JP2591037B2 - Optically active benzene derivative, production method thereof and liquid crystal material containing the same as active ingredient - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a compound represented by the general formula (I): (Wherein X is -COO-, -OCO-, -CH2O- or -OCH2
-, A represents an alkyl group or an alkoxyl group having 4 to 20 carbon atoms, R represents an alkyl group having 1 to 20 carbon atoms, and l and m are 1 or 2, respectively. The asterisk indicates that it is an asymmetric carbon. ) An optically active benzene derivative represented by the formula:
The present invention relates to a liquid crystal material containing this as an effective component and an optical switching element using the liquid crystal material.

<Prior art> At present, image display devices using liquid crystals are widely put into practical use, and a TN (Twinsted Nematic) type is known as one of the display systems, and this display system has low power consumption. In addition, since it is a light-receiving type that does not emit light by itself, it has features such as little eye fatigue, but there is a problem that the response speed is not always satisfactory.

On the other hand, display devices utilizing the optical switching phenomenon of ferroelectric liquid crystal [Applied Physics Letters (Appl. Phys. Lette.), 36 ,
899 (1980)] has been proposed and attracted attention.

Such a ferroelectric liquid crystal is said to belong to a chiral smectic C (hereinafter abbreviated as Sc ^* ) phase or a chiral smectic H (hereinafter abbreviated as SH ^* ) phase in terms of molecular arrangement. Not only for LCD TVs and other displays, but also for optical printer heads,
It is expected to be widely used as a material for electronics-related elements such as optical Fourier transform elements.

<Problems to be Solved by the Invention> However, such conventionally known liquid crystal compounds are not always sufficient in terms of stability and the like, and have problems in practicality and small spontaneous polarization. Was not always enough.

Even if the spontaneous polarization is large, for example, a compound having a halogen atom in a molecule has a problem in stability and the like.

From the above, the present inventors have studied to develop a liquid crystal compound that can be widely used in the various display methods as described above, and as a result, have found a novel optically active benzene derivative,
The present invention has been reached.

<Means for Solving the Problems> The present invention provides an optically active benzene derivative represented by the general formula (I).

Such an optically active benzene derivative has not been known at all, and is a novel compound discovered by the present inventors for the first time. (Wherein, X, A, l, m and * have the same meanings as described above).
I) reacting with an aliphatic carboxylic acid or an acid anhydride thereof or an acid halide thereof (hereinafter referred to as aliphatic carboxylic acids) represented by R-COOH (III) (wherein R has the same meaning as described above). Can be manufactured.

Here, as the aliphatic carboxylic acid represented by the general formula (III), acetic acid, propionic acid, butanoic acid, pentanoic acid,
Hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, isolacuic acid, 2- Methylbutanoic acid, 4-methylpentanoic acid, 2-methylhexanoic acid, 2-methylheptanoic acid, 2-methyloctanoic acid, 2,3-dimethylheptanoic acid, 2,3,3-trimethylbutanoic acid, 3-methylpentanoic acid , 2,3-dimethylpentanoic acid, 2,4-dimethylpentanoic acid, 2,3,3,4-tetramethylpentanoic acid, 3-methylhexanoic acid, 4-methylhexanoic acid, 2,5-dimethylhexanoic acid, etc. In the above reaction, these aliphatic carboxylic acids or their acid anhydrides or their acid halides (eg, acid bromide, acid chloride) It is used.

These aliphatic carboxylic acids may have an optically active group, and some of such optically active aliphatic carboxylic acids are obtained by oxidation of the corresponding alcohol and reductive deamination of the amino acid. Some are naturally occurring or can be derived from the following optically active amino acids and optically active oxyacids obtained by resolution.

Alanine, valine, leucine, isoleucine, phenylalanine, serine, threonine, alosreonine, homoserine, alloisoleucine, tert-leucine, 2-aminobutyric acid, norvaline, norleucine, ornithine, lysine, hydroxylysine, phenylglycine, trifluoroalanine, asparagine Acid, glutamic acid, lactic acid,
Mandelic acid, tropic acid, 3-hydroxybutyric acid, malic acid, tartaric acid, isopropylmalic acid and the like.

The reaction between the optically active alcohol compound (II) and the aliphatic carboxylic acid is usually performed in the presence or absence of a solvent,
It is generally performed in the presence of a catalyst.

