JPH04330040A - Optically active compound and liquid crystal composition containing the same - Google Patents

Abstract

PURPOSE:To obtain a new chemically stable and optically active compound capable of exhibiting extremely great spontaneous polarization or inducing great spontaneous polarization by its addition to a smectic C liquid crystal composition. CONSTITUTION:An optically active compound, e.g. (S)-4-(1-oxo-2-methylbutyl) phenyl (R)-4((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate expressed by the formula R<1>-X-R<2> [R<1> is any of formulas I to III; R IS straight-chain or branched alkyl; C(R) is asymmetric carbon; absolute configuration of formulas I and III is (S) and the absolute configuration of formula II is (R) when the absolute configuration of R<2> is (S) and the absolute configuration of formulas I and III is (R), and the absolute configuration of formula II is (S) when the absolute configuration of R<2> is (R); R2 is formula IV; R' is >=2C straight-chain or branched alkyl; X is any of formulas V to VII; Y is H or halogen]. The aforementioned compound in which X is formula VII can be produced by condensing the corresponding optically active alkanoylbiphenyl with an optically active substituted benzoic acid in the presence of a dehydrating agent.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION The present invention relates to a novel optically active compound and a chiral liquid crystal composition using this optically active compound.

0002

2. Description of the Related Art Liquid crystal display elements have characteristics such as low driving voltage, low power consumption, thinness and light weight, and are used in calculators, watches, televisions, etc. Currently, nematic liquid crystals are widely used for these display materials, but the response speed is several tens of milliseconds.
．． It had the disadvantage of being slow. As one attempt to improve this point, a display method using ferroelectric liquid crystal has been proposed (NA Clark et al.; Applied P.
hys. Lett. , 36, 899 [1980]). This method is based on the chiral smectic C phase (
The ferroelectric liquid crystal material must exhibit the Sc* phase in a wide temperature range including room temperature, have large spontaneous polarization, and have an appropriate tilt angle. It is required to have low rotational viscosity, long helical pitch, and chemical stability. However, no ferroelectric liquid crystal compound that satisfies all of these conditions is known. Therefore, when ferroelectric liquid crystals are to be used practically as electro-optical elements, it is necessary to mix several types of ferroelectric liquid crystals, compounds that induce ferroelectricity, and non-ferroelectric liquid crystals to form a composition. be.

[0003] Sc* To obtain a liquid crystal composition, Sc*
A method of mixing multiple compounds exhibiting a Sc* phase, a method of mixing a non-ferroelectric liquid crystal with a compound exhibiting an Sc* phase, a method of mixing a non-ferroelectric liquid crystal with a compound exhibiting a Sc* phase, a method of mixing an optically non-active compound or a liquid crystal composition exhibiting a smectic C phase (hereinafter abbreviated as Sc phase). There is a method of adding a compound, and the last method is currently becoming the mainstream because it is considered easy to obtain a high-speed response with low viscosity. In order to obtain a liquid crystal composition that responds quickly, the optically active compound to be added must either exhibit large spontaneous polarization itself or have the property of inducing large spontaneous polarization in the composition.

0004

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned circumstances.It is chemically stable and exhibits extremely large spontaneous polarization, or when added to an Sc liquid crystal composition, induces large spontaneous polarization. The object of the present invention is to provide a novel optically active compound, and also to provide a novel ferroelectric liquid crystal material using this optically active compound, which has a wide temperature range in the Sc* phase and responds at high speed.

[0005]

[Means for solving the problems] To summarize the present invention,
The present invention relates to an optically active compound represented by the following general formula (I) and a chiral liquid crystal composition containing the same.

[0006]

[Chemical formula 3]

[0007]

[C4]

The present invention will be explained in detail below. The feature of the present invention is that two optically active (chiral) groups are introduced into one molecule with a core region in between, and the signs of spontaneous polarization based on the optically active groups are made to be the same. The object of this invention is to realize a compound that exhibits a much larger spontaneous polarization than the sum of the spontaneous polarizations exhibited by compounds containing only optically active groups.

Compounds with a partial structure consisting of a carbonyl group directly sandwiched between the core and an asymmetric carbon exhibit large spontaneous polarization, and when a hydroxyl group is introduced at the ortho position of the alkanoyl group in this compound, the intramolecular It was previously discovered that hydrogen bonds are formed and the dipoles of carbonyl and hydroxyl groups are aligned in the same direction, resulting in an increase in spontaneous polarization, which is a remarkable effect (Japanese Patent Application No. 278,618/1982). In other words, most of the ferroelectric liquid crystals that have been reported so far have used dipoles with ester or ether groups, but the dipole sandwiched between the core and the asymmetric carbon can be used with ether groups, ester groups, or carbonyl groups. By switching to , the spontaneous polarization increases approximately in proportion to the group moment of these groups, and when a methylene group is interposed between the carbonyl group and the asymmetric carbon, the spontaneous polarization becomes extremely small.

[0010] In a compound in which the above carbonyl group-containing partial structure and another optically active group are combined with a core sandwiched between them, if the signs of the spontaneous polarizations based on the two optically active groups are the same, each It exhibits a larger spontaneous polarization than that of a compound containing only one optically active group. We have shown this in Japanese Patent Application No. 2-13382. However, the degree of increase varies depending on the type of another optically active group to be combined and the type of core. By selecting the type of another optically active group to be combined with the optically active alkanoyl group and the type of the core, the present invention achieves a spontaneous polarization that is much larger than the sum of the spontaneous polarizations exhibited by compounds containing each optically active group alone. The compound shown is realized. That is, the optically active alkanoyl group R2 represented by the following chemical formula (II) and the optically active group to be combined with the core sandwiched therebetween must be bonded to the core via the ester group.

[0011]

[C5]

Furthermore, the optically active group R1 must be one of the following chemical formulas (III), (IV) and (V).

[0013]

[C6]

At this time, the combination of the absolute configurations of R1 and R2 is such that when the absolute configuration of R2 is (S), the chemical formula (III
The absolute configuration of ) is (S), and the absolute configuration of chemical formula (IV) is (
R), the absolute configuration of chemical formula (V) is (S), and R2
When the absolute configuration of is (R), the absolute configuration of chemical formula (III) must be (R), the absolute configuration of chemical formula (IV) must be (S), and the absolute configuration of chemical formula (V) must be (R).

Furthermore, in order to achieve a dramatic improvement in spontaneous polarization, it is necessary that the core is not two rings but three rings, and the following chemical formulas (VI), (VII) and (VI
II) Any of the structures represented by:

[0016]

[C7]

The compound of the present invention having two optically active groups is
As shown in Table 9 below, it exhibits large spontaneous polarization. As Comparative Examples 1 to 7, the structures of comparative compounds are shown in Table 1 below, and their spontaneous polarizations are shown in Table 2. Here, since spontaneous polarization depends on the tilt angle, the value of PO 2 that compensated for the difference in tilt angle was used for comparison. This is the P.O.
It is determined by the relational expression =PS/sin θ, and is considered to be the spontaneous polarization value when all rotational motion within the ferroelectric liquid crystal molecules is frozen. In addition, the last column of Table 9 shows the sum of PO of the compounds each having one corresponding lycal group, and the PO of the compound of the present invention having two optically active groups is the sum of this sum. It is 2 to 3 times more.

[0018]

[Table 1]

[0019]

[Table 2]

As described above, the compounds of the present invention have much greater spontaneous polarization than the sum of the respective compounds containing only one optically active (chiral) group (comparative compounds).

It is not clear at present why the combination of the above structures brings about a dramatic improvement in spontaneous polarization. However, it is thought that some kind of interaction that exists between molecules contributes to suppressing the motion in the vicinity of the chiral part, resulting in a dramatic improvement in spontaneous polarization.

The compound of the present invention having a three-ring core not only induces a larger spontaneous polarization in a smectic liquid crystal composition than the corresponding compound having a two-ring core, but also provides a composition with a higher response speed. . If the structure of the chilyle moiety is the same, a two-ring one usually has a lower viscosity and therefore a composition with a higher response speed can be obtained. In the present invention, the reason why a composition having a higher response speed can be obtained with a three-ring core is that by changing the core from two rings to three rings, an increase in spontaneous polarization that exceeds an increase in viscosity is realized.

Introducing halogen atoms into the core is often used as a means to improve liquid crystallinity and as a means to increase spontaneous polarization, and this method is also effective in the present invention. That is, fluorine atoms,
Introduction of chlorine atoms or bromine atoms is effective in improving liquid crystallinity and increasing spontaneous polarization.

In the present invention, other components of the chiral liquid crystal composition containing the optically active compound represented by the general formula (I) may be a ferroelectric liquid crystal compound, or a non-chiral liquid crystal compound. But that's fine.

(Production method of compound) The production method of the optically active compound represented by general formula (I) will be described. First, optically active alkanoylphenol is synthesized, for example, by the following route. In the formula, R1, R2, and R' have the same meanings as above.

[0026]

[Chemical formula 8]

The optically active alkanoylresorcinol is
For example, it is synthesized by the following route.

[0028]

[Chemical formula 9]

Optically active alkanoyl biphenyl is synthesized, for example, by the following route.

[0030]

[Chemical formula 10]

Next, optically active substituted benzoic acid (B1) or optically active substituted biphenylcarboxylic acid (B2) is obtained by converting optically active acid R1H into the corresponding acid chloride using thionyl chloride, and adding p-hydroxybenzoic acid or 4 ′−
It is synthesized by reacting hydroxy-1,1'-biphenyl-4-carboxylic acid in the presence of a base such as pyridine.

Finally, the above compound (A1) or (A2
) and (B2) and (A3) and (B1) are condensed in the presence of a dehydrating agent such as dicyclohexylcarbodiimide to obtain a compound represented by general formula (I).

[0033]

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples. As examples of the present invention, the structures of compounds 1 to 24 are shown in Tables 3 to 5, and the specific rotation, melting point, phase transition temperature at cooling, and Sc* phase transition temperature 10°C below the upper limit temperature of these compounds are shown in Tables 3 to 5. Tables 6 to 8 show the spontaneous polarization at . Here, the liquid crystal phase and phase transition temperature were determined by differential scanning calorimetry (DSC) measurement and observation using a polarizing microscope equipped with a temperature control device. Moreover, spontaneous polarization was measured by the triangular wave method. In the table, the concentration in chloroform is shown in parentheses (unit: g/10
0ml). In addition, in the phase transition temperature column, I is an isotropic liquid, N* is a chiral nematic phase, SA is a smectic A phase, Sc* is a chiral smectic C phase,
SX represents an unidentified smectic phase (the same applies below).

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

[Table 5]

[0037]

[Table 6]

[0038]

[Table 7]

[0039]

[Table 8]

As is clear from Tables 6 to 8, all of the compounds of the present invention exhibit a large spontaneous polarization that was hitherto unknown.

Examples of the synthesis of the compounds of the present invention are shown below. The structure of the compound was determined by infrared absorption spectrum (IR) and proton nuclear magnetic resonance spectrum (1H NMR).

(Synthesis Example 1) (S)-4-(1-oxo-2-methylbutyl)phenyl (R)-4((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate (Compound 4) Synthesis (1) (S)-4-(1-oxo-2-methylbutyl)
Synthesis of phenol 8.25 g (76.3 mmol) of anisole was mixed with anhydrous 1
, 2-dichloroethane, cooled to below 0°C, and 9.2 g (76.3 mmol) of pulverized aluminum chloride was added little by little. After the input is complete,
(S)-(+)-2-methylbutyric acid chloride 9.2g (76
．． A solution prepared by dissolving 3 mmol) to 50 ml was added dropwise over 1 hour while stirring. After the dropwise addition was completed, the mixture was stirred at room temperature for 1 hour. A further 9.2 g (76.2 mmol) of ground aluminum chloride were then added and the reaction mixture was heated to reflux for 2 hours. After cooling to room temperature, 10 ml of the reaction mixture
of hydrochloric acid onto 200 g of crushed ice, 100 ml of chloroform was added, and the orange-yellow organic layer was separated. This solution was washed twice with a 5% aqueous sodium bicarbonate solution and three times with water, and then dried over anhydrous sodium sulfate. The drying agent was filtered off and the solvent was distilled off to obtain 10.1 g of a viscous liquid product. This crude product was purified by silica gel chromatography (eluent: chloroform), and 8.
37 g of (S)-4-(1-oxo-2-methylbutyl)phenol was obtained.

IR (cm-1): 3305, 1651,
1602, 1578, 1221

[0044]

[Chemical formula 11]

(2) (R)-4-((2-hexyloxy)propanoyloxy)-1,1'-biphenyl-4
Synthesis of '-carboxylic acid 2.35 g of (R)-2-(hexyloxy)propanoyl chloride and 2.61 g of 4-hydroxy-1,1'-biphenyl-4'-carboxylic acid were mixed in the presence of 10 ml of pyridine. The reaction was carried out in carbon chloride and the product was recrystallized from ethanol to obtain 2.30 g of (2-hexyloxy)propanoyloxy)-1,1'-biphenyl-4'-carboxylic acid.

(3) Synthesis of (S)-4-(1-oxo-2-methylbutyl)phenyl (R)-4-((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate (1) 0.20 g (1.1 mmol) of (S)-4-(1-oxo-2-methylbutyl)phenol obtained in Section 1 and (
0.37 g (1.0 mmol) of (R)-4-((2-hexyloxy)propanoyloxy)-1,1'-biphenyl-4'-carboxylic acid obtained in section 2) was added to 50 ml of anhydrous methylene chloride. Add 0.02 g of dimethylaminopyridine and 0.22 g of dicyclohexylcarbodiimide.
After adding 7 g (1.1 mmol), the mixture was stirred at room temperature all day and night. After the reaction, the generated precipitate was filtered off, and the solvent was distilled off. 0.55 g of the crude product was purified by silica gel chromatography (melt: ethyl acetate/hexane = 10/90) and further recrystallized from hexane to obtain 0.12 g of (S)-4-(1-oxo- 2-Methylbutyl)phenyl (R) 4-((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate was obtained.

IR (cm-1): 2936, 1764,
1728, 1680, 1602, 1274, 1204,
1072,890,766 1HNMR δppm (CDCl3): 0.94
(t, 3H) and 0.99 (t, 3H) [CH2C
H3] 1.22(d,3H)[-COCH(CH3)CH2
-], 1.63(d,3H)[-OCH(CH3)COO-
], 3.45 (m, 2H) [-OCH2 CH2 -], 3
．． 68 (m, 1H) [-COCH(CH3)CH2
-], 4.23(q,1H)[-OCH(CH3)COO-
], 7.24 (d, 2H) [Aromatic ring H] 7.35 (d, 2H) [Aromatic ring H] 7.67 (d, 2H) [Aromatic ring H] 7.72 (d, 2H) [ Aromatic ring H] 8.06 (d, 2H) [Aromatic ring H] 8.27 (d, 2H) [Aromatic ring H]

(Synthesis Example 2) (S)-4-(1-oxo-2-methyloctyl)phenyl (R)-4((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate (Compound 5 ) Synthesis (4) Synthesis of (S)-4-(1-oxo-2-methyloctyl)phenol Instead of (S)-(+)-2-methylbutyric acid chloride, (S)
)-(+)-2-Methyloctanoic acid chloride was used, but the reaction was carried out in exactly the same manner as in section (1) of Synthesis Example 1 to obtain (S)-4-(1-oxo-2- methyloctyl)phenol was obtained.

(5) Synthesis of (S)-4-(1-oxo-2-methyloctyl)phenyl (R)-4-((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate (4 (S)-4-(1-oxo-2-methyloctyl)phenol obtained in section ) and (R
)-4((2-(2-hexyloxy)propanoyloxy)-1,1'-biphenyl-4'-carboxylic acid was reacted in the same manner as in section (3) of Synthesis Example 1 to form (S
)-4-(1-oxo-2-methyloctyl)phenyl (R)-4-((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate was obtained.

IR (cm-1): 2924, 2852,
1770, 1736, 1682, 1600, 1262,
1210,1066,768

(Synthesis Example 3) (S)-4-(1-oxo-2-methyloctyl)phenyl (S)-4-(4-(2-methyldecyloxy)phenyl)benzoate (compound 6) Synthesis (6) (
S)-4-(2-methyldecyloxy)-1,1'
-Synthesis of biphenyl-4'-carboxylic acid (S)-2-methyldesylyl chloride 3.0g and 4-hydroxy-
3.14 g of 1,1'-biphenyl-4'-carboxylic acid was reacted in the same manner as in section (2) of Synthesis Example 1, and 2.0 g of (S
)-4-(2-methyldecyloxy)-1,1'-
Biphenyl-4'-carboxylic acid was obtained.

(7) Synthesis of (S)-4-(1-oxo-2-methyloctyl)phenyl (S)-4-(4-(2-methyldecyloxy)phenyl)benzoate (
(S)-4-(2-methyldecyloxy)-1,1'-biphenyl-4'-carboxylic acid obtained in section 6) 600
mg and 500 mg of (S)-4-(1-oxo-2-methyloctyl)phenol obtained in section (4) of Synthesis Example 2 were reacted and treated in the same manner as in section (3) of Synthesis Example 1 to obtain 420 mg of (S)-4-(1-oxo-2-methyloctyl)phenyl (S)-4-(4-(2-methyldecyloxy)phenyl)benzoate was obtained.

IR (cm-1): 2928, 2852,
1746, 1732, 1682, 1600, 1272,
1206, 1184, 1170, 1058, 766

0
(Synthesis Example 4) (S)-4'-(2-chloro-3-methylpropanoyloxy)-1,1'-diphenyl-4-carboxylic acid
Synthesis of (S)-4-(1-oxo-2-methyloctyl)phenyl (compound 7) (8) (S)-4'-(2-chloro-3-methylpropanoyloxy)-1,1' -Synthesis of diphenyl-4-carboxylic acid (S)-2-chloro-3-methylvaleric acid chloride 10.1
g (0.06 mol) and 1.28 g (0.06 mol) of 4-hydroxy-1,1'-diphenyl-4-carboxylic acid in methylene chloride in the presence of 20 ml of pyridine for 3 hours.
The mixture was heated to reflux and the product was recrystallized from ethanol to obtain 6.5 g of the title compound.

IR (cm-1): 1760, 1685,
1610, 1293

(9) (S)-4'-(2-chloro-3-
methylpropanoyloxy)-1,1'-diphenyl-
Synthesis of (S)-4-(1-oxo-2-methyloctyl)phenyl 4-carboxylic acid 0.56 g of (S)-4-(1-oxo-2-methyloctyl)phenol obtained in section (4) (2.4 mmol) and (S)-4'-(2-chloro-3-methylpropanoyloxy)-1,1'-diphenyl-4- obtained in section (8).
Dissolve 0.82 g (2.4 mmol) of carboxylic acid in 50 ml of anhydrous methylene chloride, then add 0.02 g of dimethylaminopyridine and 0.26 g of dicyclohexycarbodiimide.
g (2.52 mmol) was added, and the mixture was stirred at room temperature all day and night. After the reaction, the generated precipitate was filtered off, and the solvent was distilled off. 1.40 g of the crude product was purified by silica gel chromatography (eluent: ethyl acetate/hexane = 13/87) and further recrystallized from a mixed solvent of ethyl acetate/hexane = 5/95 to obtain the title compound 0. 68g was obtained.

IR (cm-1): 1766, 1732,
1674,1272,12041172,838 1H
NMR δppm (CDCl3): 0.94 (t,
3H) and 1.00(t, 3H) [CH2 CH3
] 1.16 (d, 3H) and 1.22 (d, 3H) [-
CHCH3] 3.41 (m, 1H) [-COCH(CH3)CH2
-], 4.41 (d, 1H) [-CHCl-], 7.25 (d
, 2H) [Aromatic ring H] 7.36 (d, 2H) [Aromatic ring H] 7.67 (d, 2H) [Aromatic ring H] 7.71 (d, 2H) [Aromatic ring H] 8.05 (d, 2H) [Aromatic ring H] 8.27 (d, 2H) [Aromatic ring H]

(Synthesis Example 5) (R)-4-(2-n-hexyloxypropanoyloxy)benzoic acid (S)-4-[4'-(1-oxo-2-methylbutyl)-1,1 '-diphenyl] (compound 8) (10) Synthesis of (S)-4-hydroxy-4'-(1-oxo-2-methylbutyl)-1,1'-diphenyl Potassium hydroxide 20 g (0.36 200 m of water containing
34 g (0.2 mol) of 4-hydroxy-1,1'-diphenyl was dissolved in a solution of 400 ml of methyl alcohol and 28.4 g (0.2 mol) of methyl iodide was added thereto. The solution was boiled and refluxed for 4 hours, cooled and poured into 1 liter of water. After filtering the white precipitate and washing with water,
Recrystallized from ethyl alcohol, 26.5 g (0.14
mol) of 4-methoxy-1,1'-diphenyl was obtained.

4-Methoxy-1,1'-diphenyl9.
16 g (49.8 mmol) of anhydrous methylene chloride 100
After cooling to below 0° C., 13.0 g (98 mmol) of ground aluminum chloride was added little by little. To this, 6.0 g of (S)-2-methylbutyric acid chloride
A solution of (49.8 mmol) dissolved in anhydrous methylene chloride was added dropwise over about 1 hour. After the addition was complete, the reaction mixture was stirred at room temperature for 3 hours and then poured onto 500 g of crushed ice. After adding methylene chloride to 100 ml and shaking, the organic layer was separated. This organic solution was washed with an aqueous sodium bicarbonate solution and water, then dried over anhydrous sodium sulfate, the desiccant was filtered off, and the solvent was distilled off to obtain 7.6 g of a crude product. This crude product was purified by silica gel chromatography (eluent: chloroform/hexane = 5
(S)-4-methoxy-4'-(1-oxo-2-methylbutyl)-1,
2.56 g of 1'-diphenyl was obtained.

IR (cm-1): 1680 (C=0),
828,770 1HNMR δppm (CDCl3): 0.94
(3H, t-CH2 CH3), 1.21(3H
, d, -C*HCH3), 1.52 and 1.86
(2H, m, -C*HCH2), 3.41 (1H,
m, C*H), 3.86 (3H, s, OCH3), 7
．． 00 (2H, d, H at the ortho position of the methoxy group), 7.
57 (2H, d), 7.64 (2H, d), 8.00 (
2H, d, H at the ortho position of the carbonyl group)

This (S)-4-methoxy-4'-(1-
oxo-2-methylbutyl)-1,1'-diphenyl2
．． 56 g was dissolved in 30 ml of anhydrous toluene, 2.0 g (15 mmol) of crushed aluminum chloride was added thereto, and the mixture was boiled and refluxed for 3 hours. Thereafter, it was cooled to room temperature and poured into 300 ml of diluted hydrochloric acid. Another 100ml
of chloroform was added and the organic layer was separated. After washing the organic layer with water, drying with anhydrous sodium sulfate and removing the desiccant,
The solvent was distilled off to obtain 1.8 g of crude product. This crude product was purified by silica gel chromatography (eluent: chloroform), and 1.28 g of (S)-4-hydroxy-4'-(1-oxo-2-methylbutyl)-1,1
'-diphenyl was obtained.

IR (cm-1): 3364, 1658 (
C=0), 1600, 1224,828 1HNMR δppm (CDCl3): 0.94
(3H, t-CH2 CH3), 1.22(3H
, d, -C*HCH3), 1.52 and 1.85
(2H, m, -C* HCH2), 3.43 (1H,
m, C*H), 5.37 (1H, s, OH), 6.94
(2H, d, H at the ortho position of the hydroxyl group), 7.53 (2H
, d), 7.63 (2H, d), 8.01 (2H, d,
H at ortho position of carbonyl group) (11) Synthesis of (R)-4-(2-n-hexyloxypropanoyloxy)benzoic acid (R)-2-n-hexyloxypropionic acid chloride 6
．． 0 g (31.2 mmol) and 4.3 g (31.2 mmol) of p-hydroxybenzoic acid were heated to reflux in methylene chloride in the presence of 10 ml of pyridine for 2 hours, and the product was recrystallized from hexane to give 4. .26 g of the title compound was obtained.

(12) (S)-4-hydroxy-4'-(1-oxo-2-methylbutyl)- obtained in section (10)
0.5 g of 1,1'-diphenyl and (R
)-4-(2-n-hexyloxypropanoyloxy)benzoic acid 0.43 g in the same manner as in section (3),
Purified by column chromatography (eluent: mixed solvent of ethyl acetate/hexane = 10/90) to a concentration of 0.35
g of (R)-4-(2-n-hexyloxypropanoyloxy)benzoic acid (S)-4-[4'-(1-oxo-2-methylbutyl)-1,1'-diphenyl] was obtained. Ta.

[α]D = +48.2° (C = 0.8,
CHCl3, 25°C) IR (cm-1): 2956, 1766, 1740, 1
678,1282,1074,762

(Synthesis Example 6) (R)-4-(2-n-hexyloxypropanoyloxy)benzoic acid (S)-4-[4'(1-oxo-
Synthesis of (S)-4-hydroxy-4'-(1-oxo-2-methyloctyl)-1,1'-diphenyl (Compound 9) In Synthesis (10), (S)-2-methyloctanoic acid chloride was used instead of (S)-2-methylbutyric acid chloride, and the same treatment was performed to obtain the title compound.

(14) (S)-4-hydroxy-4'-(1-oxo-2-methyloctyl) obtained in section (13)
-1,1'-diphenyl and (R)-4 obtained in section (11)
-(2-n-hexyloxypropanoyloxy)benzoic acid is reacted in the same manner as in section (3), and (R)-4-(2
-n-hexyloxypropanoyloxy)benzoic acid (
S)-4-[4'-(1-oxo-2-methyloctyl)-1,1'-diphenyl was obtained.

[α]D = +45.6° (C = 0.4,
CHCl3, 25°C) IR (cm-1): 2956, 1768, 1743, 1
678,1608,1285,1080,762 1H
NMR δppm (CDCl3): 0.88 (m,
6H) [CH2 CH3], 1.21 to 1.40 (m
, 17H) [-COCH(CH3)CH2- and -CH2CH2CH2-], 1.59-1.83
(m,7H)[-OCH(CH3)COO- and-
CH2 CH2 OCH(CH3)- and -COCH(
CH3)CH2CH2-], 3.50(m, 2H
) [-CH2OCH(CH3)-], 3.69(m
, 1H) [-COCH(CH3)CH2-], 4.
22(q,1H)[-OCH(CH3)COO-], 7.29(d,2H)[aromatic ring H] 7.32(d,2H)[aromatic ring H] 7.69(d,4H) [Aromatic ring H] 8.04 (d, 2H) [Aromatic ring H] 8.27 (d, 2H) [Aromatic ring H]

(Synthesis Example 7) (S)-3-hydroxy-4-(1-oxo-2-methylbutyl)phenyl (R)-4-((4-(2-hexyloxy)propanoyloxy)phenyl) Synthesis of benzoate (compound 15) (15) (S)-3-hydroxy-4-(1-oxo-
Synthesis of phenol (2-methylbutyl) Mix 16.3 g of anhydrous zinc chloride with 10.3 g of S-(+)-2-methylbutanoic acid, heat to 110°C to dissolve, and then add 13.2 g of resorcinol. The mixture was heated to 150° C. for 30 minutes while stirring. After that, cool to room temperature, add a mixture of 25 ml of concentrated hydrochloric acid and 25 ml of water, and add 50 ml of
Extracted 3 times with 1 liter of ethyl ether. The combined ether extracts were washed three times with an aqueous sodium bicarbonate solution and three times with water, dried over anhydrous sodium sulfate, and the solvent was removed to obtain 9.2 g of a liquid reaction mixture. This reaction mixture was transferred to a silica gel column (filling material: Wakogel C-200).
, Wako Pure Chemical, melt: chloroform),
6.2 g of 3-hydroxy-4-(1-oxo-2-methylbutyl)phenol were obtained as a liquid substance.

IR (cm-1): 3361, 1629,
1601, 1514, 1443, 1383, 1231,
1132

[0070]

[Chemical formula 12]

(16) (S)-3-hydroxy-4-(
1-oxo-2-methylbutyl)phenyl(R)-4-
((4-(2-hexyloxy)propanoyloxy)
Synthesis of (S)-3-hydroxy-4-(1-phenyl)benzoate obtained in section (15)
186 mg of phenol (oxo-2-methylbutyl) and (
370 mg of (R)-4-((2-hexyloxy)propanoyloxy)-1,1'-biphenyl-4'-carboxylic acid obtained in section 2) was reacted in the same manner as in section (3) of Synthesis Example 1. and treated to give 80 mg of (S)-3-hydroxy-4
-(1-oxo-2-methylbutyl)phenyl(R)-
4-((4-(2-hexyloxy)propanoyloxy)phenyl)benzoate was obtained.

IR (cm-1): 2932, 1770,
1738, 1636, 1496, 1258, 1122,
764

(Synthesis Example 8) (S)-3-hydroxy-4-(1-oxo-2-methyloctyl)phenyl (R)-4-((4-(2-hexyloxy)propanoyloxy)phenyl ) Synthesis of benzoate (compound 18) 240m synthesized by the same reaction as in section (15) of Synthesis Example 7
g of (S)-3-hydroxy-4-(1-oxo-2-
methyloctyl)phenol and (R)-4-((2-hexyloxy)propanoyloxy)-1,1'-biphenyl-4'-carboxylic acid 3 obtained in section (2) of Synthesis Example 1
70 mg was reacted and treated in the same manner as in section (3) of Synthesis Example 1 to obtain 75 mg of (S)-3-hydroxy-4-(1-
Oxo-2-methyloctyl)phenyl(R)-4-(
(4-(2-hexyloxy)propanoyloxy)phenyl)benzoate was obtained.

IR (cm-1): 2932, 2856,
1770, 1734, 1642, 1608, 1268,
1186,1122,1072,766 1HNMR δppm (CDCl3): 0.90
(m, 6H) [CH2 CH3 ] 1.22-1.84 (m, 16H) [-CHCH3 and CH2 ], 3.50 (m, 2H) [-CH2 C
H2O-], 3.72 (m, 1H) [-COCH(CH
3)CH2-],4.24(q,1H)[-OCH
(CH3)COO-], 6.84 (m, 1H) [aromatic ring H] 6.90 (m, 1H) [aromatic ring H] 7.23 (d, 2H) [aromatic ring H] 7.68 ( m, 4H) [Aromatic ring H] 7.85 (d, 1H) [Aromatic ring H] 8.25 (d, 2H) [Aromatic ring H] 12.84 (s, 1H) [OH]

(Synthesis Example 9) (S)-4'-(2-chloro-3-methylpropanoyloxy)-1,1'-diphenyl-4-carboxylic acid
Synthesis of (S)-3-hydroxy-4-(1-oxo-2-methyloctyl)phenyl (compound 21) (17) (
Synthesis of S)-3-hydroxy-4-(1-oxo-2-methyloctyl)phenol 10.0 g of (S)-(+
)-10.0 g of anhydrous zinc chloride in 2-methyloctanoic acid
After mixing and heating to 110°C to dissolve, 8.8 g of resorcin was added and heated to 150°C for 30 minutes while stirring. Thereafter, the mixture was cooled to room temperature, a mixture of 25 ml of concentrated hydrochloric acid and 25 ml of water was added, and the mixture was extracted three times with 50 ml of ethyl ether. The combined ether extracts were washed three times with an aqueous sodium bicarbonate solution and three times with water, dried over anhydrous sodium sulfate, and the solvent was removed to obtain 10.4 g of a liquid reaction mixture. This reaction mixture was purified using a silica gel column (filling material: Wako Gel C-200, Wako Pure Chemical Industries, melting liquid: chloroform), and 7.3 g of 3-hydroxy-4-(1-oxo-2-methyloctyl)phenol was purified. was obtained as a liquid material.

IR (cm-1): 3361, 1635,
1601, 1514, 1383, 1234, 1132

[
0077

[Chemical formula 13]

(18) (S)-4'-(2-chloro-3
-methylpropanoyloxy)-1,1'-diphenyl-4-carboxylic acid (S)-3-hydroxy-4-(
Synthesis of 1-oxo-2-methyloctyl)phenyl (1
0.54 g of (S)-3-hydroxy-4-(1-oxo-2-methyloctyl)phenol obtained in section 7) (2.
(16 mmol) and (S)-4'-(2-
Chloro-3-methylpropanoyloxy)-1,1'-
0.74 g (2.16 mmol) of diphenyl-4-carboxylic acid was reacted in the same manner as in section (3), and the crude product was purified by silica gel chromatography (eluent: ethyl acetate/hexane = 16/84). Recrystallization from hexane gave 560 mg of the title compound.

IR (cm-1): 1775, 1738,
1640, 1260, 1128

Compounds 1, 2 and 3 can be synthesized by the method described in Synthesis Example 1 by appropriately selecting reactants corresponding to the respective structures. Also, compounds 10, 11, 12, 13, 14, 16
, 17, 19, 20 and 24 were similarly synthesized in Synthesis Example 7.
, 8 and 9, and compounds 22 and 23 can be similarly synthesized by the method described in Synthesis Example 5.

Obtained compounds 4,5,6,7,15,1
Spontaneous polarization was measured for No. 8 and No. 20, and the results are shown in Table 9. In the table, PO is a value that compensates for the difference in tilt angle (θ), and is a value determined by the relational expression PO = PS /sin θ. This PO 2 is considered to be the spontaneous polarization value when all rotational motion within the ferroelectric liquid crystal molecules is frozen. Moreover, the PO 2 total value is the sum of PO 2 of compounds each having one corresponding chiral group. PO of the compound of the present invention having two optically active groups is:
It was two to three times this sum.

[0082]

[Table 9]

(Test Example 1) 10% of the compound of Example was added to Smectic C liquid crystal composition ZL13234B manufactured by Merck & Co.
and the phase transition temperature was measured. Furthermore, this composition is
It was sealed in a micrometer test cell (a glass plate coated with ITO, spin-coated with polyimide, rubbed in one direction, and then laminated together via a glass bead spacer), and the spontaneous polarization was measured at 25°C. ,±
The response time was determined from the change in intensity of transmitted light when 10V was applied. These results are shown in Tables 10 and 11.

[0084]

[Table 10]

[0085]

[Table 11]

As is clear from Tables 10 and 11, by adding the compound of the present invention to a smectic C liquid crystal composition, a ferroelectric liquid crystal composition with high-speed response could be obtained.

For comparison, similar compounds of the present invention having different cores (two-ring core) were tested in the same manner as above. The structures of Comparative Examples 8 and 9 are shown in Table 12, and the measurement results are shown in Table 13.

[0088]

[Table 12]

[0089]

[Table 13]

[0090] This Table 13 and the above Tables 10 and 11
Comparison with the table shows that the compound of the present invention is extremely excellent as a dopant for a smectic C liquid crystal composition, and that the response time of a liquid crystal composition can be significantly shortened by using the compound of the present invention.

(Test Example 2) Furthermore, 2-(4-octyloxyphenyl)-5-octylpyrimidine and 2-(4-octyloxyphenyl)-5-octylpyrimidine
-hexyloxyphenyl)-5-heptyloxypyrimidine (phase transition: Cr24
Compounds 5, 6, 7, 18, 20 and 21 of the present invention were added to Sc 68 SA 75 N 84 I) at a concentration of 10 w/w%, but the phase transition temperature, spontaneous polarization at 25°C, and response The time was measured in the same manner as in Test Example 1. The results are shown in Table 14.

[0092]

[Table 14]

As is clear from the results in Table 14, it can be seen that a liquid crystal composition with high-speed response can be obtained by adding the compound of the present invention.

[0094]

[Effect of the invention] As explained above, the general formula (
The compound represented by I) is a ferroelectric liquid crystal having a chemically stable molecular structure, and exhibits extremely large spontaneous polarization compared to conventionally known ferroelectric liquid crystals. It also has the extremely useful property of providing a ferroelectric liquid crystal composition that exhibits greater spontaneous polarization and operates at high speed when mixed with other liquid crystal compounds.

Claims (2)

[Claims] 1. An optically active compound represented by general formula (I). [Chemical formula 1] [Chemical formula 2] 2. A chiral liquid crystal composition containing at least one component of the optically active compound according to claim 1.