JPH02209873A - Optically active 2,5-disubstituted pyrimidine derivative - Google Patents

Abstract

NEW MATERIAL:An optically active compound shown by formula I (R<1> is 3-20C optically active alkyl, alkanoyl, alkoxyalkyl, haloalkyl or haloalkanoyl; R<2> is 1-20C alkyl or alkoxy; X<1> and X<2> are H or F). EXAMPLE:(R)-2-{-2-Fluoro-4-(1-methylheptyloxy)phenyl)}-5-(4-octylphenyl) pyrimidine. USE:A liquid crystal compound which is useful for preparing a liquid crystal composition showing SC* phase in a wide temperature range, has low viscosity, shows SC* phase in a wide temperature range and large spontaneous polarization alone or by blending, readily producible also industrially and has excellent chemical stability. PREPARATION:A compound shown by formula X is reacted with a compound shown by formula XI to give a compound shown by formula XII, which is reacted with a compound shown by formula XIII (Y is eliminable group) in the presence of a base to give a compound shown by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel liquid crystalline compound useful as an electro-optic display material, and particularly to a liquid crystalline compound exhibiting a xylsmectic C phase. be. In particular, the present invention provides compounds that are useful materials for obtaining liquid crystal materials having ferroelectric properties.

[Prior art]

Liquid crystal display devices are currently widely used due to their superior characteristics (low voltage operation, low power consumption, thin display, can be used even in bright places, and do not strain the eyes). However, in the most common TNu-fi display method,
Compared to light-emitting display systems such as CRT, the response is extremely slow, and the display cannot be memorized even when the field is turned off (memory effect). There are many restrictions on the application to moving picture screens of televisions and the like that require driving, and it cannot be said to be suitable.

Recently, Mayer et al. reported a display method using ferroelectric liquid crystal, which has a high-speed response 100 to 1000 times faster than the TN type and a memory effect, and is expected to be used as a next-generation liquid crystal display element. , active research and development is underway.

The liquid crystal phase of ferroelectric liquid crystal belongs to the tilted chiral smectic phase, but in practical terms, the chiral smectic C (hereinafter abbreviated as "sc") phase, which has the lowest viscosity, is the one that has the lowest viscosity. Most desirable.

A number of liquid crystal compounds exhibiting the SC' phase have already been synthesized and studied, but the conditions for use as ferroelectric display elements are (a) SC' phase in a wide temperature range including room temperature.
(b) In order to obtain good orientation, SC
* Having an appropriate phase series on the high temperature side of the phase and having a large helical pitch; (c) having an appropriate tilt angle;
It is preferable that (i) the viscosity is low and (e) the spontaneous polarization is large to some extent, but there is no known material that satisfies these requirements alone.

For this reason, it is currently being used for research purposes as a liquid crystal composition exhibiting an "sc" phase (hereinafter referred to as "S00 liquid crystal composition").

The method for preparing SC* liquid crystal compositions is to use liquid crystal compounds or compositions that have low viscosity, have no or very small spontaneous polarization, and exhibit a smectic C (hereinafter abbreviated as SC) phase or S09 phase over a wide temperature range. A method in which a chiral compound or composition (hereinafter referred to as a chiral dopant) capable of inducing strong spontaneous polarization in a material (hereinafter referred to as a host liquid crystal) is completely added is suitable for obtaining a high-speed response.

The base liquid crystal has low viscosity and SC or S
It is important that the temperature range in which the C* phase is exhibited is wide. However, compounds whose temperature range extends to high temperatures also have high viscosity and are not preferred as parent liquid crystals. Based on this definition, compounds such as two-ring pyrimidine compounds (4) and phenylbenzoate compounds (B) have been mainly used as the main components of parent liquid crystals, (wherein R'' and Rh are respectively independently linear or
A branched alkyl group, alkoxy group, alkanoyloxy group or alkoxycarbonyl group which may be photoactive. ) When attempting to fully realize high-speed response, it has been difficult to obtain a satisfactory response in terms of temperature range.

- As a chiral dopant, it is necessary that even a small amount of addition can induce a large spontaneous polarization, but this spontaneous polarization depends almost entirely on the shape of the optically active group, and a large total spontaneous polarization can be induced. Many optically active groups are already known.

[The invention tries to solve i! ! Title]

However, many such chiral dopants have a strong tendency to narrow the temperature range of the SC* phase when added to the host liquid crystal, and therefore, the SC* phase does not change over a wide temperature range.
* More MIM that shows phase and high-speed response, and is a friend that prevents you from getting full.

The nM to be solved by the present invention is a compound that has a low viscosity and exhibits an SC phase up to a high temperature, has good compatibility with other base liquid crystal compounds, and exhibits an SC0 phase in a wide temperature range when mixed. Furthermore, by using them as chiral dopants, we provide compounds that can cause sufficiently large spontaneous polarization even when added in small amounts, and do not narrow the temperature range of the SC'' phase. The object of the present invention is to provide a composition capable of high-speed response, and also to provide a liquid crystal display element using such a composition.

[Means to solve the problem]

The present invention uses elementary atoms to solve the above problems.

) An optically active compound represented by:

When used as a host liquid crystal, in the above general formula (I), R1 is a general formula (n) or a general formula 0 (wherein, R' fl is an optically active alkyl group having 3 to 20 carbon atoms, an alkanoyl group, represents an alkoxyalkyl group, alkoxyalkanoyl group, )10alkyl group or haloalkanoyl group, Rfl represents an alkyl group or alkoxyl group having 1 to 20 carbon atoms, and Xl and X2 each independently represent a hydrogen atom or a fluorine atom However, at least one of them is fluorine (wherein L and m are each independently 1 to
The optically active compound is preferably an optically active alkyl group or an alkanoyl group, representing an integer of 10, where cm represents an asymmetric carbon atom in the configuration or (S) configuration.

When used as a component of chiraldono9,
In the above general formula (I), R is the general formula (I), the general formula (M), the general formula (■), the general formula (■), or the general formula (■). represents the same thing as p
and q each independently represent an integer of 0 to 10, X represents a fluorine atom or a chlorine atom, and R5 represents an alkyl group. ] The optically active alkyl group, alkanoyl group, alkoxyalkyl group, alkoxyalkanoyl group, haloalkyl group, or haloalkanoyl group represented by these are preferable.

In the compound represented by the above general formula (1), when R2 is an alkoxyl group, the temperature range in which the "sc" phase is exhibited tends to be wider, but the viscosity also tends to increase. It is particularly preferable.

In the optically active group represented by the general formula ω to P,
+(1≦1, and in the optically active groups represented by the above general formulas (■) and ■, it is particularly preferable that q=Q. When p=Q in the optically active group represented by the above general formula (■), and when P=q=O
It is more preferable that

The present invention also provides a liquid crystal composition containing a compound represented by the above general formula (r). In particular, for ferroelectric liquid crystal displays and chiral smectic liquid crystals, the parent liquid crystal or chiraldo=A? It is preferable to use it as an agent. Alternatively, it can be suitably used to prevent reverse domains in normal TN liquid crystals or for STN liquid crystals.

Furthermore, the present invention particularly provides a liquid crystal display element comprising the above composition as a component, and provides a ferroelectric liquid crystal display element capable of high-speed response in a wide temperature range from a low temperature range to a high temperature range.

The compound of formula (1) according to the present invention can be produced, for example, according to the following production method.

[RX in the above formula (1), (to) and (a) K, and X are all the same as those in formula (1). Y represents a leaving group such as a chlorine atom, a bromine atom, an iodine atom, or a p-)luenesulfonyloxy group. ]Fluorine-substituted 4-hydroxyphenylamidine hydrochloride of formula (■) and 3-dimethylamine-2-(4-furkylphenyl)-N,N-cyme'F-ruderopene-(2)-ammonium perchloric acid of formula (■) The salt is reacted in anhydrous alcohol at reflux temperature in the presence of a basic substance such as alcoholade. The entire reaction mixture is cooled to room temperature, water is added, and the precipitated crystals are collected by filtration, washed with water, and then dried in vacuum. The obtained crude crystals were recrystallized from ethanol to obtain the fluorine-substituted 2-(4-
hydroxyphenyl)-5-(4-alkylphenyl)pyrimidine is obtained. Furthermore, the compound of formula (I) according to the present invention is produced by reacting this compound with R'-Y or R'-COCl in the presence of a gold base.

Here, the fluorine-substituted 4-hydroxyphenylamidine hydrochloride of formula (1) can be produced by reacting fluorine-substituted 4-cyanophenol with total ethanol and hydrochloric acid to form an imino ester hydrochloride, and further reacting with ammonia.

3-dimethylamino-2-(4-alkyl or alkoxyphenyl)-N,N-dimethylzoloben-(2)-ammonium perchlorate of formula (to) can be produced, for example, according to the following production method. can.

4-Alkylacetophenone is reacted with sulfur and morpholine to synthesize 4-(2-(4-alkyl(mahalkoxy)phenyl)-1-thioxoethyl 3-morpholine, followed by hydrolysis to form 4-alkyl(mahalkoxy)phenyl) 4-alkyl(halkoxy)phenylacetic acid is obtained.
or alkoxy)phenylacetic acid is synthesized from phosphorus oxychloride and dimethylformamide, reacted with Tomo Vilsmeier reagent, treated with perchlorate, ) phenyl) -N,N-dimethylzoloben-(2)-ammonium oversalt brewed salt can be produced.

The transition temperatures of typical compounds of formula (I) produced in this manner are listed below.

The liquid crystal phase and phase transition temperature can be measured using a polarization microscope and a differential scanning calorimeter (DSC) equipped with a temperature control stage.
However, the transition temperature varies slightly depending on the purity of the sample and measurement conditions.

/ [Examples] The present invention will be explained in detail below using all examples, but of course the gist and scope of the present invention are not limited by these examples.

Example 1 (R)-2-(2-Fluoro-4-(1-MebuLHaQSiliKiYen)Fe-J)-5-(4-Octylphene)
Synthesis of BiIJ midine (compound A2 in Table 1) 1-(&
) Synthesis of 2-fluoro-4-hydroxyphenylamidine hydrochloride 2-fluoro-4-octyloxybenzonitrile 35
．． 9'i anhydrous ester 200ml and absolute ethanol 1
4.4m1. Dissolve in water and cool to 0°C. While stirring, hydrogen chloride gas was sucked into the entire solution for 30 minutes, and after confirming that hydrogen chloride no longer absorbed gas, the mixture was stirred at room temperature for 96 hours. 200 g of anhydrous ether was added, and the precipitated crystals were counted. The separated crystals were dried under reduced pressure to obtain iminoester hydrochloride s4.2. ! i! (yield 97%).

Next, dissolve the ammonia gas in 200 d of anhydrous ethanol at 0°C for 130 minutes.7'i: Then, add the above imino ester hydrochloric acid @54.2j! Add to the mixture and stir at room temperature for 96 hours. Add 500 d'i of anhydrous ether, separate the precipitated crystals, and dry the separated crystals under reduced pressure.
5.9 (yield 97%)'f: Obtained.

I-(b) 3-dimethylamino-2-(4-octylphenyl) -N,N-dimethylzolopen-(2)-
Synthesis of ammonium perchlorate.

p-n-otatilacetophenone 98.3,! 9 and 27.2 g of sulfur were dissolved in 73.9 g of morpholine,
It was refluxed for 4 hours. Cool to 0℃ and add methanol 300-
All the nine crystals precipitated were collected by filtration, vacuum dried, and 4-(2
-(4-octylphenyl)-1-thioquinethyl 3morpholine117. ! ;' (yield 83%) was obtained.

4-(2-(4-octylphenyl)-1-thioxoethyl 3 Morpholine 1175"z Add to and dissolve in ethanol 250" water 50-1 Potassium hydroxide 46.19f
fi was added and the mixture was refluxed for 3 hours. Leave to cool to room temperature and reduce to 10%
Hydrochloric acid was added little by little until acidic. ethyl acetate 50
Add 0 t/total, and the aqueous layer becomes neutral.After washing the entire organic layer with water in step 1, separate the organic layer, evaporate all the solvent, and add triethylene to the residue; Potassium 7
7.2! j? Add and reflux for 4 hours. After cooling to room temperature, 10% hydrochloric acid was added little by little until it became acidic. Add 500 fl of ethyl acetate, wash the organic layer with water until the aqueous layer becomes neutral, then separate the organic layer, dry over anhydrous sodium sulfate, evaporate the solvent, recrystallize from hexane, and give p-octylphenyl. Acetic acid 65.5. ! i! (yield 74%) yk
Profit ratio.

Next, 92.9=i of phosphorus oxychloride was added dropwise to dimethylformamide 73.2.9 while cooling to -5° C. and stirring. After stirring at -5°C for 30 minutes, cooled to -10°C,
I understand p-octylphenyl hexaacid 49.6.9. After stirring at room temperature for 1 hour, at 60°C for 2 hours, and at 80°C for 5 hours, the mixture was cooled to 0°C and 400°C of water was added dropwise. After the dropwise addition, 44,8.9' (+-) of magnesium perchlorate was added.
-dimethylamino-2-(4-octylphenyl) -
N,N-dimethylchloin-(2)-77monium if[@81.9 (99% yield) was obtained.

+-(c) 2-(2-fluoro-4-hydroxy)
Synthesis of phenyl-5-(4-octylphenyl)pyrimidine 8.54 g of 2-fluoro-4-hydroxyphenylamidine hydrochloride obtained in 1-(!L) and 3-dimethylamino-2 obtained in I-Φ) -(4-octylphenyl)-N,N
-Dimethylpropene-(2)-Ammonium perchlorate (20.9 g) was dissolved in 200 g of absolute ethanol, prepared from 100 g of absolute ethanol and 16.8 g of sodium, and a nine-sodium ethoxide solution was added dropwise. After heating under reflux for 6 hours, the mixture was allowed to cool to room temperature, poured with 500 liters of water, and precipitated crystals 1' were collected and washed with water. After several crystals were dried under completely reduced pressure, they were recrystallized from toluene to obtain 2-(2
11.1 g (yield: 71%) of crystals of -fluoro-4-hydroxy)phenyl-5-octylpyrimidine were obtained.

Melting point 167.3℃ IR: 1620 1580 1425 1340 13
15 1270 12301160 1115 840
820 an-'I-(d) Synthesis of the compound described I-(2-(2-fluoro-4-hydroxy)phenyl-5-(4-octylphenyl)pyrimidine obtained in c-n 10.s g 2 dimethyl Formamide (DMF
) dissolved in 10d ratio. To this solution, 0.15.9% potassium t-butoxide was slowly added and stirred at room temperature.

Furthermore, (S)-1-methylheptyl p-
Next, add 0.38.9i of toluene sulfonate dropwise. After completion of the dropwise addition, the mixture was allowed to react at 50° C. for 6 hours, and then allowed to cool at room temperature 1. Water and ether t-,m were added to the reaction solution, and then diluted hydrochloric acid was added until the aqueous layer became neutral. The organic layer was washed with water;
Then, it was washed with saturated brine and dehydrated with anhydrous sodium sulfate. The next set of crystals obtained by distilling off the solvent was purified using silica gel column chromatography, and further recrystallized from ethanol (2-(2-fluoro-4)).
-(1-methylhegtyloxy)phenyl]-5-(4
-octylphenyl)pyrimidine white crystals 0.15.
! ii'e got it. (Yield 22%) The phase transition temperatures are summarized in Table 1.

Example 2 Synthesis of (S)-2-(2-fluoro-4-(2-methylbutoxy)phenyl)-5-(4-hebutylphenyl)pyrimidine (compound 41 in Table 1) In Example 1 , 2-(2-fluoro-4-hydroxy)phenyl-5-(4-octylphenyl)pyrimidine as above! -(a), (b added) Obtained in the same manner as in (c) 7t2-(2-fluoro-4-hydroxy)phenyl-5-(4-hebutylphenyl)pyrimidine 0.5
The reaction was carried out in the same manner as in Example 1, except that 0.25'l of (S)-2-methylglutylglomide was used in place of (S)-1-methylheptyl p-1rue/sulfonate. and purified to give white crystals of the title compound 0.460
Next, get p. (Yield 62%) Example 3 Synthesis of (S) = 2-(2-, yruol-4-(2-hebutyloxyglobanoyloxy)phenyl)-5-(4-octylphenyl)pyrimidine i( Compound A3 in Table 1) 0.5 g of 2-(2-fluoro-4-hydroxy)phenyl-5-(4-octylphenyl)pyrimidine obtained in I-(c) and (S)-2-heptyl Oxypronoyanic acid chloride 0.28.9 f: Refluxed for 6 hours in methylene chloride 1 o in the presence of pyridine 2. After the reaction is complete, ether and sodium bicarbonate water are added to the reaction solution to decompose unreacted acid chloride, and the organic layer is washed with water until the washing solution becomes neutral.

After dehydrating the organic substance, the solvent was distilled off to obtain the ffi
The product was purified using a silica gel column Chromadog 5F and further recrystallized from ethanol to obtain white crystals of the title compound (0.22EC yield 27%) fr.

Example 4 In Example 1, (S)-1-methylhegetyl p-
(S)-2-(2-fluoro-4-( 2-hegteroxychloroviro'M/)phenyl)-s-(4-octylphenyl)pyrimidine (
A compound of No. 1 Cloth Grave 4) was obtained.

Example 5 (S) -2- (
2-Fluoro-4-(2-methyl-1-tanoyloxy)phenylene-5-(4-octylphenyl)pyrimidine (compound numbered 5 in Table 1) was obtained.

Example 6 The phase transition temperature CQ of the liquid crystal composition made of the following two-ring pyrimidine is as follows.

This composition is 80% by weight! i! In Example 2, Tokuyou compound (
@ Compound 1 in Table 1) SC0 liquid crystal composition consisting of 20% by weight! The phase transition temperature was measured as follows.

C-→SC” 4-PSA #N” ==I 1st clothes&
Compound 1 significantly lowers the melting point of the parent liquid crystal, and also greatly increases the SC"-SA point. As a result,
It can be seen that this has the effect of expanding the temperature range of the SC* phase.

Example 7 A parent liquid crystal composition consisting of the following composition? ! I tore my IJ.

The phase inversion temperature ('O) of this composition is as follows.

To this composition, 20% by weight of the compound obtained in Example 3 (the compound of 1i-th plane 3) was added to prepare an SC" liquid crystal composition, which exhibited SCζI at 53°C or lower and SA at 81'c or lower. It shows an N phase below 83°C, and its melting point is not clear.

This composition was completely coated with polyimide, rubbed, and oriented, then filled into a cell with a thickness of 2 μm, and slowly cooled from the isotropic liquid phase to distribute the S00 phase.

A rectangular gold droplet with an electric field strength of 10 V, 1 历, and 50 Hz was applied to this cell, and the electro-optical response speed was measured.
It shows a high-speed response of 122 μsec at 25°C, and the spontaneous polarization at this time is 3. On C/cm2. Further, the tilt angle i was 18.7'.

〔Effect of the invention〕

The compounds of formula (I) according to the present invention have SC
*A compound that exhibits a phase, or a compound that exhibits large spontaneous polarization singly or in combination.

The compound of the present invention exhibits an S00 phase over a wide temperature range and is useful as a compound used for preparing a liquid crystal composition exhibiting high-speed response.

Further, as shown in the examples, it can be easily manufactured industrially, is colorless in itself, has excellent chemical stability against light, moisture, heat, etc., and is practical under extreme pressure.

Agent: Patent Attorney Katsutoshi Takahashi

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. group, haloalkyl group or haloalkanoyl group, R^2 represents an alkyl group or alkoxyl group having 1 to 20 carbon atoms, X^1 and X^2
each independently represents a hydrogen atom or a fluorine atom, and at least one of them is a fluorine atom. ) An optically active compound represented by 2. R^1 is an optically active alkyl group or alkanoyl group having 3 to 20 carbon atoms, and R^2 is a group having 1 to 2 carbon atoms.
The optically active compound according to claim 1, which is an alkyl group of 0. 3. The optically active compound according to claim 2, wherein X^1 is a hydrogen atom and X^2 is a fluorine atom. 4. The optically active compound according to claim 1, wherein R^1 is an optically active alkoxyalkyl group or an alkoxyalkanoyl group having 3 to 20 carbon atoms. 5. The optically active compound according to claim 4, wherein X^1 is a hydrogen atom and X^2 is a fluorine atom. 6. A liquid crystal composition containing the optically active compound according to claim 1. 7. The liquid crystal composition according to claim 6, which exhibits a chiral nematic phase. 8. The liquid crystal composition according to claim 6, which exhibits a chiral smectic phase. 9. A ferroelectric liquid crystal display element using the liquid crystal composition according to claim 6.