When a solvent is used in this reaction, examples of the solvent include aliphatic or aliphatic solvents such as tetrahydrofuran, ethyl ether, acetone, methyl ethyl ketone toluene, benzene, chlorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, dimethylformamide, hexane, and pyridine. Solvents which are inert to the reaction of aromatic hydrocarbons, ethers, halogenated hydrocarbons, organic amines, etc., alone or in a mixture. The amount can be used without any particular limitation.

The amount of the aliphatic carboxylic acid used in the reaction is required to be at least 1 equivalent times relative to the optically active alcohol compound,
The upper limit is not particularly limited, but is preferably 4 equivalent times.

Examples of the catalyst include dimethylaminopyridine, triethylamine, tri-n-butylamine, pyricine,
Organic or inorganic basic substances such as picoline, lysine, imidazole, sodium carbonate, sodium methylate, potassium hydrogen carbonate and the like can be mentioned. Further, an organic acid or an inorganic acid such as toluenesulfonic acid, methanesulfonic acid, or sulfuric acid can be used as a catalyst.

In using such a catalyst, pyridine is particularly preferably used, for example, when an acid halide of an aliphatic carboxylic acid is used as a raw material.

The amount of the catalyst used varies depending on the type of the aliphatic carboxylic acid and the combination of the catalyst to be used, and is not necessarily specified. For example, when an acid halide is used, it is 1 equivalent or more of the acid halide.

When an aliphatic carboxylic acid is used as the aliphatic carboxylic acid, the reaction is usually carried out by using 1 to 2 equivalents of the optically active alcohol compound and performing dehydration condensation in the presence of a condensing agent.

As the condensing agent, carbodiimides such as N, N'-dicyclolhexylcarbodiimide and N-cyclohexyl-N '-(4-diethylamino) cyclohexylcarbodiimide are preferably used. A sex base is used in combination.

In this case, the amount of the condensing agent used is usually 1 to 1.2 equivalent times relative to the aliphatic carboxylic acid, and when a base is used in combination, the amount of the base used is 0.01 to 0.2 equivalent times relative to the condensing agent.

The reaction temperature is usually -30C to 100C, preferably -25C to 80C.

The reaction time is not particularly limited, and the time when the optically active alcohol compound as the raw material disappears can be regarded as the end point of the reaction.

After completion of the reaction, the usual separation means, such as excess, extraction,
The target optically active benzene derivative represented by the general formula (I) can be isolated from the reaction mixture by liquid separation, concentration, and the like, and can be purified by column chromatography or the like, if necessary.

The optically active alcohol compound (II) as a raw material in this reaction is represented by the general formula (IV) (Wherein A, l, X and m have the same meaning as described above;
Represents a lower alkyl group. ) Is used to hydrolyze one of the optically active esters of the dl-esters (asymmetric hydrolysis) using an esterase having the ability to hydrolyze only one of the enantiomers of the esters. Can be manufactured.

Here, the above esterase means esterase in a broad sense including lipase.

The microorganism that produces esterase used in this reaction may be any microorganism that produces an esterase having the ability to asymmetrically hydrolyze dl-esters (IV), and is not particularly limited.

Specific examples of such microorganisms include, for example, Enterobacter, Arthrobacter, Previbacterium, Pseudomonas, Alcaligenes, Micrococcus, Chromobacterium, Microbacterium, Corynebacterium, Genus Pacillus, Lactobacillus, Trichoderma, Candida, Saccharomyces, Rhodotorula, Cryptococcus, Truropsima, Pichia, Penicillium, Aspergillus,
Microorganisms belonging to the genera Rhizopus, Mucor, Aureobasidium, Actinomucor, Nocardia, Streptomyces, Hansenula and Achromobacter are exemplified.

The cultivation of the microorganism is generally performed according to a conventional method. For example, a culture solution can be obtained by performing liquid culture.

For example, sterilized liquid medium [for molds and yeasts, malt extract / yeast extract medium (5 g of peptone, 10 g of glucose, 3 g of malt extract, 3 g of yeast extract in water 1;
Inoculated with microorganisms in a sweetened bouillon medium (peptone 5 g, glucose 10 g, meat extract 5 g, NaCl 3 g in water 1 and adjusted to pH 7.2) for bacteria, usually 30 to 40
The culture is performed by performing reciprocal shaking culture at 1 ° C. for 1 to 3 days, and solid culture may be performed if necessary.

Some of these microbial esterases are commercially available and can be easily obtained. Specific examples of commercially available esterases include, for example, the following.

Pseudomonas lipase [Lipase P (Amano Pharmaceutical)], Aspergillus lipase [Lipase AP (Amano Pharmaceutical)], Mucor lipase [Lipase MAP]
(Manufactured by Amano Pharmaceutical)], Lipase MY of Candida syrindrasse (manufactured by Meito Sangyo)], Lipase of the genus Alcaligenes [lipase PL (manufactured by Meito Sangyo)], Lipase of the genus Achromobacter [lipase AL (Meito Sangyo) Lipase of the genus Arthrobacter (lipase combined BSL (joint liquor purification)), lipase of the genus Chromobacterium (manufactured by Toyo Brewery), lipase of the genus Rhizopus delemar (talipase (manufactured by Tanabe Seiyaku)), genus Rhizops [Lipase Saloken (Osaka Bacteria Research Institute)].

Also, animal and plant esterases can be used,
Specific examples of these esterases include the following.

Stearpsin, pancreatin, pig liver esterase, Wheat Germ esterase.

As the esterase used in this reaction, an enzyme obtained from an animal, a plant, or a microorganism is used, and the form of use is a purified enzyme, a crude enzyme, an enzyme-containing substance, a microorganism culture solution, a culture, a cell, a culture solution. In addition, they can be used in various forms, such as those obtained by treating them, as needed, and enzymes and microorganisms can be used in combination. Alternatively, it can be used as an immobilized enzyme immobilized on a resin or the like, or an immobilized cell.

The asymmetric hydrolysis reaction is generally carried out by vigorously stirring a mixture of the raw material dl-esters (IV) and the above-mentioned enzyme or microorganism in a buffer solution.

As the buffer, sodium phosphate which is usually used,
A buffer solution of an inorganic acid salt such as potassium phosphate, a buffer solution of an organic acid salt such as sodium acetate or sodium citrate, or the like is used, and its pH is 8 to 11 in a culture solution of an alkaliphilic bacterium or an alkaline esterase. PH 5 to 8 is preferable for a culture solution of a non-alkaline microorganism or an esterase having no alkali resistance. The concentration is usually in the range of 0.05-2M, preferably 0.05-0.5M.

The reaction temperature is usually from 10 to 60 ° C, and the reaction time is generally from 3 to 70 hours, but is not limited thereto.

When a lipase belonging to the genus Pseudomonas or Arthrobacter is used as the lipase in the asymmetric hydrolysis reaction, the optically active alcohol compound (II) can be obtained with relatively high optical purity.

In addition, at the time of this asymmetric hydrolysis reaction, an organic solvent which is inert to the reaction, such as toluene, chloroform, methyl isobutyl ketone, or dichloromethane, can be used in addition to the buffer solution. Decomposition can also be performed advantageously.

By such an asymmetric hydrolysis reaction, only one of the optically active isomers of the raw material dl-esters (IV) is hydrolyzed to produce an optically active alcohol compound represented by the general formula (II). Of the dl-esters (IV), the optically active esters which are the other optically active substances remain as hydrolysis residues.

After completion of the hydrolysis reaction, the hydrolysis reaction solution is extracted with a solvent such as methyl isobutyl ketone, ethyl acetate, ethyl ether, or the like, and the solvent is distilled off from the organic layer, and the concentrated residue is subjected to column chromatography. The optically active alcohol compound (II) which is a hydrolysis product and the optically active esters which are the residue of the hydrolysis [the optically active forms in the raw material esters (IV) which were not hydrolyzed] Can be separated.

The optically active esters obtained here are further hydrolyzed as required, and can be converted into enantiomeric optically active alcohol compounds from the previously obtained optically active alcohol compounds.

The dl-esters (IV) which are the raw materials for such asymmetric hydrolysis reactions are represented by the general formula (V) (Wherein, A, l, X and m have the same meanings as described above), and reacting with a lower alkyl carboxylic acid to effect acylation.

In such an acylation, as the lower alkylcarboxylic acid as an acylating agent, an acid anhydride or an acid halide of a lower alkylcarboxylic acid is usually used, for example, acetic anhydride, propionic anhydride, acetic chloride or promide, propionic chloride or Bromide, butyryl chloride or bromide, valeroyl chloride or bromide and the like can be mentioned.

This reaction is carried out by applying a normal esterification condition and reacting with a catalyst in the presence or absence of a solvent.

