JPH02225436A - Biphenyl derivative compound and liquid crystal composition containing the same - Google Patents

Abstract

NEW MATERIAL:A biphenol derivative compound of formula I (R is 1-10C alkyl; X is Cl, F, cyano). EXAMPLE:The compound of formula VII. USE:A liquid crystal electro-optical element. It gives a liquid crystal composition which can be driven with a low operating voltage and with high chemical stability. PREPARATION:For example, 2-hydroxytolnene of formula II is converted through a compound of formula III and a compound of formula IV into a compound of formula V, after reaction of the former product with phenylmagnesium bromide. The compound of formula V is subjected to bromine addition reaction to give a compound of formula VI, which is allowed to react with copper cyanide to give a compound of formula I where X is cyano. The reaction of the compound of formula IV with p-halogenophenylmagnesium bromide gives another compound of formula I where X is chlorine or fluorine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a biphenyl derivative compound used in a liquid crystal electro-optical element and a liquid crystal composition containing the same.

[Prior Art] Liquid crystal display elements have begun to be used in various applications such as watches and calculators, and in recent years, measuring instruments, automobile instruments, copiers, cameras, etc., and have a wide operating temperature range, low operating voltage, There are various performance requirements such as high-speed response and chemical stability.

However, at present, there is no material that satisfies all of these characteristics with a single material (although liquid crystal compositions that meet the required performance by mixing multiple liquid crystal and non-liquid crystal materials). There is a desire for the development of liquid crystal materials or non-liquid crystal materials that are superior not only in all of the various properties but also in properties on two sides.

[Problems to be Solved by the Invention] Among the various properties required of liquid crystal compounds used in the field of display devices, they must be able to be driven at low voltage, have excellent compatibility with other liquid crystal materials or non-liquid crystal materials, and have excellent chemical properties. Providing physically stable materials is an important issue.

[Means for Solving the Problems] The present invention provides a novel material to solve the above-mentioned problems, which has the following formula: - R represents an alkyl group having 1 to 10 carbon atoms; X
is a chlorine atom, a fluorine atom, or a cyano group) and at least one kind thereof is provided.

The compound of general formula (I) of the present invention has extremely large positive dielectric anisotropy (Δε), has excellent compatibility with other liquid crystal materials or non-liquid crystal materials, and has chemical It is also a stable material, making it suitable for lowering the driving voltage in liquid crystal compositions.

The compound of general formula (I) of the present invention is used as a liquid crystal composition by mixing at least one of the compounds with other liquid crystal materials and non-liquid crystal materials.

Examples of substances to be mixed as the compound of the present invention include the following.

Unlike R in the present invention, R and R' in the following formula represent groups such as an alkyl group, an alkoxy group, a halogen atom, and a cyano group.

These compounds are merely examples (substitution of a hydrogen atom with a halogen atom, a cyano group, a methyl group, etc., substitution of a cyclohexane ring, a benzene ring with another six-membered ring, a five-membered ring, etc.), Many materials can be selected and used, such as changing the bonding group between them.

The composition of the present invention is used by being injected into a liquid crystal cell.

A typical liquid crystal cell is twisted nematic (TN
) There is a liquid crystal element, and transparent electrodes such as ERO Jm-, 5N02, etc. are formed in the desired pattern on the inner surface of a transparent substrate made of glass, plastic, etc., and if necessary, overcoated with SiOx, polyimide, etc., and horizontally The substrates on which alignment layers are formed are placed facing each other, the periphery is sealed, liquid crystal is injected, and the injection port is sealed, and polarizing plates are laminated on both outer surfaces. In addition, a super twisted nematic (STN) type with a high twist angle, which has recently been attracting attention, a phase change type, a guest post type, a dynamic scattering type, or a combination thereof may be used, or an electrically It may also be used for a type of writing using heat.

Furthermore, as for the structure of the cell, between the transparent substrate and the transparent electrode,
Provide an undercoat layer such as 5ins, Allow, etc., use a reflective electrode, use a multilayer electrode, use a color polarizing plate, use a color filter, use a semiconductor substrate, or use a multilayer element. It can be used in many applications such as watches, calculators, measuring instruments, and automobile instruments.

It can be used for many purposes such as games, computer terminals, etc.

In the compound of general formula (I) of the present invention, a compound in which X is a cyano group can be produced, for example, according to the following method. (In each formula, R has the same meaning as R in formula (1).) Br rz ('51+ ↓ B''.

C.I.

↓ uCN rμ.

That is, 2-hydroxytoluene, which is a compound of formula (n), is reacted with an alkyl bromide to form 2-alkoxytoluene (III), and bromine is added to this (III) to form a bromide, 2-alkoxy-5-bromo. Toluene (TV
), this (fV) is reacted with phenylmagnesium bromide to obtain a compound of formula (V), and bromine is added to this to obtain (Vl). The bromine in (Vl) is converted into a cyano group using cyanide steel to obtain a compound of the general formula (R).

Further, in the general formula (I), a compound in which X is a chlorine atom or a fluorine atom can be produced, for example, according to the following method. (In each formula, R is R in formula (I), respectively.
has the same meaning as ) That is, the compound of general formula (1) is obtained by reacting formula (IV) with p-halogenophenylmagnesium bromide.

Note that these manufacturing methods are merely examples, and various manufacturing methods can be used.

[Examples] The present invention will be explained in more detail in the following Examples using a method for producing the compound of the present invention and a liquid crystal composition using the compound of the present invention.

Example 1 54.1 g (0.50 mol) of 0-cresol and 33.7 g (0.60 mol) of potassium hydroxide were added to 10 g of water.
0 ml and 100 a+1 acetone, 0.2 g of potassium iodide was added thereto, and while heating under reflux, 92.2 g (0.75 mol) of n-propylbromide was added dropwise over 1 hour. After further refluxing for 10 hours, the mixture was cooled to room temperature, extracted with hexane, washed with water, dried, and then distilled under reduced pressure to obtain 60.0 g of 2-n-propoxytoluene.

54.6 g of the obtained 2-n-propoxytoluene (0,
364 mol) was dissolved in 100 ml of chloroform, and 61.1 g (0,382 a+ol) of bromine was dissolved at 10°C for 40 min.
The mixture was added dropwise over a period of minutes, and the mixture was further stirred at the same temperature for 1.5 hours. 100 ml of water was added to this, and after performing alkali washing, water washing, and drying, 78.8 g of 5-bromo-2-n-propoxytoluene was obtained by distillation under reduced pressure.

Magnesium (shavings) 9.93g (0,408m
A Grignard reagent was prepared by adding 61.1 g (0.3 g 4 moi) of bromobenzene dropwise at room temperature over 40 minutes to a mixed solution of 5 [) ml of anhydrous tetrahydrofuran and diluting with 250 ml of anhydrous tetrahydrofuran. 74.2 g (0,324 m+ol) of 5-bromo-2-n-propoxytoluene and bis(1,2-
Diphenylphosphino)ethane Nickel (U) chloride 0.855g (Q, OOL62mou) dissolved in anhydrous tetrahydrofuran 200++t1,
The mixture was added dropwise at ℃ over 2 hours. After further stirring at room temperature overnight, 500 ml of 5% diluted hydrochloric acid was added, extracted with toluene, washed with water, dried, and distilled under reduced pressure to obtain 27.1 g of 3-methyl-4-propoxybiphenyl.

3-Methyl-4-propoxybiphenyl 24.8g (0
110 mol) of carbon tetrachloride was dissolved in 300 ml of carbon tetrachloride, and 1.53 g (0,028@all) of iron powder was added thereto, and 18.5 g (0,116 mol) of bromine was added dropwise at 10°C over 1 hour. After stirring overnight at 10
．． 6g was obtained.

The obtained 4°-bromo-3-methyl-4-n-propoxybiphenyl IO, 6 g (0,0347 mol) and copper cyanide 3.57 g (0,0399 mol) were mixed with N,N
-Dissolved in 100ml of dimethylformamide and heated under reflux for 3 hours. A mixture of 20 g of iron (III) chloride and 50 ml of 5% diluted hydrochloric acid was added to this, and the mixture was stirred at 70°C for 20 minutes, extracted with 1,2-dichloroethane, and washed with water. After filtering off the insoluble matter and concentrating, recrystallization was performed with ethyl alcohol to obtain 4.80 g (0,019 g) of the target compound below.
1 mol) was obtained.

rl.

The assignment of the 'H-NMR (CDCa solvent, TMS internal standard) spectrum was as follows.

δ (ppm) 1,. 07 f t, -CN3. 3
H) 1.82-1.89 (m, -CHxCH
-, 2H) 3.98 (t, -0CHt
C1hCHs, 2) 1) 6.87-6.91
(m, a, romatfc, 2H) 7.37
-7.39 (tm, aroa+atfc,
LH) 7.60-7.70 (rn, aro
matic, 4H) Also, the IR spectrum of this compound (KBr tablet) is shown in FIG.

Similarly, by replacing propyl bromide with the corresponding alkyl bromide, the following compounds can be synthesized.

? + Similarly, the following compounds can be synthesized by coupling p-halogenobromobenzene with 3,4-disubstituted bromobenzene instead of bromobenzene.

Example-2 Liquid crystal composition ZLI publication 565 manufactured by Merck & Co. was injected into a cell with a substrate gap of 8 μm made by combining silicon oxide coated and rubbed ITO transparent electrodes, and the threshold value at 25°C was When the voltage was measured, it was 2.38V. The threshold voltage of the liquid crystal composition to which 10 wt % of the compound of Example 1 was added was lowered to 2.16 V, and the driving voltage could be lowered.

[Effect of the invention] As described above, the present invention provides a novel compound "■.

(In the formula, R represents an alkyl group having 1 to 10 carbon atoms, and X represents a chlorine atom, a fluorine atom, or a cyano group)
By providing a biphenyl derivative compound represented by the formula, it is possible to form a liquid crystal composition that can be driven at a low operating voltage and is chemically stable, resulting in an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is an IR spectrum diagram of the compound of Example 1 of the present invention.

Claims (3)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, R represents an alkyl group having 1 to 10 carbon atoms, and X represents a chlorine atom, a fluorine atom, or a cyano group)
A biphenyl derivative compound represented by (2) A biphenyl derivative compound of the general formula (I) according to claim 1, wherein R is a linear alkyl group. (3) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, R represents an alkyl group having 1 to 10 carbon atoms, and X represents a chlorine atom, a fluorine atom, or a cyano group)
A liquid crystal composition comprising at least one biphenyl derivative compound represented by: