JPS6033822B2 - Novel diphenyl ester exhibiting liquid crystal phase - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel diphenyl esters exhibiting a liquid crystalline phase.

These compounds, alone or as a mixture, can exhibit a liquid crystal phase, which liquid crystal phase can actually be either a nematic phase and one or more smectic phases, or both a nematic phase and one or more smectic phases. .

General formula (where R=C6 days, 3, C7 days.5 or C8 days, 7
0:X=Br or CN) is provided.

General Preparation Method The following intermediates are synthesized: 1 4-Hydroxy-4'-alkyldiphenyl 2 4
-Alkoxy 3-bromobenzoylc.

Ride. A bromine compound is synthesized from the above two intermediates, and then a cyano compound is synthesized from the bromine compound.

The synthesis of the first intermediate was carried out in the related patent application (Spec.
No. 25) gives significantly higher yields.

a Synthesis of 4-alkoxycarbonyl-4'-alkyl/yldiphenyl where R is an alkyl group.

b The synthetic group -CH2-R of 4-hydroxy-4'-alkyldiphenyl is R2=CmH2m+, (m is 1 to 1
(an integer of 0).

The synthesis of the second intermediate is identical to that disclosed in the above application.

The method, including three Ichological reactions, is restated as follows. c Synthesis of 4-alkoxy 3-furomobenzoic acid where R, is CnH2n10,0.

d Synthesis of 4-alkyl-3-promobenzoic acid where R
, is CnH2n+,oe Synthesis of 4-alkoxy (or alkyl)-3-bromobenzoyl chloride where R
, is either an alkoxy group or an alkyl group.

Next, a bromine compound is synthesized by the following reaction.

Finally, a cyano compound is synthesized by the following reaction.

Here, DMF represents dimethylformamide (solvent) Synthesis Example Reaction {Example a-: Synthesis of 4-hexyloxycarbonyl-4'-hexanoyldiphenyl.

10% of 4-hydroxydiphenyl from milk powder (0.2 mol)
Add to 0' of carbon disulfide.

Pour the solution into a ball. 5 ml (0.4 mol) of aluminum chloride are added over 5 hours. After heating to reflux temperature,
54 g (0.4 mol) of hexanoyl chloride are added over 1 hour. Heating is then continued under reflux for 3 hours.
The solution is then cooled, poured onto a mixture of 2002 g of ice and 100 g of concentrated hydrochloric acid, and extracted with benzene.

The benzene extract is then washed with deionized water and dried over magnesium sulfate.

The solvent is distilled off and the mixture is recovered and recrystallized from 200 cc of benzene/ethanol (50/50) solution.

52.5 hours of pure product were obtained, corresponding to a yield of 72%.

Example of reaction 'b': Synthesis of 4-hydroxy-4'-hexyldiphenyl 450 m (8 mol) of potassium hydroxide and 45.7 m (1.25 mol) of 4-hexyloxycarbonyl-4'-hexanoyldiphenyl is added to a solution of 1.2 gethylene glycol and 282 g (9 moles) of hydrazine hydrate.

The solution was heated under reflux for 2 hours, then mass
Water and excess hydrazine are distilled off until the temperature is 228°C. The solution is allowed to cool to 100° C. and then poured into deionized water. After heating for 1 hour, the resulting solution is made acidic to pH ˜2 with concentrated hydrochloric acid.

The product precipitates out and is extracted with ether. The extracts are washed with deionized water and dried over magnesium sulfate.

The ether is distilled off and the residual product is recrystallized from 600 cc of hexane.

28.9 hours of pure product was obtained, corresponding to a yield of 91%.

Synthesis example of bromine compound: p-hexyldiphenyl-3-bromo-4-hebutylbenzoate2. Dissolve 0.01 mole of 4-hydroxy-4'-hexyldiphenyl in 20 parts of pyridine.

Add 3.175 g (0.01 mol) of 3-furomo-4-heptylbenzoyl chloride and then stir at room temperature for 3 hours.

Pour the solution into a mixture of 70 g of ice and 8 cc of concentrated sulfuric acid. After rinsing, the reaction mixture is extracted with benzene. A crude product of 5.7% is obtained, purified by chromatography on silica and then recrystallized from ethanol to give a pure product of 3.5%.

This corresponds to a yield of 65%. Synthesis example of cyano compound:
Synthesis of p-hexyldiphenyl-3-cyano-4-heptylbenzoate 2.65 units (5 x 10-3 mol) of p-hexyldiphenyl-3-furomo-4-heptylbenzoate and 0
．． Six cups (6.7 x 10-3 moles) of cuprous chloride are added to 10' of dimethylformamide.

7. Bring the solution under reflux. After heating for an hour, it is cooled and poured into a mixture of 60 cc of deionized water and 5.5 cc of ethylenediamine. After a concentrated period of time, the solution was extracted with ether to give a crude product of 2.2 mL, which was purified by chromatography on a silica column and further recrystallized from ethanol to yield 1.
．． 6 hours of pure product is obtained. This corresponds to a yield of 66%. To facilitate the understanding of the description of the properties of compounds and mixtures, the following symbols are used below:

K: Crystalline phase S^: Smectic phase A Sc: Smectic phase C N: Nematic phase 1: Isotropic liquid phase 4
The numbers written between the phase symbols in Table 1 indicate the transition temperature in degrees Celsius.

Table 1 The compounds of the invention are used inter alia in the following electro-optical devices:

-Display system based on dynamic scattering of light.

This requires a wide temperature range and negative dielectric anisotropy. In particular, mixtures of nematic liquid crystals and compounds of the invention exhibit one of these properties. - An electro-optical device that utilizes the property that the dielectric anisotropy of liquid crystal becomes more or less pronounced depending on whether the electric field in the liquid crystal has a frequency of several thousand to several hundred hertz.

- So-called electrical effect memory type display systems or thermo-optic memory type display systems in the case of the compounds of the invention having a smectic phase (compounds B, D, F of Table 1).

Claims (1)

[Claims] 1. A diphenyl ester that exhibits at least one liquid crystal phase and is represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (where R = C_6H_1_3, C_7H_1_5 or C_8H_1_7O: . 2 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (Here, R = C_6H_1_3, C_7H_1_5 or C_8H_1_7O: X = Br or CN) A liquid crystal material consisting of diphenyl ester. 3. The liquid crystal substance according to claim 2, which contains a compound represented by the general formula ▲A mathematical formula, a chemical formula, a table, etc.▼ as an additive.