JP2002155030A - Liquid crystal compound and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal compound comprising a smectic liquid crystal compound used for a ferroelectric liquid crystal display device, an antiferroelectric liquid crystal display device, etc., and capable of decreasing brightness when the device displays black color. SOLUTION: This liquid crystal compound is expressed by the formula (1) (A is functional group composed of only C and H atoms and having a double bond, a triple bond or a ring; B is an alkyl or an alkoxyl; X is H or F; and Y is CH3 or CF3). Alkoxycarbonylphenyl phenylbenzoate structures expressed by the formulae (2) to (4) of which the each has a ring structure or a multiple bond and a branched structure made of trifluoromethyl are shown as concrete examples of the smectic liquid crystal compound to be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal compound exhibiting a smectic phase and a liquid crystal display device using such a liquid crystal compound, and more particularly to a liquid crystal compound having a ferroelectric phase or an antiferroelectric phase.

[0002]

2. Description of the Related Art Generally, most liquid crystal display devices are of the TN (twisted nematic) type using nematic liquid crystal,
It is an STN (super twist nematic) type liquid crystal display device (nematic liquid crystal display device). This nematic liquid crystal display element performs display by changing the alignment state of liquid crystal molecules using the dielectric anisotropy of the liquid crystal itself.
Therefore, the response speed of the liquid crystal is slow, and there is a need for improvement.

On the other hand, a liquid crystal display device (smectic liquid crystal display device) using a liquid crystal exhibiting a smectic phase such as a ferroelectric liquid crystal or an antiferroelectric liquid crystal has been proposed. This smectic liquid crystal display element changes the alignment state of liquid crystal molecules using spontaneous polarization of liquid crystal, and therefore has a high-speed response and a memory property that cannot be achieved by a nematic liquid crystal display element.

[0004] In particular, antiferroelectric liquid crystals exhibit a thermodynamically stable phase in which dipoles are arranged antiparallel in adjacent layers.
Therefore, a display device using an antiferroelectric liquid crystal has an advantage that it is more resistant to an external impact than a display device using a ferroelectric liquid crystal in which all dipole directions of liquid crystal molecules are the same.

[0005]

In a ferroelectric liquid crystal element and an antiferroelectric liquid crystal element, the liquid crystal is aligned by utilizing the alignment regulating force of the alignment film between electrode substrates facing each other with the alignment film interposed therebetween. It is used as a liquid crystal display element having a simple matrix structure, compared to an active type in which a TFT (thin film transistor) is provided for each pixel.

In such a liquid crystal display element having a simple matrix structure, a signal voltage is always applied regardless of the display state when displaying, so that the liquid crystal is always slightly driven and light leakage occurs even in black display. . Assuming that the luminance due to the light leakage is the driving dark luminance, the luminance during black display is the sum of the orientation dark luminance and the driving display luminance. As a result, there is a problem that the luminance at the time of black display increases and the contrast is inferior to that of the liquid crystal display element of the active drive.

In view of the above problems, the present invention provides a smectic liquid crystal compound used for a ferroelectric liquid crystal display device or an antiferroelectric liquid crystal display device, which can suppress the luminance during black display. It is an object to provide a liquid crystal display element using such a liquid crystal compound.

[0008]

According to the first aspect of the present invention, there is provided a liquid crystal compound represented by the following chemical formula 9.

[0009]

Embedded image

Here, in the above chemical formula 9, A is a functional group composed of only C atoms and H atoms,
A structure having a heavy bond or a ring structure, B is an alkyl group or an alkoxy group, X is an H atom or an F atom, and Y is CH ₃ or CF ₃ .

According to a second aspect of the present invention, there is provided a liquid crystal compound represented by the following chemical formula 10.

[0012]

Embedded image

Here, in the above chemical formula 10, A is a functional group composed of only C atoms and H atoms, and is a double bond;
It has a triple bond or a structure having a ring structure, and B is an alkyl group or an alkoxyl group.

According to the third aspect of the present invention, there is provided a liquid crystal compound represented by the following chemical formula 11.

[0015]

Embedded image

Here, in the above chemical formula 11, A is a functional group composed of a C atom and an H atom, B is an alkyl group or an alkoxy group, X is an H atom or an F atom, and Y is CH. ₃ or CF ₃ , and Z is a functional group represented by the following chemical formula 12.

[0017]

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According to a fourth aspect of the present invention, there is provided a liquid crystal compound represented by the following chemical formula 13.

[0019]

Embedded image

Here, in the above chemical formula 13, A is a functional group composed of a C atom and an H atom, B is an alkyl group or an alkoxy group, and Z is a functional group represented by the following chemical formula 14. It is.

[0021]

Embedded image

According to a fifth aspect of the present invention, in the liquid crystal compound represented by the chemical formula 11 according to the third aspect, in the chemical formula 11, B is a functional group represented by the following chemical formula 15: It is characterized by being.

[0023]

Embedded image _{-C n H 2n + 1 (n} = 2~8) Further, in the invention according to claim 6, in the liquid crystal compound represented by the chemical formula 13 of claim 4, the chemical formula 13 Wherein B is a functional group represented by the following chemical formula 16.

[0024]

Embedded image _{-C n H 2n + 1 (n} = 2~8) according to the invention described in any one of claims 1 to 6, a novel smectic liquid crystal compound, the black display when the A liquid crystal compound capable of suppressing luminance can be provided. Further, according to the invention of claim 7, it is possible to provide a liquid crystal display device using a liquid crystal compound capable of suppressing luminance during black display.

The reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0026]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. As the liquid crystal compound of the present embodiment, a smectic liquid crystal compound represented by the following chemical formula 17 can be used.

[0027]

Embedded image

Here, in the chemical formula 17, A is a functional group composed of only C atoms and H atoms and has a double bond, a triple bond, or a ring structure. And the like.

[0029]

Embedded image ◇ —C ₉ H ₁₈ —O—, C ₆ H ₁₃ —CH ＝ CH
—CH ₂ —O—, CH ₃ —CH ＝ CH—C ₆ H ₁₂ —O—,
CH = —C—C ₇ H ₁₄ —O— In Chemical Formula 18, ◇-is a cyclobutyl group. Also, for example, in Chemical Formula 17, B is CnH2n + 1 (n =
2 to 8), X is H atom or F atom, and Y is CH ₃
Or CF ₃ .

