JPS61122250A - Liquid crystal ester compound - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R is 8-12C alkyl; R' is optically active alkyl). EXAMPLE:4-[4'-(3'-chloro-4'-n-decyloxyphenyl)benzoyloxy]ben-zoic acid (active) amyl ester. USE:A liquid crsytal material for optoelectric element exhibiting chiral smectic C phase over a relatively broad temperature range near the room temperature. PREPARATION:The compound of formula I can be prepared by (1) converting the 4-(4'-alkoxy-3'-chlorophenyl)benzoic acid of formula II to acid chloride with a halogenation agent such as thionyl chloride, (2) reacting the chloride with 4-hydroxybenzaldehyde in toluene in the presence of pyridine, (3) oxidizing the resultant aldehyde with Ag2O, KMnO4, etc., in acetone, and (4) esterifying the obtained benzoic acid derivative with an optically active alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid crystalline ester compound exhibiting a chiral smectic C (hereinafter referred to as SmC) phase and used in electro-optical elements.

[Background of the invention]

Most of the liquid crystal materials widely used in electro-optical devices are nematic liquid crystals, but recently devices that utilize the ferroelectricity of the S m C' phase have attracted attention (Atsuo Fukuda, Hideo Takezoe, Nature No. 7 (1983), 36).

This element is characterized by a fast response speed, and is being considered for application in liquid crystal printers, etc. However, only a small number of substances are known as liquid crystal materials for use in this device, and it is difficult to find practical applications. It is desired to develop a certain liquid crystal material.

[Prior art and problems]

Compounds that have been studied relatively extensively so far have a Schiff group (-N=CH-) in their structure (
A,HalItsby et,at,,MailCry
st Liq Cryst, 82 (1982), 61)
.

However, this type of compound has disadvantages in that it is inferior in chemical stability and is colored, and it is thought that ester-based materials will eventually become mainstream, as in the case of nematic liquid crystal materials.

Ester compounds exhibiting 'S m C'N that have been reported to date include the following.

R-(J→+-C(J-(Ji=toc's[++t
(IIK −(J (=tζD−c (J−U−
C"S H, (Company) (R represents a straight chain alkyl group having 8 to 12 carbon atoms.

C”, H, represents an optically active aluminum group)X
Co-(J-c>-Y (m)(X and Y
represents an alkyl group having 5 to 12 carbon atoms or an alkoxyl group, at least one of which contains an alkyl group having optical activity.
m C'', ifi, but its temperature range is extremely narrow.

(B, 1. (Jstrovskii et al., F
erroelectrics.

24 (1980), 309) Furthermore, although the compound (m) has a wide temperature range, its holding temperature is 50° C. or higher, which poses a practical problem. (G,
W, Gray et al, Mul Crystal
LiqCryst 48 (197'8), 37) [
Purpose of the Invention] Therefore, the purpose of the present invention is to reduce S m C′″ near room temperature.
The object of the present invention is to provide an ester compound that exhibits a phase and has a relatively wide liquid crystal temperature range.

[Structure of the invention]

The present invention newly synthesizes the following compound (X), which is S
It has been found that it has excellent properties as a compound exhibiting m C''@, and will be explained below based on Examples.

[Embodiments of the invention]

(Synthesis method 1) One method for synthesizing the compound (X) of the present invention is the above-mentioned synthesis method 1.

Enyl) benzoic acid (■) is converted to acid chloride (VI) using a halogenating agent such as thionyl chloride or phosphorus pentoxide, and this and 4-
The aldehyde of compound (VII) is obtained by reacting with hydroxybenzaldehyde in toluene containing pyridine.

This aldehyde was mixed with Ag, 0. KMnU, etc. in acetone to obtain the benzoic acid derivative (vll).

If this benzoic acid derivative (Vlll) and an optically active alcohol are esterified by a known method, the target product (X) can be obtained.
can be obtained. This starting material ■) and intermediate material (V
ll), (■), and (Ix) are all liquid crystal substances.

Another method for synthesizing the compound ① of the present invention is as follows.

(Synthesis method 2) That is, a compound obtained in the same manner as (synthesis method 1) (
The desired compound (X) can be obtained by esterifying an ester compound of 4-hydroxybenzoic acid with an optically active alcohol, which has been synthesized in advance by a method known in Vl), in the presence of pyridine or the like.

(Synthesis method 2) is advantageous when a large amount of optically active alcohol is present, and (synthesis method 2) is advantageous when only a small amount is present.
Synthesis method 1) is preferred.

This will be explained below using specific examples.

(Example 1) Production of xyphenyl)benzoyloxy]benzoic acid <active)amyl ester.

Known methods (G.W., Gray et al., J.C.
0.1 mol of 4-(3-chloro4-n-n-decyloxyphenyl)benzoic acid synthesized by Hem 5Oc (1955), 141'3) and 30 g of thionyl chloride were combined with 5 Q CC of toluene under reflux. The reaction was carried out by heating.

After about 3 hours of reaction, excess thionyl and toluene are distilled off under reduced pressure. The residue is an acid chloride of the acid corresponding to the compound (■).

01 mol of 4-hydroxybenzaldehyde, 30 cc of pyridine, and 200 cc of toluene are added thereto, heated and stirred under reflux for about 12 hours, and then poured into water to separate the organic layer. This organic layer is washed with 6N hydrochloric acid and 2N aqueous sodium hydroxide solution, washed with water and dried, and then toluene is distilled off. The remaining residue is crystallized from ethanol 300 CO to obtain the compound mardecyloxyphenyl)benzoyloxybenzaldehyde.

The obtained aldehyde was dissolved in 1 liter of acetone,
20.9 of potassium permanganate is added little by little with stirring, stirring is continued for 4 hours and left overnight. Filter the precipitated manganese dioxide, transfer it to another container with acetone remaining in the precipitate, and add 6N hydrochloric acid toocc to decompose the manganese dioxide.

・Add 1 liter of water, wait until the decomposition of manganese dioxide is completely completed, filter with suction, and dissolve ethanol and toluene.
Recrystallization from a mixed solution of 1 to 1 yields the above-mentioned n-decyloxyphenyl)hendiyloxy]benzoic acid.

0.02 mol of the obtained acid was reacted with 5 g of thionyl chloride in the presence of 20 CC of toluene, and the excess thionyl chloride and toluene were distilled off. To the residue, 100 Ce of toluene and optically active amyl alcohol (2-methyl-1-butanol) were added. )3
g, add 10 CC of pyridine, stir, and heat to 40°C.
Leave overnight at a temperature of This was poured into water to separate the organic layer, which was then washed with 6N hydrochloric acid and 2N hydroxide). After washing with water and drying, toluene was distilled off, and the residue was recrystallized from ethanol to obtain the final target product. 4-1:
4'-(3-chloro4-n-n-decyloxyphenyl)benzoyloxy]benzoic acid (active) amyl ester is obtained.

The phase transition temperature of this compound was as follows.

When temperature rises, C3c point 53℃, 5cSa point 95℃, Sa
Point I 140'C.

When temperature falls, ISa point 140℃, 5aSc point 95℃, 2
．． At a rate of decline of 5°C/min, no phase change is observed up to 20°C, and if it is left at 15°C for a day, it changes to another smectinok phase that changes from 25°C to the S m C'' phase.

The first infrared absorption spectrum obtained from this compound is
As shown in the figure.

(Example 2) Production of enyl)benzoyloxy]benzoic acid (active) amyl ester.

Synthesis was carried out according to the method of Example 1 using (oxyphenyl)benzoic acid at °C to obtain the desired ester. The phase transition temperature of this compound was as follows.

When temperature rises, C5c point 43℃, 5cSa point 83℃, Sa
Point I 136°c.

When temperature falls, ISa point is 136°C, 5aSc point is 83°C1
No phase change was observed up to -20°C at a rate of decline of 2.5°C/min, and the sample left at 10°C for three days had a smectic phase that changed at 27°C. FIG. 2 shows an infrared absorption spectrum obtained from this compound.

(Example 3) According to the method of (Example 1), xyphenyl)benzoyloxy]benzoic acid (active) amyl ester, diphenyl)benzoyloxy]benzoic acid (active)
Amyl ester, noyloxyphenyl)benzoyloxy]benzoic acid (
Active) amyl ester was synthesized.

These esters exhibited S m C''4[.

(Example 4) An acid chloride obtained by treating 0.1 mol of 4-(3-10-4-lauryloxyphenyl)benzoic acid with thionyl chloride in the same manner as described in (Example 1); 100 cc of toluene and 20 cc of pyridine were added to 0.11 mol of rose hydroxybenzoic acid active amyl ester synthesized by a known method, stirred at 50'C for 12 hours, and poured into water to separate the organic layer. (6N hydrochloric acid and 2N hydroxide)
After washing with IJum aqueous solution, washing with water and drying, toluene was distilled off, and the residue was recrystallized from ethanol to obtain a compound. The obtained compound was the same as the compound obtained in (Example 2), and its phase transformation behavior was also the same.

(Example 5) The ester compound obtained in (Example 1) and (Example 2)
) with the ester compound obtained in the molar ratio of 1:1 shows an S m C'' phase, and the ISa point is 136 °C, 5
The aSc point was 83°C, and the smectinok state remained even after being left at a temperature of 10°C for one week.

〔Effect of the invention〕

The liquid crystalline ester compound of the present invention can be used at temperatures near room temperature).
It is useful as a new compound that exhibits an SmC' phase over a relatively wide temperature range.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are both infrared absorption spectra obtained from the ester compound of the present invention.

Claims (1)

[Claims] It is represented by the general formula ▲There are numerical formulas, chemical formulas, tables, etc.▼ (R represents an alkyl group having 8 to 12 carbon atoms, and R' represents an optically active alkyl group). A liquid crystalline ester compound consisting of an alkyl 4-[4-(3-chloro4-alkoxyphenyl)benzoyloxy]benzoic acid ester.