(Cr 23 N 84 I)

Similarly, the following compounds are obtained. 3CyPhGCy0d0, 3CyPhGCy1d0, 3CyPh1GCy0d0, 3CyP1hGCy1
d0, 3CyPh2GCy0d0, 3CyPh2GCy1d0, 3CyPh3GCy0d0, 3CyP
h3GCy1d0, 3CyPh4GCy0d0, 3CyPh4GCy1d0, 3CyPhGCyCy0d
0, 3CyPhGCyCy1d0, 3CyPh1GCyCy0d0, 3CyP1hGCyCy1d0,
3CyPh2GCyCy0d0, 3CyPh2GCyCy1d0, 3CyPh3GCyCy0d0, 3C
yPh3GCyCy1d0, 3CyPh4GCyCy0d0, 3CyPh4GCyCy1d0, 0d0C
yPhGCy3, 1d0CyPhGCy3, 0d0CyPh1GCy3, 1d0CyP1hGCy3,
0d0CyPh2GCy3, 1d0CyPh2GCy3, 0d0CyPh3GCy3, 1d0CyPh3
GCy3, 0d0CyPh4GCy3, 1d0CyPh4GCy3, 0d0CyPhGCyCy3, 1
d0CyPhGCyCy3, 0d0CyPh1GCyCy3, 1d0CyP1hGCyCy3, 0d0C
yPh2GCyCy3, 1d0CyPh2GCyCy3, 0d0CyPh3GCyCy3, 1d0CyP
h3GCyCy3, 0d0CyPh4GCyCy3, 1d0CyPh4GCyCy3

Example 3 4- [1-Methyl-2- (trans-4-vinylcyclohexyl) ethyl] -4- [trans-4- (1-propen-1-yl) cyclohexyl] -2,3 -Difluorobenzene (I
Synthesis of aa-1)

[Chemical 40]

In a 100 mL reaction vessel (N ₂ displacement, magnetic stirrer, thermometer, Dimroth condenser), the alcohol derivative ((Example 1) trans-1- (bromomethyl) -trans) was used.
1- (Bromomethyl) -4- (trans-4-vinylcyclohexyl) benzene was used instead of -4-propylcyclohexylbenzene, and trans-4- (1-propene-1) was used instead of trans-4-propylcyclohexylcarbaldehyde. Obtained by using -yl) cyclohexylcarbaldehyde. ) 20 g was dissolved in a mixed solvent of 100 mL of THF, 15 mL of carbon disulfide and 15 mL of hexamethylphosphoric triamide, and together with 3.5 g of sodium hydride and 1 g of imidazole.
After heating under reflux for 30 hours, 7 mL of dimethyl sulfate was added and the mixture was heated under reflux for 30 minutes. After adding 10 mL of acetic acid, 30 mL of water and 50 mL of toluene were added, the organic phase was separated, and the organic phase was further washed with 30 mL of water twice, further with 30 mL of saturated saline solution, and then with anhydrous sulfuric acid. It was dehydrated and dried with sodium. After distilling off the solvent
18 g of dithiocarbonate was obtained.

The total amount obtained was dissolved in 200 mL of toluene in a 1 L reaction vessel (N ₂ displacement, magnetic stirrer, thermometer, Dimroth condenser), and 21.5 g of (nC ₄ H ₉ ) ₃ SnH was added to 300 mL of toluene. It was dissolved in mL and added dropwise. After heating and refluxing for another 4 hours, 300 mL of water was added, the organic phase was separated, and the organic phase was further washed twice with 200 mL of water, further washed with 200 mL of saturated saline, and then dehydrated and dried over anhydrous sodium sulfate. Let After distilling off the solvent, silica gel column chromatography (developing solvent:
Hexane) and recrystallized from ethanol to give 4 g of 4- [1-methyl-2- (trans-4-vinylcyclohexyl) ethyl] -4- [trans-4- (1-propen-1- White crystals of (yl) cyclohexyl] -2,3-difluorobenzene (Iaa-1) were obtained. (Cr 52 N 142 I)

Similarly, the following compounds are obtained. 0d0CyPhGCy0d0, 0d0CyPhGCy1d0, 0d0CyPh1GCy0d0, 0d0C
yP1hGCy1d0, 0d0CyPh2GCy0d0, 0d0CyPh2GCy1d0, 0d0CyP
h3GCy0d0, 0d0CyPh3GCy1d0, 0d0CyPh4GCy0d0, 0d0CyPh4
GCy1d0, 0d0CyPhGCyCy0d0, 0d0CyPhGCyCy1d0, 0d0CyPh1
GCyCy0d0, 0d0CyP1hGCyCy1d0, 0d0CyPh2GCyCy0d0, 0d0C
yPh2GCyCy1d0, 0d0CyPh3GCyCy0d0, 0d0CyPh3GCyCy1d0,
0d0CyPh4GCyCy0d0, 0d0CyPh4GCyCy1d0, 0d0CyPhGCy0d
0, 1d0CyPhGCy0d0, 0d0CyPh1GCy0d0, 1d0CyP1hGCy0d0,
0d0CyPh2GCy0d0, 1d0CyPh2GCy0d0, 0d0CyPh3GCy0d0, 1d
0CyPh3GCy0d0, 0d0CyPh4GCy0d0, 1d0CyPh4GCy0d0, 0d0C
yPhGCyCy0d0, 1d0CyPhGCyCy0d0, 0d0CyPh1GCyCy0d0, 1d
0CyP1hGCyCy0d0, 0d0CyPh2GCyCy0d0, 1d0CyPh2GCyCy0d
0, 0d0CyPh3GCyCy0d0, 1d0CyPh3GCyCy0d0, 0d0CyPh4GCy
Cy0d0, 1d0CyPh4GCyCy0d0, 0d1CyPhGCy0d0, 0d1CyPhGCy
1d0, 0d1CyPh1GCy0d0, 0d1CyP1hGCy1d0, 0d1CyPh2GCy0d
0, 0d1CyPh2GCy1d0, 0d1CyPh3GCy0d0, 0d1CyPh3GCy1d
0, 0d1CyPh4GCy0d0, 0d1CyPh4GCy1d0, 0d1CyPhGCyCy0d
0, 0d1CyPhGCyCy1d0, 0d1CyPh1GCyCy0d0, 0d1CyP1hGCyC
y1d0, 0d1CyPh2GCyCy0d0, 0d1CyPh2GCyCy1d0, 0d1CyPh3
GCyCy0d0, 0d1CyPh3GCyCy1d0, 0d1CyPh4GCyCy0d0, 0d1C
yPh4GCyCy1d0, 0d0CyPhGCy0d1, 1d0CyPhGCy0d1, 0d0CyP
h1GCy0d1, 1d0CyP1hGCy0d1, 0d0CyPh2GCy0d1, 1d0CyPh2
GCy0d1, 0d0CyPh3GCy0d1, 1d0CyPh3GCy0d1, 0d0CyPh4GC
y0d1, 1d0CyPh4GCy0d1, 0d0CyPhGCyCy0d1, 1d0CyPhGCyC
y0d1, 0d0CyPh1GCyCy0d1, 1d0CyP1hGCyCy0d1, 0d0CyPh2
GCyCy0d1, 1d0CyPh2GCyCy0d1, 0d0CyPh3GCyCy0d1, 1d0C
yPh3GCyCy0d1, 0d0CyPh4GCyCy0d1, 1d0CyPh4GCyCy0d1

Example 4 Preparation of Liquid Crystal Composition (1) General-purpose host liquid crystal (H)

[Chemical 41] Was prepared. When the value of Δn of this host liquid crystal (H) was measured, it was 0.090, and the value of Δε was 4.8.

Next, 90% by mass of the host liquid crystal (H) and the compound of the formula (Iaf-1) of the present invention obtained in Example 1 were used.

[Chemical 42] A liquid crystal composition (H-1) containing 10% by mass of the compound represented by was prepared and Δn was measured. As a result, it was 0.086, and Δn could be reduced. Further, Δε was 4.0, and it was found that the compound represented by the formula (Iaf-1) had a large absolute value of negative Δε. Further, even if the amount of the compound (Iba-1) added was increased to 15% by mass and allowed to stand at -10 ° C for 8 hours, precipitation did not occur.

Comparative Example 1 In Example 4, the compound (Iaf-
Instead of 1), comparative compound A having a similar skeleton

[Chemical 43] Was mixed with the composition (H) in an amount of 10% by mass to prepare the composition (HA), and the Δn thereof was measured to be 0.091, which was a large value as compared with the compound (Iaf-1). Further, Δε was 4.2, which was less than that of the compound (Iaf-1). Further, when the addition amount of the comparative compound A was increased to 15% by mass, precipitation occurred when the mixture was allowed to stand at -10 ° C for 7 hours.

From the above, the addition of the compound (Iaf-1) gives Δn
It can be seen that it can be reduced and the compatibility with other liquid crystals is excellent. Further, the compound (Iaf-1) has a large absolute value of negative Δε, and it is found that the compound (Iaf-1) is useful for a liquid crystal composition having a negative Δε, such as a liquid crystal composition having a vertical orientation.

[0076]

As the linking group provided by the present invention, 1,
The novel liquid crystalline compound having a 2-propanediyl group is extremely excellent in compatibility with currently used general-purpose liquid crystal compounds or compositions, and has an effect of reducing Δn when added to a base liquid crystal. Furthermore, it is colorless and chemically stable.

Therefore, the liquid crystal composition containing this is extremely useful as a practical liquid crystal for a liquid crystal display requiring a small Δn.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4H006 AA01 AA03 AB64 EA35                 4H027 BD01 BD07 BD09 BD24 CR01                       CR02 CR05 CT04 CU01 CU02

Claims (9)

[Claims] 1. A compound represented by the general formula (I): (In the formula, each of R ¹ and R ² independently has 1 to 20 carbon atoms.
Represents an alkyl group, an alkoxyl group, an alkoxyl alkyl group, an alkenyl group or an alkenyloxy group, which may contain a linear, branched or cyclic part, and these are an alkoxyl group having 1 to 10 carbon atoms or a halogen having 1 to 30 carbon atoms. Optionally substituted by atoms, m represents 0 or 1 and X
^{1 to} X ⁴ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom or a cyano group. The cyclohexane ring
The 1st and 4th places are trance arrangements. ) A liquid crystal compound having a 1,2-propanediyl group represented by 2. R ¹ and R ² each independently have 1 carbon atom.
2. The compound according to claim 1, which represents an alkoxyl group of ˜7 or a straight chain alkyl group and alkenyl group of 1 to 20 carbon atoms which may be substituted by 1 to 7 halogen atoms. 3. R ¹ and R ² each independently have 1 carbon atom.
The compound of claim 1 which represents a straight chain alkyl group and an alkenyl group of ~ 7. 4. The compound according to any one of claims 1 to 3, wherein m represents 0. 5. The compound according to any one of claims 1 to 3, wherein m represents 1. 6. The compound according to claim 1, wherein X ¹ and X ² represent a fluorine atom and X ³ and X ⁴ represent a hydrogen atom. 7. The compound according to claim 1, wherein at least one of X ^{1 to} X ⁴ represents a fluorine atom. 8. The general formula (I) according to any one of claims 1 to 7.
A liquid crystal composition containing the described compound. 9. A liquid crystal device comprising the liquid crystal composition according to claim 8 as a constituent element.