JPH02212463A - Allylbiphenylcarboxylic acid derivative liquid crystal - Google Patents

Abstract

NEW MATERIAL:Allylbiphenylcarboxylic acid derivative liquid crystal expressed by formula I (R is linear or branched 1-15C alkyl or alkoxy; n is 1 or 2). EXAMPLE:3-allyl-4-pentyloxybiphenyl-4'-carboxylic acid-cyanophenyl ester. USE:Liquid crystal. Suitable for STN-type display element as having large K3/K1, positive epsilon and excellent miscibility. PREPARATION:For instance, 4-allyloxybiphenylyl-4'-carboxylic acid ethylester is subjected to Claisen rearrangement using N,N-diethylaniline as a solvent to obtain a compound expressed by formula II and reacted with alkyl bromide and sodium carbonate anhydride in acetone to obtain a compound expressed by formula III. Further, the compound expressed by formula III is hydrolyzed to obtain a compound expressed by formula IV and changed to acid chloride with thionyl chloride, then reacted with 4-cyanophenol derivative in the presence of pyridine to afford the compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel allylbiphenylcarboxylic acid derivative liquid crystal and a liquid crystal composition containing the compound.

(Prior Art) Display elements using liquid crystal gold are widely used in watches, calculators, etc.These liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials.Liquid crystal phase There are nematic liquid crystal phases, smectic liquid crystal phases, and cholesteric liquid crystal phases, and among them, the liquid crystal phase using nematic liquid crystals is the most widely put into practical use. There are display elements such as , TN (twisted nematic), DS (dynamic scattering), guest-host, and DAP types, and the liquid crystal materials used in each type exhibit a liquid crystal phase over the widest possible natural temperature range. is desirable.

At present, there is no single liquid crystal substance that satisfies these conditions, and several types of liquid crystal substances or even non-liquid crystal substances are mixed and put into practical use.

These substances are required to be stable against moisture, light, heat, air, and the like.

In addition, in recent years, multi-digit drive display of display elements has been desired, and since the display quality of the conventional TN type method is inferior, a new series of super
The twist type display element (abbreviated as STN) is M, shut (
5chadt), F, Leenhou
ts) and proposed by (Appl.

Phy+s Lett, 50.236 (1987)
), the quality is excellent even with a multi-digit drive display.

The properties of the liquid crystal desired for this method are large Ks/Kl, small Kt/Kt, and small values for Δε/t.CM-5ehadt+F, Leenh
outsSoclet7 for Informa
tton Display'Internation
al Symposium Digest of
Technical Papers Vol-XVI
New 0rleans+Louisiana May
12-14. (1987) 372-375).

[Object of the invention] The present invention provides a novel compound which is a compound having a large + value in Ks/, a positive value in ΔC, and has excellent compatibility, and is useful as a liquid crystal composition suitable for the above-mentioned STN type display element. It is to provide. Another object is to provide a liquid crystal composition characterized in that it contains a liquid crystal compound.

[Structure of the Invention] The present invention (second invention) is - maximum (in the above formula, R is a linear or branched alkyl group or alkoxy group having 1 to 15 carbon atoms, and n represents 1 or 2). This is a liquid crystal composition characterized by containing an allyl biphenylcarboxylic acid derivative liquid crystal represented by the formula and the compound.

Other components other than the compound of the present invention that can be used as a component of the liquid crystal composition of the present invention include, for example, ester-based, Schiff base-based, biphenyl-based, phenylcyclohexane-based, and heterocyclic-based liquid crystal compounds.

It will be done.

Δ (In the above formula, R%n is the same as above) That is, 4-7lyloxybi7eryl-47-carboxylic acid ethyl ester is subjected to Claisen rearrangement using N,N-diethylaniline as a solvent to produce 3-7! J-ru 4-hydroxybiphenylyl-4'-carboxylic acid ethyl ester, and then reacted with an alkyl bromide and anhydrous sodium carbonate in acetone to obtain 3-allyl-4-alkoxybiphenylyl-4'-carboxylic acid ethyl ester. And so. This was hydrolyzed using potassium hydroxide to give a carboxylic acid, this carboxylic acid and thionyl chloride were mixed to give a chloride, and then reacted with a 4-cyanophenol derivative in the presence of pyridine to produce the desired compound.

(Effects of the Invention) The compound of the present invention has good compatibility with many other liquid crystal compounds, such as ester-based, Schiff base-based, biphenyl-based, phenylcyclohexane-based, and heterocyclic-based liquid crystal compounds. When added to the t-liquid crystal composition, Ks/
Since it can increase the value of KI, it is a compound suitable for crystal compositions for STN type non-display elements. Further, the compound of the present invention has a high N-I point, and by using this compound, a liquid crystal composition with a high N-I point can be prepared.

The compounds of the present invention will be explained in more detail with reference to the following examples.

Example 1 (3-71 flu 4-pentyloxybiphenylyl-4
Production of '-carboxylic acid 4-cyanophenyl ester] 4-allylbiphenyl-4'-carboxylic acid ethyl ester 171fN, N-diethylaniline 100+m? The mixture was dissolved in water and boiled under reflux under a nitrogen atmosphere for 8 hours. After cooling, the reaction solution was added to 500 ml of 3N hydrochloric acid and stirred well. The precipitate was filtered, thoroughly washed with water, and then dried. While vigorously stirring the entire solid together with acetone IE and anhydrous sodium carbonate, 20 g of be/tyl bromide was added, and the mixture was further boiled and refluxed for 24 hours. Separate the sediment while it is still hot,
Add 300 ml of toluene to the remaining solid material from which you want to distill off the acetone.
ml, washed with 2N sodium water, and then washed with water until neutral.

After drying the toluene layer over anhydrous sodium sulfate, the toluene was distilled off under reduced pressure, and the remaining oil was dissolved in 500 mL of ethanol.
Dissolved in l. A solution of 200 d of water and 301 d of potassium hydroxide was put into a separate reactor, and the ethanol solution prepared earlier was added over 10 minutes while stirring vigorously at room temperature.

After boiling and refluxing for 5 hours, the reaction solution was cooled and diluted with 6N hydrochloric acid at 700%
ml, a precipitate was deposited. Wash thoroughly with water and dry. This is 3-allyl-4-pentyloxybiphenyl-4'-carbo/acid.

6.4 f of 3-allyl-4-pentyloxybiphenyl-4'-carboxylic acid thus produced and a large excess of thionyl chloride were heated under reflux on a mantle heater for 4 hours. Then, the pressure was reduced using the sound of a water pump, and excess thionyl chloride was distilled off to precipitate crystals. This is an acid chloride.

In another flask, 4-cyanphenol was dissolved in 2.4 ft-pyridine, to which was added the acid chloride prepared previously, and then 200 g/l of toluene was added and stirred vigorously.

After leaving it overnight, pour into 500g of water and add 10% of toluene.
Extraction was performed by adding 0 gJ. 6Nm of toluene layer! ! in,
Then, it was washed with 2N sodium hydroxide and then with water until it became neutral. After drying the toluene layer with anhydrous sulfuric acid (IJ), the toluene was distilled off under reduced pressure, and the remaining crystalline material was chromatographed with toluene solvent using an activated alumina column.

The eluted toluene was distilled off under reduced pressure, and the remaining crystals were recrystallized with ethanol to produce the desired 3-allyl-4-pentyloxybiphenyl-4'-carboxylic acid 4-cyanophenyl ester.

The yield is 8.5F (yield 43%), the crystal-nematic liquid crystal transition point (C=N point) is 85.9-86°5℃, and the nematic liquid crystal-clearing point (N-I point) is 116.4. It was ℃.

Example 2 In Example I, in place of 3-allyl-4-pentyloxybiphenyl-4'-carboxylic acid, various 3-allyl-4-[substituted biphenyl-4'-carboxylic acids were substituted and 4-
The results of preparing the desired ester derivative in tml using 4-cyano-4'-hydroxybiphenyl in place of cyanophenol are shown in Table 1 together with the results of Example 1.

Table 1 Example 3 (Application example) Trans-4-propyl-(4-cyanophenyl)cyclohexane 30% by weight trans-4-pentyl-(4-cyanophenyl)cyclohexane
4031% by weight of trans-4-hebutyl-(4-cyanophenyl)cyclohexane 30% by weight liquid crystal mixture (to) has a N-I point U52.1''C1Δg of 11.2.The viscosity at 20°C is 28. 4CP% Δ
n is 0.119 and Ks/Kt is 1.82.

A liquid crystal cell was prepared in which substrates coated with silicon oxide and having tin oxide transparent electrodes treated with two pins were assembled to face each other, and the distance between the electrodes was 10 μm, and the above liquid crystal composition (4) was sealed. When we measured its characteristics at 20°C, we found that the threshold voltage (hereinafter abbreviated as vth) was 1.
．． It was 55V.

3-allyl-4-pentyloxybiphenylyl-4 prepared in Example 1 of the present invention was added to 90% by weight of this liquid crystal composition.
7-Carboxylic acid 4-cyanophenyl ester 10! amount%
The N-I point of the dissolved liquid crystal composition is 57.5°C, and ΔC is 8
．． 5, Δn is 0.125, vth is 1.60V, and viscosity is 32. With Oep, we were able to significantly increase the N-I point. Also, Ks/KI is as large as 2.02, making it suitable for STN use.

that's all

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the above formula, R is a linear or branched alkyl group or alkoxy group having 1 to 15 carbon atoms, and n represents 1 or 2. ) Allyl biphenyl carboxylic acid derivative liquid crystal. (2) A liquid crystal composition comprising the allyl biphenylcarboxylic acid derivative liquid crystal according to claim 1.