In this reaction, the amount of the lower alkyl carboxylic acid used must be at least 1 equivalent times the dl-alcohol (V), and the upper limit is not particularly limited, but is preferably 4 equivalent times.

When a solvent is used in this reaction,
For example, tetrahydrofuran, ethyl ether, acetone, methyl ethyl ketone, toluene, benzene, chloroform, chlorobenzene, dichloromethane, dichloroethane, carbon tetrachloride, dimethylformamide, hexane,
A single or mixture of solvents inert to the reaction of aliphatic or aromatic hydrocarbons such as pyridine, ethers, halogenated hydrocarbons, organic amines and the like is used, and the amount of the solvent is not particularly limited.

Examples of the catalyst include dimethylaminopyridine, triethylamine, tri-n-butylamine, pyridine,
Organic or inorganic basic substances such as picoline, imidazole, sodium carbonate, sodium methylate, potassium hydrogencarbonate and the like can be mentioned, and the use amount thereof is not particularly limited, but is usually 1 to 5 equivalents to the raw material alcohols (V). It is.

When an organic amine is used as a solvent, the amine may act as a catalyst.

Further, acids such as toluenesulfonic acid, methanesulfonic acid, and sulfuric acid can be used as the catalyst.

The reaction temperature is usually -30C to 100C, preferably -20C to 90C.

The reaction time is not particularly limited, and the time when the alcohol (V) as the raw material disappears from the reaction system can be regarded as the reaction end point.

After completion of the reaction, usual separation means such as extraction, liquid separation,
The dl-esters (IV) can be obtained in good yield by concentration, recrystallization, etc., which can be further purified by column chromatography or the like, if necessary. It can be used as a mixture.

The raw material alcohols (V) in this reaction are:
General formula (VI) (Wherein, A, l, X and m have the same meaning as described above) can be easily produced by reducing with a reducing agent.

When the substituent X in the raw material ketones (VI) is -COO- or -OCO-, sodium borohydride, lithium tri-t-butoxyaluminum hydride, lithium tri- S-butyl borohydride, borane, etc., and when the substituent X is -CH2O- or -OCH2-, sodium borohydride, lithium borohydride, zinc borohydride, lithium aluminum hydride, aluminum isopropoxy , Lithium-tri-t-butoxyaluminum hydride, lithium-tri-S-butylboron hydride, borane, alkali metal-ammonia and the like are preferably used.

Such a reducing agent is required to be at least one equivalent or more times the amount of the starting ketones (VI), and is usually used in an amount of 1 to 10 equivalents.

The reduction reaction is usually performed in a solvent, and examples of the solvent include tetrahydrofuran, dioxane, ethyl ether, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, ethers such as toluene, benzene, chloroform, and dichloromethane, and halogenated hydrocarbons. A single solvent or a mixture of solvents inert to the reaction, such as aromatic hydrocarbons and alcohols, is appropriately selected and used.

The reaction temperature is optional in the range of -30 ° C to 100 ° C, but is preferably in the range of -20 ° C to 90 ° C.

From the reaction mixture thus obtained, dl-alcohols (V) can be obtained in good yield by operations such as liquid separation, concentration, distillation and crystallization, but dl-esters (IV) are produced. In this case, it is not necessary to isolate the dl-alcohols (V), and the reaction mixture may proceed to the next step.

By such a method, an optically active benzene derivative represented by the general formula (I) is produced. Examples of the optically active benzene derivative thus obtained include 4-C
_4-20 alkylbenzoic acid 4 '-(1-alkylcarbonyloxyethyl) phenyl ester, 4-C _4-20 alkyloxybenzoic acid 4'-(1-alkylcarbonyloxyethyl) phenyl ester, 4-C _4-20 Alkylbenzoic acid 4 '-(1-alkylcarbonyloxyethyl) -4-biphenylyl ester, 4-C _4-20 alkyloxybenzoic acid 4'-(1-alkylcarbonyloxyethyl) -4-biphenylyl ester, 4 -C
_4-20 alkyl-4'-biphenylcarboxylic acid 4-
(1-alkylcarbonyloxyethyl) phenyl ester, 4-C _4-20 alkyloxy-4'-biphenylcarboxylic acid 4- (1-alkylcarbonyloxyethyl) phenyl ester, 4-C _4-20 alkyl-4'-
Biphenylcarboxylic acid 4 '-(1-alkylcarbonyloxyethyl) -4-biphenylyl ester, 4-C
_4-20 alkyloxy-4-biphenylcarboxylic acid
4 '-(1-alkylcarbonyloxyethyl) -4-
An optically active substance such as biphenylyl ester is exemplified.

