JPH04211043A - Optically active compound having cyano group, its intermediate, production of the intermediate, liquid crystal composition and liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide a new optically active compound having cyano group, exhibiting excellent orientation and chemical stability and useful as a material for liquid crystal display element, especially a material for ferroelectric liquid crystal display having excellent response and memory property. CONSTITUTION:A compound of formula I (R<1> is 1-18C alkyl, alkoxyl, alkoxycarbonyl, etc., in which one or more H atoms may be substituted with F, Cl or cyano; R<2> is 2-18C alkyl; m is 0 or 1; ring A and ring B are 1,4- phenylene, pyridine-2,5-diyl, etc., which may be substituted with F or Cl; -Z is -COO-,-OCH2-, etc.; Y is -COO- or -CH2O-; C* and C** are asymmetric C having R and S configurations), e.g. 4-(4-octyloxyphenyl)-benzoic acid 4-(1- cyano-2-methyloctyl)phenyl ester. The compound can be produced by reacting a compound of formula II with an acid chloride of formula III in the presence of a base (e.g. pyridine).

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to novel optically active compounds and liquid crystal materials, and more particularly to ferroelectric liquid crystal display materials with excellent responsiveness and memory properties. [0002]

[Prior Art] Liquid crystal display elements are popular due to their excellent characteristics (■ Low voltage operation. ■ Low power consumption. ■ Thin display possible. ■ Can be used even in bright places without tiring the eyes. etc.) , currently widely used. However, in the TN type display method, which is the most common among them, CR
Compared to light-emitting display systems such as T, the response is extremely slow, and the display cannot be memorized when the hot water is turned off (memory effect). Furthermore, there are many limitations to its application to video screens such as televisions that require time-division drive, and it cannot necessarily be said to be a suitable display method. [0003]Recently, a display method using ferroelectric liquid crystals has been reported, which not only has a memory effect but also has a high-speed response 100 to 1000 times that of TN type liquid crystals, making it a promising candidate for next-generation liquid crystal displays. It is expected to be used as a device, and active research and development is currently underway. [0004] The liquid crystal phase of ferroelectric liquid crystal belongs to the tilted xylsmectic phase, but in practical use, xylsmectic C, which has the lowest viscosity, is used.
(hereinafter abbreviated as Sc) phase is the most desirable. [0005] Many liquid crystal compounds exhibiting the Sc phase have already been synthesized and studied, but in order to use them as ferroelectric display elements, they must satisfy the following conditions. That is, (a) exhibiting the Sc phase in a wide temperature range including room temperature;
(b) In order to obtain good orientation, the Sc phase must have an appropriate phase series on the high temperature side and its helical pitch must be large; (c) it must have an appropriate tilt angle; (d) it must have low viscosity. , (e) It is necessary to satisfy conditions such as having a certain degree of spontaneous polarization and exhibiting a high-speed response as a result of the above (c), (d), and (e).
No compound is known that satisfies these conditions alone. Therefore, it is necessary to mix several or more kinds of compounds to form a liquid crystal composition exhibiting the Sc phase (hereinafter referred to as Sc liquid crystal composition). [0006] The most common method for preparing Sc liquid crystal compositions is to add an optically active compound as a xyl dopant to a base liquid crystal that is made of an achiral compound and exhibits a smectic C (hereinafter abbreviated as Sc) phase. It is. This is because, according to this method, a composition with lower viscosity can be obtained and high-speed response is possible. The optically active compound used as a xyl dopant is not necessarily Sc when used alone.
Although it is not necessary to exhibit a phase or even a liquid crystal phase, properties such as the ability to induce sufficient spontaneous polarization in the liquid crystal composition with a small amount of addition, and the pitch of the helix induced as a xyl dopant to be sufficiently large. It is necessary to show that [0007] In order to induce large spontaneous polarization in a liquid crystal composition as a chiral dopant, it is necessary that a group having a strong dipole moment be as close as possible to the central skeleton (core) of the liquid crystal compound molecule and the asymmetric carbon. It is already known that Although a carbonyl group is generally used as a group having a strong dipole moment, a cyano group can be cited as an even stronger group. However, as compounds in which this cyano group is directly linked to an asymmetric carbon, there are only the following compounds, ■Mes-COO-CH
(CN) Compound represented by -R (JP-A-61-24
3055), ■Mes-0-CH(CN)-R (U.S. Patent Nos. 4.777, 280 and U.S. Pat.
"Walba et al. J, Org. Chem, 544939 (1989) and the above Me
s represents a liquid crystal skeleton. ) is known, and no compound in which a cyano group is directly connected to an asymmetric carbon, and that asymmetric carbon is directly connected to a core has been known so far.

[Problem to be solved by the invention]

[0008] Conventional liquid crystal compounds exhibiting an Sc phase or optically active liquid crystal compounds are insufficient in performance such as viscosity and induced spontaneous polarization when used as xyl dopants, and the present invention provides a liquid crystal material with high-speed response. There were problems, and improvements were desired.

[0009] The problem to be solved by the present invention is to provide an optically active compound that can induce large spontaneous polarization in the Sc phase or a host liquid crystal exhibiting the Sc phase when used as a xyl dopant, and to provide an optically active compound capable of high-speed response. The object of the present invention is to enable the provision of a ferroelectric liquid crystal display material.

0010

[Means for Solving the Problems] In order to solve the above problems, the present invention provides the following general formula (I) [0011]◎

[Chemical formula 5] (T) [0012] (wherein, R1 is a straight chain having 1 to 18 carbon atoms, unsubstituted or any one or two hydrogen atoms substituted with a fluorine atom, a chlorine atom, or a cyano group) represents a shaped or branched alkyl group, alkoxyl group, alkoxycarbonyl group, alkanoyloxy group, alkoxycarbonyloxy group, alkoxyalkyl group, alkoxyalkoxyl group or alkoxyalkanoyloxy group, and when an asymmetric carbon exists due to substitution or branching may be optically active or racemic, but preferably represents an alkyl group or alkoxyl group having 4 to 12 carbon atoms.R2 is an alkyl group having 2 to 18 carbon atoms.
represents a straight-chain or branched alkyl group, more preferably a straight-chain alkyl group having 2 to 8 carbon atoms. m represents 0 or 1; however, when m is O, the liquid crystallinity tends to deteriorate and the transition temperature of the composition tends to be lowered, so m is preferably 1. Ring A and Ring B are each independently optionally substituted with 1 or 2 fluorine atoms or chlorine atoms, such as a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a pyridine-2,
5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, pyridazine-3,6-diyl group or 1,3-dioxane-2,5-diyl group, preferably It represents a 1,4-phenylene group, a fluorine-substituted 1,4-phenylene group, a trans-1,4-cyclohexylene group or a pyrimidine-2,5-diyl group, and particularly preferably a 1,4-phenylene group. represent. Z is -COO-1-OCO-1-CH20-1-0CH
2-1CH2CH2-1-C=C- or a single bond, with a single bond being preferred. Y is -CO〇- or -CH
Represents 20-. C and C are each independently (R)
Or represents an asymmetric carbon atom with (S) configuration. ) provides an optically active compound having a cyano group represented by: [0013] The present invention also provides a liquid crystal composition using the novel optically active compound represented by the above general formula (I). [0014] The liquid crystal composition referred to in the present invention contains at least one optically active compound represented by the above general formula (I) as a constituent component. In particular, as a liquid crystal composition for a ferroelectric liquid crystal display element, at least one optically active compound represented by the above general formula (I) is added as a part of xyl dopant or Sc liquid crystal compositions obtained by adding all the components are preferred. [0015] The optically active compound of the present invention can also be used as a TN liquid crystal to prevent so-called reverse domains or as an STN liquid crystal by adding a small amount to a nematic liquid crystal. [0016] The optically active compound having a cyano group represented by the above general formula (I) of the present invention can be produced according to the following route. [0017] When Y represents -CO〇-, the following -
General formula (II) [0018]◎

embedded image (II) [0019] (wherein, R2, C, and C are of the general formula (I)
expresses the same meaning as ) and the following general formula (V) [00201◎

[Chemical formula 7] (V) An acid chloride represented by [00211 (wherein, R1, ring A, ring B, m, and Z have the same meanings as in general formula (I)) in the presence of a base such as pyridine. The optically active compound represented by general formula (I) can be easily synthesized by the reaction. [0022] The optically active compound of the present invention has the above general formula (
II) and the following general formula (VI) [00
23]◎ [Chemical formula 8] (VI) [0024] (wherein, R1, ring A, ring B, m,
Z represents the same meaning as in general formula (I). ) and dicyclohexylcarbodiimide (D
It can also be produced by reacting in the presence of a condensing agent such as CC). [0025] Also, when Y represents -CH20-,
The optically active compound of the present invention is a compound represented by the above general formula (II) and the following general formula (VII) [0026]◎

embedded image (VLI) [0027] (wherein, R1, ring A, ring B, m,
Z represents the same meaning as in general formula (I), and X represents a halogen atom of chlorine, bromine or iodine. ) in the presence of a base or a silver salt such as silver tetrafluoroborate. [0028] Here, the optically active phenol derivative having a cyano group of general formula (II) is also a novel compound,
The present invention also provides this compound and a method for producing the same. [0029] The intermediate for synthesizing an optically active compound represented by general formula (II) can be produced as follows. (003014-methoxyphenylacetonitrile to butyllithium, lithium diisopropylamide (LDA)
) in the presence of a strong base such as general formula (III) [0031]◎

(III) [0032] (In the formula, R2 and C have the same meanings as in the general formula (I).) By reacting with an optically active tosylate represented by the general formula (IV) [0033] ◎

An optically active compound represented by (IV) [0034] (wherein R2 and C have the same meanings as in general formula (I)) is obtained. The compound represented by the general formula (IV) is a mixture of two diastereomers, but it can be separated by conventional separation means such as column chromatography to obtain each isomer. [0035] The compound represented by the general formula (II) can be obtained by demethylating each of these isomers, but in this case, it is preferable to use dimethyl sulfide-aluminum chloride. [0036] Also, general formula (I I I), general formula (V
), - Most of the compounds represented by general formula (VI) or general formula (VII) are already known and can be obtained by ordinary synthetic chemical techniques. [0037] Although the optically active compound of the present invention represented by the general formula (I) is obtained as described above, individual specific compounds belonging thereto and individual specific intermediates belonging to the above general formula (II) The body has melting point, phase transition temperature, infrared absorption spectrum (IR), nuclear magnetic resonance spectrum (NM
R) and mass spectrometry (MS). [0038] Examples of the compounds of general formula (I) thus obtained are listed in Table 1. [0039]◎

[Table 1] [0040] (In the table, Cr represents the crystalline phase, SA represents the smectic A phase, and ■ represents the isotropic liquid phase.) [004
11 One of the outstanding features of the compound represented by general formula (I)
One of the reasons is that the spontaneous polarization (PS) induced when this compound is added as a xyl dopant to a liquid crystal composition is sufficiently large. [0042] For example, the spontaneous polarization value at 25° C. of an Sc liquid crystal composition obtained by adding 10% by weight of the compound shown in Example 2 below to a parent liquid crystal exhibiting an Sc phase is 9.
．． It is 2nC/cm2. Furthermore, when the compound shown in Example 3 was added to the base liquid crystal in an amount of 5.6 nC/cm2,
This induces a large spontaneous polarization. The magnitude of the spontaneous polarization of these liquid crystal compositions is determined by the Sc compound derived from (S)-2-methylbutanol, which is most commonly used as an asymmetric source in liquid crystals, such as (S)-2-methylbutyl p This is clear when compared with the spontaneous polarization of about 4 nC/cm 2 when -decyloxybenzylidene aminocinnamate (DOBAMBC) is used alone. This is because the asymmetric center in the optically active compound represented by general formula (I) is directly connected to the central skeleton portion (core) of the liquid crystal molecule and the cyano group having a strong dipole moment, and in addition, This is thought to be due to the fact that free rotation around the molecular axis is suppressed by the methyl group on the achiral carbon, and for this reason, adding about 2% by weight or more to the base liquid crystal of an achiral compound or composition is sufficient for high-speed response. It becomes possible to induce a certain degree of spontaneous polarization. [0043]Furthermore, the optically active compound represented by the general formula (I) does not exhibit an Sc phase alone, and some do not even exhibit a liquid crystal phase, but since only a small amount of the optically active compound is added, it can be used in liquid crystal compositions. It is possible to obtain an Sc composition with a wide temperature range without significantly lowering the upper limit temperature of the Sc phase. [0044] Compounds to be used as the Sc liquid crystal composition to which the optically active compound of the present invention represented by the general formula (I) is added as a xyl dopant include, for example, the following general formula (A) [0045] ◎

embedded image (A) [0046] (wherein R and R represent a linear or branched alkyl group, alkoxyl group, alkoxycarbonyl group, alkanoyloxy group or alkoxycarbonyloxy group, and are the same as each other) ) or the general formula (B) [0047]◎

embedded image (B) [0048] (wherein R and R represent a linear or branched alkyl group, alkoxyl group, alkoxycarbonyl group, alkanoyloxy group or alkoxycarbonyloxy group, even if they are the same as each other) (The pyrimidine compounds may be different.) [0049] Also, the above general formula (A) and general formula (B)
General formula (C) including the compound represented by

[0050]
◎

embedded image (C) [00511 (wherein, R and R are the same as in general formula (A), ring, ring M is a 1,4-phenylene group, trans-1
, 4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2゜5
-diyl group, pyridazine-3,6-diyl group, ■, 3-
It represents a dioxane-2,5-diyl group or a fluorine-substituted product thereof, and may be the same or different. Z is -COO-1-0CO1CH20-1-〇C
Represents H2-1CH2CH2-1-C=C-1 or a single bond. ) can also be used for the same purpose. [0052] Also, for the purpose of expanding the temperature range of the Sc phase to a high temperature range, general formula (D) [0053]◎

embedded image (D) [0054] (wherein R and R are the same as in general formula (A) and ring, ring M and ring N are ring in the above general formula (C),
It is the same as ring M and may be the same or different from each other. ) can be used. [0055] Although it is effective to mix these compounds and use them as a Sc liquid crystal composition, it is sufficient that the composition exhibits an Sc phase, and it is not necessary for each individual compound to exhibit an Sc phase. [0056] The optically active compound represented by the general formula (I) of the present invention is added to the Sc liquid crystal composition thus obtained,
Furthermore, by adding other optically active compounds as xyl dopants, if necessary, it is possible to easily obtain a liquid crystal composition that exhibits the Sc phase over a wide temperature range including room temperature. [0057] The Sc liquid crystal composition obtained by adding the optically active compound of the present invention represented by the general formula (I) as a dopant to another Sc compound or Sc liquid crystal composition can be formed between two transparent glass electrodes. By encapsulating it as a thin film of about 1 to 20 μm, it can be used as a display cell. [0058] In order to obtain good contrast, the liquid crystal layer needs to be a uniformly aligned monodomain. Many methods have been tried for this purpose, but in order to improve the alignment, it is necessary to increase the helical pitch in the xyl nematic (N) phase and Sc phase of the liquid crystal material. In order to increase the helical pitch of the liquid crystal material, it is sufficient to mix appropriate amounts of xyl compounds whose twist directions are opposite to each other. On the other hand, since the compound of the present invention represented by the general formula (I) may be added in a small amount to the liquid crystal composition, the helical pitch of the liquid crystal material induced by the added chiral dohant does not become very short. . Therefore, by using the optically active compound of the present invention, it becomes easy to adjust the helical pitch of the liquid crystal material. [0059]

EXAMPLES The present invention will be specifically explained below with reference to Examples, but of course the gist and scope of the present invention are not limited by these Examples. [0060] The structure of each compound was confirmed by nuclear magnetic resonance spectrum (NMR), infrared absorption spectrum (IR) and mass spectrum (MS). The phase transition temperature was measured using a polarizing microscope equipped with a temperature control stage and a differential scanning calorimeter (DSC). In IR (KB
r) represents the measurement by tablet molding, (neat) represents the measurement using a liquid film, and (Nujol) represents the measurement in a suspended state in liquid paraffin. In NMR (
CDC13) and (CC14) represent a solvent, S represents a singlet, d represents a doublet, t represents a triplet, q represents a quartet, and m represents a multiplet, respectively, and broad represents broad absorption. For example, dd represents a double double line. Further, J represents a coupling constant. M in MS represents a family peak, and the number in parentheses represents the relative intensity of that peak. Also, temperature is expressed in °C. All percentages in the compositions refer to percentages by weight. (00611 (Example 1) Optically active 3-methyl-2-(4-hydroxyphenyl)
Synthesis of nonanenitrile (compound of general formula (II)) [0
062] 1-a (3R)-3-methyl-2-(4
Synthesis of -methoxyphenyl)nonanenitrile [0063
]◎

[0064] 1°04 g (7.1 mmol) of 4-methoxyphenylacetonitrile in tetrahydrofuran (
4.8 ml (7.7 mmol) of a 1.6 M hexane solution of butyl lithium was added to 20 ml of THF solution at -78°C, and then hexamethyl phosphoric acid triamide (HMPA) was added at -78°C.
) and stirred for 1 hour. p at -78℃
-Toluenesulfonic acid (S)-1-methylheptyl 64
A solution of 0 mg (2.3 mmol) in 10 ml of THF was added, and the mixture was stirred at -20°C for 1.5 hours. Furthermore, a saturated ammonium chloride aqueous solution was added to this solution, and then neutralized with dilute hydrochloric acid. This solution was extracted with 250 ml of ether, washed with saturated brine, and concentrated. The residue was separated by column chromatography (Kieselgel 60, hexane:ethyl acetate-20/1), and then preparative high performance liquid chromatography (Tosoh, 5ilica-60, 21).
, 5mmI DX300mm, hexane/ethyl acetate=
80/1) to obtain the (-) form of (2S,3R)-3-methyl-2-(4-methoxyphenyl)nonanenitrile (yield 34%, optical purity 98). %ee) of the (+) body as the polar component (2R,
253 m of a 5=1 mixture of (3R)-3-methyl-2-(4-methoxyphenyl)nonanenitrile (97% ee) and (S)-1-methylheptyl p-toluenesulfonate
g was obtained. [00651 Identification data are shown below. (2S,3R)-(-)-3-methyl-2-(4-methoxyphenyl)nonanenitrile oil [0066] [α]D20-11° (c=0.95, CHCl3)
i [0067] IR(neat) 2930
．． 2860.2330.1540.1250.1175
．． 1030.830cm-' [0068] 'HNMR (CDC13) δ 0
．． 88 (t, J=6.6Hz, 3H), 0.97 (
d, J=6°7Hz, 3H), 1.27-1.52
(m, l0H), 1.86 (m, LH), 3.7
8 (d, J=5.4Hz. LH), 3.81 (s, 3H), 6.89 (d
, J=8°7Hz, 2H), 7.21 (d,
J=8.7Hz, 2H) [0069] (2R
,3R)-(+)-3-methyl-2-(4-methoxyphenyl)nonanenitrile (p-toluenesulfonic acid (S
)-1-Methylheptyl 5:1 mixture) Oil [0070] IR(neat) 2930.2
900.2330.1610.1505.1450.1
250.1170.1030.900.830crrr
'[00711'HNMR (CDC13) δ 0
．． 87 (t, J=4.7Hz, 3H), 0.98 (
d, J=6゜7Hz, 3H), 1.16-1
．． 38 (m, 9H), 1°47-1.54 (m,
IH), 1.90-1.96 (m. IH), 3.63 (d, J=6.5Hz, LH)
, 3.81 (s, 3H), 6.89 (d,
J=8.7Hz, 2H), 7.20 (d, J=
8.7Hz, 2H) [0072] 1-b Synthesis of (28,3R)-(-)-3-methyl-2-(4-hydroxyphenyl)nonanenitrile [0073]◎

[0074] Aluminum chloride 493mg (3.7m
160 mg (0.62 mmol) of (2S.
10 ml of dichloromethane solution of ) was added, and the mixture was heated and stirred for 1 hour. A saturated aqueous sodium bicarbonate solution was added to this solution, extracted with 250 ml of ether, washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to column chromatography (Kieselgel
60, hexane/ethyl acetate = 3/1) to obtain (2S, 3R) -(-)-3-methyl-2-
(4-Hydroxyphenyl)nonanenitrile 139■(
A yield of 92%) was obtained. [0075] Identification data is shown below. White crystal Melting point 42-43℃ [0076] [α]D20-11° (c=1.03, CHCl3)
[0077] IR(neat) 3400.2
940.2860.2240.1710.1615.1
515.1440.1380.1240.1175.8
35cm1 [0078] 'HNMR (CDC13) δ0.
88 (t, J=6.6Hz, 3H), 0.96 (
d, J=6°7Hz, 3H), 1.25-1.42 (
m, 9H), 1°46-1.51 (m, LH)
, 1.82-1.89 (m. LH), 3.77 (d, J=5.5Hz, LH)
, 3.53 (s, LH), 6.83 (d, J=
8.6Hz, 2H), 7.15 (d, J=8.
6Hz, 2H) [0079] MS m/z:
245 (M, 3), 219 (3), 134 (10)
, 133(100), 132(11) [008011-c Synthesis of (2R,3R)-(+)-3-methyl-2-(4-hydroxyphenyl)nonanenitrile [00811(
2S,3R)-(-)-3-methyl-2-(4-hydroxyphenyl)nonanenitrile, (2R
,3R)-(+)-3-methyl-2-(4-methoxyphenyl)nonanenitrile (p-toluenesulfonic acid (S
)-1-methylheptyl 5:1 mixture), (2R
,3R)-(+)-3-methyl-2-(4-hydroxyphenyl)nonanenitrile was obtained. (Yield 8:2%) [0082] Identification data are shown below. oily substance

[α]D20+33.7° (c=1.
09, CHCl3) [0084] IR (neat) 3400.2
930.2860.2250.1615.1600.1
510.1450.1380.1260.1220.8
30 cm1 [0085] 'HNMR (CDC13) δ 0
．． 87 (t, J=6.7Hz, 3H), 0.97
(d, J=6°7 Hz, 3H), 1.19-
1.40 (m, 9H), 1゜48-1.54 (m
, IH), 1.89-1.96 (m. LH), 3.61 (d, J=6.5Hz, LH)
, 3.61 (s, LH), 6.82 (d, J
=8.6Hz, 2H), 7.15 (d, J=8.6
Hz, 2H) [0086] (Example 2) 4-(4-octyloxyphenyl)benzoic acid-4-(
1-cyano-2-methyloctyl)phenyl (general formula (
Synthesis of the compound represented by I) and described in No. 1 and No. 2 of Table 1 [0087] ◎

[0088]2-a (2S,3R)-(-)-3-methyl-2-(4-hydroxyphenyl)nonanenitrile 5 obtained in Example 1
0 mg and 70 μ of 4-(4-octyloxyphenyl)benzoic acid chloride were dissolved in 4 ml of dichloromethane, 0.2 ml of pyridine was added thereto, and the mixture was stirred for 6 hours under reflux of the solvent. Furthermore, 50 ml of ether was added to this solution, and 1
After washing with 0% hydrochloric acid, the mixture was washed with water until the aqueous layer became neutral. After further washing with saturated brine, drying over anhydrous sodium sulfate, and distilling off the solvent, a crude product was obtained. The crude product was subjected to column chromatography (Kieselgel 6
4-
(4-octyloxyphenyl)benzoic acid (Is, 2R
) 75 mg of -4-(1-cyano-2-methyloctyl)phenyl (compound described in Table I No. 1) was obtained. Further, when recrystallized from ethanol and measured its phase transition temperature, the melting point was 100.3°C, and it showed an SA phase up to 125.5°C. [00891 Identification data are shown below. IR (Nujol) 1740.1605.129
0.1280.1200.1180.1080.830
．． 770crrr'[00901'HNMR (CDC1s) δ 0.
72-1, 08 (m, 9H), 1.08-2.
12 (m, 23H), 3.86 (d,
LH), 4.00 (t, 2H), 6.88-
7.24 (m, 12H) [009112-b (2S, 3R) -( used in 2-a above)
-) -3-methyl-2-(4-hydroxyphenyl)
(2R,3R) −(+)−3 in place of nonanenitrile
4-(4-
octyloxyphenyl)benzoic acid (IR, 2R)-4
-(1-cyano-2-methyloctyl)phenyl (Table I
Compound No. 2) was synthesized. Its phase transition temperature is shown in Table 1.
It is also shown in . (0092) (Example 3) 1-[4-(4-hexylphenyl)benzyloxy]-4-(1-cyano-2-methyloctyl)benzene (represented by general formula (I), Table INo. 3 and No.
Synthesis of the compound described in 4) [0093]◎

embedded image [0094] 3-a (2R,3R) −(+) −3− obtained in Example 1
76 mg of methyl-2-(4-hydroxyphenyl)nonanenitrile in 20 ml of dimethylformamide (DMF)
dissolved in. Add 3 potassium t-butoxy to this solution at room temperature.
6 ml was added and stirred for 1 hour. A solution of 104 cm of 4-(4-hexylphenyl)benzyl bromide in 5 ml of DMF was added to the above solution and stirred for an additional 6 hours. Furthermore, 100 ml of ether was added to this solution, washed with water and saturated brine, and then dried over anhydrous sodium sulfate. The crude product obtained by distilling off the solvent was subjected to column chromatography (Ki
eselgel 60, hexane/ethyl acetate mixture system) to separate and purify 1-[4-(4-hexylphenyl)
104 mg of benzyloxy]-4-[(IR,2R)-1-cyano-2-methyloctyl]benzene (compound of Table I No. 4) was obtained. Furthermore, when we recrystallized from methanol and measured its phase transition temperature, the melting point was 87.5℃.
, and did not exhibit liquid crystallinity. [00951 Identification data are shown below. IR (Nujol) 1520.1250.118
0.1050.830.810 cm-1 [0096] 'HNMR (CDC13) 60.
85-0, 99 (m, 9H), 1.20-1.
67 (m, 19H), 1.67-1.94 (m,
LH), 2.65 (t. 2H), 3.63 (d, 2H), 5.10 (d,
2H), 6.97-7.62 (m, 12H) [0
097] 3-b (2R,3R) −(+) used in 3-a above
Exactly the same except that (28,3R)-(-)-3-methyl-2-(4-hydroxyphenyl)nonanenitrile was used instead of -3-methyl-2-(4-hydroxyphenyl)nonanenitrile. 1-[4-(4-hexylphenyl)benzyloxy]-4-[(Is,
2R)-1-cyano-2-methyloctyl]benzene (
The compound in Table INo. 3) was synthesized. The phase transition temperature is also shown in Table 1. [0098] (Example 4) Preparation of Sc liquid crystal composition [00991 A base liquid crystal (H-1) exhibiting a Sc phase having a composition of 00991 or less was prepared. [01001◎

##STR20## The phase transition temperature of this parent liquid crystal was as follows. (0102] 13 (Cr→5c)68 (Sc-
3A) 73°5 (SA -N) 83.5 (N -
I) (N represents a nematic phase.) [0103] Also, another parent liquid crystal (H
-2) was prepared. [0104]◎

embedded image [0105] The phase transition temperature of this parent liquid crystal was as follows. [0106] 12.5 (Cr-+5C)55.
5 (Sc-8A) 64.5 (SA-N) 7
0 (N-I) [0107] 4-a Sc liquid crystal composition was prepared by mixing 90% of the above parent liquid crystal (H-1) and 10% of the compound of Table I No. 1 synthesized in 2-a of Example 2. (M-1) was prepared. Its phase transition temperature was as follows. [0108] 50.7 (SCSA) 89.3 (SA I) Melting point was not clear. [0109] 4-b Sc liquid crystal composition (M-2) was prepared by mixing 95% of the base liquid crystal (H-1) and 5% of the compound of Table I No. 1 synthesized in 2-a of Example 2. did. Its phase transition temperature was as follows. [0110164(Sc-8A) 78.5 (
SA-N) 84.5 (N-I) Melting point was not clear. [011114-c Sc liquid crystal composition (M-3) was prepared by mixing 95% of the base liquid crystal (H-2) and 5% of the compound of Table I No. 3 synthesized in 3-b of Example 3. Its phase transition temperature was as follows. [0112] 49.5 (Sc 5a) 67 (SA N)
69 (N-■) The melting point was not clear. [0113] 4-d Sc liquid crystal composition (M-4) was prepared by mixing 95% of the base liquid crystal (H-2) and 5% of the compound of Table I No. 4 synthesized in 3-a of Example 3. did. Its phase transition temperature was as follows. [0114] 50 (SCSA) 66 (SA-N) 68
(N-I) The melting point was not clear. [0115] 4-e Sc liquid crystal composition (M-5) was prepared by mixing 85% of the base liquid crystal (H-2) and 15% of the compound of Table I No. 4 synthesized in 3-a of Example 3. did. Its phase transition temperature was as follows. [0116] 34.5 (Sc -3A) 65 (
SA-I) The melting point was not clear. (0117) (Example 5) Creation of liquid crystal display element [0118] Sc liquid crystal composition obtained in Example 4 (M-
1) is heated to an isotropic liquid phase, and this is heated to a 2 μm thick 2
A display element was prepared by filling spaces between glass cells consisting of two transparent electrode plates (previously subjected to orientation treatment by polyimide coating and rubbing). When this was slowly cooled to room temperature, a uniformly oriented Sc phase cell was obtained. [0119] This cell has an electric field strength of 10 Vp-p/μm
When a 50 Hz rectangular wave was applied and the electro-optical response speed was measured, a fast response of 105 μsec at 25° C. was confirmed. [01201 The tilt angle at this time was 7.8°, and the contrast was also good. [0121] The spontaneous polarization was −9.2 nC/cm”. [0122] Similarly, Sc liquid crystal compositions (M-2) to
A liquid crystal device was created using (M-5) and its characteristics were measured. The results are shown below. [0123] (M-2): Response 116 μsec, tilt angle 24.0°
, spontaneous polarization -5.7nC/cm2, good contrast [
0124] (M-3): Response 69 μsec, tilt angle 19.1°,
Spontaneous polarization -5.2nC/cm2, good contrast [0
125] (M-4): Response 79 μsec, tilt angle 17.1°,
Spontaneous polarization +5.6nC/cm2, good contrast [0
126] (M-5): Response 30 μs, tilt angle 10.6°, spontaneous polarization +9.4 nC/cm2, good contrast [
0127]

Effects of the Invention The optically active compound represented by the general formula (I) of the present invention partially exhibits a liquid crystal phase and can be added as a so-called xyl dopant to another Sc liquid crystal composition or a host liquid crystal composed of an Sc liquid crystal composition. By doing so, large spontaneous polarization can be induced, and high-speed response of the liquid crystal display element can be achieved. Furthermore, the optically active compound of the present invention and its intermediates can be easily produced industrially, are colorless, and have excellent chemical stability against water, light, heat, etc., and are therefore practical. [0128] Further, the liquid crystal material comprising the xylsmectic liquid crystal composition of the present invention can realize a high-speed response of 50 μsec or less, and is extremely useful as a light switching element for display. (72) Inventor Kayoko Nakamura

Claims (13)

[Claims] Claim 1: General formula (I)◎ [Formula 1] (I) (wherein, R1 is unsubstituted or any one having 1 to 18 carbon atoms
A linear or branched alkyl group, alkoxyl group, alkoxycarbonyl group, alkanoyloxy group, alkoxycarbonyloxy group, alkoxyalkyl group in which one or two hydrogen atoms are substituted with a fluorine atom, chlorine atom or cyano group, represents an alkoxyalkoxyl group or an alkoxyalkanoyloxy group, R2 represents a linear or branched alkyl group having 2 to 18 carbon atoms, m represents O or 1, and Ring A and Ring B each independently represent one or 1,4-phenylene group optionally substituted with two fluorine atoms or chlorine atoms, trans-1,4-cyclohexylene group, pyridine-2,5
Diyl group, pyrimidine-2,5-diyl group, pyrazine 2
．． 5-diyl group, pyridazine-3,6-diyl group or 1,3-dioxane-2,5-diyl group, Z is -COO-1-OCO-1-CH20-1OCH2CH
2CH2-1-C=C- or a single bond, Y is -
It represents COO- or -CH20-, and C and C each independently represent an asymmetric carbon atom in the (R) or (S) configuration. ) An optically active compound having a cyano group represented by 2. The optically active compound having a cyano group according to claim 1, wherein in the general formula (I), ring B represents a 1,4 phenylene group. 3. The optically active compound having a cyano group according to claim 2, wherein in the general formula (I), m is 1. 4. The optically active compound having a cyano group according to claim 3, wherein in the general formula (I), ring A represents a 1,4 phenylene group. 5. The optically active compound having a cyano group according to claim 4, wherein in the general formula (I), Z represents a single bond. 6. In general formula (I), R1 has 4 carbon atoms.
The optically active compound having a cyano group according to claim 5, which represents an alkyl group or an alkoxyl group of -12. 7. In general formula (I), R2 has 2 carbon atoms.
The optically active compound having a cyano group according to claim 6, which represents an alkyl group of -8. 8. A liquid crystal composition containing at least one optically active compound having a cyano group represented by the general formula (I) according to claim 1. 9. A liquid crystal composition containing at least one of the optically active compounds having a cyano group according to claim 2, 3, 4, 5, 6, or 7. 10. The liquid crystal composition according to claim 8 or 9, which exhibits a ferroelectric xylsmectic phase. [Claim 11] Claim 8, Claim 9 or Claim 1
1. A liquid crystal display element constructed using the liquid crystal composition according to 0. 12. General formula (II) ◎ [Chemical formula 2] (II) (wherein, R2 represents a linear or branched alkyl group having 2 to 18 carbon atoms, and C and C are each independently represents an asymmetric carbon atom with (R) or (S) configuration.)
An optically active compound represented by 13. In the presence of a strong base, 4-methoxyphenylacetonitrile is prepared by the general formula (II I) ◎ [Chemical formula 3] (HI) (wherein, R2 is a linear or branched (C represents an asymmetric carbon atom of the (R) or (S) configuration.) is reacted with an optically active tosylate represented by the general formula (IV) (In the formula, R2 and C have the same meanings as in general formula (III).) A diastereomer mixture represented by the formula (III) is separated, and then the methyl group is eliminated. A method for producing an optically active compound represented by general formula (II) described in 12.