By using the liquid crystal compound represented by the chemical formula 17 as a component of a liquid crystal material in a liquid crystal display device, a ferroelectric liquid crystal compound or an antiferroelectric liquid crystal compound capable of suppressing luminance during black display is provided. be able to. Hereinafter, the reason will be described.

FIG. 1 is a graph showing light transmittance characteristics when a triangular wave voltage is applied to a liquid crystal cell (liquid crystal display element) using an antiferroelectric liquid crystal. Here, although not shown, the liquid crystal cell is formed by laminating a pair of substrates each having a transparent electrode, an insulating film, and an alignment film sequentially laminated on one surface side such that the one surface side faces each other. Is disposed in contact with both alignment films to align the liquid crystal. And by applying a voltage between both substrates,
It changes the alignment state and changes the transmittance.

In FIG. 1, the horizontal axis is the applied electric field, and the vertical axis is the light transmittance (relative transmittance) of the cell. In the case of an antiferroelectric liquid crystal display device, the applied electric field may be positive or negative, so that the electric field-transmittance characteristic has double hysteresis. Shows the case.

As described above, when a triangular wave voltage is applied to the antiferroelectric liquid crystal, the light transmittance has a hysteresis characteristic.
Thus, when the light transmittance is close to 0% (black display) and 100%
The same as in the case of a ferroelectric liquid crystal, having a hysteresis characteristic with respect to an applied electric field between the vicinity (representative display).

Further, in FIG. 1, when the light transmittance rises (a portion shown by a thick line in the figure), light leakage slightly occurs as a precursor phenomenon. Here, assuming that the amount of light leakage is T, the applied electric field is V, and the proportionality constant is β, T = β
It is known that V ² can be approximated.

A method of displaying light and dark (black and white) using the antiferroelectric liquid crystal cell will be described. As shown in FIG. 2, when displaying light (white), as shown by the arrow in the figure, after applying an electric field whose light transmittance is saturated once, the saturation luminance (the thick line in the figure) is applied. A bright display is performed by applying a signal waveform centering on an electric field (V1 in the figure) that can maintain the portion A).

Further, as shown in FIG. 3, when displaying dark (black), an electric field (V2 in the figure) which can directly maintain dark luminance (the thick line portion B in the figure) is used as a center. Dark display is performed by applying a signal waveform. And usually, the electric field V
1 and V2 are set to have the same electric field value, and as shown in FIG. 4, light and dark are separately written around the electric field V3.

At this time, the liquid crystal having a large β value also has a large dark luminance (B) value. Therefore, in order to suppress the luminance of black display and increase the contrast, it is necessary to reduce the value of β. The liquid crystal compound represented by Chemical Formula 17 is a novel compound discovered by the present inventors as a result of intensive studies as antiferroelectric liquid crystals and ferroelectric liquid crystals having a small β.

[0038]

Next, the present invention will be described based on the following examples.
Although described more specifically, the present invention is not limited to this embodiment. As shown in FIG.
Three and four liquid crystal compounds were prepared as examples. First, a general synthesis method for synthesizing these compounds 1 to 4 will be described with reference to FIGS.

As shown in FIG. 6, the compound represented by the general formula (3) is obtained by converting 4'-alkyloxybiphenylcarboxylic acid (1) and optically active hydroxybenzoate (2) into a solvent such as chloroform or methylene chloride. Melted into D
The desired product can be obtained by performing a reaction using a dehydrating condensing agent such as CC and a base such as DMAP.

Here, the 4'-alkyloxybiphenylcarboxylic acid (1) in FIG. 6 is, as shown in FIG.
Has a leaving group (eg, Cl, Br, I, OTs, OMs, O
It can be obtained by reacting the compound (4) having Tf) with the 4′-hydroxybenzoic acid ester (5) in the presence of an alkali, for example, using potassium carbonate. Conversion of compound (6) to compound (1) in FIG. 7 is a general ester hydrolysis reaction.

Here, the compound (4) is obtained by converting the hydroxyl group of the compound (11) in FIG.
g. Chem. , 51 , 2386 (1986)). FIG. 8 shows an outline of the synthesis of alcohol compounds such as the compound (11).

Hereinafter, a method for synthesizing a 4'-alkyloxybiphenylcarboxylic acid as individually shown will be described. First, as shown in FIG. 9, a formulation described in the literature (eg, Liebi) under basic conditions, for example, in the presence of an organolithium reagent.
gs. Ann. Chem. , 1257 (1980)) and 1- (bromomethyl) cyclobutane (1
By reacting 3) with an alkyne terminal compound (8a), a compound (9a) having a cyclobutyl group at the terminal is obtained.

After reducing the triple bond of the compound (10a) converted by a general deprotection reaction using a palladium (II) catalyst, the hydroxyl group is tosylated in the presence of, for example, pyridine, and subsequently, is added with ethyl p-hydroxybenzoate. Is carried out under basic conditions, for example, in the presence of potassium carbonate, followed by an ester hydrolysis reaction under basic conditions, whereby intermediate 4- (4 ′-(9 ″ -cyclobutylnonyl) is obtained. (Oxy) phenyl) benzoic acid (1a) (wherein R1 in the above compound (3) is a cyclobutyl group and A1 is an alkyl bond) can be obtained.

Further, 4- (4 '-(tra) shown in FIG.
ns-7 "-noneneoxy) phenyl) benzoic acid (1
b) (wherein R1 in the above compound (3) is a methyl group and A1 is a double bond) is prepared according to a formulation described in the literature (eg, Gaz
z. Chim. Ital. , 110 (4), 237 (1
980)).
Using 1-ol (11b) as a raw material, tosylation, etherification, and ester hydrolysis were performed under the same conditions as in the above-mentioned formulation to synthesize.