In the above examples, alkyl is methyl, ethyl,
Propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl,
Heptadecyl, octadecyl, nonadecyl and eicosyl, isopropyl, 1-methylpropyl, 1,2-dimethylpropyl, 1,2,2-trimethylpropyl, 1-methylbutyl, 1,3-dimethylbutyl, 1,2,2,3- Tetramethylbutyl, 3-methylbutyl, 1-methylpentyl, 2
-Methylpentyl, 3-methylpentyl, 1,3-dimethylpentyl, 1-methylhexyl, 1-methylheptyl and the like, and _C4-20 alkyl excludes an alkyl group having 1 to 3 carbon atoms among them. It was done.

Further, among these alkyl groups, those having an asymmetric carbon may be optically active groups.

In the above example, the optically active benzene derivative in which the bonding group is -COO- is shown, but -OCO instead of -COO-
-, - The same applies to compounds wherein - CH ₂ O-or -OCH _2.

The optically active benzene derivative (I) specified in the present invention is used as a liquid crystal material, and most of them are S _A
It exhibits a liquid crystal phase belonging to the phase or Sc ^* phase.

By the way, in general, in particular, in the Sc ^* phase, which is a ferroelectric liquid crystal, molecules are arranged in a tilted manner in a specific direction, and the tilting direction is slightly shifted from layer to layer.
A helical structure is generated in the molecular orientation [Molecular Crystal and Liquid Crystals (mol.Cryst.and
Liq. Cryst., 40 , 30 (1977)], it is said that the spontaneous polarization lies in a direction perpendicular to this helical axis, and the condition of such a ferroelectric liquid crystal is a helical structure. To have an optically active group at the molecular end to induce spontaneous polarization, and to have a substituent having a permanent dipole almost perpendicular to the long axis of the liquid crystal molecule at the molecular end to induce spontaneous polarization. ing.

In addition, it is essential to have an optically active group in the molecule, but it has been considered that it is preferable to bring the optically active group close to the core in order to induce a larger spontaneous polarization [Liquid Crystals, and Ordered Fluids (Liquid Crystals and Ordered Fluids) vol.4,1-3
2 (1982)], on the other hand, it was considered that the liquid crystal phase was hard to appear when the optically active center was close to the core.

However, there is no known liquid crystal compound having an optically active group at a position adjacent to the core.

However, the optically active benzene derivative represented by the general formula (I) of the present invention satisfies the above conditions as a liquid crystal compound and has an unprecedentedly novel structure having an optically active center at a position adjacent to the core. It has an excellent feature of having a very large spontaneous polarization and can be advantageously used as a liquid crystal material.

The use of such a liquid crystal compound is not limited to the case where only the optically active benzene derivative of the present invention is used. For example, the spontaneous polarization as a liquid crystal composition may be added to another ferroelectric liquid crystal material having only a very small spontaneous polarization. It can also be applied to increase.

For these reasons, the liquid crystal material in the present invention is:
Even if it is not confirmed that the optically active benzene derivative of the present invention itself exhibits a liquid crystal phase, it includes a case where it is effectively used as a liquid crystal composition.

When the optically active benzene derivative (I) of the present invention is specifically used as a liquid crystal material, the derivative itself may be used as a liquid crystal material.
Those having the Sc ^* phase are more useful, and those having the Sc ^* phase in entropy are considered more preferable. From such a viewpoint, X: -OCO-, l: 2, m: 1 An optically active benzene derivative is more preferably used.

For other optically active benzene derivatives, other liquid crystals that have no spontaneous polarization, or even a very small spontaneous polarization Sc phase even if they themselves do not take the Sc ^* phase By increasing the spontaneous polarization of the liquid crystal composition by adding it to the compound, the response speed can be increased, and the compound can be used as a mixture. In this case, the optically active benzene derivative of the present invention has high compatibility and excellent stability when mixed with each other, so that it is practically useful.

As described above, the optically active benzene derivative of the present invention is very useful as a liquid crystal material, and the liquid crystal material is effectively used as an optical switching element and a liquid crystal element material according to a conventional method.

In actual use, the optically active benzene derivative of the present invention may be used alone or in combination with other liquid crystal compounds or the like according to the respective purposes and circumstances, as described above. Often, its use is arbitrary.

<Effect of the Invention> Thus, the novel optically active benzene derivative of the present invention is effectively used as a novel liquid crystal material, and its industrial utility value is very high.

<Example> Hereinafter, the present invention will be described with reference to examples.

Example 1 A four-necked flask equipped with a stirrer and a thermometer was charged with 40.2 g (0.1 mol) of 4'-acetyl-4-biphenylyl ester of 4-pentyloxybenzoic acid, 100 ml of ethanol and 100 ml of chloroform. At 30 ° C., 1.9 g (0.05 mol) of sodium borohydride are added over 10 minutes.

After keeping at the same temperature for 3 hours, the mixture is poured into ice water and extracted twice with 200 ml of chloroform.

The organic layer was washed with water and concentrated under reduced pressure to obtain 40.1 g (yield 99.1%) of 4 '-(1-hydroxyethyl) -4-biphenylyl ester of 4-pentyloxybenzoic acid.

Next, 20.2 g (0.05 mol) of the above-obtained 4-pentyloxybenzoic acid ester was dissolved in a mixed solution of 100 ml of pyridine and 200 ml of chloroform.
5.5 g (0.07 mol) are added over 1 hour at 10-15 ° C. Thereafter, it is kept at 40 to 50 ° C. for 2 hours.

After completion of the reaction, 200 ml of water is added at 10 ° C. or lower, and the organic layer is separated. The organic layer was washed successively with 3N hydrochloric acid, water, 7% sodium hydrogen carbonate and water, and then concentrated under reduced pressure to give 4 '-(1-acetoxyethyl) of 4-pentyloxybenzoic acid.
21.6 g of 4-biphenylyl ester (97% yield) was obtained.

8.9 g of this ester of 4-pentyloxybenzoic acid (0.
02 mol) is vigorously stirred with 300 ml of 0.3 M phosphate buffer (pH 7), 20 ml of chloroform and 1.8 g of Base “P” at 35-40 ° C. for 24 hours.

After completion of the reaction, the reaction mixture is extracted with 300 ml of chloroform.

The organic layer was concentrated under reduced pressure, and the residue was purified by column chromatography using a mixture of chloroform: ethyl acetate = 20: 1 as an eluent to give 4 ′-(1-hydroxyethyl) of (+)-4-pentyloxybenzoic acid. 3.6 g of) -4-biphenylyl ester were obtained. [Mp 186-188 ° C, ▲ [α] ²⁰ _D
▼ + 24.2 ゜ (c = 1, CHCl ₃ )] (Compound No. II-1) Also, the reaction and post-treatment were carried out according to the above method except that the ketones shown in Table 1 were used as starting materials. , Table-1
Various optically active alcohol compounds shown in the following were obtained.

(+)-P-octyloxybenzoic acid obtained here
4.47 g (10 mmol) of 4 '-(1-hydroxyethyl) -4-biphenylyl ester is dissolved in 100 ml of dry pyridine, and 2.7 g (15 mmol) of octanoyl chloride is added dropwise. Thereafter, the mixture is stirred at room temperature for 1 hour, poured into 2N hydrochloric acid 1 and extracted with 500 ml of toluene. The toluene layer is washed with water, washed with a 7% aqueous sodium bicarbonate solution, further washed with water, and dried over anhydrous magnesium sulfate. The toluene solution was treated under reduced pressure to remove the solvent, and the obtained white solid was purified by column chromatography packed with 400 g of silica gel to give (+)-p-octyloxybenzoic acid 4 '-(1 -Heptylcarbonyloxyethyl) -4-biphenylyl ester 5.58 g
(95% yield). (Compound No. 1) This was further purified by recrystallization treatment using ethanol.

▲ [α] ²⁵ _D ▼ + 49.4 ゜ (c = 1, chloroform) Phase transition point (℃) In addition, in this esterification, (+)-p-octyloxybenzoic acid 4 '-(1-hydroxyethyl)-
The same reaction and post-treatment were conducted except that (+)-p-octyloxybenzoic acid 4- (1-hydroxyethyl) phenyl ester was used instead of 4-biphenylyl ester and hexanoyl chloride was used instead of octanoyl chloride. To give (+)-p-octyloxybenzoic acid 4- (1-pentylcarbonyloxyethyl) phenyl ester. (Compound No. 2) ▲ [α] ²⁵ _D ▼ = + 51 ゜ (c = 1, CHCl ₃ ) In addition, esterification and post-treatment were conducted in the same manner as in the above example except that acetyl chloride was used instead of hexanoyl chloride. (+)-P-octyloxybenzoic acid 4-
(1-Acetylcarbonyloxyethyl) phenyl ester was obtained. (Compound No. 3) 〔[α] ²⁵ _D ＝= + 60 ゜ (c = 1, CHCl ₃ ) Various optically active benzene derivatives shown in Table 2 were produced according to the above method.

