JP2560459B2 - Optically active biphenyl compound, method for producing the same, liquid crystal composition containing the same and liquid crystal device using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel organic compound, a method for producing the same, a liquid crystal composition containing the same, and a liquid crystal device using the same. The present invention relates to an optically active biphenyl compound useful as an additive for imparting properties as an optically active liquid crystal material to an active liquid crystal material, a method for producing the same, a liquid crystal composition containing the same, and a liquid crystal device using the same.

<Prior Art> Conventionally, by adding an optically active compound to a non-optically active liquid crystal material to impart various properties, for example, by adding an optically active compound to a TN liquid crystal material and using it as an STN display element material, etc. It has been known.

However, conventionally known additives cause a decrease in liquid crystal order (order parameter), deterioration in directional resistance, destabilization of a liquid crystal phase, or a significant change in the physical properties important as a liquid crystal. Due to its drawbacks,
I wasn't necessarily satisfied.

<Problems to be Solved by the Invention> From the above, the present invention provides a practical and novel liquid crystal additive capable of overcoming the above-mentioned drawbacks and expanding the liquid crystal temperature range to a range including room temperature. It is provided.

<Means for Solving the Problems> That is, the present invention provides a compound represented by the general formula (I): (In the formula, R represents an alkyl group having 1 to 15 carbon atoms which may be substituted with a halogen atom. S is 0 or 1.
The * mark indicates an asymmetric carbon atom. ) An optically active biphenyl compound represented by
A liquid crystal composition containing the same and a liquid crystal element using the same.

 Hereinafter, the present invention will be described in detail.

The s of the optically active biphenyl compound (I) of the present invention is 1
The compound represented by can be produced by the following method.

That is, the general formula (II) (In the formula, * indicates an asymmetric carbon atom.) And an optically active alcohol represented by the general formula (III) RCOOH (III) (wherein R is a halogen having 1 to 15 carbon atoms). It represents an alkyl group which may be substituted with an atom.).

The above-mentioned optically active alcohols (II) are novel compounds found by the present inventors for the first time, and can be produced, for example, by the method shown below.

(In the formula, R ″ represents a lower alkyl group.) Examples of the substituent R of the carboxylic acid (III) include the following alkyl groups.

Methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, 1-methylethyl, 2-methylbutyl, 2,3-dimethylbutyl, 2,3,3. 3-trimethylbutyl, 2-methylpentyl, 3-methylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 2,3,3,4-tetramethylpentyl, 2-methylhexyl, 3-methylhexyl Four
-Methylhexyl, 2,5-dimethylhexyl, 2-methylheptyl, 2-methyloctyl, 2-trihalomethylpentyl, 2-trihalomethylhexyl, 2-trihalomethylheptyl, 2-halopropyl, 3-halo-2- Methylpropyl, 2,3-dihalopropyl, 2-halobutyl, 3-halobutyl, 2,3-dihalobutyl, 2,4-dihalobutyl, 3,4-dihalobutyl, 2-halo-3-methylbutyl, 2-halo-3,3 -Dimethylbutyl, 2-halopentyl, 3-halopentyl, 4-halopentyl, 2,4-dihalopentyl, 2,5-dihalopentyl, 2-halo-3-
Methylpentyl, 2-halo-4-methylpentyl, 2-
Halo-3-monohalomethyl-4-methylpentyl, 2-
Halohexyl, 3-halohexyl, 4-halohexyl,
5-halohexyl, 2-haloheptyl, 2-halooctyl (however, halo in the above alkyl group represents fluorine, chlorine, bromine or iodine).

In the above reaction, as the carboxylic acid (III), an aliphatic carboxylic acid having these substituents, an acid anhydride or acid halide thereof, or an acid halide such as acid bromide is used.

Incidentally, these aliphatic carboxylic acids or their derivatives may be racemic or optically active.

Some of the above optically active carboxylic acids are obtained by oxidation of the corresponding alcohols, reductive deamination of amino acids. Some can be derived from optically active amino acids and optically active oxyacids that occur naturally or are obtained by resolution, such as:

Alanine, valine, leucine, isoleucine, phenylalanine, serine, threonine, arosreonine, 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, etc.

The reaction of such an optically active alcohol (II) with an aliphatic carboxylic acid or its derivative is usually carried out in the presence or absence of a solvent, generally in the presence of a catalyst.

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

In the reaction, when the acid anhydride or acid halide of the above aliphatic carboxylic acid is used, the amount used is required to be 1 equivalent or more times the amount of the optically active alcohol (II), and the upper limit is Although not particularly limited, preferably 4
Equivalent times.

Examples of the catalyst include dimethylaminopyridine, triethylamine, tri-n-butylamine, pyridine,
Picoline, collidine, imidazole, sodium carbonate,
Examples thereof include organic or inorganic basic substances such as sodium methylate and potassium hydrogen carbonate. Further, an organic acid or an inorganic acid such as toluenesulfonic acid, methanesulfonic acid or sulfuric acid may be used as a catalyst.

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

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

When an aliphatic carboxylic acid is used in the reaction, it is dehydrated and condensed by using the carboxylic acid in the presence of a condensing agent, usually in an amount of 1 to 2 equivalents with respect to the optically active alcohol (II). An optically active biphenyl compound {s = 1 in the general formula (I)} can be obtained.

As the condensing agent, a carbodiimide such as N, N'-dicyclohexylcarbodiimide or N-cyclohexyl-N '-(4-diethylamino) cyclohexylcarbodiimide is preferably used, and if necessary, an organic base such as 4-pyrrolidinopyridine, pyridine or triethylamine. Are used together.

The amount of the condensing agent used is 1 to 1.2 equivalent times the carboxylic acid, and the amount of the base used is 0.01 to 0.2 equivalent times the condensing agent.

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

The reaction time is not particularly limited, and the time point at which the optically active alcohol (II) as the raw material disappears can be the end point of the reaction.

After completion of the reaction, usual separation means such as extraction, liquid separation,
An optically active biphenyl compound can be obtained in good yield by an operation such as concentration, and this can be purified by column chromatography, recrystallization or the like, if necessary.

Next, a method for producing an optically active biphenyl compound in which s is 0 in the general formula (I) will be described.

In the following description, the alkylating agent is represented by the general formula (IV) X—R (IV) (wherein R represents an alkyl group having 1 to 15 carbon atoms and optionally substituted with a halogen atom. X is a halogen). Atom or --OSO ₂ R, wherein R represents a lower alkyl group or an optionally substituted phenyl group).

The above compound {where s is 0 in the general formula (I)} is carried out by reacting an optically active alcohol (II) with an alkylating agent (IV).

This reaction is usually carried out in the presence of a basic substance, and examples of the basic substance include alkali metal hydrides such as sodium hydride and potassium hydride, alkali metals such as lithium, sodium and potassium, sodium ethylate, Examples thereof include alkali metal alcoholates such as sodium methylate, alkali metal carbonates such as sodium carbonate and potassium carbonate, and butyllithium.

The basic substance is required to be 1 equivalent or more with respect to the optically active alcohol, and the upper limit is not particularly limited, but it is preferably in the range of 1 to 5 equivalents.

The alkylating agent used in this reaction is a halide or sulfate such as chloride, bromide, iodo having an alkyl group which may be substituted with a halogen atom having 1 to 15 carbon atoms as exemplified below. And the like (methane sulfonate, ethane sulfonate, benzene sulfonate, toluene sulfonate, etc.).

Methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl.

Furthermore, 1-methylethyl, 2-methylbutyl, 2,
3-dimethylbutyl, 2,3,3-trimethylbutyl, 2-methylpentyl, 3-methylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 2,3,3,4-tetramethylpentyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 2,5-dimethylhexyl, 2
-Methylheptyl, 2-methyloctyl, 2-trihalomethylpentyl, 2-trihalomethylhexyl, 2-trihalomethylheptyl, 2-halopropyl, 3-halo-
2-methylpropyl, 2,3-dihalopropyl, 2-halobutyl, 3-halobutyl, 2,3-dihalobutyl, 2,4-dihalobutyl, 3,4-dihalobutyl, 2-halo-3-methylbutyl, 2-halo-3 , 3-Dimethylbutyl, 2-halopentyl, 3-halopentyl, 4-halopentyl, 2,4
-Dihalopentyl, 2,5-dihalopentyl, 2-halo-
3-methylpentyl, 2-halo-4-methylpentyl,
2-halo-3-monohalomethyl-4-methylpentyl,
2-halohexyl, 3-halohexyl, 4-halohexyl, 5-halohexyl, 2-haloheptyl, 2-halooctyl (however, halo in the above alkyl group represents fluorine, chlorine, bromine or iodine, but in practice fluorine or chlorine Is preferred).

The alkyl group having 1 to 15 carbon atoms which may be substituted with a halogen atom may be an optically active group.

The halides or sulfates having these optically active groups are derived from the corresponding alcohols, and some of the optically active alcohols can be easily prepared by the asymmetric metal catalyst of the corresponding ketone, asymmetric reduction by microorganisms or enzymes. Is obtained. Others can be derived from optically active amino acids and optically active oxyacids that occur naturally or are obtained by resolution, such as:

Valine, leucine, isoleucine, phenylalanine, threonine, arosreonine, homoserine, alloisoleucine, tert-leucine, 2-aminobutyric acid, norvaline, norleucine, ornithine, lysine, hydroxylysine, phenylglycine, aspartic acid, glutamic acid, mandelic acid, tropa Acid, 3-hydroxybutyric acid, malic acid, tartaric acid, isopropylmalic acid and the like.

The alkylating agent may be used in an amount of 1 equivalent or more with respect to the optically active alcohol (II), but is usually in the range of 1 to 5 equivalents.

As the reaction solvent, in addition to the solvents exemplified above, dimethyl sulfoxide, hexamethylphosphorylamide, N-
A polar solvent such as methylpyrrolidone can be used.

The reaction temperature is generally -50 ° C to 120 ° C, preferably -30 ° C.
The range is up to 100 ° C.

After completion of the reaction, usual separation means such as extraction, liquid separation,
An optically active biphenyl compound {s = 0 in the general formula (I)} can be obtained in good yield by an operation such as concentration.
This can be purified by column chromatography, recrystallization, etc., if necessary.

The liquid crystal composition of the present invention contains at least one kind of the optically active biphenyl compound represented by the above general formula (I) as a blending component. In this case, 0.1 to 99.9% by weight, particularly preferably 1 to 9% by weight of the liquid crystal composition from which the optically active biphenyl compound represented by formula (I) can be obtained.
Used at a rate of 9% by weight. Further, by using such a liquid crystal composition, it can be effectively used also as a liquid crystal element, for example, an optical switching element. However, the method of using the liquid crystal composition in this case is not particularly limited to a conventionally known method. .

<Effects of the Invention> Thus, according to the present invention, the novel optically active biphenyl compound represented by the general formula (I) can be easily obtained in a good yield, and the compound is excellent as a liquid crystal additive. Since it has characteristics, it can be effectively used as a liquid crystal composition and as a liquid crystal device using the same.

<Example> Reference example 1 4-acetyl-4'-cyanobiphenyl 44.2 g (0.2 mol), tetrahydrofuran 200 ml and methanol 100 ml.
Was charged, and at room temperature sodium borohydride 5.7 g (0.15
Mol) was added over 2 hours. After stirring at room temperature for 3 hours,
Pour the reaction mixture into 500 ml of ice water and add 2 to 300 ml of ethyl acetate.
It was extracted twice. The organic layer was washed with water and dried over magnesium sulfate. The solvent was distilled off under reduced pressure to give 4- (1-hydroxyethyl) -4'-cyanobiphenyl 42.9 g (yield 96
%) Was obtained.

Melting point 151 ° C. 4- (1-hydroxyethyl) -4′-cyanobiphenyl 2.3 g (0.1 mol), pyridine 20 ml and toluene 60 m
To a mixture of 1 was added 9.4 g (0.12 mol) of acetyl chloride dropwise at 0 to 10 ° C. 1 hour at the same temperature, 3 at 25-30 ° C
Stirred for hours. The reaction mixture was washed successively with 5% hydrochloric acid, water, 5% sodium carbonate and water. The organic layer was concentrated under reduced pressure, and the obtained residue was purified by column chromatography with toluene-ethyl acetate (40: 1). 4- (1-acetoxyethyl)
24.9 g (yield 94%) of -4'-cyanobiphenyl was obtained.
N ²⁰ _D 1.5914 4- (1-acetoxyethyl) -4'-cyanobiphenyl 23.9 g (0.09 mol), 0.2
A mixture of 800 ml of M-phosphate buffer (pH 7.0) and 3.0 g of amanolipase "P" was vigorously stirred at 25-30 ° C for 25 hours. The reaction mixture was extracted with 100 ml of ethyl acetate.
The organic layer was concentrated under reduced pressure. The obtained residue is toluene-
Purified by column chromatography with ethyl acetate (20: 1).

(+)-4- (1-Hydroxyethyl) -4'-cyanobiphenyl (II-a) 9.6 g (48% yield) ▲ [α] ²⁰ _D
▼ + 44 DEG _{(c = 1, CHCl 3)} , mp 165 ° C. and (-) - 4
-(1-acetoxyethyl) -4'-cyanobiphenyl
12.05 g (yield 50.5%) was obtained.

▲ n ²⁰ _D ▼ 1.5909, ▲ [α] ²⁰ _D ▼ -106 ° (c = 1, CHC
l ₃ ) (−)-4- (1-acetoxyethyl) -obtained above
5.3 g (0.02 mol) of 4'-cyanobiphenyl, methanol
20 ml and 20 g of 20% caustic soda (0.04 mol) were stirred at 20-30 ° C for 3 hours. After completion of the reaction, methanol was distilled off, and the obtained residue was extracted with 50 ml of ethyl acetate. After washing the organic layer with water, the solvent was distilled off under reduced pressure. The obtained residue was purified by column chromatography with toluene-ethyl acetate (20: 1).

There were obtained 4.35 g (yield 97.5%) of (-)-4- (1-hydroxyethyl) -4'-cyanobiphenyl (II-b).
(Α) ²⁰ _D -40 ° (c = 1, CHCl ₃ ), melting point 162 ° C. Example 1 (+)-4- (1-hydroxyethyl) obtained in Reference Example
1.12 g (5 mmol) of 4'-cyanobiphenyl (II-a) is dissolved in 20 ml of anhydrous dimethylformamide, 0.24 g (6 mmol) of 60% sodium hydride is added, and the mixture is stirred at 30 ° C for 1 hour. Then, at 20 ℃ ethyl iodide 1.56g
(10 mmol) was added and the temperature was maintained at the same temperature for 2 hours, then 30-
The reaction was carried out at 40 ° C for 2 hours. After the reaction is complete, add 20
The mixture was poured into 0 ml, extracted with 200 ml of toluene, separated, and the organic layer was washed well with water and dried over anhydrous magnesium sulfate.
The solvent was distilled off under reduced pressure, and the obtained residue was separated by silica gel column chromatography (eluent; toluene: ethyl acetate). Purification yielded 1.06 g (85% yield) of (+)-4- (1-ethoxyethyl) -4'-cyanobiphenyl.

▲ [α] ²⁰ _D ▼ + 87.5 ° (c = 1, CHCl ₃ ) n ²⁰ _D ▼ 1.5914 Examples 2 to 4 (+)-4- (1-hydroxyethyl) -4 obtained in Reference Example 1 The reaction and post-treatment were carried out in the same manner as in Example 1 except that 1.12 g (5 mmol) of'-cyanobiphenyl (II-a) was used and the reagents shown in Table 1 were used as the alkylating agent.
The results shown in 1 were obtained.

Example 5 1.12 g (5 mmol) of (+)-4- (1-hydroxyethyl) -4'-cyanobiphenyl obtained in Reference Example 1 was dissolved in 5 ml of pyridine and 10 ml of toluene to give 0.47 g (6 mmol) of acetyl chloride. Was added and reacted at 30-40 ° C for 2 hours. After the reaction was completed, it was poured into 200 ml of water, adjusted to pH 1-2 with 4N hydrochloric acid, extracted with 200 ml of toluene, and separated.
The organic layer is washed with water, 5% aqueous sodium hydrogen carbonate and water in this order. afterwards,
It was dried over anhydrous magnesium sulfate, and the residue obtained by distilling off the organic solvent under reduced pressure was separated by silica gel column chromatography (eluent; toluene: ethyl acetate). Purification yielded 1.27 g (96% yield) of (+)-4- (1-acetoxyethyl) -4'-cyanobiphenyl.

 The results are shown in Table-2.

Example 6 The reaction and post-treatment were carried out in the same manner as in Example 4, except that 1.61 g (7.5 mmol) of hexanoic anhydride was used as the acylating agent used, and the results shown in Table 2 were obtained.

Example 7 1.12 g (5 mmol) of (+)-4- (1-hydroxyethyl) -4'-cyanobiphenyl obtained in Reference Example 1 and 1.2 g (6 mmol) of dodecanoic acid were dissolved in 20 ml of dichloromethane, and N, N'-dicyclohexylcarbodiimide 1.4g
And 4-pyrrolidinopyridine (0.1 g) were added, and the mixture was stirred at room temperature for 24 hours. After completion of the reaction, the precipitate was filtered off, 200 ml of toluene was added, and the mixture was washed with water, 5% acetic acid, water, 5% aqueous sodium hydrogen carbonate and water in that order, and the organic layer was dried over anhydrous magnesium sulfate and then under reduced pressure. The solvent was distilled off. The obtained residue is purified by silica gel column chromatography (eluent;
Toluene: ethyl acetate) to give (+)-4- (1-dodecanoyloxyethyl) -4'-cyanobiphenyl 1.89
g (93% yield) was obtained. The results are shown in Table-2.

Example 8 Using 1.12 g (5 mmol) of (-)-4- (1-hydroxyethyl) -4'-cyanobiphenyl obtained in Reference Example 1, the acylating agent shown in Table 2 was used. ,
Reaction and post-treatment were carried out in the same manner as in Example 7, and
2 were obtained.

Example 9 1.12 g (5 mmol) of (-)-4- (1-hydroxyethyl) -4'-cyanobiphenyl obtained in Reference Example 1
And the reaction according to Example 1 except that the reagents shown in Table 2 were used as the alkylating agent. After the post-treatment, the results shown in Table 2 were obtained.

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Claims (7)

(57) [Claims] 1. A general formula (In the formula, R represents an alkyl group having 1 to 15 carbon atoms which may be substituted with a halogen atom. S is 0 or 1.
The * mark indicates an asymmetric carbon atom. ) An optically active biphenyl compound represented by: 2. The optically active biphenyl compound according to claim 1, wherein s is 1. 3. The optically active biphenyl compound according to claim 1, wherein s is 0. 4. A general formula (In the formula, * indicates an asymmetric carbon atom.) And an optically active alcohol represented by the general formula RCOOH (wherein R is substituted with a halogen atom having 1 to 15 carbon atoms). And a carboxylic acid represented by the formula) is reacted. 5. A general formula (In the formula, * indicates an asymmetric carbon atom.) And an optically active alcohol represented by the general formula X-R (wherein R is substituted with a halogen atom having 1 to 15 carbon atoms). X represents a halogen atom or —OSO ₂ R, wherein R represents a lower alkyl group or an optionally substituted phenyl group. The method for producing an optically active biphenyl compound according to claim 3, wherein 6. A liquid crystal composition comprising at least one kind of the optically active biphenyl compound according to claim 1 as a blending component. 7. A liquid crystal device using a liquid crystal composition containing at least one kind of the optically active biphenyl compound according to claim 1 as a blending component.