JPH0429978A - Optically active compound and display element containing the same as liquid crystal material - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R is 6-18C alkyl; R<2> is 4-12C alkyl; C with * is asymmetric carbon). EXAMPLE:(R)-2-(4-Decyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1- trifluoromethylheptyloxycarbonyl)phenyl ester. USE:A ferrodielectric liquid crystal display element capable of displaying intermediate color tones. PREPARATION:A compound of formula II is made to react with a compound of formula III in a solvent such as toluene at -20 to 60 deg.C to prepare a compound of formula IV. The compound of formula IV is hydrogenation- debenzylated in a solvent such as ethanol under the ordinary pressure and the prepared compound of formula V is further made to react with a compound of formula VI in the presence of dicyclohexylcarbodiimide as a dehydrative- condensing agent and in the presence of N,N-dimethyl-4-aminopyridine as a catalyst in a solvent such as methylene dichloride.

Description

DETAILED DESCRIPTION OF THE INVENTION A1.Object of the invention (industrial application field) The present invention relates to a novel optically active compound. This compound is useful as a ferroelectric liquid crystal material exhibiting a chiral smectic C phase and as an antiferroelectric liquid crystal material exhibiting a chiral smectic Cq phase having a tristable state. Therefore, the present invention also relates to a liquid crystal display element using this novel optically active compound as a liquid crystal material, and particularly to a ferroelectric liquid crystal display element capable of intermediate display.

(Prior Art) Currently, liquid crystal display elements are widely used as various display elements due to their low voltage drivability, low power consumption, small size, and thinness.

Recently, high-speed response liquid crystal devices using ferroelectric smectic liquid crystals have been actively researched. Since ferroelectric smectic liquid crystals have spontaneous polarization, it is known that they have a large driving force when interacting with an electric field and exhibit high-speed response to changes in the electric field. Utilizing this high-speed response, research is progressing into display elements such as liquid crystal televisions, and optoelectronic elements such as optical printers and light valves. Currently, most of the ferroelectric liquid crystal phases that are being used in these devices are chiral smectic C phases, and display is attempted in a surface-stabilized ferroelectric liquid crystal mode.

However, in this surface-stabilized display mode,
Since the two stable states that molecules can take are used, it is possible to display in two ways, bright and dark, but it is difficult to display intermediate tones.

4-(5-octylpyrimidin-2-yl)benzoic acid-4-[1-() is used as an antiferroelectric liquid crystal material exhibiting a chiral smectic Ca phase with three stable states, which enables display of intermediate tones. (Lifluoromethyl)hebutyloxycarbonyl]phenyl ester (JP-A-1-316367
JP-A No. 1-213390) is known, and an element using an acid compound composed of a pentacyclic ester compound (JP-A-1-213390) is known as a liquid crystal display element.

(Problems to be Solved by the Invention) The present invention provides an antiferroelectric liquid crystal material and a display element using the same which are different in chemical structure from the conventional ferroelectric smectic liquid crystal material. The present invention provides a liquid crystal material having a tristable state capable of displaying halftones, which is difficult to achieve, and a liquid crystal display element using the same.

Structure and Effects of the Invention (Means for Solving the Problems) The optically active compound according to the present invention has the following -formation% formula% (However, in the above formula (1), R1 is an alkyl group having 6 to 18 carbon atoms. R2 represents an alkyl group having 4 to 12 carbon atoms.C with * represents an asymmetric carbon atom.
The optically active compound represented by is used as a liquid crystal material.

(However, in the above formula (1), R1 represents an alkyl group having 6 to 18 carbon atoms, and R2 represents an alkyl group having 4 to 12 carbon atoms. C with an asterisk represents an asymmetric carbon atom. ) (Effects of the present invention) The optically active compound according to the present invention exhibits useful performance as a ferroelectric liquid crystal material exhibiting a chiral smectic C phase and an antiferroelectric liquid crystal material exhibiting a chiral smectic C11 phase having a tristable state. have.

Therefore, a liquid crystal display element using this optically active compound as a liquid crystal material is capable of displaying in two ways, bright and dark, as well as in intermediate tones. Such characteristics allow the liquid crystal display element of the present invention to be used in a variety of ways beyond those of conventional products.

(Optically active compound) In the general formula (1), the alkyl group having 6 to 18 carbon atoms in R1 includes a hexyl group, a heptyl group, an octyl group,
Examples include linear or branched alkyl groups such as a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a J\xadecyl group, a heptadecyl group, and an octadecyl group.

On the other hand, the alkyl group having 4 to 12 carbon atoms for R2 may be a linear or branched alkyl group such as a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. An example is an alkyl group.

Some of the compounds represented by the general formula (1) according to the present invention are as follows.

No. 1: (S) -2-(4-hexyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-
Trifluoromethylpentyloxycarbonyl) phenyl ester No. 2: (S) -2-(4-octyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-
Trifluoromethylpentyloxycarbonyl) phenyl ester No. 3: (S) -2-(4-decyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-trifluoromethylpentyloxycarbonyl) phenyl ester No. 4 : (S) -2-(4-dodecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-
Trifluoromethylpentyloxycarbonyl) phenyl ester No. 5: (S) -2-(4-tetradecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(
1-1-lifluoromethylpentyloxycarbonyl)
Phenyl ester No. 6: (S)-2-(4-hexadecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(
1-trifluoromethylpentyloxycarbonyl) phenyl ester No. 7: (S)-2-(4-octadecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-1
-Lifluoromethylpentyloxycarbonyl) phenyl ester No. 8: (R) -2-(4-hexyloxyphenyl)-5-pyrimidinecarphonic acid-4-(1 trifluoromethylhebutyloxycarbonyl) phenyl ester No. 9: (R)-2-(4-octyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-trifluoromethylhebutyloxycarbonyl) phenyl ester No. 10: (R)-2-( 4-decyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-
Trifluoromethylhebutyloxycarbonyl) phenyl ester No. 11: (R) -2-(4-dodecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1
-trifluoromethylpentyloxycarbonyl) phenyl ester No. 12: (R) -2-(4-tetradecyloxyphenyl)-5-pyrimidinecarboxylic acid-4(
1-1-lifluoromethylhebutyloxycarbonyl)
Phenyl ester No. 13: (R)-2-(4-hexadecyloxyphenyl)-5-pyrimidinecarboxylic acid-4(
1-trifluoromethylhebutyloxycarbonyl) phenyl ester No. 14: (R) -2-(4-octadecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-
(1-1-lifluoromethylhebutyloxycarbonyl) phenyl ester No. 15: (R) -2-(4-hexyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1
-trifluoromethylnonyloxycarbonyl)phenyl ester No. 16: (R) -2-(4-octyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1
-trifluoromethylnonyloxycarbonyl)phenyl ester No. 17: (R) -2-(4-decyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-
Trifluoromethylnonyloxycarbonyl) phenyl ester No. 18: (R) -2-(4-dodecyloxyphenyl)-5-pyrimidinecarboxylic acid-4= (1-
Trifluoromethylnonyloxycarbonyl) phenyl ester No. 19: (R) -2-(4-tetradecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-
(1-) Lifluoromethylnonyloxycarbonyl) phenyl ester No. 20: (R) -2-(4-hexadecyloxyphenyl)-5-pyrimidinecarphonic acid-4-
(1-)Rifluoromethylnonyloxysulfonyl) phenyl ester No. 21: (R) -2-(4-octadecyloxyphenyl)-5-pyrimidinecarboxylic acid-4(
1-trifluoromethylnonyloxycarbonyl)phenyl ester No. 22: (S)-2-(4-hexyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-trifluoromethylundecyloxycarbonyl)phenyl Ester No. 23: (S)-2-(4-octyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-trifluoromethylundecyloxycarbonyl)phenyl ester No. 24: (S)-2- (4-decyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-trifluoromethylundecyloxycarbonyl)phenyl ester No. 25: (S)-2-(4-dodecyloxyphenyl)-5-pyrimidine Carboxylic acid-4-(1-trifluoromethylundecyloxycarbonyl)phenyl ester No. 26: (S)-2-(4-te!-labyloxyphenyl)-5-pyrimidinecarboxylic acid-4(1-
Trifluoromethylundecyloxycarbonyl) phenyl ester No. 27: (S)-2-(4-hexadecyloxyphenyl)-5-trimicincarboxylic acid-4(1-trifluoromethylundecyloxycarbonyl)phenyl ester No. 28: (S)-2-(4-octadecyloxyphenyl)-5-pyrimidinecarboxylic acid-4(1-trifluoromethylundecyloxycarbonyl)phenyl ester The chemical structures of these compounds are shown in the table below. That's right.

(Production of compound) The optically active compound represented by general formula (1) can be produced by any suitable method.

One suitable method of preparation is according to the reaction scheme below. In the formula, R1 and R2 are the same as those defined in the general formula (1), and the number in parentheses in the formula represents the compound in the upper row.

In the reaction step (I), toluene, diethyl ether, tetrahydrofuran, etc. are used as a reaction solvent, and the reaction temperature is -2.
It can be carried out in the range of 0 to 60°C. Reaction step (II) is a debenzylation step, which can be carried out by a known method. For example, this can be easily carried out by hydrogenation at normal pressure using palladium/charcoal as a catalyst and ethanol, acetic acid, etc. as a solvent. Moreover, reaction step (III)
is a compound of general formula (1) using dicyclohexylcarbodiimide as a dehydration condensation agent, an organic base such as N,N-dimethyl-4-aminopyridine as a catalyst, and methylene chloride or chloroform as a solvent. can lead.

The compound of formula (6) used in the reaction step (III) can also be synthesized by hydrolyzing a cyano compound obtained by a known method described in, for example, Japanese Patent Publication No. 55-6632.

(Liquid Crystal Display Element) As described above, the compound of general formula (1) according to the present invention is useful as a liquid crystal material.

The liquid crystal phase possessed by the compound of the present invention has characteristics different from the chiral smectic C phase, which is currently being extensively studied. It is known that in the conventional chiral smectic C phase, two stable states exist in the surface-stabilized ferroelectric liquid crystal mode, and by utilizing this, bright,
It is known that two types of dark display can be performed, but in the chiral smectic CQ phase, the chiral smectic C
In addition to the two stable states of the phase, there is a third stable state. Furthermore, since this third stable state exists in a region centered on the electric field strength of zero, in addition to conventional bright and dark displays, it is possible to display an intermediate brightness using the third stable state. Therefore, in the liquid crystal display element according to the present invention, three types of display can be performed by changing the applied electric field strength.

Except for the point that the liquid crystal material used is a compound of general formula (1), the liquid crystal display element according to the present invention does not essentially differ from conventionally known ones, including conventional ones.

Therefore, basically, the production of the liquid crystal display element of the present invention involves injecting a liquid crystal compound into a cell obtained by laminating two glass substrates with transparent electrodes and alignment-treated surfaces with a spacer in between. This can be done by

For the production of the cell, a conventional technique for producing a liquid crystal element using a liquid crystal compound having a chiral smectic C phase can be applied. For example, alumina beads, glass fiber polyester film, etc. can be used as the spacer. In addition, as the orientation treatment material scarlet, PVA, PI, S
Examples include i○, 5IO2, etc.

The liquid crystal display element according to the present invention is capable of displaying bright, dark, and intermediate tones, so it has versatile display functions by adding gray display compared to the conventional display of only black and white. There is. Therefore, such liquid crystal display elements are used for a variety of purposes compared to conventional two-color black and white displays, focusing on their versatile display functions.

(Example) The following example is for explaining the present invention more specifically. Measurement of phase transition temperature and phase identification in Examples were carried out by DSC measurement and polarized light microscopy observation. Cry represents a crystalline phase, S m C0* represents a chiral smectic CQ phase, SmA represents a smectic A phase, and Iso represents an isotropic phase.

Example 1 (Synthesis Example) (R)-2-(4-decyloxyphenyl)5-pyrimidinecarboxylic acid-4-(1-)lifluoromethyl J\butyloxycarbonyl) phenyl ester (Compound No.
, 10) (I) (R) -4-J Preparation of sunzyloxybenzoic acid-1-trifluoromethylheptyl ester 4-
1 684 mg (3-Ommol
), and 10 m of thionyl chloride were heated under reflux for 3 hours, and then excess thionyl chloride was distilled off under reduced pressure to obtain 4-benzyloxybenzoic acid chloride. This product was not particularly purified and was used in the next step as a tetrahydrofuran solution. On the other hand, 552 mg (3.0 mmol) of (R)-1-)lifluoromethylheptatool was added to 15 m of tetrahydrofuran! Sodium hydride dissolved in
A tetrahydrofuran solution of alcoholade obtained by adding 32 m, g (3.3 mmol as purity 60%) was added dropwise to the previously obtained tetrahydrofuran solution of the above acid chloride while stirring at room temperature for about 30 minutes. , and 1 more
Stirred for 2 hours. After adding 60 ml of water, the mixture was extracted with 90 ml of methylene chloride, and the organic layer was washed with 5% aqueous sodium bicarbonate and water, and then dried over anhydrous magnesium sulfate. After filtering off the desiccant, methylene chloride was distilled off to obtain a crude target product. This product was purified by silica gel column chromatography to obtain 1057 mg (2.68 mmol) of oily (R)-rubenzyloxybenzoic acid-1-trifluoromethyl hebutyl ester.

(II) Production of (R)-4-hensyloxybenzoic acid-1-trifluoromethylheptyl ester obtained in (I) 1000m, g (2,5
4mmol) and 20m of acetic acid! After dissolving it in a hydrogen atmosphere, it was brought into contact with 280 mg of 5% palladium/charcoal at room temperature for 5 hours. Palladium/charcoal was filtered off, and acetic acid was distilled off under reduced pressure to obtain the crude desired product. This product was purified by silica gel column chromatography to obtain 726 mg of oily (R)-4-hydroxybenzoic acid-1-trifluoromethylheptyl ester (2,38 mmo
l) was obtained.

(m)(R)-2-(4-decyloxyphenyl)5-
Production of pyrimidinecarphonic acid-4-(1-trifluoromethylhebutyloxycarbonyl)phenyl ester (R)-4-hydroxybenzoic acid obtained in (II)
1-trifluoromethyl hebutyl ester 304 mg (
1,00m, mol), 9392mg (1,1
After dissolving 67 mg (0.55 mmol) of N,N-dimethyl-4-aminopyridine in 10 ml of methylene chloride at room temperature, 268 mg (1.30 mmol) of dicyclohexylcarbodiimide was added and Allowed time to react.

After the reaction was completed, the precipitated solid was separated by filtration, washed with water, washed with a 5% acetic acid aqueous solution, washed with water, and then dried over anhydrous magnesium sulfate. After filtering off the drying agent, methylene chloride was distilled off to obtain the crude desired product.

This product was purified by silica gel column chromatography and further recrystallized from hexane to obtain the target (R)-2-(4-decyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-trifluoromethylhebutyl). oxycarbonyl) phenyl ester 285mg
(0.41 mmol) was obtained. The physical properties of this compound were as follows.

IH-NMR spectrum (CD C13, I) I)m
) 0.87 (t, 3■), 0.89 (t, 3H), 1.
28-1.52 (m, 22H), 1.81-1.92 (
m, 4H), 4.06 (t, 211), 5.55 (m,
1N), 7.01 (d, 2H), 7.39 (d, 2H)
, 8.19 (d, 2H), 8.53 (d, 2N), 9.
41 (s, 2HTR spectrum (K B r disk,
cm-')2920.2870.1?40.1450.
1260.1210,800,760 mass spectrum (
El method, m/e (relative intensity)) 642 (8, M+), 3
39(100) Phase transition temperature (DSC, (g light microscopy observation 2°C) Example 2 (Synthesis example) (R)-2-(4-1'decyloxyphenyl)-5-
Pyrimidinecarboxylic acid-4-(1-trifluoromethylhebutyloxycarbonyl)phenyl ester (Compound No. 11) (R)-4-hydroxy obtained by the methods of Example 1 (1) and (II) Benzoic acid-1-trifluoromethylheptyl ester 304 mg (1°00 mmo
l), 423 mg (1,10 mmol) of 2-(4-dodecyloxyphenyl)-5-pyrimidinecarboxylic acid and 67 mg of N, N-dimethyl-4-aminopyridine
(0.55 mmol) in methylene chloride 10 mK
After dissolving at room temperature, 268 mg (1°30 mmol) of dicyclohexylcarbodiimide was added, and 1°
The reaction was allowed to proceed for 6 hours.

After the reaction was completed, the precipitated solid was separated by filtration, washed with water, washed with a 5% acetic acid aqueous solution, washed with water, and then dried over anhydrous magnesium sulfate. After filtering off the drying agent, methylene chloride was distilled off to obtain the crude desired product.

This product was purified by silica gel column chromatography and further recrystallized from hexane to obtain the desired (R)-2-(4-dodecyloxyphenyl)-5-pyrimidinecarboxylic acid-4-(1-trifluoromethyl). Phyloxycarbonyl) phenyl ester 349m
g (0.51 mmof) was obtained. The physical properties of this compound were as follows.

IH-NMR spectrum (CD CJ'-3, pI)
m) 0.86 (t, 3N), 0.89 (t, 3N),
1.27-1.52 (m, 26) 1), 1.81-
1.91 (m, 4N), 4.06 (t, 2H)
, 5.55 (m, 1N), 7.02 (d,
2H)', 7.38(d, 2H), 8.19
(d, 2H), 8.52 (d, 2H), 9
．． 41 (s, 2HIR spectrum (KBr disk, c
m-')2920.2860.1?40.1440.1
270.1, 220, 800, 750 mass spectrum (
EI method, m/e (relative intensity)) 670 (9, M+), 3
67 (100) phase transition temperature (DSC, polarizing microscope observation 2
°C) Example 3 (Synthesis example) (R) -2-(4-teI・labsyloxyphenyl)
-5-pyrimidinecarboxylic acid-4,-(1-trifluoromethylhebutyloxycarbonyl)phenyl ester (compound No. 12) (R)- obtained by the methods (I) and (II) of Example 1 4-Hydroxybenzoic acid-1-trifluoromethylbutyl ester 304 mg (1,00 mmol
), 2-(4-tetradecyloxyphenyl)-5-
Pyrimidinecarboxylic acid 451Lmg (1,10mmo
l) and N,N-dimethyl-4-aminopyridine (67 mg (0,55 mmol)) in methylene chloride 10
After dissolving in mu at room temperature, 268 mg (1,30 mmol) of dicyclohexylcarbodiimide was added,
The reaction was allowed to proceed at room temperature for 16 hours.

After the reaction was completed, the precipitated solid was separated by filtration, washed with water, washed with a 5% acetic acid aqueous solution, washed with water, and then dried over anhydrous magnesium sulfate. After the desiccant was filtered off, methylene chloride was distilled off to obtain the crude target product.

This product was purified by silica gel column chromatography and further recrystallized from hexane to obtain the desired (R)-2-(4-tetradecyloxyphenyl)-5.
-pyrimidinecarboxylic acid-4-(1-1-lifluoromethylheptyloxycarbonyl)phenyl ester 47
0 mg (0.67 mmol) was obtained. The physical properties of this compound were as follows.

H-NMR spectrum (CD CJ13.ppIn
) 0.86 (t, 3H), 0.89 (t, 3) 1),
1.27-1.51 (m, 30H), 1.79-1.
84 (m, 2) 1), 1.87-1. ．． 92 (m
, 2H), 5.55 (m, IN), 7.
02(d, 2H), 7.38(d, 2N)
, 8.20(d, 2H), 8.52(d,
2H), 9.41 (s, 2H) IR spectrum (KB r disk, cm') 2910
．． 2850.1730.1440. +260.122
0,800,750 mass spectrum (EI method, m/e (
Relative intensity)) 698 (13, M+), 395 (100)
Phase transition temperature (DSC, polarized light microscopy observation 2°C) Example 4
(Performance as a liquid crystal element) After applying polyimide to a glass substrate on which two transparent electrodes were formed, Example 1 was applied to a cell with a spacing of 3 μm between the glass substrates, which were assembled so that their rubbing directions were parallel to each other. A liquid crystal device was fabricated by injecting the compound obtained in step 1 and sandwiching it between two polarizing plates running perpendicularly to each other. 85 to this one
When the optical response speed was measured by applying a voltage of ±30 V at a temperature of .degree. C., a very fast response time of 85 .mu.sec was obtained.

Example 5 (Performance as a liquid crystal element) When a triangular wave of ±20 V was applied at 85° C. to the cell prepared in Example 4, three kinds of states including bright, dark, and halftone states near the voltage OV were obtained. Changes were observed.

Claims (1)

[Claims] [1] An optically active compound represented by the following general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) (However, in the above formula (1), R^1 represents an alkyl group having 6 to 18 carbon atoms, and R^2 represents an alkyl group having 4 to 12 carbon atoms. group. C with * represents an asymmetric carbon.) [2] A display element using an optically active compound represented by the following general formula (1) as a liquid crystal material. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) (However, in the above formula (1), R^1 represents an alkyl group having 6 to 18 carbon atoms, and R^2 represents an alkyl group having 4 to 12 carbon atoms. represents a group.C with * represents an asymmetric carbon atom.)