Further, 4- (4 '-(tra) shown in FIG.
ns-2 "-noneneoxy) phenyl) benzoic acid (1
c) (wherein R1 in the above compound (3) is a hexyl group and A1 is a double bond) is prepared by using a commercially available trans-2-nonen-1-ol (11c) as a raw material in the same formulation as described above. And synthesized.

The 4- (4 '-(8 "-) shown in FIG.
Noninoxy) phenyl) benzoic acid (1d) (in the above compound (3), R1 is hydrogen and A1 is a triple bond)
Is 8-nonin-1-ol (9d) (for example, J. Or.
g. Chem. Soc. , 44 (21), 3643 (1
(Synthesized according to the prescription described in the literature such as 979)) as a raw material, and synthesized according to the same prescription as described above.

Next, a specific method for synthesizing each of the compounds 1 to 4 based on the above general synthesis method will be described with reference to FIGS.
6 will be described. The chemical structure of the compound was determined by
The measurement was performed by 1H-NMR, IR, and specific rotation, and the measurement of the phase transition temperature and the identification of the phase were performed by DSC and a polarizing microscope.

(Compound 1: (R) -4- (4 ′-(9 ″)
-Cyclobutylnonyloxy) phenylbenzoic acid 3-
Method for synthesizing fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester): Regarding intermediate compounds 1a, 1b, and 1c in the present synthesis method,
As shown in FIG.

"Intermediate compound 1a: 1- (bromomethyl)
Synthesis of cyclobutane "cyclobutanecarboxylic acid (25.
2g, 251.7 mmol) of MTBE (50 mL) was treated with lithium aluminum hydride (10.9 g) -MT.
The BE (150 mL) suspension was added dropwise at an internal temperature of 5 ° C to 12 ° C with stirring. After completion of the dropwise addition, the mixture was stirred at room temperature for 4 hours and left standing overnight.

After confirming the completion of the reaction, water, 6N
-Hydrochloric acid was added dropwise at an internal temperature of 23 ° C or less to decompose unreacted lithium aluminum hydride. The reaction mixture was extracted with MTBE, and the MTBE layer was washed with a 5% aqueous sodium hydroxide solution and water, dried over anhydrous magnesium sulfate and concentrated.

The obtained pale yellow oily residue was added with pyridine (12
0 mL), and after dissolving, p-toluenesulfonic acid chloride (33.6 g, 170 mmol) at an internal temperature of 4 ° C. with stirring.
Was added and stirred at room temperature for 5 hours. After confirming the completion of the reaction, cold water was added, and the mixture was extracted with toluene. The toluene layer was washed with water, 6N-hydrochloric acid and water, and then concentrated.

The obtained pale yellow oily residue (40.47 g)
Was purified by a silica gel column (eluent: hexane / ethyl acetate = 8/1) to obtain a colorless liquid p-toluenesulfonic acid ester derivative (29.4 g). Lithium bromide (23.1 g, 220 mmol), DMF
(63 mL) solution was added, and the mixture was heated with stirring at an internal temperature of 70 to 75 ° C for 2 hours.

After confirming the completion of the reaction, the reaction mixture was added with cold water and extracted with pentane. The organic layer was washed with saturated saline, dried over anhydrous magnesium sulfate and concentrated to give a colorless transparent liquid 1
-(Bromomethyl) cyclobutane was obtained (intermediate compound 1
a) (15.5 g).

"Intermediate compound 1b: Synthesis of 9-cyclobutylnonane p-toluenesulfonic acid" Under argon atmosphere, 90% lithium acetylide-ethylenediamine complex (4.47 g, 46.3 mmol) in DMSO (21.
5 mL) The mixture was stirred at an internal temperature of 8 to 13 ° C at 2- (6-
Bromohexyloxy) -tetrahydropyran (12
g, 43 mmol) -DMSO (54 mL) solution was added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 5.5 hours and allowed to stand overnight.

After confirming the completion of the reaction, the reaction mixture was decomposed,
Extracted with toluene. The toluene layer was washed with water and concentrated, and the residue (9.7 g) was purified by a silica gel column (eluent: hexane / ethyl acetate = 6/1) to obtain a alkyne terminal compound as a transparent oil (6.3 g). After dissolving this compound (6.2 g) in dry THF (22.5 mL) under an argon atmosphere, a 1.6 M butyllithium-hexane solution (2
2.3 mL, 35.6 mmol) was added dropwise at an internal temperature of -5 to 1 ° C.

After completion of the dropwise addition, the mixture was stirred at an internal temperature of 0 to 5 ° C. for 2 hours, and then a solution of 1- (bromomethyl) cyclobutane (intermediate compound 1a) (6.1 g) in HMPA (39.4 mL) was added at an internal temperature of −2 to 2. It was added dropwise at 5 ° C. The reaction mixture was slowly returned to room temperature, stirred for 3 hours, and allowed to stand overnight. After confirming the completion of the reaction, the reaction mixture was decomposed by adding cold water and extracted with toluene. The toluene layer was washed with water and concentrated, and the residue (7.6 g) was obtained.
Was purified by a silica gel column (eluent: hexane / ethyl acetate = 8/1) to give a colorless oily terminal cyclobutyl compound (3.9 g).

To this compound was added methanol (37 mL), p
-Toluenesulfonic acid (0.07 g) was added and the internal temperature was 60
The mixture was heated and stirred at -65 ° C for 4 hours. After confirming the completion of the reaction, the reaction mixture was cooled, and a 5% aqueous sodium hydrogen carbonate solution and cold water were added thereto, followed by extraction with toluene. The toluene layer was washed with water and concentrated, and the residue (7.6 g) was purified by a silica gel column (eluent: hexane / ethyl acetate = 6/1) to obtain a cyclobutyl alkynol compound (2.0 g).

This compound (1.9 g) was added to ethanol (6
0 mL) and 5% Pd-C (0.1 g), and the mixture was heated under hydrogen pressure (7.3 kg / cm ² ) at an internal temperature of 28 to 30 ° C.
Stir for 5 hours. After confirming the completion of the reaction, the catalyst was filtered off and the filtrate was concentrated. The residue (7.6 g) was purified by silica gel column (eluent: hexane / ethyl acetate = 6/1) to give 9-
Cyclobutyl nonan-1-ol was obtained (1.6 g).

