JPH0832660B2 - Optically active ester derivative and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to an optically active ester derivative useful as an organic electronic material such as a liquid crystal material, particularly a liquid crystal material having excellent responsiveness for image display, and a method for producing the same. is there.

<Prior Art> Various compounds have been developed as constituents of liquid crystals, but a compound having an asymmetric carbon atom directly bonded to a core part (that is, a core part such as a phenyl group or a biphenyl group) has been developed. The optically active ester derivative, which is a novel compound found by the present inventors and having a very small amount and a specific structure among the compounds, can be used as a ferroelectric liquid crystal compound and / or a ferroelectric liquid crystal composition. However, the optically active ester derivative and its industrially advantageous and novel production method are not known so far.

<Problems to be Solved by the Invention> The present invention thus provides an optically active ester derivative useful as a ferroelectric liquid crystal compound and / or a ferroelectric liquid crystal composition, and a novel production method thereof. .

<Means for Solving the Problems> The present invention has the general formula (II) (Wherein A represents an alkyl group or an alkoxyl group having 3 to 20 carbon atoms, and 1 represents 1 or 2), and a general formula (III) (In the formula, R represents an alkyl group or an alkyloxyalkyl group which may be substituted with a halogen atom having 1 to 20 carbon atoms, R'represents a hydroxyl group or a halogen atom. M is 1 or 2, and an * mark Represents an asymmetric carbon atom.) An optically active carboxylic acid represented by the general formula (I) (Wherein A, R, l, m and * have the same meanings as described above) and an optically active ester derivative thereof and a method for producing the same.

One of the raw materials used in the present invention, phenols (II)
Are mostly known compounds and can be produced according to the methods described in the literature.

As such phenols (II), 4-alkoxyphenol, 4-alkylphenol, 4'-alkoxy-4-hydroxybiphenyl, 4'-alkyl-4-
Hydroxybiphenyls are mentioned, which can also be used as metal phenolates.

Here, as the alkyl forming the above alkyl or alkoxy, specifically, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, Examples include nonadecyl and eicosyl.

The optically active carboxylic acids (III) containing an asymmetric carbon atom, which is the other raw material in this reaction, is a novel compound. For example, acetyl benzoic acid benzyl ester or 4-acetyl-4'-benzyloxycarbonylbiphenyl is hydrogenated. After reduction with sodium borohydride to convert the acetyl group to an α-hydroxyethyl group, acetyl chloride-pyridine is converted to an acetic acid ester, and this acetic acid ester is then asymmetrically hydrolyzed using an esterase such as lipase to give an optically active α. -Hydroxyethyl group, followed by esterification with an aliphatic carboxylic acid or its derivative, and finally by hydrogenation in the presence of a palladium-based catalyst for debenzylation.

As such optically active carboxylic acids, 4- (1-
Alkylcarbonyloxyethyl) benzoic acid, 4'-
Examples include (1-alkylcarbonyloxyethyl) -4-biphenylcarboxylic acid, 4- (1-alkoxyalkylcarbonyloxyethyl) benzoic acid and 4 '-(1-alkoxyalkylcarbonyloxyethyl) -4-biphenylcarboxylic acid. These can also be used as acid halides (eg acid chloride, acid bromide).

Here, the above-mentioned alkylcarbonyl or alkoxyalkylcarbonyl corresponds to -CO-R in the general formula (III), and the substituent R is specifically methyl, ethyl, propyl, butyl, pentyl, hexyl,
Heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, 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), methoxymethyl,
Methoxyethyl, methoxypropyl, methoxybutyl,
Methoxypentyl, methoxyhexyl, methoxyheptyl, methoxyoctyl, methoxynonyl, methoxydecyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, ethoxybutyl, ethoxypentyl, ethoxyhexyl, ethoxyheptyl, ethoxyoctyl, ethoxynonyl, ethoxydecyl, propoxymethyl , Propoxyethyl, propoxypropyl, propoxybutyl, propoxypentyl, propoxyhexyl, propoxyoctyl, propoxydecyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxybutyl, butoxypentyl, butoxyhexyl, butoxyheptyl, butoxynonyl, pentyloxymethyl, Pentyloxyethyl, Pentyloxypropyl, Pentyloxybutyl, Pentyloxy Ethyl, pentyloxyoctyl, pentyloxydecyl, hexyloxymethyl, hexyloxyethyl, hexyloxypropyl, hexyloxybutyl, hexyloxypentyl, hexyloxyhexyl, hexyloxyoctyl, hexyloxynonyl, hexyloxydecyl, heptyloxymethyl, Heptyloxyethyl, heptyloxypropyl,
Examples include heptyloxypentyl, octyloxymethyl, octyloxyethyl, decyloxymethyl, decyloxyethyl, decyloxypropyl and the like.

The alkyl group or alkoxyalkyl group which may be substituted with these halogen atoms may be an optically active group.

Some of the optically active carboxylic acids having these optically active groups can be obtained by oxidation of the corresponding alcohol and 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.

Phenols (II) and optically active carboxylic acids (III)
The usual esterification method can be applied to the reaction with, and the reaction can be carried out by reacting with a catalyst in the presence or absence of a solvent.

When a solvent is used in this reaction, the solvent is, for example, tetrahydrofuran, ethyl ether, acetone, methyl ethyl ketone, toluene, benzene, chlorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, dimethylformamide, hexane or pyridine. Or an aromatic hydrocarbon,
Examples thereof include ethers, halogenated hydrocarbons, organic amines, and other solvents inert to the reaction, alone or in a mixture. The amount used can be used without particular limitation.

In this reaction, since the optically active carboxylic acids (III) are expensive, it is preferable to carry out the reaction by using an excess amount of the phenols (II) which are the counterpart raw materials for these, usually 1 to 4 equivalent times. , Preferably 1 to 2 equivalent times.

Examples of the catalyst include dimethylaminopyridine, triethylamine, tri-n-butylamine, pyridine,
Examples thereof include organic or inorganic basic substances such as picoline, lysine, imidazole, sodium carbonate, 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.

The amount of the catalyst used varies depending on the type of each reaction raw material used and the combination of the catalysts used and cannot be specified. However, for example, when an acid halide is used, it is more than 1 equivalent of basic acid with respect to the acid halide. The substance is used.

Furthermore, when the optically active carboxylic acid represented by the general formula (III) is an optically active carboxylic acid, N, N'-dicyclohexylcarbodiimide, N-cyclohexyl-
Carbodiimides such as N '-(4-diethylamino) cyclohexylcarbodiimide are preferably used as the condensing agent, and if necessary 4-pyrrolidinopyridine, pyridine,
An organic base such as triethylamine can also be used in combination.

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

Phenols (II) and optically active carboxylic acids (III)
The reaction temperature in the reaction with is usually -30 ° C to 100 ° C, preferably -25 ° C to 80 ° C.

 The reaction time is not particularly limited.

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

As the optically active ester derivative thus obtained,
Specifically, the following compounds are exemplified.

4- [1-Alkyl (C1-20) carbonyloxyethyl] benzoic acid 4- [Alkyl (C3-20)
)] Phenyl ester, 4- [1-alkyl (C1-20) carbonyloxyethyl] benzoic acid 4- [alkyl (C3-20) oxy] phenyl ester,
4- [1-alkyl (C1-C20) carbonyloxyethyl] benzoic acid 4 '-[alkyl (C3-C20)
)] Biphenyl ester, 4- [1-alkyl (C1-20) carbonyloxyethyl] benzoic acid 4'-
[Alkyl (C3-20 oxy) biphenyl ester, 4- {4- [1-alkyl (C1-20) carbonyloxyethyl]} benzoic acid [4- [Alkyl (C3-20) )] Phenyl ester, 4- {4-
[1-alkyl (C1-C20) carbonyloxyethyl] phenyl} benzoic acid [4-alkyl (C3-C3)
20) oxy] phenyl ester, 4- {4- [1-alkyl (C1-20) carbonyloxyethyl] phenyl} benzoic acid [4'-alkyl (C3-20)
)] Biphenylyl ester, 4- {4- [1-alkyl (C1-20) carbonyloxyethyl] phenyl} benzoic acid [4'-alkyl (C3-20) oxy] biphenylyl ester .

The alkyl exemplified above (having 1 to 20 carbon atoms) may be substituted with a halogen atom, and the alkyl optionally substituted with these halogen atoms may be a branched alkyl.

Moreover, these alkyls may be optically active alkyls.

Further, alkyloxyalkylcarbonyloxyethylphenyl (or biphenylyl) benzoates exemplified below are also included.

4- [1-alkyloxyalkyl (C1-20
) Carbonyloxyethyl] benzoic acid 4- [alkyl (C3-20)] phenyl ester, 4- [1-alkyloxyalkyl (C1-20) carbonyloxyethyl] benzoic acid 4- [alkyl (C3-C20
)] Oxy] phenyl ester, 4- [1-alkyloxyalkyl (C1-20) carbonyloxyethyl] benzoic acid 4 '-[alkyl (C3-20)] biphenylyl ester, 4- [ 1-alkyloxyalkyl (C1-20 carbonyloxyethyl) benzoic acid 4 '-[alkyl (C3-20) oxy] biphenylyl ester, 4- {4- [1-alkyloxyalkyl ( Carbonyloxyethyl having 1 to 20 carbon atoms]}
Benzoic acid [4- [alkyl (having 3 to 20 carbon atoms)] phenyl ester, 4- {4- [1-alkyloxyalkyl (having 1 to 20 carbon atoms) carbonyloxyethyl] phenyl} benzoic acid [4-alkyl Oxy] phenyl ester (having 3 to 20 carbon atoms), 4- {4- [1-alkyloxyalkyl (carbonyloxyethyl] phenyl having 1 to 20 carbon atoms) phenyl} benzoic acid [4′-alkyl (having 3 to 4 carbon atoms)
20)] Biphenylyl ester, 4- {4- [1-alkyloxyalkyl (C1-20) carbonyloxyethyl] phenyl} benzoic acid [4'-alkyl (C3-20) oxy] Biphenylyl ester. The alkyloxyalkyl (having 1 to 20 carbon atoms) of the above alkyloxyalkylcarbonyloxyethylphenyl (or biphenylyl) benzoate may be substituted with a halogen atom, or alkyloxy which may be substituted with these halogen atoms. The alkyl may be a branched alkyloxyalkyl.

Further, these alkyloxyalkyl may be optically active alkyloxyalkyl.

In the above example, alkyl (having 1 to 20 carbon atoms)
Carbonyloxy or alkyloxyalkyl (having 1 to 20 carbon atoms) carbonyloxy alkyl or alkyloxyalkyl includes those exemplified above.

<Effect of the Invention> Thus, according to the method of the present invention, a very useful optically active ester derivative, which is used as a material for an optical switching element or a liquid crystal element, is industrially advantageously produced.

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

Example 1 (+)-4- (1-butyryloxyethyl) benzoic acid
An acid chloride prepared from 2.36 g (10 mmol) and oxalyl chloride is added at room temperature to a solution consisting of 3.58 g (12 mmol) 4'-octyloxy-4-hydroxybiphenyl, 10 g pyridine and 30 g dichloroethane.
After stirring at the same temperature for 5 hours, the mixture is further stirred at 50 ° C. for 3 hours. After the reaction was completed, 30 g of dichloroethane was added, and water, 1
Wash sequentially with N-hydrochloric acid water, 2% sodium carbonate, and water. The dichloroethane layer was concentrated under reduced pressure to remove the solvent,
The obtained white solid was purified by silica gel column chromatography to obtain 4.8 g of (+)-4- (1-butyryloxyethyl) benzoic acid 4 '-(octyloxy) -4-biphenylyl ester (yield 93%. ) Got.

 Further purification was by recrystallization from ethanol.

Optical rotation ▲ [α] ²⁰ _D ▼ + 60 ° (c = 1, CHCl ₃ ) Example 2 (+)-4- (1-butyryloxyethyl) benzoic acid (+)-4- (1- Hexanoyloxyethyl) benzoic acid was reacted, worked up and purified in the same manner as in Example 1 except that 2.6 g of (+)-4- (1-hexanoyloxyethyl) benzoic acid 4 '-(octyloxy) was used. ) -4
-5.28 g (94% yield) of biphenylyl ester were obtained.

▲ [α] ²⁰ _D ▼ + 57 ° (c = 1, CHCl ₃ ) Example 3 (+)-4- (1-butyryloxyethyl) benzoic acid (+)-4- (1-decanoyl) Oxyethyl)
Reaction as in Example 1, but using 3.2 g of benzoic acid,
Post treatment and purification gave 5.75 g (93% yield) of (+)-4- (1-decanoyloxyethyl) benzoic acid 4 '-(octyloxy) -4-biphenylyl ester.

[Α] ²⁰ _D ▼ + 40 ° (c = 1, CHCl ₃ ) Examples 4 to 12 According to the method of Example 1, the compounds shown in Table 1 were obtained.
Table 1 shows the phase transition temperature of each compound.

The phase transition temperatures of the compounds obtained in Examples 1 to 3 are also shown in Table-1.

Example 13 2.5 g (10 mmol) of (−)-4- (1-2 (S) -methylbutyryloxyethyl) benzoic acid and 3.58 g (12 mmol) of 4′-octyloxy-4-hydroxybiphenyl were dried. Dissolve in 50 ml of dichloromethane, add 2.47 g (12 mmol) of dicyclohexylcarbodiimide and 4-
Add 0.08 g of pyrrolidinopyridine and stir at room temperature for 10 hours.

After the reaction was completed, the white precipitate formed was filtered off, the filtrate was concentrated under reduced pressure, and the obtained concentrated residue was purified by silica gel column chromatography to obtain (-)-4- (1-2 (S)-
Methylbutyryloxyethyl) benzoic acid 4-octyloxybiphenylyl ester 4.88 g (yield 92%) was obtained.

▲ [α] ²⁰ _D ▼ -39.5 ° (c = 1, CHCl ₃ ) Example 14 (+)-4 ′-(1-hexanoyloxyethyl)-
4-biphenylcarboxylic acid 3.65 g (10 mmol) and 4-
2.27 g (12 mmol) of octyloxyphenol is dissolved in 50 ml of anhydrous dichloromethane, 3.09 g (15 mmol) of dicyclohexylcarbodiimide and 0.1 g of 4-pyrrolidinopyridine are added thereto, and the mixture is stirred at room temperature for 6 hours.

After the reaction was completed, the white precipitate formed was filtered off and 150 g of dichloromethane was added to the organic layer, followed by water, 5% acetic acid water, water and 5%.
Wash sequentially with sodium bicarbonate water and water.

The dichloromethane layer was concentrated under reduced pressure, and the obtained white solid residue was purified by silica gel column chromatography to obtain (+)-4 '-(1-hexanoyloxyethyl)-
4-Biphenylcarboxylic acid 4-octyloxyphenyl ester 4.96 g (yield 92.5%) was obtained.

 Further purification was by recrystallization from ethanol.

Optical rotatory power [α] ²⁰ _D ▼ + 55 ° (c = 1, CHCl ₃ ) Examples 15 to 24 According to the method of Example 14, the compounds shown in Table 2 were obtained.
Table 2 shows the phase transition temperature of each compound.

Example 25 (-)-4- (1-acetyloxyethyl) benzoic acid
An acid chloride prepared from 2.08 g (10 mmol) and oxalyl chloride was added to 4- (octyloxy) phenol 2.
Add at room temperature to a solution consisting of 66 g (12 mmol), 10 g of pyridine and 30 g of toluene. 40 at the same temperature for 1 hour
Stir at ~ 50 ° C for 3 hours. After completion of the reaction, post-treatment and purification were conducted according to Example 1 to obtain 3.95 g (yield 96%) of (-)-4- (1-acetyloxyethyl) benzoic acid 4- (octyloxy) phenyl ester. .

Optical rotation ▲ [α] ²⁰ _D ▼ −54 ° (c = 1, CHCl ₃ ) Example 26 (−)-4- (1-acetyloxyethyl) benzoic acid (−)-4- (1- Hexanoyloxyethyl) benzoic acid was reacted, post-treated and purified in the same manner as in Example 25 except that 2.6 g of (-)-p- (1-hexanoyloxyethyl) benzoic acid 4- (octyloxy) was used. 4.43 g (yield 95.5%) of phenyl ester was obtained.

Optical rotation ▲ [α] ²⁰ _D -40 ° (c = 1, CHCl ₃ ) Reference example 1 Table 3 shows the measured values of the spontaneous polarization of the optically active ester derivative.

In addition, all measured values are values at a temperature 10 ° C lower than the upper limit temperature of ▲ S ^* _c ▼.

Reference example 2 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 exhibited a chiral smectic C phase (Sc ^* ) at 38 ° C. or lower, and the spontaneous polarization at 25 ° C. was 30 nC / cm ² .

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

(Liquid crystal element manufacturing method)

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

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

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

Reference Example 3 A liquid crystal composition was prepared in the same manner as in Reference Example 2, except that the optically active ester derivative of the present invention, which alone did not exhibit the Sc ^* phase, was used in place of the compound No. 2 of the present invention. The spontaneous polarization was measured for each. The results are shown in Table-4.

As a result, these compounds of the present invention by themselves have 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.

Claims (2)

[Claims] 1. A general formula (In the formula, A is an alkyl group or an alkoxyl group having 3 to 20 carbon atoms, and R ″ is 1 to 1 carbon atoms substituted with a halogen atom.
An alkyl group having 20 carbon atoms or an alkoxyalkyl group having 1 to 20 carbon atoms which may be substituted with a halogen atom. l and m are 1 or 2, respectively, and * indicates that they are asymmetric carbon atoms. ) An optically active ester derivative represented by: 2. General formula (Wherein A represents an alkyl or alkoxyl group having 3 to 20 carbon atoms, and 1 represents 1 or 2), and a general formula (In the formula, R represents an alkyl group or an alkyloxyalkyl group which may be substituted with a halogen atom having 1 to 20 carbon atoms, R'represents a hydroxyl group or a halogen atom. M is 1 or 2, and an * mark Represents an asymmetric carbon atom.) A general formula characterized by reacting an optically active carboxylic acid represented by (In the formula, A, R, l, m and * have the same meanings as described above.) A method for producing an optically active ester derivative represented by