JP2848471B2 - Optically active compound and liquid crystal composition containing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optically active compound and a chiral liquid crystal composition using the 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 applied to calculators, watches, televisions and the like. Currently, nematic liquid crystals are widely used for these display materials, but the response speed is several tens of msec.
And had the disadvantage of being slow. As one of attempts to improve this point, a display method using a ferroelectric liquid crystal has been proposed (NAClark et al .; Applied Phys. Lett., 36, 899 [198]
0]). This method utilizes a chiral smectic C phase (hereinafter abbreviated as Sc ^* phase) of a ferroelectric liquid crystal.
It is required to exhibit the c ^* phase, to have a large spontaneous polarization, to have an appropriate tilt angle, to have a low rotational viscosity, to have a long helical pitch, and to be chemically stable. However, a ferroelectric liquid crystal compound satisfying all of these conditions is not known. Therefore, when a ferroelectric liquid crystal is practically used as an electro-optical element, it is necessary to use a mixture of several types of ferroelectric liquid crystal, a compound that induces ferroelectricity, and a non-ferroelectric liquid crystal. is there.

In order to obtain a Sc ^* liquid crystal composition, a method of mixing a plurality of compounds exhibiting the Sc ^* phase, a method of mixing a nonferroelectric liquid crystal with the compound exhibiting the Sc ^* phase, a smectic C phase (hereinafter referred to as Sc phase), There is a method of adding an optically active compound to a non-optically active compound or a liquid crystal composition showing the abbreviation), and the last method is considered to be easy to obtain a high-speed response with low viscosity. is there.
In order to obtain a liquid crystal composition that responds at a high speed, the added optically active compound must exhibit a large spontaneous polarization by itself or have a property of inducing a large spontaneous polarization in the composition.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is chemically stable and exhibits extremely large spontaneous polarization or induces large spontaneous polarization by adding it to a Sc liquid crystal composition. It is an object of the present invention to provide a novel optically active compound and to provide a novel ferroelectric liquid crystal material having a wide temperature range of the Sc ^* phase and a high-speed response using the optically active compound.

[0005]

SUMMARY OF THE INVENTION In summary of the present invention,
The present invention provides an optically active compound represented by the following general formula (I) and a chiral liquid crystal composition containing the same.

[0006]

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[0007]

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Hereinafter, the present invention will be described in detail. A feature of the present invention is that two optically active (chiral) groups are introduced into one molecule with a core portion interposed therebetween, and the signs of the spontaneous polarization based on the optically active groups are the same, whereby It is to realize a compound exhibiting a spontaneous polarization much larger than the sum of the spontaneous polarizations exhibited by a compound containing an optically active group alone.

A compound having a partial structure consisting of a carbonyl group directly interposed between a core and an asymmetric carbon exhibits a large spontaneous polarization. In this compound, when a hydroxyl group is introduced at the ortho-position of an alkanoyl group, the intramolecular It has previously been found that hydrogen bonds are formed, and the dipoles of the carbonyl group and the hydroxyl group are aligned to increase the spontaneous polarization (Japanese Patent Application No. 63-278618). That is, most of the ferroelectric liquid crystals reported so far use an ester group or an ether group dipole, but a dipole sandwiched between a core and asymmetric carbon is converted from an ether group or an ester group to a carbonyl group. The spontaneous polarization increases almost in proportion to the group moment of these groups, and the spontaneous polarization becomes extremely small when a methylene group is interposed between the carbonyl group and the asymmetric carbon.

Compounds obtained by combining the above-mentioned partial structure containing a carbonyl group and another optically active group with a core interposed therebetween have the same sign of spontaneous polarization based on the two optically active groups, respectively. Shows a spontaneous polarization larger than that of the compound containing the optically active group alone. We have shown this in Japanese Patent Application No. 2-13382. However, the degree of the increase varies depending on the type of the other optically active group or the type of the core to be combined. The present invention provides a spontaneous polarization that is much larger than the sum of the spontaneous polarizations of compounds containing each optically active group alone by selecting another type of optically active group and a type of core to be combined with the optically active alkanoyl group. The compound shown is realized. That is, the optically active alkanoyl group R ² represented by the following chemical formula (II) and the optically active group combined with the core interposed therebetween need to be bonded to the core via an ester group.

[0011]

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Further, the optically active group R ¹ needs to be ^one of the following chemical formulas (III), (IV) and (V).

[0013]

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At this time, the combination of the absolute configurations of R ¹ and R ² is determined in order to make the signs of the spontaneous polarization based on the two coincide.
When the absolute configuration of R ² is (S), the absolute configuration of chemical formula (III) is (S), the absolute configuration of chemical formula (IV) is (R), and the absolute configuration of chemical formula (V) is (S); When the absolute configuration of R ² is (R), the absolute configuration of chemical formula (III) is (R), the absolute configuration of chemical formula (IV) is (S), and the absolute configuration of chemical formula (V) is (R). No.

Further, in order to realize a dramatic improvement in spontaneous polarization, the core needs to have three rings instead of two rings, and is represented by the following chemical formulas (VI), (VII) and (VIII). Is one of the structures.

[0016]

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The compound of the present invention having two optically active groups is
It shows a large spontaneous polarization as shown in Table 9 below.
As Comparative Examples 1 to 7, Table 1 below shows the structure of the comparative compound, and Table 2 shows its spontaneous polarization. Here, since the spontaneous polarization depends on the tilt angle, when the comparison was used a value of P _O that compensates the difference of the tilt angles. This means that P _O = P
_It is determined by the relational expression of _S / sin θ, and is considered to be the spontaneous polarization value when all the rotational motions in the ferroelectric liquid crystal molecules are frozen. Further, in the last column of Table 9, P _O corresponding Raikaru based on which the sum of P _O of the compound having one each is shown, the compounds of the present invention having two optically active group, this Two or three times the sum.

[0018]

[Table 1]

[0019]

[Table 2]

As described above, the compound of the present invention is much larger than the sum of spontaneous polarizations of the compound containing only one optically active (chiral) group (comparative compound).

It is not yet clear why the combination of the above structures results in a drastic improvement in spontaneous polarization. However, it is thought that some interaction existing between the molecules contributes to the suppression of the movement near the chiral portion, and leads to a dramatic improvement in spontaneous polarization.

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

Introducing a halogen atom into the core is often used as a means for improving liquid crystallinity and a means for increasing spontaneous polarization, but this method is also effective in the present invention. That is, a fluorine atom,
The introduction of a chlorine atom or a bromine atom enhances liquid crystallinity and is effective in increasing spontaneous polarization.

In the present invention, the other component 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. May be.

(Method for producing compound) The method for producing the optically active compound represented by the general formula (I) will be described. First, optically active alkanoylphenol is synthesized, for example, by the following route. In the formula, R ¹ , R ² and R ′ have the same meanings as described above.

[0026]

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The optically active alkanoyl resorcinol is
For example, they are synthesized by the following route.

[0028]

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The optically active alkanoylbiphenyl is synthesized, for example, by the following route.

[0030]

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Next, the optically active substituted benzoic acid (B ₁ ) or the optically active substituted biphenylcarboxylic acid (B ₂ ) is prepared by converting the optically active acid R ¹ H into the corresponding acid chloride with thionyl chloride, and adding p-hydroxybenzoic acid thereto. It is synthesized by acting an acid or 4'-hydroxy-1,1'-biphenyl-4-carboxylic acid in the presence of a base such as pyridine.

Finally, the compound (A ₁ ) or (A ₂ )
And (B ₂ ), (A ₃ ) and (B ₁ ) in the presence of a dehydrating agent such as dicyclohexylcarbodiimide,
The compound represented by the general formula (I) is obtained.

[0033]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, 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, the melting point, the phase transition temperature at the time of temperature decrease, and the Sc ^*
Tables 6 to 8 show the spontaneous polarization at 0 ° C. Here, the determination of the liquid crystal phase and the determination of the phase transition temperature were performed by differential scanning calorimetry (DSC) measurement and observation with a polarizing microscope equipped with a temperature controller. The spontaneous polarization was measured by the triangular wave method. In the table, the concentration in chloroform is shown in parentheses in the column of specific light intensity (unit: g / 100 m).
l). In the column of phase transition temperature, I is an isotropic liquid, N
^{* Indicates} chiral nematic phase, S _A indicates smectic A
Phase, Sc ^* is a chiral smectic C phase, S _X represents a smectic phase unidentified respectively (hereinafter the same).

[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 show a large spontaneous polarization which has not been known hitherto.

Hereinafter, synthesis examples of the compound of the present invention will be described.
The structure of the compound was determined by infrared absorption spectrum (IR) and proton nuclear magnetic resonance spectrum ( ¹ H NMR).

(Synthesis Example 1) (S) -4- (1-oxo-2-methylbutyl) phenyl (R) -4 ((4- (2-hexyloxy) propanoyloxy) phenyl) benzoate (compound 4) (1) (S) -4- (1-oxo-2-methylbutyl)
Synthesis of phenol 8.25 g (76.3 mmol) of anisole was dissolved in 100 ml of anhydrous 1,2-dichloroethane, cooled to 0 ° C. or lower, and 9.2 g (76.3 mmol) of crushed aluminum chloride was slightly added thereto. We put in one by one. After completion of the charging, 9.2 g of (S)-(+)-2-methylbutyric acid chloride was obtained.
(76.3 mmol) dissolved in 50 ml was added dropwise with stirring for 1 hour. After the addition, the mixture was stirred at room temperature for 1 hour. Thereafter, a further 9.2 g (76.2 mmol) of ground aluminum chloride were added and the reaction mixture was
Heated to reflux for hours. After cooling to room temperature, the reaction mixture is
Pour over 200 g of crushed ice containing 0 ml of hydrochloric acid,
100 ml of chloroform was added, and the orange-yellow organic layer was separated. This solution was washed with a 5% aqueous sodium hydrogen carbonate solution for 2 hours.
The mixture was washed three times with water and 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).
37 g of (S) -4- (1-oxo-2-methylbutyl) phenol were obtained.

IR (cm ^-1 ): 3305,1651,1
602, 1578, 1221

[0044]

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(2) (R) -4-((2-hexyloxy) propanoyloxy) -1,1'-biphenyl-
Synthesis of 4'-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 added in the presence of 10 ml of pyridine. The reaction was performed in carbon tetrachloride and the product was recrystallized from ethanol to give 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 item (2) and (R) -4-((2-hexyloxy)) obtained in item (2).
Propanoyloxy) -1,1'-biphenyl-4'-
0.37 g (1.0 mmol) of carboxylic acid was dissolved in 50 ml of anhydrous methylene chloride, and 0.02 g of dimethylaminopyridine and 0.2 ml of dicyclohexylcarbodiimide were further dissolved.
After addition of 27 g (1.1 mmol), the mixture was stirred at room temperature for 24 hours. After the reaction, the formed precipitate was separated by filtration 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 give 0.12 g.
(S) -4- (1-Oxo-2-methylbutyl) phenyl (R) 4-((4- (2-hexyloxy) propanoyloxy) phenyl) benzoate.

IR (cm ^-1 ): 2936, 1764, ¹
728, 1680, 1602, 1274, 1204, 1
072,890,766 ¹ H NMR δ ppm (CDCl ₃ ): 0.94 (t, 3H) and 0.99 (t, 3H) [C
H ₂ C H _3] 1.22 (d, 3H) [- COCH (C H ₃₎ CH
₂ -], 1.63 (d, 3H) [- OCH (C H ₃₎ COO
-], 3.45 (m, 2H) [- OC H ₂ CH ₂ -], 3.68 (m, 1H) [- COC H (CH ₃₎ CH
₂ -], 4.23 (q, 1H) [- OC H (CH ₃₎ 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) (4) Synthesis of (S) -4- (1-oxo-2-methyloctyl) phenol Instead of (S)-(+)-2-methylbutyric acid chloride,
Except for using (S)-(+)-2-methyloctanoic acid chloride, the reaction was carried out in exactly the same manner as in item (1) of Synthesis Example 1 to give (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) )) And the (R) -4 ((2- (2-hexyloxy) propane) obtained in Section (2) of Synthesis Example 1 with (S) -4- (1-oxo-2-methyloctyl) phenol. (Noyloxy) -1,1'-biphenyl-4'-carboxylic acid was reacted by the same operation as in item (3) of Synthesis Example 1 to give (S) -4- (1-oxo-2-methyloctyl) phenyl (R) -4-((4- (2-Hexyloxy) propanoyloxy) phenyl) benzoate was obtained.

IR (cm ^-1 ): 2924, 2852, ¹
770, 1736, 1682, 1600, 1262, 1
210,1066,768

Synthesis Example 3 Synthesis of (S) -4- (1-oxo-2-methyloctyl) phenyl (S) -4- (4- (2-methyldecyloyloxy) phenyl) benzoate (Compound 6) Synthesis (6)
(S) -4- (2-methyldecyloyloxy) -1,
Synthesis of 1'-biphenyl-4'-carboxylic acid 3.0 g of (S) -2-methyldecyloyl chloride
3.14 g of -hydroxy-1,1'-biphenyl-4'-carboxylic acid was reacted in the same manner as in item (2) of Synthesis Example 1,
2.0 g of (S) -4- (2-methyldecyloyloxy) -1,1'-biphenyl-4'-carboxylic acid were obtained.

(7) Synthesis of (S) -4- (1-oxo-2-methyloctyl) phenyl (S) -4- (4- (2-methyldecyloyloxy) phenyl) benzoate The obtained (S) -4- (2-methyldecyloxy) -1,1'-biphenyl-4'-carboxylic acid 60
0 mg and (S) -4- (1-) obtained in item (4) of Synthesis Example 2.
Oxo-2-methyloctyl) phenol (500 mg) was reacted and treated in the same manner as in item (3) of Synthesis Example 1 to give 420 mg.
(S) -4- (1-Oxo-2-methyloctyl) phenyl (S) -4- (4- (2-methyldecyloyloxy) phenyl) benzoate.

IR (cm ^-1 ): 2928, 2852, ¹
746, 1732, 1682, 1600, 1272, 1
206, 1184, 1170, 1058, 766

(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.
After heating under reflux, the product was recrystallized from ethanol to obtain 6.5 g of the title compound.

IR (cm ^-1 ): 1760, 1686, ¹
610,1293

(9) (S) -4 '-(2-chloro-3-
Methylpropanoyloxy) -1,1′-diphenyl-
Synthesis of 4-carboxylic acid (S) -4- (1-oxo-2-methyloctyl) phenyl 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 item (8).
0.82 g (2.4 mmol) of carboxylic acid was dissolved in 50 ml of anhydrous methylene chloride, and 0.02 g of dimethylaminopyridine and 0.26 g of dicyclohexcarbodiimide were further dissolved.
After adding g (2.52 mmol), the mixture was stirred at room temperature for 24 hours. After the reaction, the formed precipitate was separated by filtration and the solvent was distilled off. The crude product (1.40 g) was purified by silica gel chromatography (eluent: ethyl acetate / hexane = 13/87), and recrystallized from a mixed solvent of ethyl acetate / hexane = 5/95 to afford the title compound (0.4 g). 68 g were obtained.

IR (cm ^-1 ): 1766, 1732, ¹
674, 1272, 12041172, 838 ¹ H NMR δ ppm (CDCl ₃ ): 0.94 (t, 3H) and 1.00 (t, 3H) [C
H ₂ C H _3] 1.16 (d, 3H) and 1.22 (d, 3H) [-
CHC H _3] 3.41 (m, 1H) [- COC H (CH ₃₎ CH
₂ -], 4.41 (d, 1H) [- C H Cl @ -], 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-
Synthesis of (2-methylbutyl) -1,1'-diphenyl] (compound 8) (10) Synthesis of (S) -4-hydroxy-4 '-(1-oxo-2-methylbutyl) -1,1'-diphenyl Water 200 containing 20 g (0.36 mol) of potassium hydroxide
34 g (0.2 mol) of 4-hydroxy-1,1'-diphenyl were dissolved in a solution of 400 ml of methyl alcohol and 400 ml of methyl alcohol, and 28.4 g (0.2 mol) of methyl iodide was added thereto.
Was added. The solution is boiled and refluxed for 4 hours, cooled and then cooled for 1 hour.
Injected into liter of water. The resulting white precipitate was filtered, washed with water, and recrystallized from ethyl alcohol to give 26.5 g (0.
14 mol) of 4-methoxy-1,1'-diphenyl.

4-methoxy-1,1'-diphenyl9.
16 g (49.8 mmol) of anhydrous methylene chloride 100
After cooling to 0 ° C. or lower, 13.0 g (98 mmol) of pulverized aluminum chloride was added little by little. To this, 6.0 g of (S) -2-methylbutyric chloride was added.
(49.8 mmol) in anhydrous methylene chloride was added dropwise over about 1 hour. After the addition was completed, the reaction mixture was stirred at room temperature for 3 hours and then poured onto 500 g of crushed ice. After further adding 100 ml of methylene chloride and shaking, the organic layer was separated. The organic solution was washed with an aqueous solution of sodium hydrogencarbonate and water, 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 is subjected to silica gel chromatography (eluent: chloroform / hexane = 5).
0/50 mixed solvent) to give (S) -4-methoxy-4 '-(1-oxo-2-methylbutyl) -1,
2.56 g of 1'-diphenyl were obtained.

IR (cm ^-1 ): 1680 (C = 0), 8
28,770 ¹ H NMR δ ppm (CDCl ₃ ): 0.94 (3
_{H, t -CH 2 C H 3} ), 1.21 (3H, d, -C
^* HCH _3), 1.52 and 1.86 (2H, m, -
_{^{C * HC H 2), 3.41}} (1H, m, C * H), 3.
86 (3H, s, OCH ₃ ), 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-
2.56 g of (oxo-2-methylbutyl) -1,1'-diphenyl were dissolved in 30 ml of anhydrous toluene, and 2.0 g (15 mmol) of pulverized aluminum chloride was added thereto.
Was added and the mixture was boiled and refluxed for 3 hours. Thereafter, the mixture was cooled to room temperature and poured into 300 ml of diluted hydrochloric acid. 100m more
l of chloroform was added and the organic layer was separated. The organic layer was washed with water, dried over anhydrous sodium sulfate, and after removing the desiccant, the solvent was distilled off to obtain 1.8 g of a crude product. The 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 ¹ H NMR δ ppm (CDCl ₃ ): 0.94 (3
_{H, t -CH 2 C H 3} ), 1.22 (3H, d, -C
^* HCH _3), 1.52 and 1.85 (2H, m, -
_{^{C * HC H 2), 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 the ortho position of the carbonyl group) (11) Synthesis of (R) -4- (2-n-hexyloxypropanoyloxy) benzoic acid (R)- Heat 6.0 g (31.2 mmol) of 2-n-hexyloxypropionate chloride and 4.3 g (31.2 mmol) of p-hydroxybenzoic acid in methylene chloride in the presence of 10 ml of pyridine for 2 hours under reflux. The product was recrystallized from hexane to give 4.26 g of the title compound.

(12) The (S) -4-hydroxy-4 '-(1-oxo-2-methylbutyl)-obtained in the item (10).
0.5 g of 1,1'-diphenyl was reacted with 0.43 g of (R) -4- (2-n-hexyloxypropanoyloxy) benzoic acid obtained in item (11) in the same manner as in item (3). , Column chromatography (eluent: ethyl acetate /
(Hexane / mixture solvent of 10/90).
35 g of (R) -4- (2-n-hexyloxypropanoyloxy) benzoic acid (S) -4- [4 '-(1-
Oxo-2-methylbutyl) -1,1'-diphenyl]
I got

[Α] _D = + 48.2 ° (C = 0.8, C
HCl ₃ , 25 ° C.) IR (cm ⁻¹ ): 2956, 1766, 1740, 16
78, 1282, 1074, 762

(Synthesis Example 6) (R) -4- (2-n-hexyloxypropanoyloxy) benzoic acid (S) -4- [4 '(1-oxo-2)
Synthesis of (-methyloctyl) -1,1'-diphenyl (compound 9) (13) Synthesis of (S) -4-hydroxy-4 '-(1-oxo-2-methyloctyl) -1,1'-diphenyl In (10), the title compound was obtained in the same manner as described below, except that (S) -2-methyloctanoic acid chloride was used instead of (S) -2-methylbutyric acid chloride.

(14) (S) -4-hydroxy-4 '-(1-oxo-2-methyloctyl) obtained in (13)
-1,1'-diphenyl and (R) -4 obtained in item (11)
-(2-n-hexyloxypropanoyloxy) benzoic acid was reacted in the same manner as in the item (3) to obtain (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, C
HCl ₃ , 25 ° C.) IR (cm ⁻¹ ): 2956, 1768, 1743, 16
_{^{78,1608,1285,1080,762 1 HNMR δppm (CDCl 3)}} : 0.88 (m,
6H) [CH ₂ C H _3], 1.21~1.40 (m, 1
7H) _{[- COCH (C H 3) CH} 2 - and -CH ₂
C H ₂ CH ₂ -], 1.59~1.83 (m, 7H)
[-OCH (C H ₃₎ COO- and -C H ₂ CH ₂ O
CH (CH ₃₎ - and _{-COCH (CH 3) C H 2} CH 2
-], 3.50 (m, 2H) [- C H ₂ OCH (C
H ₃₎ -], 3.69 (m, 1H) [- COC H (CH
₃ ) CH _2- ], 4.22 (q, 1H) [-OC H (C
H ₃₎ 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 2-methylbutyl) phenol 10.3 g of S-(+)-2-methylbutanoic acid was mixed with 16.3 g of anhydrous zinc chloride, heated to 110 ° C. and dissolved, and 13.2 g of resorcinol was added. The mixture was heated to 150 ° C. for 30 minutes with stirring. Thereafter, the mixture was cooled to room temperature, and a mixed solution of 25 ml of concentrated hydrochloric acid and 25 ml of water was added.
Extract three times with ml of ethyl ether. The combined etal extracts were washed three times with an aqueous solution of sodium hydrogen carbonate 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 is applied to a silica gel column (filler: Wakogel C-20).
0, purified by Wako Pure Chemical Industries, melt: chloroform) to give 6.2 g of 3-hydroxy-4- (1-oxo-2).
-Methylbutyl) phenol was obtained as a liquid substance.

IR (cm ^-1 ): 3361, 1629, ¹
601, 1514, 1443, 1383, 1231, 1
132

[0070]

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(16) (S) -3-hydroxy-4-
(1-oxo-2-methylbutyl) phenyl (R) -4
Synthesis of-((4- (2-hexyloxy) propanoyloxy) phenyl) benzoate (S) -3-hydroxy-4- (1-) obtained in section (15)
186 mg of (oxo-2-methylbutyl) phenol and (R) -4-((2-hexyloxy) obtained in the item (2).
Propanoyloxy) -1,1'-biphenyl-4'-
370 mg of carboxylic acid was reacted and treated in the same manner as in item (3) of Synthesis Example 1 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, ¹
738, 1636, 1496, 1258, 1122, 7
64

(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 item (3) of Synthesis Example 1 to give 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, ¹
770, 1734, 1642, 1608, 1268, 1
186, 1122, 1072, 766 ¹ H NMR δ ppm (CDCl ₃ ): 0.90 (m,
6H) [CH ₂ C H _3] 1.22-1.84 (m, 16H) [- CHC H ₃ and C H _2], 3.50 (m, 2H) [- CH ₂ C H ₂ O
-], 3.72 (m, 1H) [- COC H (CH ₃₎ C
H _2- ], 4.24 (q, 1H) [-OC H (CH ₃ )
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, IH) [aromatic ring H] 8.25 (d, 2H) [aromatic ring H] 12.84 (s, 1H) [O H]

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) (S) -3-Hydroxy-4- (1-oxo-)
Synthesis of 2-methyloctyl) phenol 10.0 g of (S)-(+)-2-methyloctanoic acid was mixed with 10.0 g of anhydrous zinc chloride, heated to 110 ° C. and dissolved, and then resorcinol 8 was added. Then, the mixture was heated to 150 ° C. in 30 minutes with stirring. Thereafter, the mixture was cooled to room temperature, and a mixed liquid of 25 ml of concentrated hydrochloric acid and 25 ml of water was added.
Extracted three times with 0 ml of ethyl ether. The combined ether extracts were washed three times with aqueous sodium bicarbonate and three times with water.
After washing twice, it was dried over anhydrous sodium sulfate, and the solvent was removed to obtain 10.4 g of a liquid reaction mixture. This reaction mixture is applied to a silica gel column (filler: Wakogel C-
200, purified by Wako Pure Chemical Industries, melt: chloroform, 7.3 g of 3-hydroxy-4- (1-oxo-
2-Methyloctyl) phenol was obtained as a liquid substance.

IR (cm ^-1 ): 3361, 1635, ¹
601, 1514, 1383, 1234, 1132

[0077]

Embedded image

(18) (S) -4 '-(2-chloro-3
-Methylpropanoyloxy) -1,1'-diphenyl-4-carboxylic acid (S) -3-hydroxy-4- (1
Synthesis of -oxo-2-methyloctyl) phenyl (S) -3-hydroxy-4- (1-
Oxo-2-methyloctyl) phenol 0.54 g
(2.16 mmol) and (S) -4'- obtained in item (8).
(2-chloro-3-methylpropanoyloxy) -1,
0.74 g of 1'-diphenyl-4-carboxylic acid (2.1
6 mmol) was reacted in the same manner as in item (3), and the crude product was subjected to silica gel chromatography (eluent: ethyl acetate /
(Hexane = 16/84) and recrystallized from hexane to obtain 560 mg of the title compound.

IR (cm ^-1 ): 1775, 1738, ¹
640, 1260, 1128

Compounds 1, 2, and 3 can be synthesized by the method described in Synthesis Example 1 by appropriately selecting a reactant corresponding to each structure. Compounds 10, 11, 12, 13, 14, 1
6, 17, 19, 20, and 24 can be synthesized in the same manner by the methods described in Synthesis Examples 7, 8, and 9, and compounds 22 and 23 can be synthesized in the same manner as in Synthesis Example 5. It can be synthesized by a method.

Compounds 4,5,6,7,15,1
The spontaneous polarization was measured for 8 and 20, and the results are shown in Table 9. In the table, P _O is a value that compensates for the difference in the tilt angle (θ), and is a value obtained by the relational expression of P _O = P _S / sin θ. This P _O is considered to be the spontaneous polarization value when all the rotational motion in the ferroelectric liquid crystal molecules is frozen. Also, P _O sum is the sum of P _O compounds having one corresponding chiral group, respectively. P _O of the compound of the present invention having two optically active groups is 2 to 3 of the sum.
It was twice.

[0082]

[Table 9]

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

[0084]

[Table 10]

[0085]

[Table 11]

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

For comparison, similar compounds of the present invention having different cores (bicyclic cores) were used in the same manner as described 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]

Table 13 and Tables 10 and 11
The comparison with the table shows that the compound of the present invention is extremely excellent as a dopant for the smectic C liquid crystal composition, and that the use of the compound of the present invention can significantly reduce the response time of the liquid crystal composition.

Test Example 2 Further, 2- (4-octyloxyphenyl) -5-octylpyrimidine and 2- (4
-Hexyloxyphenyl) -5-heptyloxypyrimidine (equivalent mixture composition (phase transition: Cr 24 Sc)
68 SA 75 N 84 I) to which the compounds 5, 6, 7, 18, 20, and 21 of the present invention were added at a concentration of 10 w / w%, but the phase transition temperature, spontaneous polarization at 25 ° C., and the response 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 is understood that a liquid crystal composition having a high response speed can be obtained by adding the compound of the present invention.

[0094]

As described above, the compound represented by the general formula (I) of the present invention is a ferroelectric liquid crystal having a molecular structure stable to a chemical formula. It shows an extremely large spontaneous polarization in comparison. In addition, it has a very useful property that, when mixed with another liquid crystal compound, it exhibits larger spontaneous polarization and gives a ferroelectric liquid crystal composition which operates at high speed.

Continued on the front page (58) Fields investigated (Int. Cl. ⁶ , DB name) C07C 69/773 C09K 19/20 CA (STN) REGISTRY (STN) WPI / L (QUESTEL)

Claims (2)

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