This compound (1.0 g, 5.04 mmol)
To a solution of l) in pyridine (10 mL) was added p-toluenesulfonic acid chloride (1.2 g) at an internal temperature of 4 ° C, and the mixture was stirred at room temperature for 5.5 hours. After confirming the completion of the reaction, cold water was added to the reaction mixture, and the mixture was extracted with toluene. The toluene layer was washed and concentrated in the order of water, diluted hydrochloric acid, and water to obtain a colorless and transparent liquid p-toluenesulfonic acid ester derivative (intermediate compound 1b). The NMR and IR data of the intermediate compound 1b are as follows.

1H-NMR (CDCl ₃ ): δ (pp
m) = 1.2-1.3 (m, 14H), 1.64 (qu
intet, 2H, J = 6.8 Hz), 1.82 (m,
4H), 2.01 (m, 2H), 2.23 (septe
t, 1H, J = 7.7 Hz), 2.45 (s, 3H),
4.02 (t, 2H, J = 6.4 Hz), 7.33
(D, 2H, J = 7.9 Hz), 7.78 (d, 2H,
J = 8.0 Hz).

IR (neat): ν (cm ⁻¹ ) = 292
6,2854,1599,1466,1364,130
7,1189,1178,1099,956,815,
774,665,577,556.

"Intermediate compound 1c: 4- (4 '-(9"-)
Synthesis of cyclobutylnonyloxy) phenyl) benzoic acid "ethyl 4- (4'-hydroxyphenyl) benzoate (1.2 g, 3.4 mmol) prepared in advance with a p-toluenesulfonic acid ester derivative (intermediate compound 1b) (1.2 g, 3.4 mmol) 0.82 g, 3.4 mmol), potassium carbonate (1.
05g), DMF (11.2mL) mixed solution at an internal temperature of 75 ° C
, And heated and stirred at an internal temperature of 70 to 80 ° C for 6 hours.

After confirming the completion of the reaction, the reaction mixture was cooled,
Cold water was added and extracted with toluene. The toluene layer was washed with water and concentrated, and the residue was purified by a silica gel column (eluent: hexane / toluene = 6/1) to obtain ethyl 4- (4 '-(9 "-cyclobutylnonyloxy) phenyl) benzoate. (1.2 g) 85% potassium hydroxide (0.4 g), ethanol (5 mL) and water (2.5 g) were added to the ester compound.
mL), and the mixture was heated and refluxed at an internal temperature of 80 to 85 ° C. for 2 hours with stirring.

After confirming the completion of the reaction, the reaction mixture was cooled,
6N-hydrochloric acid and water were added to perform MTBE extraction. MTB
The E layer was washed with water, concentrated, and the residue (wet 5.9 g) was heated and dispersed in ethanol (59 g). The crystals are collected by filtration and
(4 ′-(9 ″ -cyclobutylnonyloxy) phenyl) benzoic acid (intermediate compound 1c) (1.0 g) was obtained.

"Compound 1: (R) -4- (4 '-(9")
-Cyclobutylnonyloxy) phenyl) benzoic acid 3
Synthesis of -fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester "4- (4 '
-(9 "-cyclobutylnonyloxy) phenyl) benzoic acid (intermediate compound 1c) (0.88 g, 2.2 mmol)
1), (R) -3-fluoro-4-hydroxybenzoic acid 1-trifluoromethylpentyl ester (0.65
g, 2.2 mmol) and DMAP (0.02 g) in dichloromethane (15.2 mL) under ice-cooling and stirring.
C (0.51 g, 2.5 mmol) was added, and the mixture was stirred at room temperature for 3 hours and left standing overnight.

After confirming the completion of the reaction, the resulting insolubles were separated by filtration.
It was washed with chloroform. The combined filtrate and washings are concentrated,
The residue (1.8 g) was purified by a silica gel column (eluent: toluene) and recrystallized from ethanol to give (R) -4 as white crystals.
-(4 '-(9 "-Cyclobutylnonyloxy) phenyl) benzoic acid 3-fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester (Compound 1) (1.2 g) was obtained. NM of compound 1
The R, IR and optical rotation data are as follows.

1H-NMR (CDCl ₃ ): δ (pp
m) = 0.93 (t, 3H, J = 6.4 Hz), 1.1
8 (m, 2H), 1.2 to 1.5 (m, 20H), 1.
81 (quintet, 4H, J = 7.5 Hz), 1.
88 (q, 2H, J = 6.8 Hz), 2.02 (m, 2
H), 2.23 (septet, 1H, J = 7.7H)
z), 4.02 (t, 2H, J = 6.5 Hz), 5.5
7 (sextet, 1H, J = 6.5 Hz), 7.01
(D, 2H, J = 8.6 Hz), 7.17 (dd, 2
H, J = 4.6 Hz, 7.2 Hz), 7.60 (d, 2
H, J = 8.5 Hz), 7.71 (d, 2H, J = 8.
0 Hz), 8.07 (t, 1H, J = 8.6 Hz),
8.21 (d, 2H, J = 8.2 Hz).

IR (KBr): ν (cm ⁻¹ ) = 292
3,2852,1736,1604,1500,127
9,1245,1188,1129,1064,82
8,767. [Α] ²⁰ _D = + 25.30 (c = 2.00
0, chloroform).

(Compound 2: (R) -4- (4 ′-(tr
ans-2 "-noneneoxy) phenyl) benzoic acid 3
-Fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester synthesis method): FIG. 14 shows the intermediate compound 2a in this synthesis method.

"Intermediate compound 2a: 4- (4 '-(tra
Synthesis of ns-2 "-noneneoxy) phenyl) benzoic acid" trans-2-nonen-1-ol (8.1 g,
56.9 mmol) in pyridine (9 g) under stirring.
At an internal temperature of 4 ° C., p-toluenesulfonic acid chloride (13 g,
68.3 mmol) and stirred at room temperature for 5.5 hours. After confirming the completion of the reaction, cold water was added to the reaction mixture, and the mixture was extracted with toluene. The toluene layer was washed with water, diluted hydrochloric acid, and water in that order, and concentrated.

The obtained colorless oily residue (2.7 g)
4 g (8.1 mmol) of ethyl 4- (4′-hydroxyphenyl) benzoate prepared in advance (2 g, 8.1 mm)
ol), potassium carbonate (2.5 g), DMF (27 m
L) The mixture was dropped at an internal temperature of 75 ° C, and heated and stirred at 70 to 80 ° C for 6 hours.

After confirming the completion of the reaction, the reaction mixture was cooled,
Cold water was added and extracted with toluene. The toluene layer was washed with water and concentrated, and the residue was purified by a silica gel column (eluent: hexane / toluene = 1/1 → 1/5) to give 4- (4 ′-(t
tran-2 "-Nonenoxy) phenyl ethyl benzoate was obtained (2.6 g).

Ethyl ester (3.6 g, 9.8 mmol) synthesized several times in the same manner was added to 85% potassium hydroxide (0.4 g), ethanol (5 mL), and water (2.5 m).
L) was added and the mixture was refluxed at 80 to 85 ° C for 2 hours. After confirming the completion of the reaction, the reaction mixture was cooled and extracted with MTBE by adding 6N-hydrochloric acid and water. The MTBE layer was washed with water, concentrated, and the residue (wet 5.9 g) was dispersed by heating with ethanol (59 g). The crystals were collected by filtration and 4- (4 '-(trans-2 ")
-Noneneoxy) phenylbenzoic acid (intermediate compound 2a)
(2.9 g) was obtained.

"Compound 2: (R) -4- (4 '-(tr
ans-2 "-noneneoxy) phenyl) benzoic acid 3
Synthesis of -fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester "4- (4 '
-(Trans-2 "-noneneoxy) phenylbenzoic acid (intermediate compound 2a) (1.15 g, 3.3 mmol)
l), (R) -3-fluoro-4-hydroxybenzoic acid 1-trifluoromethylpentyl ester (1.0
g, 3.3 mmol) and DMAP (0.02 g) in dichloromethane (23.5 mL) under ice-cooling and stirring.
C (0.78 g, 3.8 mmol) was added, and the mixture was stirred at room temperature for 1 hour and left to stand overnight.

After confirming the completion of the reaction, the resulting insolubles were separated by filtration.
After washing with chloroform, the filtrate and the washing solution were combined and concentrated.
The residue (2.3 g) was purified by a silica gel column (eluent: toluene) and recrystallized from ethanol to give (R) -4 as white crystals.
-(4 '-(trans-2 "-noneneoxy) phenyl) benzoic acid 3-fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester (Compound 2) (1.5 g) was obtained. NM of 2
The R, IR and specific rotation data are as follows.

1H-NMR (CDCl ₃ ): δ (pp
m) = 0.92 (m, 3H), 1.65 (m, 14
H), 1.80 (quintet, 2H, J = 6.9H)
z), 1.88 (q, 2H, J = 6.8 Hz), 2.0
0 (brs, 2H), 4.02 (t, J = 6.8H)
z), 5.43 (brs, 1H), 5.57 (sext
et, 1H, J = 6.5 Hz), 7.01 (d, 2H,
J = 8.5 Hz), 7.16 (m, 2H), 7.71
(D, 2H, J = 8.2 Hz), 8.07 (t, 1H,
J = 8.1 Hz), 8.21 (d, 2H, J = 8.2H)
z).

IR (KBr): ν (cm ⁻¹ ) = 296
4,2931,2859,1741,1723,160
4,1499,1276,1245,1184,115
1,1127,1053,824,767. [Α] ²⁰ _D
= + 26.86 (c = 2.010, chloroform).

(Compound 3: (R) -4- (4 ′-(tr
ans-7 "-noneneoxy) phenyl) benzoic acid 3
-Fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester synthesis method): FIG. 15 shows the intermediate compounds 3a, 3b, and 3c in this synthesis method.

"Intermediate compound 3a: Synthesis of 7-nonin-1-ol" 6-bromo-1-hexanol (25.2
g, 139.2 mmol), 3,4-dihydropyran (35.5 g, 422 mmol), and a solution of p-toluenesulfonic acid (0.63 g) in MTBE (317 mL) were stirred at room temperature for 5 hours. After confirming the completion of the reaction, the reaction mixture was washed with a 5% aqueous sodium hydrogen carbonate solution and water and concentrated.
The residue (39.4 g) was distilled under reduced pressure (120 to 125 ° C./5
mmHg) to obtain a protected THP.

This compound (8.5 g, 40.4 mmol)
l) was dissolved in DMSO (145 mL), and then lithium acetylide-ethylenediamine complex (3.2 g, 31.3 mmol) -DMS at an internal temperature of 12 to 15 ° C under an argon stream.
An O (14.5 mL) solution was added dropwise, and the mixture was stirred at room temperature for 5.5 hours and left overnight.

After confirming the completion of the reaction, the reaction mixture was extracted with toluene, and the toluene layer was washed with water and concentrated. The residue was purified by a silica gel column to give colorless liquid 7-octyne-1-oxytetrahydropyran (3.4 g). This compound (5.5 g, 2
6.2 mmol) in dry THF (2
After dissolving in 1.6 mL butyllithium-hexane solution (19.9 mL, 31.8 mmol)
l) was added dropwise at an internal temperature of -5 to 1 ° C.

After completion of the dropwise addition, the mixture was stirred at an internal temperature of 0 to 5 ° C. for 2 hours, and then methyl iodide (6.1 g) in HMPA (3 g) was added.
9.4 mL) solution was added dropwise at an internal temperature of 3-4 ° C. The reaction mixture was slowly returned to room temperature and stirred for 3 hours. After confirming the completion of the reaction, the reaction mixture was decomposed by adding cold water and extracted with hexane. The hexane layer was washed with water and concentrated.

The obtained yellow oily residue (5.6 g) was added to methanol (56 mL) and p-toluenesulfonic acid (0.1 g).
5 g) was added, and the mixture was heated and stirred at an internal temperature of 60 to 65 ° C for 6 hours. After confirming the completion of the reaction, the reaction mixture was cooled and neutralized with sodium carbonate. After methanol distillation, MTBE extraction was performed,
The MTBE layer was washed with water and concentrated. The residue was purified by a silica gel column (eluent: hexane / ethyl acetate = 10/1) to give 7-nonin-1-ol (intermediate compound 3a) (2.
6 g) were obtained.

"Intermediate compound 3b: Synthesis of trans-p-toluenesulfonic acid 7-nonene" 7-nonin-1-ol (intermediate compound 3a) (2.5 g, 17.g) was added to a diglyme suspension of lithium aluminum hydride. 8 mmol)
Of diglyme solution at an internal temperature of 18 to 25 ° C.
It heated and stirred at 131 degreeC for 16 hours. After confirming the completion of the reaction, the reaction mixture was cooled, and water (18 m
L) was added dropwise to decompose.

Water (18 mL) and 6N-hydrochloric acid were added to dissolve the salt, followed by MTBE extraction. The MTBE layer was washed with water and concentrated. After dissolving the obtained residue in pyridine (10 mL), p-toluenesulfonic acid chloride (3.8 g,
19.9 mmol) and stirred at room temperature for 5 hours.

After confirming the completion of the reaction, the reaction mixture was added with cold water and extracted with toluene. The toluene layer was washed and concentrated in the order of water, diluted hydrochloric acid, and water, and the residue (6 g) was purified by a silica gel column (eluent: toluene) to obtain 7-nonene trans-p-toluenesulfonic acid (intermediate compound 3b).
(3.7 g). The NMR and IR data of this intermediate compound 3b are as follows.

1H-NMR (CDCl ₃ ): δ (pp
m) = 1.2-1.3 (m, 6H), 1.5-1.6
(M, 2H), 1.63 (s, 3H), 1.9-2.0
(M, 2H), 2.45 (s, 3H), 4.02 (t,
2H, J = 6.3 Hz), 5.38 (m, 2H), 7.
34 (d, 2H, J = 7.8 Hz), 7.78 (d, 2
H, J = 7.9 Hz).

IR (neat): ν (cm ⁻¹ ) = 345
6.2931, 2857, 1599, 1496, 145
5,1362,1307,1292,1211,118
9,1177,1098,965,816,665,5
56.

"Intermediate compound 3c: (R) -4- (4'-
Synthesis of (trans-7 "-noneneoxy) phenyl) benzoic acid" trans-p-toluenesulfonic acid 7-
Nonene (intermediate compound 3b) (3.5 g, 11.8 mmol)
l) previously prepared 4- (4'-hydroxyphenyl)
A mixture of ethyl benzoate (2.7 g, 11.1 mmol), potassium carbonate (3.4 g) and DMF (35 mL) was added dropwise at an internal temperature of 70 to 71 ° C, and the mixture was heated and stirred at an internal temperature of 70 to 80 ° C for 5 hours. .

After confirming the completion of the reaction, the reaction mixture was cooled,
Cold water was added and extracted with toluene. The toluene layer was washed with water, concentrated, and the residue was purified by a silica gel column (eluent: hexane / toluene = 1/2) to give trans-4- (4'-
Ethyl (7 "-noneneoxy) phenyl) benzoate was obtained, and 85% potassium hydroxide (1.
3 g), ethanol (35 mL) and water (8.2 mL) were added, and the mixture was heated under reflux at an internal temperature of 78 to 82 ° C. for 2 hours with stirring.

After confirming the completion of the reaction, the reaction mixture was cooled,
6N-hydrochloric acid and water were added to perform MTBE extraction. MTB
The E layer was washed with water, concentrated, and the residue (wet 4.9 g) was heated and dispersed in ethanol (30 g). The crystals were collected by filtration and (R) -4- (4 '-(trans-7 "-noneneoxy) phenyl) benzoic acid (intermediate compound 3c) (2.8)
g) was obtained.

"(R) -4- (4 '-(trans-
Synthesis of 7 "-noneneoxy) phenyl) benzoic acid 3-fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester" trans-4-
(4 ′-(7 ″ -noneneoxy) phenyl) benzoic acid (intermediate compound 3c) (1.15 g, 3.3 mmol),
(R) -3-fluoro-4-hydroxybenzoic acid 1-
Trifluoromethylpentyl ester (1.0 g, 3.
3 mmol) and a mixture of DMAP (0.02 g) in dichloromethane (23.5 mL) under ice-cooling and stirring.
78 g, 3.8 mmol), stirred for 1 hour at room temperature, and allowed to stand overnight.

The resulting insolubles were separated by filtration, washed with chloroform, and the filtrate and the washing were combined and concentrated. The residue (2.2 g) was purified by a silica gel column (eluent: toluene) and recrystallized from ethanol to give white crystals. (R) -trans-4-
(4 '-(7 "-noneneoxy) phenyl) benzoic acid
3-Fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester (Compound 3) was obtained. The NMR, IR and specific rotation data of this compound 3 are as follows.

1H-NMR (CDCl ₃ ): δ (pp
m) = 0.92 (m, 3H), 1.38-1.65
(M, 14H), 1.80 (quintet, 2H, J
= 6.9 Hz), 1.88 (q, 2H, J = 6.8H)
z), 2.00 (brs, 2H), 4.02 (t, 2
H, J = 6.3 Hz), 5.43 (brs, 1H),
5.57 (sextet, 1H, J = 6.5 Hz),
7.01 (d, 2H, J = 8.4 Hz), 7.16
(M, 2H), 7.60 (d, 2H, J = 8.4H)
z), 7.71 (d, 2H, J = 8.2 Hz), 8.0
7 (t, 1H, J = 8.1 Hz), 8.21 (d, 2
H, J = 8.2 Hz).

IR (KBr): ν (cm ⁻¹ ) = 293
4,2866,1742,1724,1603,149
9,1277,1245,1178,1163,113
0,1062,965,827,764. [Α] ²⁰ _D =
+27.19 (c = 2.015, chloroform).

(Compound 4: (R) -4- (4 ′-(8 ″)
-Noninoxy) phenyl) benzoic acid 3-fluoro-
Synthetic Method of 4- (1-Trifluoromethylpentyloxycarbonyl) phenyl Ester): FIG. 16 shows the intermediate compounds 4a and 4b in this synthetic method.

"Intermediate compound 4a: Synthesis of 8-nonine p-toluenesulfonic acid" 3-nonin-1-ol (8.
Sodium amide (4.3 g) was added to a solution of 8 g (62.8 mmol) of 1,3-diaminopropane (100.5 mL) under an argon stream, and the mixture was heated with stirring at an internal temperature of 78 to 85 ° C for 4 hours.

After confirming the completion of the reaction, the reaction mixture was cooled,
Ice water was added to perform MTBE extraction. The MTBE layer was diluted with hydrochloric acid,
Washed with water and concentrated. The obtained residue was dissolved in pyridine (30 mL) after azeotropic distillation with toluene, and p-toluenesulfonic acid chloride (6.7 g, 35.1 mmol) was dissolved at an internal temperature of 5 ° C.
l) was added and the mixture was stirred at room temperature for 5 hours.

After confirming the completion of the reaction, ice water (1
00 mL) and extracted with toluene. The toluene layer was washed and concentrated with water, diluted hydrochloric acid and water in this order, and the residue (5.7 g) was obtained.
Was purified by a silica gel column (eluent: hexane / ethyl acetate = 8/1) to obtain a colorless liquid p-toluenesulfonic acid ester derivative (intermediate compound 4a) (6.4).
g). The NMR and IR data of this intermediate compound 4a are as follows.

1H-NMR (CDCl ₃ ): δ (pp
m) = 1.2-1.35 (m, 6H), 1.48 (qu
intet, 2H, J = 6.9 Hz), 1.64 (qu
intet, 2H, J = 6.9 Hz), 1.93 (br
s, 1H), 2.15 (dt, 2H, J = 2.2 Hz)
and 6.8 Hz), 2.45 (s, 3H), 4.0
3 (t, 3H, J = 6.4 Hz), 7.34 (d, 2
H, J = 7.9 Hz), 7.78 (d, 2H, J = 8.
0 Hz).

IR (neat): ν (cm ⁻¹ ) = 329
4,2937,2860,2116,1599,146
5,1359,1189,1177,1098,96
2,932,816,665,556.

"Intermediate compound 4b: 4- (4 '-(8"-)
Synthesis of Noninoxy) phenyl) benzoic acid "p-toluenesulfonic acid 8-nonine (intermediate compound 4a) (4 g,
13.6 mmol) of ethyl 4- (4'-hydroxyphenyl) benzoate (3.1 g, 12.8 m) previously prepared.
mol), potassium carbonate (3.9 g), DMF (40 m
L) The mixture was dropped at an internal temperature of 70 to 71 ° C.
The mixture was heated and stirred at 8 ° C for 5 hours.

After confirming the completion of the reaction, the reaction mixture was cooled,
Cold water was added and extracted with toluene. The toluene layer was washed with water and concentrated, and the residue was purified by a silica gel column (eluent: toluene) to obtain ethyl 4- (4 '-(8 "-noninoxy) phenyl) benzoate.
% Potassium hydroxide (1.5 g), ethanol (38
g) and water (9.5 mL), and the mixture is stirred at an internal temperature of 78-8.
The mixture was refluxed at 2 ° C. for 2 hours.

After confirming the completion of the reaction, the reaction mixture was cooled,
6N-hydrochloric acid and water were added to perform MTBE extraction. MTB
The E layer was washed with water, concentrated, and the residue (wet 3.8 g) was heated and dispersed in ethanol (38 g). The crystals are collected by filtration and
-(4 '-(8 "-noninoxy) phenyl) benzoic acid (intermediate compound 4b) was obtained (3.5 g).

"(R) -4- (4 '-(8" -noninoxy) phenyl) benzoic acid 3-fluoro-4- (1-
Synthesis of trifluoromethylpentyloxycarbonyl) phenyl ester "4- (4 '-(8" -noninoxy) phenyl) benzoic acid (intermediate compound 4b) (1.14
g, 3.3 mmol), (R) -3-fluoro-4-hydroxybenzoic acid 1-trifluoromethylpentyl ester (1.0 g, 3.3 mmol), DMAP (0.
Then, DCC (0.78 g, 3.8 mmol) was added to a mixture of 02g) and dichloromethane (23.5 mL) under ice-cooling and stirring, and the mixture was stirred at room temperature for 3 hours and allowed to stand overnight.

After confirming the completion of the reaction, the resulting insolubles were separated by filtration.
After washing with chloroform, the filtrate and the washing solution were combined and concentrated.
The residue (2.4 g) was purified by a silica gel column (eluent: toluene) and recrystallized from ethanol to give (R) -4 as white crystals.
-(4 '-(8 "-noninoxy) phenyl) benzoic acid 3-fluoro-4- (1-trifluoromethylpentyloxycarbonyl) phenyl ester (compound 4)
(1.8 g) was obtained. The NMR, IR and specific rotation data of this compound 4 are as follows.

1H-NMR (CDCl ₃ ): δ (pp
m) = 0.92 (m, 3H), 1.4 to 1.57 (m,
10H), 1.83 (quintet, 2H, J = 7.
4 Hz), 1.89 (q, 2H, J = 6.8 Hz),
4.02 (t, 2H, J = 6.4 Hz), 5.57 (s
extet, 1H, J = 6.6 Hz), 7.01 (d,
2H, J = 8.5 Hz), 7.16 (m, 2H), 7.
60 (d, 2H, J = 8.5 Hz), 7.71 (d, 2
H, J = 8.2 Hz), 8.07 (t, 1H, J = 8.
1 Hz), 8.21 (d, 2H, J = 8.5 Hz).

IR (KBr): ν (cm ⁻¹ ) = 331
7,2938,2865,1742,1609,149
8,1299,1274,1246,1181,114
8, 1128, 1054, 829, 768. [Α] ²⁰ _D
= + 27.61 (c = 2.010, chloroform).