Table 2 shows the optical rotation and the phase transition point of the obtained compound.

Example 2 In a four-necked flask equipped with a stirrer and a thermometer, 4-
(4-octyloxy) benzyloxyacetophenone
14.17 g (0.04 mol), 30 ml of tetrahydrofuran and 10 ml of methanol are charged, and 1.51 g (0.04 mol) of sodium borohydride is added thereto over 2 hours at 15 to 25 ° C. After keeping at the same temperature for 5 hours, the mixture is poured into ice water and extracted twice with 500 ml of ethyl acetate. The organic layer was concentrated under reduced pressure to obtain 13.75 g of 4- (4-octyloxy) benzyloxy-1-phenethyl alcohol (yield 96.5%).

Next, 4- (4-octyloxy) benzyloxy-
10.68 g (0.03 mol) of 1-phenethyl alcohol is dissolved in a mixture of 30 ml of toluene and 5 ml of pyridine, and 2.59 g (0.033 mol) of acetyl chloride is added thereto at 15 to 20 ° C. over 2 hours. Incubate at the same temperature for 1 hour and at 40-50 ° C for 2 hours.

After completion of the reaction, the reaction mixture is cooled to 10 ° C. or lower, and water (200 ml) is added. The organic layer is separated and washed successively with 1N hydrochloric acid, water, 5% sodium carbonate and water. The organic layer was concentrated under reduced pressure, and further purified by column chromatography to obtain 11.71 g (98% yield) of acetic acid ester of 4- (4-octyloxy) benzyloxy-1-phenethyl alcohol.

This 4- (4-octyloxy) benzyloxy-1
-Mix 9.95 g (0.025 mol) of acetic acid ester of phenethyl alcohol with 70 ml of 0.3 M lyacid buffer (pH 7.5) and 1 g of Amano lipase "P" and stir vigorously at 40-45 [deg.] C for 40 hours. After completion of the reaction, the reaction mixture is extracted with 50 ml of ethyl acetate. The organic layer was concentrated under reduced pressure, and the residue was purified by column chromatography using a mixture of toluene: ethyl acetate = 5: 2 as an eluent to give (+)-4- (4-octyloxy) benzyloxy-1-phenethyl alcohol 3.56. g (40% yield)
I got

[▲ [α] ²⁵ _D ▼ + 23.1 ゜ (c = 1, CHCl ₃ )] In addition, the reaction and post-treatment are carried out according to the above method except that the ketones shown in Table 3 are used as starting materials. Table-3
Various optically active alcohol compounds shown in the following were obtained.

2.0 g (4.6 mmol) of (+)-4- (4-octyloxy) benzyloxy-4 '-(1-hydroxyethyl) biphenyl obtained here was dissolved in 20 ml of pyridine, and 0.9 g (5.5 g) of octanoyl chloride was added thereto. Mmol). Thereafter, the mixture is stirred at 40 to 45 ° C for 1 hour. After completion of the reaction, the reaction solution is poured into 400 ml of 3N hydrochloric acid and extracted with 300 ml of toluene. After washing the toluene layer with water, it is washed with 7% aqueous sodium bicarbonate,
Further, it is washed with water and dried over anhydrous magnesium sulfate. The organic layer was evaporated under reduced pressure, and the obtained pale yellow solid was purified by column chromatography on silica gel to give (+)-4- (4-octyloxy) benzyloxy-.
4 '-(1-octanoyloxyethyl) biphenyl 2.
4 g (96%) were obtained. [▲ [α] ²⁵ _D ▼ = + 47 ゜ (c = 1, C
HCl ₃ )] (Compound No. 42) According to the above method, various optically active benzene derivatives shown in Table 4 were obtained.

 The optical rotation of the obtained compound is shown in Table-4.

Reference Example 1 Table-5 shows the measured values of the spontaneous polarization of the optically active benzene derivative.

