JPH0813804B2 - 2,5-Diphenylpyrimidine compound, liquid crystal composition and electro-optical element - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel organic compound and a liquid crystal composition containing the same, and more specifically to a 2,5-diphenylpyrimidine compound having an optically active group and the same. The present invention relates to an optically active liquid crystal composition containing it and an electro-optical element using the same.

[Conventional technology]

The liquid crystal display element has low voltage operation, low power consumption,
Since it has excellent features such as thin display,
It is widely used as various display elements for watches, calculators, televisions, computer terminals, and the like.

At present, the TN (twisted nematic) display method is most widely used as a display element, but in terms of response speed, it is inferior to light-emitting display elements such as electroluminescence and plasma displays. Has not been significantly improved despite various attempts.

However, in a new display system using ferroelectric liquid crystal, which has been actively studied recently, there is a possibility that the response speed can be remarkably improved. (Clark et al. Applied Phy
S. Lett., 36 , 899 (1980)). This display system uses a chiral smectic C phase (hereinafter abbreviated as Sc ^* phase) exhibiting ferroelectricity, or another smectic phase such as chiral smectic F, G, H, or I phase.
Compared to the TN type display element, it is possible to realize high-speed response of several hundred to several thousand times, memory effect due to bistability, etc., and it is used in various fields such as large TVs that can display moving images, high-speed optical shutters, etc. Application to is expected.

[Problems to be solved by the invention]

However, despite these excellent properties, currently known compounds have not yet exhibited sufficient high-speed response. This is because no compound having a sufficiently large spontaneous polarization value in the ferroelectric liquid crystal phase has been known. The spontaneous polarization value and the response speed are in a proportional relationship, and it is known that increasing the spontaneous polarization value is the first in order to obtain high-speed response. No compounds have been found yet.

An object of the present invention is to provide an optically active compound having a large spontaneous polarization value necessary for realizing characteristics suitable for the above-mentioned display system, which has been recently studied, particularly high-speed response.

[Means for solving problems]

The present invention provides the following formula: (However, in the above formula, R ¹ represents an alkyl group or an alkoxy group having 1 to 20 carbon atoms, R ² represents an alkyl group containing 1 to 20 carbon atoms, an acyl group or a 2-alkoxypropionyl group, * Indicates that the carbon atom is an asymmetric carbon) and a liquid crystal composition containing a 2,5-diphenylpyrimidine compound and at least one thereof.

The compounds of the present invention do not necessarily exhibit a ferroelectric liquid crystal phase, but when they are used as components of a ferroelectric liquid crystal composition, they have the effect of significantly increasing the spontaneous polarization value. , It is possible to greatly improve the response speed. As will be described later in Examples, by adding a few to several tens% by weight to a liquid crystal composition exhibiting a non-chiral smectic C phase that does not exhibit a spontaneous polarization value, a significantly large spontaneous polarization value is induced in the composition, and For example, as described in Example 2, 80 μse at 25 ° C.
It is possible to obtain a composition having an extremely fast response speed called c.

Furthermore, the compound of the present invention also has the property of deriving a suitable ferroelectric liquid crystal temperature range when used as a component of a liquid crystal composition. For example, as shown in Example 2, the composition to which the compound of the present invention was added increased the upper limit of the Sc ^* phase by 4.4 ° C. as compared with that before the addition, and can be said to be an excellent compound.

In addition, since the compound of the present invention has an asymmetric carbon, it has the ability to induce a twisted structure when added to a nematic liquid crystal. A nematic liquid crystal having a twisted structure, that is, a chiral nematic liquid crystal, has a TN
Since the so-called reverse domain of the pattern display element is not generated, it can be used as a reverse domain generation inhibitor.

The pitch of the chiral nematic liquid crystal composition containing the compound of the present invention was 21.4 at 25 ° C. when measured by adding 1% by weight to the nematic liquid crystal composition ZLI-1132 manufactured by Merck Ltd., as shown in Example 3. It is as short as μm, and it becomes easy to obtain a necessary and sufficient pitch length by adding a small amount, and it is understood that the compound of the present invention is useful as a pitch adjusting agent for a chiral nematic liquid crystal composition.

 Next, a method for producing the compound of the present invention will be described.

The compound (I) of the present invention can be suitably produced, for example, by the following route.

(In the formula (I), R ² is a 2-alkoxypropionyl group).

(However, in the above formula, R ¹ represents an alkyl group or an alkoxy group, R represents an alkyl group, and A represents a removable protective group such as a methyl group or a benzyl group).

That is, p-substituted phenylacetic acid (II) is reacted with phosphorus oxychloride, dimethylformamide, and then magnesium perchlorate to obtain (III). P-Alkylbenzamidine hydrochloride or p-alkoxybenzamidine hydrochloride was allowed to act on this under basic conditions to obtain (IV). After deprotecting group reaction to this product (V),
(VI) was obtained by reacting with S-2-tetrahydropyranyloxy-1- (p-toluenesulfonyloxy) propane described in JP-A 64-49. Further deprotection was carried out under acidic conditions to obtain (VII). A variety of alkyl halides are allowed to act on this compound under basic conditions, and among the compounds of formula (I), those in which R ² is an alkyl group are treated with various fatty acids or various 2-alkoxypropanoic acids. By acting, each R ² in the formula (I) has an acyl group or a 2-alkoxypropanoyl group.

The compound names of representative compounds of the present invention obtained as described above and showing excellent responsiveness are specifically shown below.

5- [4- (2-butyloxypropyloxy) phenyl] -2- (4-propylphenyl) pyrimidine, 5- [4- (2-hexanoyloxypropyloxy)
Phenyl] -2- (4-propylphenyl) pyrimidine, 5- {4- [2- (2-methylheptanoyloxy) propyloxy] phenyl} -2- (4-propylphenyl) pyrimidine, 2- (4- Propylphenyl) -5- {4- [2- (2
-Pentyloxypropionyloxy) propyloxy] phenyl} pyrimidine, 2- (4-propyloxyphenyl) -5- [4- (2
-Pentanoyloxypropyloxy) phenyl] pyrimidine, 5- {4- [2- (2-butyloxypropionyloxy) propyloxy] phenyl} -2- (4-propyloxyphenyl) pyrimidine, 2- (4-butyl Phenyl) -5- [4- (2-butyryloxypropyloxy) phenyl] pyrimidine, 2- (4-butylphenyl) -5- {4- [2- (2-
Propyloxypropionyloxy) propyloxy]
Phenyl} pyrimidine, 2- (4-butyloxyphenyl) -5- [4- (2-
Pentyloxypropyloxy) phenyl] pyrimidine, 2- (4-butyloxyphenyl) -5- {4- [2-
(2-Methylpentanoyloxy) propyloxy] phenyl} pyrimidine, 2- (4-butyloxyphenyl) -5- {4- [2-
(2-Butyloxypropionyloxy) propyloxy] phenyl} pyrimidine, 5- [4- (2-hexyloxypropyloxy) phenyl] -2- (4-pentylphenyl) pyrimidine, 5- {4- [2- ( 3-Methylhexanoyloxy) propyloxy] phenyl} -2- (4-pentylphenyl) pyrimidine, 2- (4-pentylphenyl) -5- {4- [2- (2
-Pentyloxypropionyloxy) propyloxy] phenyl} pyrimidine, 5- [4- (2-pentanoyloxypropyloxy)
Phenyl] -2- (4-pentyloxyphenyl) pyrimidine, 5- {4- [2- (2-butyloxypropionyloxy) propyloxy] phenyl} -2- (4-pentyloxyphenyl) pyrimidine, 5- [ 4- (2-butyryloxypropyloxy) phenyl] -2- (4-hexylphenyl) pyrimidine, 5- {4- [2- (2-propyloxypropionyloxy) propyloxy] phenyl} -2- (4 -Hexylphenyl) pyrimidine, 2- (4-hexyloxyphenyl) -5- [4- (2
-Propyloxypropyloxy) phenyl] pyrimidine, 2- (4-hexyloxyphenyl) -5- {4- [2
-(2-Methylhexanoyloxy) propyloxy]
Phenyl} pyrimidine, 2- (4-hexyloxyphenyl) -5- {4- [2
-(2-pentyloxypropionyloxy) propyloxy] phenyl} pyrimidine, 5- [4- (2-butyloxypropyloxy) phenyl] -2- (4-heptylphenyl) pyrimidine, 2- (4-heptylphenyl) -5- {4- [2- (1
-Methylheptanoyloxy) propyloxy] phenyl} pyrimidine, 2- (4-heptylphenyl) -5- {4- [2- (2
-Pentyloxypropionyloxy) propyloxy] phenyl} pyrimidine, 2- (4-heptylphenyl) -5- [4- (2-pentanoyloxypropyloxy) phenyl] pyrimidine, 5- {4- [2- (2 -Butyloxypropionyloxy) propyloxy] phenyl} -2- (4-pentyloxyphenyl) pyrimidine, 5- [4- (2-hexanoyloxypropyloxy)
Phenyl] -2- (4-octylphenyl) pyrimidine, 5- {4- [2- (2-hexyloxypropionyloxy) propyloxy] phenyl} -2- (4-octylphenyl) pyrimidine, 2- (4- Octyloxyphenyl) -5- [4- (2
-Pentyloxypropyloxy) phenyl] pyrimidine, 5- {4- [2- (3-methylheptanoyloxy) propyloxy] phenyl} -2- (4-octyloxyphenyl) pyrimidine, 5- {4- [2 -(2-heptyloxypropionyloxy) propyloxy] phenyl} -2- (4-octyloxyphenyl) pyrimidine, 5- [4- (2-butyloxypropyloxy) phenyl] -2- (4-nonylphenyl) Pyrimidine, 2- (4-nonylphenyl) -5- [4- (2-pentanoyloxypropyloxy) phenyl] pyrimidine,
S-form mp123.2 ° C 5- [4- (2-heptanoyloxypropyloxy)
Phenyl] -2- (4-nonylphenyl) pyrimidine, 5- {4- [2- (2-methylbutyryloxy) propyloxy] phenyl} -2- (4-nonylphenyl) pyrimidine, S, S form mp109 .5 ° C. 5- {4- [2- (3-methylpentanoyloxy) propyloxy] phenyl} -2- (4-nonylphenyl) pyrimidine, S-form mp121.1 ° C. 2- (4-nonylphenyl)- 5- {4- [2- (2-
Propyloxypropionyloxy) propyloxy]
Phenyl} pyrimidine, 5- {4- [2- (2-butyloxypropionyloxy) propyloxy] phenyl} -2- (4-nonylphenyl) pyrimidine, S, S form mp98.0 ° C 2- (4-nonyl Phenyl) -5- [4- (2-hexyloxypropyloxy) phenyl] pyrimidine, R-form 2- (4-decylphenyl) -5- {4- [2- (2-
Pentyloxypropionyloxy) propyloxy]
Phenyl} pyrimidine, 5- [4- (2-hexanoyloxypropyloxy)
Phenyl] -2- (4-decyloxyphenyl) pyrimidine, 5- [4- (2-hexanoyloxypropyloxy)
Phenyl] -2- (4-undecylphenyl) pyrimidine, 5- [4- (2-hexanoyloxypropyloxy)
Phenyl] -2- (4-undecyloxyphenyl) pyrimidine, 5- {4- [2- (2-propyloxypropionyloxy) propyloxy] phenyl} -2- (4-undecyloxyphenyl) pyrimidine, 5 -[4- (2-Butyloxypropyloxy) phenyl] -2- (4-dodecylphenyl) pyrimidine, 5- {4- [2- (2-butyloxypropionyloxy) propyloxy] phenyl} -2- ( 4-dodecylphenyl) pyrimidine, 5- [4- (2-butyryloxypropyloxy) phenyl] -2- (4-dodecyloxyphenyl) pyrimidine, 5- [4- (2-pentyloxypropyloxy) phenyl] -2- (4-tridecylphenyl) pyrimidine, 5- {4- [2- (2-pentyloxypropionyl) Alkoxy) propyloxy] phenyl} -2- (4-tridecylphenyl) pyrimidine, 5- [4- (2-pentanoyloxy propyloxy)
Phenyl] -2- (4-tridecyloxyphenyl) pyrimidine.

〔Example〕

Hereinafter, the compounds of the present invention will be described in more detail with reference to Examples.

Example 1 S-5- {4- [2- (2-butyloxypropionyloxy) propyloxy] phenyl} -2- (4-nonylphenyl) pyrimidine: (In the formula (I), R ¹ is C ₉ H ₁₉ -, Preparation of (first stage) 5- (4-methoxyphenyl) -2- (4-nonylphenyl) pyrimidine (in the formula (IV), R ¹ is C ₉ H ₁₉ —
To 146 g of dimethylformamide, 184 g of phosphorus oxychloride was added dropwise at 0 ° C, and then 66 g of p-methoxyphenylacetic acid was added little by little at a temperature of -10 ° C. The mixture was stirred at 20 ° C. for 1 hour, 60 ° C. for 2 hours, and 80 ° C. for 5 hours. Dimethylformamide was distilled off in vacuo, the residue was cooled and poured into a saturated aqueous solution of magnesium perchlorate. The precipitated crystals are filtered off and washed with ether to give a melting point of 133.3-13
67 g of salt at 4.4 ° C. were obtained.

60 g of this salt, 48 g of p-nonylbenzamidine hydrochloride,
A mixture of 13.6 g of sodium methylate and 600 ml of ethanol was refluxed for 6 hours. Toluene was added, and the mixture was washed with alkali and then with water, the solvent was distilled off, and the residue was ethanol-
Recrystallized from a mixed solvent of ethyl acetate to give 5- (4-methoxyphenyl) -2- (4-nonylphenyl) pyrimidine.
60g was obtained. This shows liquid crystallinity, and the phase transition point is C
-S _A point is 88.9 ℃, S _A -N point is 186.0 ℃, NI point is 194.4
° C.

(Second stage) 5- (4-hydroxyphenyl) -2- (4-nonylphenyl) pyrimidine (in the formula (V), R ¹ is C ₉ H ₁₉
A mixture of 60 g of 5- (4-methoxyphenyl) -2- (4-nonylphenyl) pyrimidine, 240 g of hydrobromic acid, and acetic acid 1 was refluxed for 40 hours. After distilling off most of the acetic acid, the mixture was poured into a 2N-sodium hydroxide aqueous solution and the precipitated crystals were collected and recrystallized from ethyl acetate to give 5-
32.6 g of (4-hydroxyphenyl) -2- (4-nonylphenyl) pyrimidine was obtained. It exhibits liquid crystallinity, and the phase transition point is 98.4 ° C at C-S _A point and 138.6 ° C at S _A- I point.
Met.

(Third stage) 5- [4- (2-hydroxypropyloxy) phenyl] -2- (4-nonylphenyl) pyrimidine ((VI
In formula I), R ¹ is C ₉ H ₁₉ −) 20 g of tetrahydrofuran with 20 g of 5- (4-hydroxyphenyl) -2- (4-nonylphenyl) pyrimidine on 2.8 g of sodium hydride in 20 ml of tetrahydrofuran A 100 ml solution was gradually added dropwise, 200 ml of dimethylformamide was added, and the mixture was stirred for 1 hour. In the same manner as described in JP-A 64-49, S-2-tetrahydropyranyloxy-
1- (p-toluenesulfonyloxy) -propane 20g
Was added, and the mixture was stirred at about 65 ° C. for 3 hours. Add toluene,
After washing with 2N-sodium hydroxide and washing with water, toluene was distilled off, the residue was dissolved in 300 ml of ethanol, 30 ml of hydrochloric acid was added, and the mixture was stirred at about 60 ° C for 2 hours. After adding 2N-sodium hydroxide to make it basic, the precipitated crystals were filtered and recrystallized from ethyl acetate to give 5- [4- (2-
11.6 g of hydroxypropyloxy) phenyl] -2- (4-nonylphenyl) pyrimidine was obtained. This compound shows liquid crystallinity, and its phase transition point is 96.8 ° C at C-S _A point and S _A- I
The point was 211.1 ° C.

(4th stage) Preparation of title compound 5- [4- (2-hydroxypropyloxy) phenyl] -2- (4-nonylphenyl) pyrimidine 5 g, S-
A mixture of 2.6 g of 2-butyloxypropanoic acid, 4 g of dicyclohexylcarbodiimide, 0.3 g of dimethylaminopyridine and 60 ml of dichloromethane was stirred for 2 hours. The precipitated crystals are separated by filtration, toluene is added to the filtrate, and after washing with alkali,
It was washed with water, the solvent was distilled off, and recrystallized from a mixed solvent of ethanol-ethyl acetate to give 4 g of S-5- {4- [2-butyloxypropionyloxy) propyloxy] phenyl} -2- (4-nonyl). Phenyl) pyrimidine was obtained.
Melting point 98.0 ° C. The elemental analysis value of this product was as follows and was in good agreement with the calculated value.

Analytical value C ₃₅ H ₄₇ O ₄ N ₂ experimental value Calculated value C 74.90% 75.10% H 8.40 8.46 O 11.30 11.43 N 5.20 5.01 Example 2 (Use Example 1) First, a composition using the following liquid crystal compound was prepared. .

The phase transition points of the above composition were as follows.

The compound of Example 1 in 80% by weight of the above composition: S-5- {4
-[2- (2-Butyloxypropionyloxy) propyloxy] phenyl} -2- (4-nonylphenyl)
20% by weight of pyrimidine was added to prepare a chiral smectic liquid crystal composition. This composition was coated with polyvinyl alcohol as an alignment treatment agent, rubbed on the surface, and injected into a cell having a cell thickness of 1.8 μm equipped with a transparent electrode subjected to parallel alignment treatment. When it was installed between the analyzer and the analyzer and an electric field intensity of 5 V / μm was applied, a change in the transmitted light intensity was confirmed.

The response speed is calculated from the change in transmitted light intensity at this time.
It was 80 μsec at ° C. The magnitude of spontaneous polarization and the tilt angle of this composition were 37.8 nC / cm ² and 24.0 ° at 25 ° C., and the phase transition points were as follows.

As described above, the compound of the present invention was found to be an extremely useful ferroelectric liquid crystal material.

Example 3 (Use Example 2) Nematic liquid crystal composition (using ZLI 1132 manufactured by Merck)
To the compound of the present invention: 2- (4-nonylphenyl) -5-
A chiral nematic liquid crystal is prepared by adding 1% by weight of [4- (2-hexyloxypropyloxy) phenyl] pyrimidine (in the formula (I), R ¹ is C ₉ H ₁₉ — and R ² is —OC ₆ H ₁₃ ). When the composition was injected into a wedge-shaped cell subjected to parallel alignment treatment and observed under a deflection microscope, the helical pitch was observed as follows.

As described above, the temperature dependence of the pitch is extremely flat, and it was found that the compound of the present invention is an excellent pitch adjusting agent for a chiral nematic liquid crystal composition.

Example 4 (Use Example 3) When a nematic liquid crystal composition consisting of the above was injected into a cell having an electrode interval of 10 μm to form a TN type display cell, and this was observed with a polarization microscope, it was observed that a reverse twist domain was generated. The cell used was coated with polyvinyl alcohol as an orientation treatment agent, and its surface was rubbed for parallel orientation treatment.

2- (4-nonylphenyl) -5- {4- which is one of the compounds of the present invention is added to the above nematic liquid crystal composition.
[2- (3-Methylpentanoyloxy) propyloxy] phenyl} pyrimidine: (In the formula (I), R ¹ is C ₉ H ₁₉ —, When 0.1% by weight was added and observed in the same TN type cell, the reverse twist domain was eliminated and a uniform nematic phase was observed.

(Effects of the Invention) According to the compound of the present invention, any of them can be used as a component of a ferroelectric liquid crystal composition, and has an action of remarkably increasing the spontaneous polarization value. It can be applied to materials that enable responsive displays.

Further, when the compound of the present invention is used as a component of a liquid crystal composition, it is a very useful ferroelectric liquid crystal material for deriving a suitable ferroelectric liquid crystal temperature range. Furthermore, the chiral nematic liquid crystal composition obtained by adding the compound of the present invention to the nematic liquid crystal composition is useful as a pitch adjusting agent.

Claims (5)

[Claims] 1. A general formula (However, in the above formula, R ¹ represents an alkyl group or an alkoxy group having 1 to 20 carbon atoms, R ² represents an alkyl group containing 1 to 20 carbon atoms, an acyl group or a 2-alkoxypropionyl group, * Indicates that the carbon atom is an asymmetric carbon)), a 2,5-diphenylpyrimidine compound. 2. General formula (However, in the above formula, R ¹ represents an alkyl group or an alkoxy group having 1 to 20 carbon atoms, R ² represents an alkyl group containing 1 to 20 carbon atoms, an acyl group or a 2-alkoxypropionyl group, * Represents that the carbon atom is an asymmetric carbon), and at least one 2,5-diphenylpyrimidine compound represented by the formula (3) is contained in the liquid crystal composition. 3. The liquid crystal composition according to claim 2, wherein the liquid crystal phase exhibited is a chiral smectic phase. 4. The liquid crystal composition according to claim 2, wherein the liquid crystal phase exhibited is a chiral nematic phase. 5. A general formula (However, in the above formula, R ¹ represents an alkyl group or an alkoxy group having 1 to 20 carbon atoms, R ² represents an alkyl group containing 1 to 20 carbon atoms, an acyl group or a 2-alkoxypropionyl group, * Indicates that the carbon atom is an asymmetric carbon) and at least one 2,5-diphenylpyrimidine compound is contained in the liquid crystal composition.