The above is the description of the liquid crystal compounds 1 to 1 used in this example.
4 is a synthesis method. Then, the liquid crystal compound 1 shown in FIG.
20 wt% was added to the host liquid crystal for each of the liquid crystal compounds shown in Nos. 1 to 4 and Comparative Example. The phase transition temperature of the host liquid crystal is shown below.

(73.6 ° C.) (77.9 ° C.) (96.7 ° C.) SmCA * → SmC * → SmA → Isotropic Liquid Here, SmCA * is a smectic CA phase, SmC * is a smectic C phase, SmA is a smectic A phase. An antiferroelectric liquid crystal composition in which each of the liquid crystal compounds 1 to 4 and the liquid crystal compounds shown in Comparative Examples were blended with the above host liquid crystal was injected into a liquid crystal cell to produce a liquid crystal display device.

Although not shown, the liquid crystal cell comprises a pair of glass substrates having a rubbed alignment film made of polyimide or the like formed on a transparent electrode made of ITO or the like with an insulating film interposed therebetween. Each of the liquid crystal compositions was injected between the two substrates, gradually cooled, and aligned.

An antiferroelectric liquid crystal display device using an antiferroelectric liquid crystal composition blended with each of the liquid crystal compounds 1 to 4 and the liquid crystal compounds shown in the comparative examples was equipped with a photomultimeter while applying an electric field. Was observed at 30 ° C., the applied electric field-light transmittance characteristics were determined at 30 ° C., and the β was measured. FIG. 17 shows measured values of β for each of the liquid crystal compounds 1 to 4 and the comparative example.

The value of β of the liquid crystal compound of the comparative example was hardly lower than that of the host liquid crystal. However, the value of β of the liquid crystal compound of the present example was less than that of the host liquid crystal. The value could be significantly reduced.

Therefore, according to the present embodiment, it is possible to provide a liquid crystal compound capable of suppressing luminance during black display, and to suppress luminance during black display by using such a liquid crystal compound. Thus, a liquid crystal display device having an improved liquid crystal display element can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing light transmittance characteristics when a triangular wave voltage is applied to a liquid crystal display device using an antiferroelectric liquid crystal.

FIG. 2 is a diagram showing a method of displaying light in a liquid crystal display device using an antiferroelectric liquid crystal.

FIG. 3 is a diagram illustrating a method of displaying darkness in a liquid crystal display device using an antiferroelectric liquid crystal.

FIG. 4 is a diagram showing a method of writing and separating light and dark in a liquid crystal display device using an antiferroelectric liquid crystal.

FIG. 5 is a view showing chemical structures of liquid crystal compounds of Examples and Comparative Examples.

FIG. 6 is a diagram for explaining a general method for synthesizing the compounds of Examples.

FIG. 7 is a diagram for explaining a general method for synthesizing the compounds of Examples.

FIG. 8 is a diagram for explaining a general method for synthesizing the compounds of Examples.

FIG. 9 is a diagram for explaining a general method for synthesizing the compounds of Examples.

FIG. 10 is a diagram for explaining a general method for synthesizing the compounds of Examples.

FIG. 11 is a diagram for explaining a general method for synthesizing the compounds of Examples.

FIG. 12 is a diagram for explaining a general method for synthesizing the compounds of Examples.

FIG. 13 is a view showing a chemical structure of an intermediate compound in a method for synthesizing Compound 1 of Example.

FIG. 14 is a view showing a chemical structure of an intermediate compound in a method for synthesizing compound 2 of an example.

FIG. 15 is a view showing a chemical structure of an intermediate compound in a method for synthesizing compound 3 of an example.

FIG. 16 is a view showing a chemical structure of an intermediate compound in a method for synthesizing compound 4 of an example.

FIG. 17 is a table showing measured values of β for each of the liquid crystal compounds 1 to 4 of Examples and Comparative Examples.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hitoshi Hayashi 1-1-1, Showa-cho, Kariya, Aichi Prefecture Inside Denso Corporation (72) Inventor Tetsuo Toyama 1-1-1, Showa-cho, Kariya City, Aichi Prefecture Denso Corporation (72) Inventor Hitoshi Suenaga 5-41 Senmon, Itami-shi, Hyogo, Japan Imperial Chemical Industry Co., Ltd.Itami Plant F term (reference) 4H006 AA01 AB64 BJ20 BJ50 BP30 KA06 KF10 4H027 BA03 BB09 BB10 CF05 CF08

Claims (7)

[Claims] [Chemical Formula 1] In the above chemical formula 1, A is a functional group composed of only C atoms and H atoms and has a double bond, a triple bond, or a ring structure, and B is an alkyl group or an alkoxy group. X is an H atom or an F atom, and Y is CH ₃
Or liquid crystal compound characterized by is CF _3. 2. The following chemical formula 2: In the above chemical formula 2, A is a functional group composed of only a C atom and an H atom and has a double bond, a triple bond, or a ring structure, and B is an alkyl group or an alkoxyl group. A liquid crystal compound characterized by being a group. 3. The chemical formula 3 below:In the above chemical formula 3, A is composed of a C atom and a H atom.
B is an alkyl group or an alkoxy group
X is H or F atom, Y is CH _ThreeOr
CF_ThreeAnd Z is the following chemical formula 4:A liquid crystal compound characterized by being a functional group represented by
object. 4. The following chemical formula 5: In the above chemical formula 5, A is a functional group composed of a C atom and an H atom, B is an alkyl group or an alkoxy group, and Z is the following chemical formula 6: A liquid crystal compound characterized by being a functional group represented by: 5. The chemical formula 3 wherein B is a functional group represented by the following chemical formula 7: —C _n H _{2n + 1} (n = 2-8). 4. The liquid crystal compound according to 3. 6. The chemical formula 5 wherein B is a functional group represented by the following chemical formula 8: —C _n H _{2n + 1} (n = 2-8). 5. The liquid crystal compound according to 4. 7. A liquid crystal display device using the liquid crystal compound according to claim 1. Description: