JPH0543566A - Optically active compound and liquid crystal composition - Google Patents

Abstract

PURPOSE:A new compound having excellent chemical stability, low melting point and excellent compatibility, inducing large spontaneous polarization and increasing the response rate by the addition of a small amount when changed into a ferroelectric liquid crystal composition. CONSTITUTION:An optically active compound having a dialkyloxirane of formula I [R1 is 1-18C alkyl, 1-18C alkenyl, etc.; R<2> is 1-18C alkyl; X is single bond, -O-, -CO2-, etc.; Y is -OCO-, -OCH2-; A is group of formula II-IV (G is H, F, Cl, cyano, methyl, etc.), etc.; * is asymmetric carbon]. E.g. (2' S) -2 [4- (2', 3'-epoxy-3'-pentyl) octyloxyphenyl]-5-octyloxypyrimidine. The compound of formula I is produced by starting from the reaction of a compound of formula V with a compound of formula VI.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel optically active substance and a liquid crystal composition containing the same.

[0002]

2. Description of the Related Art Liquid crystals, which are widely used as display materials at present, belong to a nematic phase and have characteristics such that eyes are not tired and power consumption is extremely small because they are of a light receiving type. However, it has drawbacks such as being slow, and the display cannot be seen depending on the viewing angle.

A display device that uses a ferroelectric liquid crystal as a liquid crystal display device that has characteristics of a nematic liquid crystal such that eyes are not tired and power consumption is extremely low, and that has high-speed response and high contrast comparable to a light-emitting display device. Printer heads are being considered.

Ferroelectric liquid crystal was introduced in 1975 by Meyer (R.
B. Meyer) et al. Announced its existence for the first time (J. Physique 36, L-69 (1975)) and has a chiral smectic C phase (hereinafter abbreviated as Sm ^* C phase). A typical example is p-decyloxybenzylidene-p′-amino-2-methylbutyl cinnamate (hereinafter abbreviated as DOBAMBC) represented by the following formula.

[0005]

[Chemical 3]

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Most of BC and some of the ferroelectric liquid crystal materials proposed thereafter have a narrow temperature range showing the ferroelectricity (temperature range in which the Sm ^* C phase exists), and are practically difficult to use alone. Therefore, in general, various ferroelectric liquid crystals are mixed and S
Attempts have been made to extend the temperature range showing the m ^* C phase to the low temperature side and the high temperature side around room temperature. Further, for printer heads that require ultra-high-speed response, ferroelectric liquid crystals having a spontaneous polarization larger than those of conventionally developed ferroelectric liquid crystals are required. As an optically active substance having an oxirane ring structure as an asymmetric source, J. Appl. Phys.
No. 27, L2241 (1988) and the like can be mentioned as an example, but the helical pitch of the cholesteric phase of the composition containing the optically active substance is short and there is a problem in terms of compounding control.

The object of the present invention is chemically stable, has no coloration, is excellent in light stability, and when incorporated into a liquid crystal composition by having one asymmetric carbon, the liquid crystal composition has an asymmetric carbon. Two
(EN) It is intended to provide an optically active substance exhibiting a large spontaneous polarization equal to or more than that of an oxirane ring having one and having a long helical pitch of a cholesteric phase, and a liquid crystal composition containing the same.

[0008]

That is, the gist of the present invention is an optically active substance represented by Chemical formula 1 and a liquid crystal composition containing at least one of them.

[0009]

[Chemical 1] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkenyl group having 1 to 18 carbon atoms, an alkoxy moiety having 1 to 12 carbon atoms and an alkyl moiety carbon) A linear or branched alkoxyalkyl group of the formulas 1 to 16, or one of these substituents in which one or more hydrogen atoms are halogen-substituted, and a structure capable of having an optically active group, Represents an optically active group or a racemic body, R ₂ represents a linear or branched alkyl group having 1 to 18 carbon atoms,
X is a single bond, -O -, - CO ₂ - or -OCO- indicates, Y is -OCO- or -OCH ₂ - indicates, A is

[Chemical 2] And G and Z each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, a methyl group, a methoxy group or a trifluoromethyl group, and V is a single bond, —CH ₂ O—, —O.
CH ₂ -, - CO ₂ - or -OCO- indicates, * indicates that the carbon to which it is applied is an asymmetric carbon. )

In the optically active substance of the present invention, R ₁ of Chemical formula ₁ is a straight chain or branched chain alkyl group having 4 to 14 carbon atoms, a straight chain or branched chain alkenyl group having 4 to 14 carbon atoms, and an alkyl moiety. Valerolactone derivatives having a linear or branched alkoxyalkyl group having 4 to 14 carbon atoms, a linear or branched alkylthioalkyl group having 4 to 16 carbon atoms and an alkyl group can be exemplified as preferable ones. Examples of the straight-chain alkyl group include n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group,
Examples thereof include n-tetradecyl group, and the branched-chain alkyl group is — (CH ₂ ) _a C (CH ₃ ) H (CH ₂ ) _b CH ₃ (a is an integer of 0 to 10 and b is 1 to 11). Indicates an integer, 1
≦ a + b ≦ 11. Examples of such a methyl-branched alkyl group can be used, and in the case of such a methyl-branched alkyl group, both optically active ones and racemic ones can be preferably used.

Examples of halogen-substituted straight chain alkyl groups include-(CH ₂ ) _k C (W) H (CH ₂ ) _i CH ₃ (where W represents fluorine, chlorine or bromine, and k and i is an integer of 0 to 12 and 2 ≦ k + i ≦ 12 can be exemplified as a preferable example, and it is more preferable that this is an optically active group.

Examples of the halogen-substituted one having a branched chain alkyl group include an alkyl group having a trifluoromethyl branch, which is also preferably an optically active group. _{- (CH 2) a C (} CF 3) H (CH 2) b CH 3 (a, b represents the above-mentioned meanings.)

A straight-chain alkoxyalkyl group _is- (CH ₂ ) _c OC _j H _{2j + 1.}

The branched-chain alkoxyalkyl group is-(CH ₂ ) _k C (CH ₃ ) H (CH ₂ ) _j OC _j H _{2j + 1-} (CH ₂ ) _k C (OC _j H _{2j + 1} ) H. (CH ₂ ) _i CH ₃ (j is an integer of 1 to 3, c is an integer of 4 to 14, k and i have the above-mentioned meanings), and in the case of a branched alkoxyalkyl group, a racemic mixture. Or may be an optically active group.

A is phenylene, fluorine, chlorine, or phenylene substituted with a cyano group, naphthalene, biphenylene, biphenylene in which one fluorine group is introduced into at least one benzene nucleus;

[Chemical 4]

Or a fluorine or cyano group introduced into one of the two benzene nuclei of these compounds;

[Chemical 5]

Or a compound in which fluorine is introduced into the phenylpyrimidine nucleus of these compounds;

[Chemical 6]

Alternatively, a compound in which a fluorine or cyano group is introduced into the benzene nucleus on the left end of these compounds;

[Chemical 7]

Or a compound in which a fluorine or cyano group is introduced into one of the benzene nucleus or phenylpyrimidine nucleus of these compounds;

[Chemical 8]

Examples thereof include those in which fluorine or chlorine is introduced into the benzene nucleus of these compounds; and the like. Among these, biphenylene and 1 in at least one benzene nucleus
Preferred are those in which two fluorine-introduced biphenylenes, two or three rings are directly bonded and one of the rings is a pyrimidine ring.

As the optically active substance of the present invention, X in the chemical formula 1 is preferably a single bond, —O— or —CO ₂ — from the viewpoint of ease of synthesis, and V has a low viscosity. From the viewpoint of the dipole moment and the ease of synthesis, a single bond is a single bond from the standpoint of the ease with which the liquid crystal phase appears, etc., and —CH ₂ O—, —OCH ₂ —, —CO ₂ — or —. OCO
It is preferably −.

The compound of Chemical formula 1 can be produced by the following method.
In the following, R ₁ , R ₂ , X, A and Y have the above-mentioned meanings.

[0023] Y: -OCH ₂ -

[Chemical 9]

Y: -OCO-

[Chemical 10]

Some of the optically active substances of the present invention show a liquid crystal phase, and some do not show a liquid crystal phase by themselves.
Isotropic phase-nematic phase (hereinafter abbreviated as N phase) -smectic A phase (hereinafter abbreviated as SmA phase) -smectic C phase (hereinafter abbreviated as SmC phase) or Ferroelectric phase (Sm ^* C phase) can be obtained by adding 0.1 to 90 mol% to a non-chiral liquid crystal or a liquid crystal composition showing a phase sequence of isotropic phase-N phase-SmC phase within a range not destroying liquid crystallinity. Since it has the property of inducing, it is useful as an additive for a ferroelectric liquid crystal composition even if it does not exhibit a liquid crystal phase by itself.

As the liquid crystal, for example, when the liquid crystal is used in a display device such as a display, it is preferable to use not only a single liquid crystal compound but a plurality of liquid crystal compounds or a mixture thereof with a compounding compound. This is advantageous because the physical properties such as the temperature range (the temperature range showing the ferroelectricity), the tilt angle, the spiral pitch, the spontaneous polarization value, and the rotational viscosity can be changed.

As the liquid crystal composition used for adding the optically active substance of the present invention, any compound can be used as long as it is a compound or composition exhibiting ferroelectricity, the above-mentioned non-chiral liquid crystal or liquid crystal composition. You can

The composition containing the optically active substance of the present invention is
The composition has a spontaneous polarization equal to or higher than that of a conventional composition containing an optically active substance having an oxirane ring structure having two asymmetric carbon atoms, and has a long helical pitch in the cholesteric phase. The following compounds can be exemplified as preferable compounds that can be mixed with the optically active substance represented by Chemical formula 1 in the liquid crystal composition.

[0029]

[Chemical 11]

[0030]

[Chemical formula 12]

[0031]

[Chemical 13]

[0032]

[Chemical 14]

[0033]

[Chemical 15]

[0034]

[Chemical 16]

[0035]

[Chemical 17]

[0036]

[Chemical 18]

[0037]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the examples.

[Example 1] (2'S) -2- [4-
(2 ', 3'-epoxy-3'-pentyl) octylo
Synthesis of [xyphenyl] -5-octyloxypyrimidine

[Chemical 19]

Triethylphosphonoacetate 10.
2 g of an n-butyllithium hexane solution (1.66 mol / l) was added dropwise to 50 ml of anhydrous THF and the mixture was added dropwise at −10 ° C., followed by stirring for 15 minutes, and subsequently 7 g of undecanone was added dropwise and stirred overnight. Water was added to the reaction solution, which was extracted with ether, washed with a saturated saline solution, dehydrated with magnesium sulfate, distilled off the solvent and purified by silica gel column chromatography to obtain 7.8 g of ethyl 3-pentyl-2-octenoate. Obtained.

3 g of this product was dissolved in toluene to prepare DIB
Add a toluene solution of AL-H (1.02 mol / l) to 27
ml, added dropwise at −10 ° C., stirred for 1 hour, added methanol and stirred for 1 hour, and then filtered the resulting gel,
The solvent was distilled off and the residue was purified by silica gel column chromatography to obtain 1.3 g of 3-pentyl-2-octen-1ol.

Next, titanium tetraisopropoxide 79
In a solution of 0 mg dissolved in 15 ml of dichloromethane, a solution of (+) tartaric acid in 5.5 ml of dichloromethane was -25.
After dropping at 0 ° C, the mixture was stirred for 10 minutes, 500 mg of 3-pentyl-2-octen-1ol in 13 ml of dichloromethane was added dropwise at the same temperature, and the mixture was stirred for 20 minutes, followed by tert.
2.65 ml of a dichloromethane solution of -butyl hydroperoxide (2.1 mol / l) was added and the mixture was allowed to stand at -25 ° C to -20 ° C for 3 days.

7.5 ml of 10% tartaric acid was added to this solution, followed by addition of 1 ml of dimethyl sulfide, extraction with dichloromethane three times, washing with water, concentration, dissolution in 30 ml of ether, and addition of 9 ml of 1N NaOH aqueous solution at 0 ° C. 30
Stir for minutes. This solution was extracted 3 times with ether, washed with saturated saline, dried over magnesium sulfate, and evaporated to remove the solvent, followed by purification by silica gel column chromatography.
(2S) -3,3-dipentylglycidol 340 mg
Got The optical purity of this product was 79% ee as MTPA ester.

211 mg of this product and 272 mg of 3,5-dinitrobenzoyl chloride were dissolved in 3 ml of benzene and 3 ml of pyridine, stirred for 2 hours, then poured into 1N aqueous hydrochloric acid and extracted with ether, and an aqueous solution of copper sulfate, an aqueous solution of sodium hydrogen carbonate and saturated sodium chloride were added. After washing with water, dehydration was performed on magnesium sulfate, the solvent was distilled off, and recrystallization was repeated using hexane-ether as a recrystallization solvent to obtain 90% ee.

100 mg of this product was dissolved in 2 ml of methanol, 200 mg of potassium carbonate was added, and the mixture was stirred for 1 hour, poured into water, extracted with ether, and the solvent was distilled off.
21 mg purified by silica gel column chromatography, and 2- (4-hydroxyphenyl) 5-
Octyloxypyrimidine (30 mg), triphenylphosphine (26 mg) and diethyl azodicarboxylate (20 mg) were dispersed in benzene and stirred for 15 hours, then the solvent was distilled off, followed by silica gel column chromatography followed by recrystallization from a hexane-ether mixed solvent. Target (2 '
31 mg of S) -2- [4- (2 ′, 3′-epoxy-3′-pentyl) octyloxyphenyl] -5-octyloxypyrimidine was obtained.

The melting point of this product was 42.degree. The NMR spectrum data of this product are shown below. (90MH
z, CDCl ₃ ) 0.7 to 1.1 (m, 9H), 1.1
~ 2.0 (m, 28H), 3.16 (t, J = 5Hz,
1H), 4.08 (t, J = 6Hz, 2H), 4.18
(D, J = 5 Hz, 2H), 7.00 (d, J = 9H
z, 2H), 8.29 (d, J = 9Hz, 2H), 8.
42 (s, 2H)

[Example 2] (2'R) -2- [4-
(2 ', 3'-epoxy-3'-pentyl) octanoy
Luoxyphenyl] -5-octyloxypyrimidine
Synthesis

[Chemical 20]

90% ee synthesized in Example 1 was used (2
30 mg of (S) -3,3-dipentylglycidol was dissolved in 0.36 ml of carbon tetrachloride, 0.36 ml of acetonitrile and 0.55 ml of water, and 135 mg of sodium periodate and 0.67 mg of ruthenium chloride were added thereto and vigorously stirred at room temperature. After stirring for 2 hours, the mixture was poured into a saline solution, extracted with ethyl acetate, washed with an aqueous sodium thiosulfate solution and a saturated saline solution, dehydrated on magnesium sulfate, and the solvent was distilled off to give crude (2R) -2,3. -Epoxy-3-pentyloctanoic acid 18 mg was obtained.

This product, 24 mg of 2- (4-hydroxyphenyl) -5-octyloxypyrimidine, 16 mg of dicyclohexylcarbodiimide and 3 mg of N, N-dimethylaminopyridine were dissolved in 1 ml of dichloromethane and stirred for 14 hours, and then the solvent was distilled off. After that, 19 mg of the target product was obtained by silica gel column chromatography and subsequent recrystallization from a hexane-ether mixed solvent.

The melting point of this product was 31.degree. The NMR spectrum data of this product are shown below. (90MH
z, CDCl ₃ ) 0.7 to 1.0 (m, 9H), 1.1
.About.2.0 (m, 28H), 3.58 (s, 1H), 4.
08 (t, J = 6 Hz, 2H), 7.20 (d, J = 9)
Hz, 2H), 8.37 (d, J = 9Hz, 2H),
8.42 (s, 2H)

Example 3 The following compounds were mixed in the following compounding ratio to obtain a liquid crystal composition.

[Chemical 21] This composition exhibits the following phase transitions:

[Equation 1] In the above, Cryst. Indicates a crystal, and Iso indicates an isotropic phase, and the numbers near the arrows indicate the transition temperature (° C.) to the phase.

Since this compound is composed only of a non-chiral compound, it is not a ferroelectric liquid crystal and does not exhibit spontaneous polarization. 98 mol% of this composition was mixed with 2 mol% of the optically active substance obtained in Example 1 to obtain a ferroelectric liquid crystal composition. This ferroelectric liquid crystal composition has an S content in the temperature range from near room temperature to 47 ° C.
m ^* C phase, showing SmA phase at 47 to 61 ° C., 61 to 66
Chiral nematic phase (hereinafter abbreviated as N ^* phase) at ℃,
Above that, it became an isotropic liquid.

Separately, polyimide was applied as an alignment treatment agent, and a cell having a thickness of 2 μm provided with a transparent electrode whose surface was subjected to parallel alignment treatment by rubbing was prepared. A dielectric liquid crystal element was created. This element was placed between two orthogonal polarizers and an electric field was applied. It was observed that the intensity of the transmitted light changed by the application of ± 10V, and the time (response time) for the transmitted light intensity to change from 0% to 50% was calculated.
It was 2 μsec. The spontaneous polarization is 1.2n at 25 ° C.
C / cm ² , spiral pitch of chiral nematic phase is 6
It was 26 μm at 3 ° C.

Example 4 A ferroelectric liquid crystal composition was obtained in the same manner as in Example 3 except that the optically active substance obtained in Example 2 was used instead of the optically active substance obtained in Example 1. When the response time was measured, this ferroelectric liquid crystal composition showed an Sm ^* C phase in the temperature range from near room temperature to 46 ° C.
SmA phase at 61 ℃, N ^* phase at 61 ℃ ~ 66 ℃, isotropic liquid above it, response time is 99μse at 25 ℃
It was c. Also, spontaneous polarization is 4.1 nC / c at 25 ° C.
The helical pitch of m ² and the chiral nematic phase was 8 μm at 63 ° C.

As described above, the optically active substance of the present invention, which exhibits liquid crystallinity, exhibits high spontaneous polarization as a ferroelectric liquid crystal, has no coloring, and is excellent in chemical stability such as hydrolysis resistance. It has excellent light stability, and even if it does not show liquid crystallinity, it can be mixed with a non-ferroelectric liquid crystal composition to form a ferroelectric liquid crystal composition, or it can be used as an additive. When used as a compounding component in a liquid crystal composition, it enhances spontaneous polarization as a composition, increases the helical pitch, and is effective in improving the response speed, and does not color the composition upon addition or compounding. It exhibits excellent properties that it does not deteriorate the stability to chemicals or light.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuriko Nakaoka 3816 Noborito, Tama-ku, Kawasaki City, Kanagawa Mitsubishi Rayon Co., Ltd. Tokyo Research Laboratory (72) Inventor Kenji Mori 1-20-6, Bunkyo-ku, Tokyo

Claims (2)

[Claims] 1. An optically active substance having a dialkyloxirane represented by Chemical formula 1. [Chemical 1] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkenyl group having 1 to 18 carbon atoms, an alkoxy moiety having 1 to 12 carbon atoms and an alkyl moiety carbon) A linear or branched alkoxyalkyl group of the formulas 1 to 16, or one of these substituents in which one or more hydrogen atoms are halogen-substituted, and a structure capable of having an optically active group, Represents an optically active group or a racemic body, R ₂ represents a linear or branched alkyl group having 1 to 18 carbon atoms,
X represents a single bond, —O—, —CO ₂ — or —OCO—, Y represents —OCO— or —OCH ₂ —, and A represents And G and Z each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, a methyl group, a methoxy group or a trifluoromethyl group, and V is a single bond, —CH ₂ O—, —O.
CH ₂ -, - CO ₂ - or -OCO- indicates, * indicates that the carbon to which it is applied is an asymmetric carbon. ) 2. A liquid crystal composition containing at least one kind of the optically active substance according to claim 1.