JP2001139525A - Optically active fluorene derivative, liquid crystal composition containing the same, and liquid crystal display device - Google Patents

Abstract

(57) [Summary] (Modifications) [PROBLEMS] To provide a novel optically active compound which can be suitably used for a liquid crystal display device, particularly an antiferroelectric liquid crystal display device. SOLUTION: General formula (1) (Wherein R ¹ is an alkyl group, and the —CH ₂ — groups present in these groups are each independently —O—, —CO—O
—, —C≡C— or —CH ＝ CH—, R ² may be an alkyl group, and —CH _{3 at the} end of the alkyl chain may be replaced by —CF ₃ or —CH ₂ F. , A ¹ is —CH ₂ —, —CF ₂ — or —CO—, and A ² is 1,4-phenylene or one or more hydrogen atoms each independently represents F, Cl, Br or trifluoro. 1,4-phenylene substituted with a methyl group, A ³ is an alkyl group or a fluorinated alkyl group, A ⁴ is a single bond, —O— or —COO—, and X
Is -COO -, - CH ₂ O- or -OCH ₂ - and is,
m is an integer of 0 to 10, and C ^* represents an asymmetric carbon.
A compound represented by the formula:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel optically active compound and a liquid crystal composition using the same, which can be suitably used for a liquid crystal display device, especially an antiferroelectric liquid crystal display device.
And a liquid crystal display device using the liquid crystal composition.

[0002]

2. Description of the Related Art Liquid crystals are widely used as materials for display devices. Many liquid crystal display elements are a twisted nematic type (TN type) which is a display type using a nematic liquid crystal, a super twisted nematic type (STN type) having a twist angle of 200 ° or more, and a thin film transistor (STN type) as a switching element for each pixel. An active matrix system using TFTs) or the like. These liquid crystal display devices have a cathode ray tube (CR) in view of the electro-optical response speed.
It is inferior to the display using T). On the other hand, display devices using antiferroelectric liquid crystals are superior to nematic liquid crystal display devices in terms of high-speed response and wide viewing angle. Recently, it has been actively researched and its development has been attempted.

The antiferroelectric phase shows three stable states, two ferroelectric states and one antiferroelectric state, and uses the three-state switching for display. The feature of this three-state switching is that it exhibits a steep threshold characteristic and a wide optical hysteresis at the transition between the antiferroelectric phase and the ferroelectric phase (AD L. Chandani et al., Journal of Appl.・
Applied Physics, 27, No. 5, L729, 19
88). By combining this feature with the simple matrix method, a display having both a wide viewing angle and a high contrast can be achieved.

[0004] Recently, a thresholdless antiferroelectric liquid crystal having no threshold value (Daira et al., J. Mater. Chem., 6
(4), p. 671, 1996). These liquid crystals exhibit a V-shaped optical response, and a display element that can easily perform gradation display, which is difficult with a simple matrix system, can be realized by combining with an active matrix system such as a TFT.

[0005]

When a tristable antiferroelectric liquid crystal is used for a display device, characteristics such as a wide operating temperature range including around room temperature and a low threshold voltage are required. Must meet. In the case of a thresholdless antiferroelectric liquid crystal, there is no clear threshold value, a V-shaped optical response is required, and a liquid crystal material with little hysteresis is required. Further, as in the case of a general liquid crystal compound, stability to light and heat, good compatibility, and the like are required.

[0006]

The inventors of the present invention have made intensive studies to find an antiferroelectric liquid crystal compound satisfying the above conditions, and have completed the following invention. That is, the present inventors have found that at least one fluorene such as a fluorene-2,7-diyl group, a fluorenone-2,7-diyl group or a 9,9-difluorofluorene-2,7-diyl group in the molecular skeleton. Have a skeleton,
Among the substituted fluorene derivatives in which the linking group between the core structure and the optically active group is an ester bond, a compound that can be suitably used as a component of an antiferroelectric liquid crystal composition has been found, and the present invention has been completed. .

Some ferroelectric liquid crystal compounds having a fluorene skeleton structure are known. For example, Takato et al. (Mol. Cryst. Liq. Cryst., 183B, p. 339, 1990)
Reports the compound [FL1]. However, in [FL1], the optically active group moiety is an ether bond, and the structural similarity with the compound of the present invention is extremely small. Also, these compounds are not intended for use in antiferroelectric liquid crystals.

[0008]

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The present invention relates to an optically active compound (first to ninth inventions), a liquid crystal composition containing the same (tenth invention), and a liquid crystal display device using the liquid crystal composition (eleventh invention).
Consists of

A first aspect of the present invention relates to an optically active compound having a fluorene skeleton represented by the following general formula (1).

Embedded image (Wherein, R ¹ is a linear or branched C 3-20
And one of the-
CH ₂ — or _two non-adjacent —CH ₂ — may be each independently replaced with —O—, —CO—O—, —C≡C— or —CH ＝ CH—, and R ² is A linear or branched alkyl group having 1 to 10 carbon atoms,
-CH ₃ alkyl chain ends -CF ₃ or -CH ₂ F
A ¹ may be replaced by -CH _2- , -CF _2-
Or -CO-, wherein A ² is 1,4-phenylene or one or more hydrogen atoms each independently represents F,
1,4-phenylene substituted with Cl, Br or a trifluoromethyl group, wherein A ³ is —CH ₃ , —CFH ₂ ,
_{-CF 2 H, -CF 3, -CH} 2 CH 3, -CH 2 CF 3, -
CF ₂ CH ₃ or —CF ₂ CF ₃ , wherein A ⁴ is a single bond,
-O- or -COO-, and X is -COO-, -C
H ₂ O— or —OCH ₂ —, m is an integer of 0 to 10, and C ^* represents an asymmetric carbon. )

A second aspect of the present invention is that in the formula (1), A¹
Is -CH_Two-. Third and Third Embodiments of the Invention
4 is A in formula (1).¹Is -CH_Two-And
A^TwoIs 1,4-phenylene (third), or
One or more hydrogen atoms are each independently F,
1,4 substituted by Cl or trifluoromethyl group
-The case of phenylene (fourth). The fifth of the present invention
And sixth, in formula (1), A¹Is -CO-
Is -CF_Two-And A^TwoIs 1,4-phenylene
(Fifth) or one or more hydrogen atoms
Each independently of F, Cl, Br or trifluoromethyl
Is 1,4-phenylene substituted with a group (Sixth)
It is. Seventh to ninth aspects of the present invention are directed to formula (1):¹
Is a linear alkyl group having 3 to 20 carbon atoms,
One -CH present in these groups_Two-Or adjacent
Not two -CH_Two-May be replaced by -O-
K, R^TwoIs a linear alkyl group having 1 to 10 carbon atoms
A¹Is -CH_Two-And A^TwoIs 1,4-phenylene
Or one or more hydrogen atoms are each independently
Substituted with F, Cl, Br or trifluoromethyl group
1,4-phenylene, A^ThreeIs -CH _ThreeOr-
CF_ThreeAnd A^FourIs a single bond or -O-, and X is-
COO- (seventh), -CH_TwoO-
8) or -OCH_Two-(Ninth). Book
A tenth aspect of the present invention is any one of the first to ninth aspects.
It is a liquid crystal composition containing at least one compound. Departure
An eleventh aspect of the present invention relates to any one of the first to ninth inventions.
Using a liquid crystal composition containing at least one compound
Liquid crystal device.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred groups for A ^{2 in} formula (1) are shown below.

[0013]

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As the compound represented by the general formula (1), specifically, the following five types of structures (1-1), (1-2),
(1-3), (1-4) and (1-5) are preferred.

[0015]

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Further, when limiting to A ² , the following 2
Seven compounds are particularly preferred.

[0017]

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[0018]

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[0019]

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In these formulas, R ¹ is preferably an alkyl group or an alkoxyl group having 3 to 20 carbon atoms,
More preferably, it is a linear alkyl group or an alkoxyl group having 5 to 16 carbon atoms. Specifically, as the alkyl group, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and hexadecyl are preferred. As specific alkoxyl groups, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy, tetradecyloxy, pentadecyloxy, and hexadecyloxy are preferred.

The optically active group of the compound of the present invention is linked to the core structure by an ester bond. Therefore, in the production of the optically active part, an R- or S-form optically active secondary alcohol is used as a raw material. The optically active alcohol can be represented by the general formula (2).

[0022]

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The alcohol represented by the general formula (2) is represented by R
² is a linear or branched alkyl group having 1 to 10 carbon atoms, -CH _{3 at the} terminal of the alkyl chain may be replaced by -CF ₃ or -CH ₂ F, and A ³ is -CH ₃ , −
_{CFH 2, -CF 2 H, -CF} 3, -CH 2 CH 3, -CH 2
CF ₃ , —CF ₂ CH ₃ or —CF ₂ CF ₃ , wherein A ⁴ represents a single bond, —O— or —COO—, and m represents 0 to 1.
It is an integer of 0, and C ^* represents an asymmetric carbon.

In the alcohol represented by the general formula (2), A ³ represents —CH ₃ , —CFH ₂ , —CF ₂ H, —CF ₃ ,
—CH ₂ CH ₃ , —CH ₂ CF ₃ or —CF ₂ CF ₃ , A ⁴ is a single bond, and R ² is a linear C 1 to C 1
Most of the alcohols having an alkyl group of 0 and m being an integer of 0 to 10 are known compounds and can be easily obtained. For example, 1- (trifluoromethyl) -alkanols can be produced by the method of Suzuki et al. (Liquid Crystals, Vol. 6, No. 2, p. 167, 1989). The specific structure is shown below.

[0025]

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[0026]

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In the alcohol represented by the general formula (2), A ³ is —CF ₃ , A ⁴ is a single bond, and R ² is a branched alkyl group having 1 to 10 carbon atoms. , M is an integer of 0 to 10, and the compound of the general formula (1) is important because the compound can increase the tilt angle. Such alcohols are disclosed in
It can be produced by the method described in JP-A-195004. The specific structure of the alcohol is shown below.

[0028]

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In the optically active alcohol represented by the general formula (2), A ³ represents —CH ₃ or —CF ₃ , A ⁴ represents —O— or —COO—, and R ² represents a linear An alcohol having an alkyl group having 1 to 10 carbon atoms (-CH _{3 at the} terminal of the alkyl chain may be replaced by -CF ₃ or -CH ₂ F) and m is an integer of 0 to 10 is
JP-A-64-3154, JP-A-5-983, JP-A-10-139706 and JP-A-10-139706
No.-87541, and the present inventors further describe a method for producing a compound having the structure described in JP-A-10-24.
No. 8593. Therefore, these optically active alcohols can be produced as starting materials for producing the compound of the present invention. The specific structure is shown below.

[0030]

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Next, production examples of the compound of the present invention will be shown. The compound represented by the general formula (1) of the present invention can be produced by the following route. General formulas (1-1), (1-2), (1
-3), to produce the compound represented by (1-4),
7-substituted fluorene-2- represented by general formula [FL2]
A carboxylic acid derivative is used as a raw material. General formula [FL
The compound of 2] can be produced as follows.

[0032]

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A compound [F] represented by the general formula [FL2], wherein R ¹ represents an alkoxyl group, and A ¹ represents -CH _2-
L2-1] was produced with reference to the method of Gray et al. (J. Chem. Soc., P. 3228, 1957). That is, 2-acetylfluorene (b) can be obtained by a Friedel-Crafts reaction between fluorene (a) and acetyl chloride. When (b) is oxidized by the Bayer-Villiger reaction, 2-acetoxyfluorene (c) can be obtained.
2-acetoxy-7-acetylfluorene (d) can be obtained by a Friedel-Crafts reaction between (c) and acetyl chloride. After hydrolyzing (d),
By etherification reaction with an alkyl halide, 2-alkoxy-7-acetylfluorene (e) can be obtained. By oxidizing (e) with an oxidizing agent such as sodium hypobromite, 7-alkoxyfluorene-2-carboxylic acid [FL2-1] can be produced.

Among the compounds represented by the general formula [FL2], a compound [FL2-2] wherein R ¹ represents an alkoxyl group and A ¹ represents —CO— can be produced as follows. 2-alkoxy-7-acetylfluorene (e)
Is oxidized with oxygen to give 2-alkoxy-7-acetylfluorenone (f). (F) is oxidized with an oxidizing agent such as sodium hypobromite to give 7-alkoxyfluorenone-2-carboxylic acid [FL
2-2] can be produced.

[0035]

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Among the compounds represented by the general formula [FL2], the compound [FL2-3] in which R ¹ represents an alkyl group and A ¹ represents —CH ₂ — can be obtained by the method of Davison et al. (Mol. Cryst.
Liq. Cryst., Vol. 129, 17, 1985).

That is, by the Friedel-Crafts reaction between fluorene (a) and alkyl carboxylic acid chloride,
The corresponding 2-acylfluorene (g) is obtained.
By reducing (g) with hydrazine, 2-alkylfluorene (h) can be obtained. 2-acetyl-7-alkylfluorene (i) can be obtained by Friedel-Crafts reaction of (h) with acetyl chloride.
By oxidizing (i) with an oxidizing agent such as sodium hypobromite, 7-alkylfluorene-2-carboxylic acid [FL2-3] can be produced. General formula [FL
Compound [FL2-4] in which R ¹ represents an alkyl group and A ¹ represents —CO— among the compounds represented by [2], is prepared in the same manner as [FL2-2] using (i) as a starting material. It can be manufactured by a process.

[0038]

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In the compound represented by the general formula (1), (1-
The compound represented by 1) can be produced as follows. That is, the hydroxy group of the 4-hydroxybenzoic acid derivative was protected with an appropriate protecting group [Ph
1] (wherein P represents a protecting group) and an optically active alcohol represented by the general formula (2), whereby an optically active ester derivative (3) is obtained. When P is an acetyl group, (3) can be deprotected (deacetylated) with ammonia, diethylamine or the like to obtain the corresponding optically active phenol derivative (4). (4) and fluorenic acid derivative [FL2-1] or [FL2-3]
A compound represented by the general formula (1-1) can be produced by an esterification reaction with

[0040]

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The compound represented by the general formula (1-2) can be produced as follows. That is, (4)
And [FL2-2] or [FL2-4] by an esterification reaction. The compound represented by the general formula (1-3) can be produced as follows. The corresponding thioketal (5) can be obtained by reacting (1-2) with a Lewis acid such as boron trifluoride and reacting with ethanedithiol. (1-3) can be produced by fluorinating (5) with a hydrogen fluoride pyridine complex or the like in the presence of N-iodosuccinimide or N-bromosuccinimide.

[0042]

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The compound represented by the general formula (1-4) can be produced as follows. That is, [FL
2] is esterified with ethanol or methanol in the presence of an acid catalyst such as sulfuric acid, and then reduced with lithium aluminum hydride or the like to obtain the corresponding alcohol (j). (1-4) can be produced by etherifying (j) with the optically active phenol (4) using diethyl azocarboxylate and triphenylphosphine.

[0044]

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The compound represented by the general formula (1-5) can be produced as follows. That is, (e)
Is oxidized by a Bayer-Villiger reaction using a peroxide, and the oxide is hydrolyzed to give a 2-alkoxy-
7-Hydroxyfluorene (k) is obtained. (K) and the optically active ester (6), which can be produced by the method of Japanese Patent No. 2511760, are converted to (1-5) by an etherification reaction using a base such as potassium hydroxide, sodium hydroxide or sodium hydride. Can be manufactured.

[0046]

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[0047]

The compounds of the present invention will be described in more detail with reference to the following Examples and Comparative Examples. In the following Examples and Comparative Examples, various physical property values were measured by the following methods. Phase transition temperature: The sample was placed on a slide glass, the one covered with a cover glass was placed on a hot stage, and the temperature was measured at a rate of 1 ° C./min under a deflection microscope. N at phase transition
Is a nematic phase, SA is a smectic A phase, SC is a smectic C phase, SC ^* is a chiral smectic C phase, S
CA ^* indicates an antiferroelectric phase, SCγ ^* indicates a ferrielectric phase, SX indicates an unidentified smectic phase, and Iso indicates a clearing point. Melting point: 1 ° C./min using differential scanning calorimetry (DSC)
And the temperature was measured. Optical response: Each composition was injected into an alignment-treated cell having an electrode spacing of 2 μm, and measured from the change in transmitted light intensity when a rectangular wave having a Vpp of 20 V and a frequency of 1 kHz was applied. Threshold voltage: one of a pair of substrates obtained by applying a polyimide-based alignment film to a glass substrate provided with a transparent electrode is rubbed to face each other, and is injected in a liquid phase into a cell having an electrode spacing of 5 μm. Slowly cooled to SCA ^* phase. The threshold voltage of the transition between the antiferroelectric phase and the ferroelectric phase is determined by observing the optical response and applied voltage when a triangular wave of 50 mHz is applied to the liquid crystal cell using a two-phenomenon oscilloscope. It was measured from the change in the optical response under a suitably determined applied voltage.

Example 1 Preparation of Compound No. [4] (First Step) 150 g of fluorene was added to 1 L of dichloromethane.
The solution added to was cooled to 0 ° C., and 126 g of anhydrous aluminum chloride was added little by little. Then 74 g of acetyl chloride
And a solution consisting of 400 ml of dichloromethane was added dropwise at 0 ° C.
While stirring for one hour. The reaction solution was poured into 1 L of 6N hydrochloric acid containing ice, and the precipitated solid was separated by filtration. After drying, this was recrystallized using toluene to obtain 165 g of 2-acetylfluorene. (Melting point: 129 ° C)

(Second step) 2-acetylfluorene is added to 1
40 ml of sulfuric acid was added to a solution consisting of 65 g, 320 g of formic acid, 120 g of acetic anhydride and 1 L of dichloromethane, and then 120 ml of aqueous hydrogen peroxide were added dropwise. After stirring at room temperature for 30 minutes, the mixture was heated to 40 ° C. and further stirred for 5 hours. One liter of water was added, the dichloromethane layer was separated, washed with saturated aqueous sodium carbonate, aqueous sodium bisulfite and water in that order, dried over anhydrous magnesium sulfate and concentrated to obtain a solid. This was recrystallized using a mixed solvent of heptane and ethyl acetate 1: 1 to give 2-acetoxyfluorene 14
9 g were obtained. (Melting point: 130 ° C)

(Third Step) 2-Acetoxyfluorene 1
A solution obtained by adding 40 g to 1 L of dichloromethane was cooled to 0 ° C., 189 g of anhydrous aluminum chloride was added, and then a solution composed of 62 g of acetyl chloride and 100 ml of dichloromethane was added dropwise, and the mixture was stirred for 5 hours while maintaining 0 ° C. The reaction solution was poured into 6N hydrochloric acid, extracted with dichloromethane, dried over anhydrous magnesium sulfate and concentrated to obtain a solid. This was recrystallized using a mixed solvent of ethanol and ethyl acetate to obtain 143 g of 2-acetoxy-7-acetylfluorene. (Melting point: 134 ° C)

(Fourth Step) 150 g of 2-acetoxy-7-acetylfluorene, 30 g of potassium hydroxide, 400 ml of ethylene glycol, 1 L of ethanol and 50 ml of water were charged and refluxed for 5 hours. Ethanol was distilled off under reduced pressure, and the remaining solution was poured into 1 L of 6N hydrochloric acid. The precipitated solid was separated by filtration, dried, and recrystallized using acetic acid to obtain 106 g of 2-acetyl-7-hydroxyfluorene. (Melting point: 220-222 ° C)

(Fifth step) A solution comprising 20 g of 2-acetyl-7-hydroxyfluorene, 22.5 g of octyl bromide, 18 g of potassium carbonate and 200 ml of dimethylformamide was refluxed for 3 hours. 6N hydrochloric acid was added to the reaction solution, extracted with toluene, washed with water, dried over anhydrous magnesium sulfate and concentrated. The concentrate was recrystallized using heptane to obtain 26 g of 2-acetyl-7-octyloxyfluorene. (Phase transition temperature: Cr 98 SX 108.5
Iso)

(Sixth step) 10 g of 2-acetyl-7-octyloxyfluorene was once dissolved in 180 ml of dioxane, and the solution was cooled to 0 ° C. To the solution, 18.6 g of sodium hydroxide dissolved in 90 ml of water was added 6.
Sodium hypobromite prepared by adding 6 ml was added dropwise. After slowly returning to room temperature and stirring for 1 hour, the temperature was raised to 40 ° C. and stirred for 1 hour. 6N
1 L of hydrochloric acid was added, and the precipitated crystals were separated by filtration and dried. The obtained crude crystals were recrystallized using acetic acid to obtain 11 g of 7-octyloxyfluorene-2-carboxylic acid.
(Phase transition temperature: Cr 206.5SX 226.5 N 2
52.5 Iso)

(Seventh stage) 6 g of 4-acetoxy-benzoic acid chloride, R-(+)-octanol (optical purity 99
% Ee) A solution of 4.1 g, 20 ml of pyridine and 50 ml of toluene was refluxed for 3 hours. Add water and add toluene layer 6
After washing sequentially with N hydrochloric acid and saturated aqueous sodium carbonate, it was dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was mixed with 50 ml of methanol and 5 ml of 30% aqueous ammonia and stirred for 1 hour at room temperature. The residue obtained by distilling off the solvent was diluted with toluene and separated, and the toluene layer was sequentially washed with 6N hydrochloric acid and saturated aqueous sodium carbonate, and then dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was purified by silica gel column chromatography using toluene / ethyl acetate as a solvent to give 4-hydroxy- (1-
4 g of methylheptaoxycarbonyl) benzene were obtained.

(Eighth step) 1 g of 4-hydroxy- (1-methylheptaoxycarbonyl) benzene and 1.3 g of 7-octyloxyfluorene-2-carboxylic acid were added to 100 ml of chloroform to form a suspension, and the solution was added with dicyclohexyl. 1 g of carbodiimide was added, and the mixture was stirred at room temperature for 12 hours. Water was added and the organic layer was washed successively with 6N hydrochloric acid and saturated sodium carbonate, and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was purified by silica gel column chromatography using toluene, and further recrystallized twice with acetone to give 4- (1-methylheptaoxycarbonyl) phenyl = 7-octyloxy. 0.9 g of fluorene-2-carboxylate were obtained. The phase transition temperatures are shown in the structural diagram.

Example 2 Preparation of Compound No. [137] (First Step) 4-Acetoxy-2-fluorobenzoic acid 6
To 0 g, 60 ml of thionyl chloride and several drops of dimethylformamide were added, and the mixture was refluxed for 3 hours. Then, excess thionyl chloride was distilled off. The residue was purified by distillation under reduced pressure to obtain 64 g of 4-acetoxy-2-fluorobenzoic acid chloride. (Boiling point: (3.99 hPa) 111-115 ° C)

(Second stage) 6 g of 4-acetoxy-2-fluorobenzoic acid chloride, R-(+)-6-ethoxy-
A solution of 5 g of 1,1,1-trifluoro-2-hexanol (99% ee optical purity), 20 ml of pyridine and 50 nl of toluene was refluxed for 3 hours. Add water and add toluene layer 6
After washing sequentially with N hydrochloric acid and saturated aqueous sodium carbonate, it was dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue obtained was mixed with 50 ml of diethylamine and refluxed for 1 hour. The residue obtained by distilling off diethylamine was diluted with toluene, and this toluene solution was washed sequentially with 6N hydrochloric acid and saturated aqueous sodium carbonate, and then dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was purified by silica gel column chromatography using toluene / ethyl acetate as a solvent to give 4-hydroxy-2-fluoro- (1-trifluoromethyl-5-ethoxy-pentaoxycarbonyl 4) 4 g of benzene were obtained. (Melting point: 86-87 ° C)

(Third step) 0.9 g of 4-hydroxy-2-fluoro- (1-trifluoromethyl-5-ethoxy-pentaoxycarbonyl) benzene, 0.94 g of 7-octyloxyfluorene-2-carboxylic acid, 0.7 g of dicyclohexylcarbodiimide, 100 m of chloroform
Using l, in the same manner as in Example 1, Step 8,
0.3 g of 3-fluoro-4- (1-trifluoromethyl-5-ethoxy-pentaoxycarbonyl) phenyl = 7-octyloxyfluorene-2-carboxylate was obtained. The phase transition temperatures are shown in the structural diagram.

Example 3 Preparation of Compound No. [16] (First Step) 102 g of fluorene was added to 1 L of dichloromethane.
The solution added to was cooled to 0 ° C., and anhydrous aluminum chloride 1
Of octanoyl chloride 1
00 g was added dropwise. After stirring at 0 ° C. for 3 hours, the reaction solution was poured into 1 L of 6N hydrochloric acid to terminate the reaction. The mixture was extracted with dichloromethane, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain a solid. This was recrystallized from a mixed solvent of heptane and ethyl acetate to obtain 158 g of 2-octanoylfluorene.

(Second stage) 158 g of 2-octanoylfluorene was heated in 1 L of diethylene glycol (100 g).
C.), and 73 g of potassium hydroxide and then 65 g of hydrazine were added, and the mixture was heated to 250 ° C. while draining water with a Dean Stark and stirred for 6 hours. Water was added, extracted with diethyl ether, the ether layer was washed with water, and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was recrystallized from ethanol,
3 g of 2-octylfluorene were obtained. (Melting point: 64 ~
66 ° C)

(Third Step) 2-octylfluorene 80
g in 800 ml of dichloromethane was cooled to 0 ° C. and 42 g of anhydrous aluminum chloride was added. Next, 22 g of acetyl chloride was added dropwise, and the mixture was stirred for 2 hours while maintaining 0 ° C. The reaction solution was poured into 1 L of 6N hydrochloric acid, extracted with diethyl ether, and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was purified by silica gel column chromatography and recrystallization to obtain 73 g of 2-acetyl-7-octylfluorene.

(Fourth Step) After once dissolving 60 g of 2-acetyl-7-octylfluorene in 1 L of dioxane, the solution was cooled to 0 ° C. Sodium hypobromite prepared by adding 40 ml of bromine to a solution of 112 g of sodium hydroxide in 550 ml of water was added dropwise thereto. Return to room temperature slowly and stir for 1 hour, then to 40 ° C
The temperature was increased until stirring for 30 minutes. 2 L of 6N hydrochloric acid was added, and the precipitated crystals were separated by filtration and dried. The obtained crude crystals were recrystallized using acetic acid to obtain 40 g of 7-octylfluorene-2-carboxylic acid.

(Fifth step) Using 1.1 g of 4-hydroxy- (1-methylheptaoxycarbonyl) benzene, 1.4 g of 7-octylfluorene-2-carboxylic acid, 1 g of dicyclohexylcarbodiimide and 100 ml of chloroform, 1, 4- by the same method as in the eighth step
(1-methylheptaoxycarbonyl) phenyl = 7-
2 g of octylfluorene-2-carboxylate were obtained. The phase transition temperatures are shown in the structural diagram.

Example 4 Preparation of Compound No. [192] (First Step) A solution composed of 16 g of 2-acetyl-7-octyloxyfluorene, 2 g of powdered potassium hydroxide and 250 ml of 2-butanone was heated to reflux while heating. Oxygen was bubbled through the solution for 1 hour and further stirred at room temperature for 1 hour. Hydrochloric acid water was added, extracted with chloroform, dried over anhydrous magnesium sulfate, and the solvent was distilled off. The resulting residue was purified by silica gel column chromatography and recrystallization to obtain 10 g of 2-acetyl-7-octyloxyfluorenone. Obtained.

(Second step) 9.5 g of 2-acetyl-7-octyloxyfluorenone was once dissolved in 150 ml of dioxane, and the solution was cooled to 0 ° C. Sodium hypobromite prepared by adding 6 ml of bromine to a solution of 16.8 g of sodium hydroxide in 83 ml of water was added dropwise thereto. After slowly returning to room temperature and stirring for 1 hour, the temperature was raised to 40 ° C. and stirred for 1 hour. 6N
Hydrochloric acid was added and the precipitated crystals were separated by filtration and dried. The obtained crude crystals were recrystallized using acetic acid to obtain 7 g of 7-octyloxyfluorenone-2-carboxylic acid.

(Third Step) 1.8 g of 4-hydroxy-2-fluoro- (1-methylheptyloxycarbonyl) benzene, 2.3 g of 7-octyloxyfluorenone-2-carboxylic acid, 1.6 g of dicyclohexylcarbodiimide
Example 1 and 8 using 5 g and 200 ml of chloroform.
2 g of 3-fluoro-4- (1-methylheptyloxycarbonyl) phenyl) = 7-octyloxyfluorenone-2-carboxylate was obtained in the same manner as in the step. The phase transition temperatures are shown in the structural diagram.

Example 5 Preparation of Compound No. [200] (First Step) 3-fluoro-4- (1-methylheptyloxycarbonyl) phenyl) = 7-octyloxyfluorenone-2-carboxylate 2 g and ethanedithiol 1 ml Was dissolved in 35 ml of dichloromethane at 0 ° C.
After cooling, 2 ml of boron trifluoride etherate was added thereto. After raising the temperature to room temperature and stirring for 6 hours, a saturated aqueous solution of sodium carbonate was added thereto, the dichloromethane layer was separated, and dried over anhydrous magnesium sulfate. Purification by silica gel column chromatography using toluene and recrystallization gave 1.5 g of 3-fluoro-4- (1-methylheptyloxycarbonyl) phenyl) = 7-octyloxyfluorenone-2-carboxylate ethylenedithioketal. Was. (Melting point: 54 ° C)

(Second Step) N-Iodosuccinimide 1.
A solution consisting of 48 g and 20 ml of dichloromethane is
After cooling to 0 ° C., 3 ml of 70% hydrogen fluoride pyridine complex was added dropwise. After raising the internal temperature to -30 ° C,
Fluoro-4- (1-methylheptyloxycarbonyl) phenyl) = 7-octyloxyfluorenone-2
-1.5 g of carboxylate ethylene dithioketal
Was dissolved in 10 ml of dichloromethane. −
After stirring at 30 ° C. for 30 minutes, the reaction solution was poured into saturated aqueous sodium carbonate to complete the reaction. The mixture was extracted with dichloromethane and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was purified by silica gel column chromatography, and further purified by recrystallization to give 3-fluoro-4- (1-methylheptyloxycarbonyl) phenyl) = 9,9-difluoro-7. 1 g of octyloxyfluorene-2-carboxylate was obtained. The phase transition temperatures are shown in the structural diagram.

Example 6 Preparation of Compound No. [213] (First Step) 5.7 g of 2-decyloxyfluorenecarboxylic acid was refluxed in 4 ml of sulfuric acid and 130 ml of ethanol for 12 hours. Toluene and water were added to the residue obtained by distilling off ethanol and extracted. The toluene layer was neutralized with aqueous sodium carbonate and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was recrystallized from ethanol to give 3.8 g.
Of ethyl 2-decyloxyfluorenecarboxylate was obtained. Its phase transition temperature is Cr 94 SA 1
07.7 Iso.

(Second step) 1.8 g of lithium aluminum hydride was added to 30 ml of ether to form a solution,
A solution of 1.8 g of ethyl 2-decyloxyfluorenecarboxylate dissolved in 50 ml of ether was added dropwise, and the mixture was stirred at room temperature for 8 hours. A 20% aqueous sulfuric acid solution (80 ml) was added, and the mixture was extracted with ethyl acetate (50 ml) and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was recrystallized from ethanol to obtain 1.1 g of 2-hydroxymethyl-7-decyloxyfluorene. (Melting point 142
℃)

(Third Step) 2-Hydroxymethyl-7-
0.3 g of decyloxyfluorene, 4-hydroxy-2
-Fluoro- (1-methylheptyloxycarbonyl)
0.23 g of benzene, 0.26 g of triphenylphosphine
Was dissolved in 20 ml of THF. This solution was once cooled to 0 ° C., and 40 ml of a 40% toluene solution of diethylazocarboxylic acid was added thereto, followed by stirring at room temperature for 12 hours. The toluene layer extracted by adding water and toluene was washed successively with 6N hydrochloric acid and saturated aqueous sodium hydrogen carbonate, and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was purified by silica gel column chromatography (toluene) and recrystallization (acetone), and 0.24 g of compound number [213] was obtained.
I got The phase transition temperatures are shown in the structural diagram.

Example 7 Preparation of Compound No. [221] (First Step) 7.2 g of 2-acetyl-7-octyloxyfluorene was prepared in the same manner as in Example 1 (second step) to give 2-acetoxy-7-. Octyloxyfluorene 4.
1 g was obtained. (Melting point: 101-102 ° C)

(Second Step) 4.1 g of 2-acetoxy-7-octyloxyfluorene and 0.6 g of lithium hydroxide were refluxed for 1 hour in 50 ml of ethylene glycol. The reaction solution was poured into 100 ml of water, and the precipitated crystals were separated by filtration and dried. The crude crystals were recrystallized from chloroform to give 3 g of 2
-Octyloxy-7-hydroxyfluorene was obtained.
(Melting point: 151-152 ° C)

(Third step) 2.5 g of 2-octyloxy-7-hydroxyfluorene, 1-methylheptyl = 4
2.6 g of -bromomethylbenzoate and 0.54 g of potassium hydroxide were refluxed in 100 ml of dimethylformamide for 5 hours. Toluene and water were added, the layers were separated, and the organic layer was washed sequentially with 6N hydrochloric acid, saturated aqueous sodium carbonate and water, and dried over anhydrous magnesium sulfate. The residue obtained by distilling off the solvent was purified by silica gel column chromatography, and recrystallized twice with acetone to give Compound No. [221].
I got The phase transition temperatures are shown in the structural diagram. According to Examples 1 to 7, compounds 1-230 represented by general formula (1)
Was manufactured. 1 shows the structure and phase transition temperature of a compound.

[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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[0090]

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[0091]

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[0092]

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[0093]

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[0094]

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[0095]

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[0096]

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[0097]

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Example 8 (Anti-ferroelectric liquid crystal composition exhibiting clear hysteresis) An anti-ferroelectric liquid crystal composition (MIX1) having the following composition was prepared.

[0099]

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The above composition (MIX1) showed good compatibility without causing phase separation, and a uniform composition was obtained.
1 shows the phase transition temperature of this composition. Cr Room temperature or less SCA ^* 114.3 SCγ ^* 115.
5 SC ^* 116.4SA 150.2 Iso FIG. 1 shows the result of comparing the threshold voltages of the composition (MIX1) and the compound [M] at each temperature. Composition (M
IX1) shows a much lower threshold voltage than compound [M] alone, and its temperature dependence is also very small and improved.

Example 9 (Anti-ferroelectric liquid crystal composition showing no clear threshold value) A liquid crystal composition (MIX2) having the following composition was prepared.

[0102]

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The phase transition temperature of the composition (MIX2) is shown below. Cr Room temperature or less SCA ^* 88.4 SA 93.8 Is
o The optical response to a triangular wave voltage at 75 ° C. is shown in FIG. Figure 4 shows a V-shaped optical response without hysteresis.

[0104]

The compound of the present invention is characterized in that many of the compounds exhibit an antiferroelectric phase over a wide temperature range, or those which do not exhibit an antiferroelectric liquid crystal phase have potential antiferroelectric properties. It is to have. Also, when mixed with other antiferroelectric liquid crystal components, it shows good compatibility without causing phase separation and is sufficiently stable against heat, light, etc. Has properties. When a composition is prepared by adding an antiferroelectric liquid crystal compound as the second component to the compound of the present invention, not only the threshold voltage is lowered but also the temperature dependence thereof is very small and the composition is improved. Is obtained. Furthermore, by appropriately selecting the components of the compound to be added to the compound of the present invention, it is possible to adjust a composition showing a V-shaped optical response which does not show a clear threshold.

[Brief description of the drawings]

FIG. 1 is a view showing the results of comparison of the threshold voltage at each temperature of a composition (MIX1) and a compound [M].

FIG. 2 is a diagram showing an optical response of a composition (MIX2) to a triangular wave voltage at 75 ° C.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/13 500 G02F 1/13 500 1/141 1/137 510 (72) Inventor Hideo Saito Chiba 195 Iinuma, Hara-shi 6

Claims (11)

[Claims] 1. A compound of the general formula (1) (Wherein, R ¹ is a linear or branched C 3-20
And one of the-
CH ₂ — or _two non-adjacent —CH ₂ — may be each independently replaced with —O—, —CO—O—, —C≡C— or —CH ＝ CH—, and R ² is A linear or branched alkyl group having 1 to 10 carbon atoms,
-CH ₃ alkyl chain ends -CF ₃ or -CH ₂ F
A ¹ may be replaced by -CH _2- , -CF _2-
Or -CO-, wherein A ² is 1,4-phenylene or one or more hydrogen atoms each independently represents F,
1,4-phenylene substituted with Cl, Br or a trifluoromethyl group, wherein A ³ is —CH ₃ , —CFH ₂ ,
_{-CF 2 H, -CF 3, -CH} 2 CH 3, -CH 2 CF 3, -
CF ₂ CH ₃ or —CF ₂ CF ₃ , wherein A ⁴ is a single bond,
-O- or -COO-, and X is -COO-, -C
H ₂ O— or —OCH ₂ —, m is an integer of 0 to 10, and C ^* represents an asymmetric carbon). 2. In the general formula (1), A ¹ represents —CH ₂ —
The compound according to claim 1, which is 3. The compound according to claim 2, wherein in the general formula (1), A ² is 1,4-phenylene. 4. In the general formula (1), A ² is 1,4-phenylene in which one or more hydrogen atoms are each independently substituted with F, Cl or a trifluoromethyl group. The compound according to the above. 5. In the general formula (1), A ¹ represents —CO—
Wherein A ² is 1,4-phenylene or 1,4-phenylene in which one or more hydrogen atoms are each independently substituted with F, Cl or a trifluoromethyl group. Compound. 6. In the general formula (1), A ¹ represents —CF ₂ —
Wherein A ² is 1,4-phenylene or 1,4-phenylene in which one or more hydrogen atoms are each independently substituted with F, Cl or a trifluoromethyl group. Compound. 7. In the general formula (1), R¹Is linear
An alkyl group having 3 to 20 carbon atoms;
One existing -CH_Two-Or two that are not adjacent
-CH_Two-May be replaced by -O-, and R^TwoIs straight
A chain alkyl group having 1 to 10 carbon atoms,¹Is-
CH_Two-And A^TwoIs 1,4-phenylene or one
Or two or more hydrogen atoms are each independently F, Cl,
1,4 substituted by Br or trifluoromethyl group
-Phenylene, A^ThreeIs -CH _ThreeOr -CF_ThreeIn
A^FourIs a single bond or -O-, and X is -COO-
The compound according to claim 1, which is 8. In the general formula (1), R¹Is linear
An alkyl group having 3 to 20 carbon atoms;
One existing -CH_Two-Or two that are not adjacent
-CH_Two-May be replaced by -O-, and R^TwoIs straight
A chain alkyl group having 1 to 10 carbon atoms,¹Is-
CH_Two-And A^TwoIs 1,4-phenylene or one
Or two or more hydrogen atoms are each independently F, Cl,
1,4 substituted by Br or trifluoromethyl group
-Phenylene, A^ThreeIs -CH _ThreeOr -CF_ThreeIn
A^FourIs a single bond or -O-, and X is -CH_TwoO-
The compound according to claim 1, which is 9. In the general formula (1), R¹Is linear
An alkyl group having 3 to 20 carbon atoms;
One existing -CH_Two-Or two that are not adjacent
-CH_Two-May be replaced by -O-, and R^TwoIs straight
A chain alkyl group having 1 to 10 carbon atoms,¹Is-
CH_Two-And A^TwoIs 1,4-phenylene or one
Or two or more hydrogen atoms are each independently F, Cl,
1,4 substituted by Br or trifluoromethyl group
-Phenylene, A^ThreeIs -CH _ThreeOr -CF_ThreeIn
A^FourIs a single bond or -O-, and X is -OCH_Two−
The compound according to claim 1, which is 10. A liquid crystal composition containing at least one compound according to claim 1. Description: 11. A liquid crystal device comprising a liquid crystal composition containing at least one compound according to claim 1. Description: