JPS63107951A - Optically active substance and liquid crystal composition containing said substance - Google Patents

Abstract

NEW MATERIAL:A compound shown by formula I (R is 1-16C alkyl; C* is asymmetric carbon; m is 1 or 2). EXAMPLE:p-2-Fluorooctyloxybenzoic acid. USE:A liquid crystal component preventing occurrence of reversed domain of TN type liquid crystal composition, having improving effects on electric field response of chiral nematic liquid crystal or chiral smectic liquid crystal and controlling liquid crystal state. PREPARATION:An optically active 2-fluoro-1-alkanol shown by formula II is tosylated, halogenated and reacted with p-hydroxybenzoic acid and p- hydroxybiphenylcarboxylic acid to give a compound shown by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel optically active substance and a liquid crystal composition containing the same.

As various optical elements characterized by having an optical activity of 11, many are known as exemplified below.

1) Those that utilize the cholesteric-nematic phase transition effect in the liquid crystal state (J. J., Wysoki, A.
Adams and W, Haas; Ph2S, Rev
, Letl, 20.1024 (19H)).

2) Those that utilize the White-Tiller type guest φ-host effect in the liquid crystal state (D, L, White and
G, N, Taylor; J, Appl, Phy
s, 45.4718 (1974)).

3) Chiral competition smectic C phase in liquid crystal state, H
Those that utilize the ferroelectric effect of phase, F phase, 1 phase, G phase, K phase, and J phase (N, A, C: 1ark and S, ↑.

Lagervall; Appl, Phys, f, ett
, 3G, 899 (1880)), 4) By fixing a cholesteric phase in a liquid crystal state into a matrix, its selective scattering properties can be utilized to utilize it as a notch filter, bandpass filter, or filter ( F.J.

Kahn, Appl, Phys, Lett, 18
, 231 (1971)), those used as circularly polarized beam splitters using circular polarization characteristics (S, D, Ja
cobs, 5PIE, 37, 8B (1981)) H et al.

Although a detailed explanation of each method will be omitted, all of them are important as display elements and modulation elements.

Optically active compounds are used as main components of the functional materials constituting these optical elements, or as important functional components, albeit in relatively small amounts.For example, H, A.
rnald, Z, Phys, Ches,, 22J14B
(19B4) is a method of controlling the type and temperature range of the liquid crystal phase developed in a liquid layer state by adding other optically active substances or liquid crystal compounds to the above-mentioned optical element materials, especially liquid crystal materials. Disclose. It is also expected that by introducing compounds with large dipoles into liquid crystal materials driven by electric field response, it will be possible to obtain liquid crystal materials with better electric field response.

However, in conventionally known optically active substances, it is not easy to change the length of the group introduced, and many of them are unsuitable for controlling the liquid crystal state.

Further, there are almost no known compounds in which a group having a large dipole moment is directly introduced into an asymmetric carbon, and a sufficient effect for improving the electric field responsiveness of the above-mentioned optical element has not been obtained.

In view of the above circumstances, the main object of the present invention is to provide an optically active compound in which a group that is useful for controlling the liquid crystal state and has a large dipole moment is directly introduced into an asymmetric carbon, and a liquid crystal composition containing the same. It's about providing things.

More specifically, one object of the present invention is to provide a compound exhibiting excellent electric field response by introducing a group having a large dipole moment into an asymmetric carbon.

In addition, in the present invention, it is easy to change the length of the alkyl group, which allows H, Arnold, Z, Phys.
.

Ches, 22Ef, 14B (1984) D. A liquid crystal compound capable of controlling the type and temperature range of a liquid crystal phase developed in a liquid crystal state, and a liquid crystal composition containing at least one compound thereof as a compounding component. The purpose is to provide

Furthermore, the present invention provides LB (Langmuir-Blodget)
t) It is an object of the present invention to provide a compound whose hydrophobic groups can be easily controlled and which can be stably formed into a film when a monomolecular cumulative film is produced by a desorption method.

The present invention first relates to the general formula CI) (where R is an alkyl group having 1 to 16 carbon atoms, and C
8 represents an asymmetric carbon atom; 0m is 1 or 2; ) provides an optically active substance represented by:

The compound represented by the formula (I) has the effect of controlling the liquid crystal state and improving electric field response as described above, and also has an effect of improving its optical activity because the asymmetric carbon atom and the reactive carboxyl group are separated from each other. It is also expected that various derivatives can be synthesized by combining with other functional intermediates without losing the properties. However, to date, no optically active compound as represented by formula (I) is known.

Based on the above findings, the present inventors have conducted extensive research and have succeeded in synthesizing the compound represented by the above formula (I), completing the present invention. For example, the above compound (I) is ,
The following general formula (II) R-C''H-CH2-OH (II
) It is obtained by tosylating and halogenating an optically active 2-fluoro-1-alkanol represented by the following formula and then reacting it with p-hydroxybenzoic acid and p-hydroxybiphenylcarboxylic acid. In addition, after tosylating and halogenating 2-fluoro-1-alkanol, p-hydroxyacetophenone, p-hydroxy-p'-7 cetylbiphenyl, or p-cyanophenol, p-
It is obtained by reacting with -hydroxy-p'-cyanobiphenyl and then fermenting.

The novel optically active substance represented by the general formula (I) of the present invention can be used as a useful liquid crystal component by itself as described above. For example, twisted nematic (T N)
By adding a very small amount to a nematic liquid crystal composition for type display elements, it can be effectively used to prevent the occurrence of striped patterns (reverse domains) on the display surface and to increase the uniformity of the display.

That is, the present invention also provides a liquid crystal composition characterized by containing at least one type of optically active compound represented by the above general formula (I).

According to the present invention, in order to produce the optically active compound of formula (I), optically active 2-fluoro-1-flukanol represented by formula (II) is first used as a starting material. Such optically active 2-fluoro-1-flukanol can be obtained by adding hydrogen fluoride to an optically active 1,2-epoxyalkane, as shown in the specification of Japanese Patent Application No. 60-232886. easily obtained by

Next, p-hydroxybenzoic acid and p-hydroxybiphenylcarboxylic acid are added to the optically active 2-fluoro-1-bromoalkane derived from the p-toluenesulfonic acid ester of the optically active 2-fluoro-1-flukanol or the optically active alcohol. Alternatively, reacting p-hydroxyacetophenone, p-hydroxy-p'-acetylbiphenyl, or p-cyanophenol, p-hydroxy-P'-cyanobiphenyl, and reacting the resulting ketone body or cyanide. The optically active compound of formula (1) can be obtained by oxidation or hydrolysis.

An example of the above series of reactions can be shown by a first-order reaction scheme.

(a)
(b) ■ R-CHCH,Br (C) (wherein R and m have the same meanings as defined above) The optically active compound represented by formula (I) of the present invention is used as a starting material. By changing the number of carbon atoms in the alkane moiety of 2-fluoro-1-flukanol, the above R can be changed widely, but in the present invention, R is
Particularly preferred are alkyl radicals having 1 to 16 carbon atoms.

Examples of optically active compounds represented by general formula (1) synthesized in this manner are shown below.

4-(2-fluorohexyloxy)benzoic acid, 4-
(2-fluoropeptyloxy)benzoic acid, 4-(2
-fluorooctyloxy)benzoic acid, 4-(2-fluorononyloxy)benzoic acid, 4-(2-fluorodecyloxy)benzoic acid, 4-(2-fluoroundecyloxy)benzoic acid, 4- (2- fluorododecyloxy)benzoic acid, 4-(2-fluorotridecyloxy)
Benzoic acid, 4-(2-fluorotetradecyloxy)
Benzo 1m, 4-(2-fluorohexadecyloxy)benzoic acid, 4-(2-fluorooctadecyloxy)benzoic acid, 4'-(2-fluorohexyloxy)biphenyl-4-carboxylic acid, 4'-(2 -fluoroheptyloxy)biphenyl-4-carboxylic acid, 4'-(2-fluorooctyloxy)biphenyl-4-carboxylic fi,
4'-(2-fluorodecyloxy)biphenyl-4-
Carboxylic acid, 4'-(2-fluorododecyloxy)biphenyl-4-carboxylic acid.

The optically active compound represented by the formula CI) thus obtained utilizes its carboxyl group in place of optically active chain hydrocarbon derivatives, amino acid derivatives, camphor derivatives, cholesterol derivatives, etc., as described above. do,
It can be combined with other intermediates through ester bonds, ether bonds, urethane bonds, carbonate bonds, etc. For this reason, it is useful as an intermediate for manufacturing functional materials that form optical elements, and is also used as an intermediate for the synthesis of various natural optically active substances.

Further, the optically active substance of formula (I) is effective in preventing the occurrence of reverse domains in a TN type cell by adding it to a nematic liquid crystal. In this case, it is preferable to use the optically active substance of formula (1) in a proportion of o, oi to 50% by weight of the resulting liquid crystal composition.

Also, by adding it to nematic liquid crystal or chiral nematic liquid crystal, it can be used as chiral nematic liquid crystal.
It can be used as a liquid crystal composition for phase change type liquid crystal elements and White Tiller type guest-host type liquid crystal elements. In this case, 0.01 to 80% of the obtained liquid crystal composition
It is preferable to use the optically active substance of formula (I) in such a proportion as to be in weight percent.

Further, the optically active substance of formula (1) may be added to a liquid crystal composition exhibiting a ferroelectric chiral smectic liquid crystal state by itself in a proportion of 0.01 to 80% by weight of the resulting liquid crystal composition. By adding the optically active substance of formula (1) to the material, properties such as durability can be improved. Furthermore.

It can also be added to smectic liquid crystals whose structural formulas and phase transition temperatures are shown below as 1) to 5) to provide a liquid crystal composition exhibiting a ferroelectric chiral smectic phase. In this case, it is preferable to add the optically active substance of formula (1) in a proportion of 0.01 to 80% by weight of the resulting liquid crystal composition.In order to provide a chiral smectic liquid crystal composition in this way, When the optically active substance of the formula (I) is added and utilized, it becomes possible to obtain a large spontaneous polarization, thereby shortening the response time and lowering the threshold voltage.

”).6H1,.■伜…吾..,□,.

4.4'-decyloxyazoxybenzene Cryst,
77”tE 5IIC120”c N 12
3. 'OIso.

Cryst, 120"OS+eCt89'OSmA
21G"Olso.

2-(4'-octyloxyphenyl)-5-nonylpyrimidine Cn5t, 3rd column% GOT! Sm
A 75' CIso.

4'-Pentyloxyphenyl-4-octyloxybenzoate Crrst-"ReSi"-SmA"ear N
2Isa, where the symbols indicate the following phases, respectively.

Crystal: crystal phase, SmA: smectic A phase, 5IIB: smectic B phase, 5ll
IC: smectic C phase, N: nematic phase,
tso, : Tokichi phase.

As described above, the present invention provides an optically active substance represented by formula (I) in which a fluorine group having a large dipole moment is directly introduced into an asymmetric carbon atom.

In addition, by blending at least one of these optically active substances, properties such as preventing the formation of glue/(-stomes) in the TN type liquid crystal composition or improving the electric field response of chiral nematic liquid crystal or chiral smectic liquid crystal can be improved. It is also possible to control the liquid crystal state.

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

p-2-fluorooctyloxybenzoic acid represented by the above formula was produced by the following two methods.

[First method] (1) 2-fluorooctyl-p-)luenesulfonic acid ester.

2-Fluoro-n-oct/-L Log (67, 6mm
ol) in pyridine 201 and cooled to 0°C, P-
) Luenesulfonic acid chloride 15, 5g (81,
1 gmol) of pyridine solution was added dropwise, and the mixture was heated at θ°C to 5°C.
The reaction mixture was reacted at 15° C. to 20° C. for 7 hours, then poured into ice water 2001, and then made acidic with 2N HCl aqueous solution.

Further extraction was performed using methylene chloride, the extracted layer was washed with water, and after confirming that the aqueous layer was neutral, it was dried using magnesium sulfate, and the solvent was distilled off. Further, purification was performed using silica gel column chromatography to obtain 13.0 g of 2-fluorooctyl-P-)luenesulfonic acid ester.

(2) p-2-fluorooctyloxybenzonitrile.

2-Fluorooctyl-P-)ruenesunoC-phonic acid ester obtained in (1) 13.0 g (43 mmol).

p-cyanophenol 5.25g (43s+s+ol)
, Butanol 201 was made into a homogeneous solution at room temperature, and a solution of 2.9 g of potassium hydroxide dissolved in 25 L of butanol was added dropwise to this, and after the completion of the dropwise addition, the mixture was heated under reflux for 5 hours. , poured into ice water 2001, separated the organic layer, further extracted the aqueous layer with isopropyl ether, washed with water together with the previously separated organic layer components, and after confirming that the aqueous layer was neutral, added sulfuric acid. After drying with magnesium, the solvent was distilled off to obtain 13.2 g of a crude product. This was purified using silica gel column chromatography, and p-2-fluorooctyloxybenzonitrile 7
．． 25g was obtained.

(3) p-2-fluorooctyloxybenzoic acid.

P-2-fluorooctyloxybenzonitrile 5,
53g (22, 2m*ol) and conc.

Dissolve 23g of HCl in 150ml of ethanol,
The mixture was heated under reflux for an hour. After that, about 100 ml of ethanol was distilled off, and an aqueous solution 1501 containing 25 g of sodium hydroxide was added to the remainder, and the mixture was further heated under reflux for 10 hours. There was no acid amide compound, which is a raw material or a reaction intermediate, in the reaction solution. After confirming that, conc, HcJL28g
was poured into water 2001 and cooled, and the above-mentioned reaction solution was added dropwise little by little to this. After the addition, 6N-HCl aqueous solution was added until the aqueous solution became acidic, and the precipitated white crystals were separated. This was recrystallized from methanol/water to obtain 4.12 g of p-2-fluorooctyloxybenzoic acid.

IR (cm-”): 2960.2930.2860.2680°2570.
1B85.1608.1590゜1518.1432,
1330.1300.1260.1175. 850
．． 775°655° [Second method] (1) Synthesis of 2-fluorooctyl bromide.

LiBr1.
51 g (17.4 m5 ol) was added, and the air was sufficiently replaced with dry nitrogen. Add 4 parts and 1 part of dry acetonitrile to it. Furthermore, a solution of 3.50 g (11.6 mmol) of 2-fluorooctyl-p-toluenesulfonic acid ester and 41 grams of dry acetonitrile was added. Thereafter, the mixture was heated under reflux for about 5 hours. At this time, as the temperature rose, the solution became homogeneous and paratoluenesulfone ugly lithium salt was immediately precipitated. After the reaction was completed, acetonitrile was distilled off from the solution, and water foul and ether Loaf were added for extraction. It was further extracted twice with 1 oaf of ether, and the ether layer was dried over anhydrous sodium sulfate. Remove the solvent and distill 2
-Fluoro-octyl bromide 2.24g (yield 91%)
, 87-88°C/a4 28mmHg). [(XI −2,4°(C
IcH, 0 sentence 2) (2) Synthesis of p-2-fluorooctyloxybenzoic acid.

P-hydroxybenzoic acid 1 in a 100 ml volumetric flask
, 52 g (,11s+5ol), ethanol 2
I put 0 Otori 1. There, 1.45 g (2
6 intestines o1) and 51 solutions of water were added, and further 2.15 g of 2-fluorooctyl bromide (lossol) and 2 ml of ethanol were added, and the mixture was heated under reflux for 25 hours.

After that, 1.45 g of potassium hydroxide (26 intestines of
), and water 31 were added, and the mixture was heated and refluxed for 5 hours. After completion of the reaction, the mixture was cooled on ice and neutralized by adding conc and HCl to precipitate crystals. Filter this and remove the crystals with 50ml of water.
Wash and dry, 1. p-2- of OOg (yield 37%)
Fluorooctyloxybenzoic acid was obtained.

Supporting remains” Cs H1? C'' HCHt O+C0OH p-2-fluorodecyloxybenzoic acid represented by the above formula was produced by the following reaction steps.

(1) Synthesis of 2-fluorodecyl p-toluenesulfonic acid.

17 g of 2-fluorodecanol and a pyridine bowl were placed in a Mitsuro 3001 round bottom flask, cooled to 0° C., and 24 g of P-toluenesulfonic acid chloride was added over 15 minutes while stirring. 1 hour at 0℃, then 20℃
After reacting for 7 hours while maintaining the following conditions, it was poured into water, the reaction solution was made molar using hydrochloric acid, and extracted with dichloromethane. The organic layer was washed with water, dried over magnesium sulfate, and purified by silica gel column chromatography using dichloromethane as a mobile phase to obtain 23 g of 2-fluorodecyl P-toluenesulfonate.

(2) Synthesis of p-(2-fluorodecyloxy)acetophenone.

P-toluenesulfonic acid 2- obtained in the step (1)
9.2 g of fluorodecyl, 3.8 g of p-hydroxyacetophenone, and 101 g of butanol were placed in a 1001 three-bottle round bottom flask, and while stirring, a solution of 1.5 g of sodium hydroxide in 10 ml of butanol was added dropwise. added. After heating under reflux for 6 hours, pour into water,
Extracted with isopropyl ether and dried over magnesium sulfate. The solvent was distilled off and hexane:ethyl acetate-10:
4.6 g of p-(2-fluorodecyloxy)acetophenone was obtained by purification by silica gel column chromatography using the mixed solvent of No. 1 as a mobile phase and recrystallization using hexane.

(3) Synthesis of p-(2-fluorodecyloxy)benzoic acid.

Dissolve 11.3 g of sodium hydroxide in 751 water,
The mixture was placed in a 300 ml Mitsuroh flask and cooled to 0°C, and 12.3 g of bromine was added over 15 minutes with stirring, followed by 30 ml of dioxane. This mixed solution is added to the step (2) above.
5.2 g of p-(2-fluorodecyloxy)7cetophenone obtained in step 1 was dissolved in dioxane 1701, and added dropwise over 40 minutes to a solution in which water fowl was added.
The reaction was carried out for 3.5 hours while maintaining the temperature below 0°C. Thereafter, excess hypobromite was removed by adding an aqueous hydrosulfide solution, acidified by adding a 6N aqueous hydrochloric acid solution, 500 ml of water was added, and one portion of the precipitated crystals was collected. Recrystallization was carried out using isopropyl ether and 4.1 g of p
-(2-fluorodecyloxy)benzoic acid was obtained.

IR (cm-凰): 2950.2930.2860.2670°2550.
1682, 1608.1436.1300.1260.
1178, 942.880, 855. 775.
650°! 1] 5 parts by weight of the optically active substance of Example 1 was added to 95 parts by weight of p, p'-pentylazoxybenzene to obtain a liquid crystal composition. It was observed that a TN cell (twisted nematic cell) using this liquid crystal composition had a significantly reduced reverse domain compared to a TN cell manufactured without adding this compound.

A liquid crystal composition was obtained by adding 5 parts by weight of the optically active substance of Example 2 to 95 parts by weight of MORAS having the structure shown below. This liquid crystal composition exhibits a SmC'' phase, has a spontaneous polarization 1.5 times that of MORA8 alone, and has a response time of 25m5ec at 25°C under the condition of ±15V applied, which is about 6
It became 0%.

0RAS CH.

Claims (1)

[Claims] 1. The following general formula (I) ▲There are numerical formulas, chemical formulas, tables, etc.▼(I) (Here, R is an alkyl group having 1 to 16 carbon atoms, and C
^* indicates an asymmetric carbon atom. m is 1 or 2. ) An optically active substance represented by 2. General formula (I) below ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (I) (Here, R is an alkyl group having 1 to 16 carbon atoms, and C
^* indicates an asymmetric carbon atom, m is 1 or 2. ) A liquid crystal composition containing at least one type of optically active substance represented by: