JPS608251A - Ester derivative of 2-cyano-4-alkylphenol - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R and R' are 1-15C alkyl; the ring X is group of formula II or III). EXAMPLE:4-Pentylterphenyl-4''-carboxylic acid 2-cyano-4-heptylphenyl ester. USE:A liquid crystal substance. It has negative dielectric anisotropy, high compatibility, and high nematic-clear point. PREPARATION:The compound of formula I (the ring X is group of formula III) is prepared by reacting 4-alkylterphenyl-4''-carboxylic acid of formula IV with thionyl chloride, and reacting the resultant acid chloride with 2-cyano-4-alkylphenol in the presence of pyridine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ester derivative of 1, and relates to a novel liquid crystal compound having negative charge anisotropy and a liquid crystal composition containing the same.

Liquid crystal display elements make full use of the optical anisotropy and dielectric anisotropy of liquid crystal materials, and are classified into TN type (TN type) depending on the display style.
There are various types such as twisted nematic type (twisted nematic type), DB type (dynamic scattering type), guest-host type, and DABmA, and the properties of the product materials suitable for each use are different. It is common for all liquid crystal materials to be stable against moisture, air, heat, light, etc., and materials that exhibit a liquid crystal phase over as wide a temperature range as possible, centered around room temperature, are desired. .

At present, there is no single compound that satisfies these conditions, and liquid crystal compositions obtained by mixing several types of compounds or non-liquid crystal compounds are used.

Recently, guest display, which is a color LCD display method, has been
Host-type liquid crystal display devices have started to attract attention. This uses a mixture of liquid crystal and dye, and a liquid crystal with negative dielectric anisotropy is used for the positive guest-host display crystal, and the various properties of the liquid crystal components, such as Liquid crystal compounds with good compatibility and negative dielectric anisotropy values are being sought.

The object of the present invention is to provide novel compounds and compositions thereof that are suitable for such uses and have good compatibility, exhibit negative anisotropy, and have a high nematic clearing point.

That is, the present invention relates to the general formula (in the above formula, R and R' each have 1 to 15 carbon atoms -0-
Indicates that it is one of the following. 2-cyano-4-alkylphenol ester conductor coated with ) and a liquid crystal composition characterized by cooling the conductor.

The compounds of the present invention have a high clearing point, such as 4-(trans-4-pentylcyclohexyl)biphenylyl-4'-carbonyl-2-cyano-4-hebutylphenyl ester, which is one of the compounds of the present invention. The crystal-nematic point (hereinafter abbreviated as C-N point) is 74.2°C, and the nematic-clearing point (hereinafter abbreviated as N-1 point) is 24a5.
'C, the liquid crystal phase shows a wide temperature range, and all liquid crystals exhibit a phase of 11
By adding it as a component of the proboscis, it is possible to raise the clearing point without making the viscosity of the liquid crystal compound so high. Furthermore, since the dielectric anisotropy value (hereinafter abbreviated as △e) of the compound of the present invention is about -3, it can be used for guest-host type display devices by mixing it with other nematic products. It is possible to obtain a crystal composition having anisotropy of tL.Also, by combining it with one having positive dielectric anisotropy, it can be used for a dual-frequency display element.

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

A method for producing an ester in which XKX is 0 in formula (1) is shown by reacting 4-alkylterphenyl-41-carboxylic acid (compound * (1)) with thionyl chloride to produce acid chloride (compound * (n)) and reacted with 2-cyano-4-alkylphenol in the presence of pyridine to obtain the desired 4-alkylterphenyl-41-carboxylic ct-2.
-cyano 4-furkylphenyl ester (compound (I)
ll) ) k! 'Can be built.

A method for producing one and four esters in which −+ is XX in formula (1) is shown below.
))'fr, reacted with thionyl chloride to form acid chloride (compound (■)), and converted to 2-cyano-4- in the presence of pyridine.
React with alkylphenol to obtain the desired 4-(trans-4-alkylcyclohexyl)biphenylyl-4'-
Carboxylic acid-2-cyano-4-alkylphenyl ester (compound ql(VD)k) can be prepared.

The above is represented by a chemical formula: (V) N (Vl) (R and R' are the same as above) The compounds of the present invention will be explained in more detail with reference to Examples below.

Example 1 4-Pentylterphenyl-4"-carboxylic acid-2-cyano-4-hebutylphenyl ester (compound efa (
m) Production of 4-pentylterphenyl-4'-carboxylic acid (compound (1)) 0.96 t*8 with thionyl chloride 10
Heated to 0°C. The reaction pattern becomes uniform in 2 hours, and the length increases by 1
The reaction continued for hours. Then, excess thionyl chloride was distilled off under reduced pressure, leaving a crystalline acid chloride (compound (■)). Separately 2-cyano-4-hebutylphenol 0.649
Dissolve 5 parts of K pyridine and add 10 parts of toluene to this.
The above acid chloride (compound (■)), which had been purified to -, was added while stirring. After the reaction, add toluene 50 ml after the night.
- was added and poured into water. 61 in the layered separable toluene layer
The mixture was dried using 7J hydrochloric acid, 2N 7J (added sodium oxide, washed with water, and finally rinsed with anhydrous sulfur). Next, toluene was distilled off under constant reduced pressure to obtain a crystalline product, which was recrystallized with vinegar and SOETEL to obtain the desired 4-pentylterphenyl-41-carboxylated-2-cyano-4-heptylphenyl ester (compound 41) ) 0.769
(yield 50.1%). The C-N point of this is 6
The temperature was 6.4°C, and the temperature at N-1 was 220.2°C.

Example 2 4-()9-4-pentylcyclohexyl)biphenylyl-4'-carboxylic acid-2-cyano-4-hebutylphenyl ester (Chemical formula 11 (Vl> and R is n-05'l)
1, R/ is n'7H15) 4-()2-4-benethylcyclohexyl)biphenylyl-4'-carphonic acid (
Compound 叡)) 1.17r and 2-cyano-4-hebutylphenol O,'i'7F! ! 7.4-()Lance-4-pentylcyclohexyl)biphenylyl-4'
-Carvone+ff-2-cyano-4-hebutylphenyl ester (compound mC station) 1.01 SF (yield 55.
3%). The 0-N point of this product is 74.2℃, 8-
One point was 246.5°C.

Implementation 1j3 (Usage Example) The N -1 point of the ester-based nematic liquid crystal composition (Rixon F Par 45 manufactured by Chisso Tun 9) is 63.4°C, and ΔC is -
The viscosity at 0, 9 and 20°C is 18.50p. A commercially available dye (G-224 manufactured by Merck & Co., Ltd., West Germany) was added to the mixture.
A guest-host cell was created by enclosing a cell containing k, IN, and hL in a cell with a spacing of 10μ7n between opposing transparent electrodes, and its threshold voltage was determined to be 3.8.
It was 01.

Next, the compound of the present invention, 4-pentylterphenyl-
4'-Carbonl'-2-cyano-4-heptyl phenyl ester 5 A % and (j 4-(trans-
4-pentylcyclohexyl)biphenylyl-4'-carbo/l [-2-cyano-4-hegederphenyl ester 10 MNt% k Product composition ql (IP'N-4
5) A product composition mixed with 85 Mm% was prepared.

The N-1 point of the composition 1 is 84.9°C, Δε is -1,2,
The viscosity at 20°C was 31.7 cp, and to this, 1 weight percent of dye G-224 was added as before.
When I made a guest-host liquid crystal cell sealed in the same cell as described above and determined the threshold voltage (11"), the voltage significantly decreased to 3.26 V.

that's all

Claims (2)

[Claims] (1) An ester derivative of 2-cyano-4-alkylphenol represented by the general formula (in the above formula, R and R' each have 1 to 15 carbon atoms). (2) A liquid crystal composition characterized by containing an ester derivative of 2-cyano-4-alkylphenol represented by the general formula (in the above formula, R and R' are each represented by carbon a1 to a15).