Note that all measured values are values at a temperature 10 ° C. lower than the Sc ^* upper limit temperature.

Example 3 The above three liquid crystal compounds were mixed while being heated and melted at a predetermined molar ratio to prepare a liquid crystal composition.

The obtained liquid crystal composition showed a chiral smectic C phase (Sc ^* ) at a temperature of 38 ° C. or lower, and the spontaneous polarization at 25 ° C. was 40 nC / cm ² .

The equimolar mixture of the above two known compounds showed a Sc ^* phase at 35 ° C. or lower, and the spontaneous polarization was 4 nC / cm ² .

(Liquid crystal element manufacturing method)

A polyimide-based polymer film is provided on a glass substrate on which an indium oxide transparent electrode is provided, and wrapped using gauze in a certain direction, and glass fibers (diameter 6 μm) are set so that the lapping directions of the two substrates are parallel. Is used as a spacer to assemble a liquid crystal cell, and the liquid crystal composition is vacuum-sealed into the liquid crystal cell to obtain a liquid crystal element.

This liquid crystal element is placed between two orthogonal polarizers,
When an electric field was applied, a change in transmitted light intensity was observed by applying 20 V.

The response time is calculated from the change in transmitted light intensity at this time.
The value was 0.5 ms, and the contrast was also 1:20.

Example 4 A liquid crystal composition was prepared in the same manner as in Example 3, except that the optically active benzene derivative of the present invention, which did not show a Sc ^* phase by itself, was used instead of the present compound No. 9, The spontaneous polarization was measured for each. The results are shown in Table-6.

As a result, these compounds of the present invention are themselves Sc ^*
Even if the compound does not show a phase, it can be understood that blending with a known compound is effective in expanding spontaneous polarization.

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Claims (7)

(57) [Claims] 1. The compound of the general formula (I) (Wherein X is -COO-, -OCO-, -CH2O- or -OC
A represents H2-, A represents an alkyl group having 4 to 20 carbon atoms or an alkoxyl group, R represents an alkyl group having 1 to 20 carbon atoms, and l and m are 1 or 2, respectively. The asterisk indicates that it is an asymmetric carbon. ) An optically active benzene derivative represented by 2. A compound of the general formula (II) (Wherein, X, A, l, m and * represent the same meaning as described above).
I) R-COOH (III) (wherein, R has the same meaning as described above), and reacted with an aliphatic carboxylic acid or an acid anhydride or an acid halide thereof represented by the general formula (I) ). 3. A compound of the general formula (IV) (Wherein X, A, l and m have the same meanings as described above, and R ′ represents a lower alkyl group.) A dl-ester represented by the following formula: Asymmetric hydrolysis using an esterase having an ability to preferentially hydrolyze to obtain an optically active alcohol compound represented by the general formula (II), and then converting the optically active alcohol compound represented by the general formula (III) A process for producing an optically active benzene derivative represented by the general formula (I), which comprises reacting an aliphatic carboxylic acid, an acid anhydride thereof, or an acid halide thereof. 4. The formula (V) (Wherein X, A, l and m have the same meanings as described above). The dl-alcohols represented by the general formula (IV) are reacted with lower alkyl carboxylic acids to obtain the dl-esters represented by the general formula (IV). Then, an asymmetric hydrolysis using an esterase having the ability to preferentially hydrolyze only one of the enantiomers of the ester to obtain an optically active alcohol compound represented by the general formula (II), Then, the optically active alcohol compound is reacted with an aliphatic carboxylic acid or an acid anhydride thereof or an acid halide thereof represented by the general formula (III). Manufacturing method. 5. A compound of the general formula (VI) (Wherein, X, A, l and m have the same meanings as described above) by using a reducing agent to obtain a dl-alcohol represented by the general formula (V), Then, it is reacted with a lower alkyl carboxylic acid to obtain a dl-ester represented by the general formula (IV), and then an esterase having an ability to preferentially hydrolyze only one of the enantiomers of the ester is used. To give an optically active alcohol compound represented by the general formula (II), and then to convert the optically active alcohol compound to an aliphatic carboxylic acid represented by the general formula (III), an acid anhydride thereof, or an acid thereof. General formula (I) characterized by reacting with a halide
A method for producing an optically active benzene derivative represented by the formula: 6. A liquid crystal material comprising an optically active benzene derivative represented by the general formula (I) as an active ingredient. 7. An optical switching element using the liquid crystal material according to claim 6.