JPH0832664B2 - Optically active ester and its production method - Google Patents

Description

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

<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 esters, which are novel compounds 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 and its industrially advantageous and novel production method have not been known so far.

<Problems to be Solved by the Invention> The present invention provides an optically active ester 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) (In the formula, A represents an alkyl group or an alkoxyl group having 3 to 20 carbon atoms, R'represents a hydroxyl group or a halogen atom, and l is 1 or 2.) and a carboxylic acid compound represented by the general formula ( III) (In the formula, R is an alkyl group or an alkyloxyalkyl group which may be substituted with a halogen atom having 1 to 20 carbon atoms, m is 1 or 2, and * is an asymmetric carbon atom. The general formula (I) is characterized by reacting an optically active phenol compound represented by (In the formula, A, R, l, m and * have the same meanings as described above.) And an optically active ester thereof and a method for producing the same.

One of the starting optically active phenol compounds (III) used in the present invention is, for example, 4-hydroxyacetophenone or 4-acetyl-4'-hydroxybiphenyl obtained by using sodium hydride and benzyl bromide to convert the hydroxyl group into a benzyl ether. After that, the acetyl group is reduced by using sodium borohydride or the like to lead to α-hydroxyethyl, and then the acetic acid ester is converted to acetyl chloride-pyridine. After making it an optically active α-hydroxyethyl group, it is esterified with an aliphatic carboxylic acid (optically active aliphatic carboxylic acid) or its derivative, and finally debenzylated by hydrogenation in the presence of a palladium catalyst. It can be manufactured.
As such an optically active phenol compound (III), 4- (1-alkylcarbonyloxyethyl) phenol, 4 '-(1-alkylcarbonyloxyethyl)-
4-hydroxybiphenyl, 4- (1-alkoxyalkylcarbonyloxyethyl) phenol, 4 '-(1
-Alkoxyalkylcarbonyloxyethyl) -4-
Examples thereof include hydroxybiphenyl, and these can also be used as a metal phenolate.

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, isopropyl, 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-halo-hexyl, 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, pentyloxymethyl Propyl,
Pentyloxybutyl, pentyloxypentyl, pentyloxyoctyl, pentyloxydecyl, hexyloxymethyl, hexoxyoxyethyl, hexyloxypropyl, hexyloxybutyl, hexyloxypentyl, hexyloxyhexyl, hexyloxyoctyl, hexyloxynonyl, hexyl Examples thereof include oxydecyl, heptyloxymethyl, heptyloxyethyl, heptyloxypropyl, 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.

The optically active phenol compound (III) having these optically active groups can be obtained by esterification with an optically active aliphatic carboxylic acid as described above. Obtained by oxidation, 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,
Maldelic acid, tropic acid, 3-hydroxybutyric acid, malic acid, tartaric acid, isopropylmalic acid, etc.

Most of the other raw material, carboxylic acid compound (II), is a known compound and can be produced according to the method described in the literature. Examples of the carboxylic acid compound (II) include 4-alkoxybenzoic acid, 4-alkylbenzoic acid, 4′-alkoxy-4-biphenylcarboxylic acid,
Mention may be made of 4'-alkyl-4-biphenylcarboxylic acids, which can also be used as acid halides (eg acid chloride, acid bromide).

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 reaction between the optically active phenol compound (III) and the carboxylic acid compound (II) can be carried out by a conventional esterification method, and is carried out by reacting with a catalyst in the presence or absence of a solvent. You can

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, an optically active phenol compound (II
Since I) is expensive, it is preferable to carry out the reaction by using an excess amount of the carboxylic acid compound (II) which is the counterpart raw material, and usually 1 to 4 equivalent times, preferably 1 to 2 times.
Equivalent times used.

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. For example, when an acid halide is used, the amount of the base is 1 equivalent or more times that of the acid halide. A sexual substance is used.

Further, when the carboxylic acid compound represented by the general formula (II) is a carboxylic acid, a carbodiimide such as N, N′-dicyclohexylcarbodiimide or N-cyclohexyl-N ′-(4-diethylamino) cyclohexylcarbodiimide is a condensing agent. If desired, an organic base such as 4-pyrrolidinopyridine, pyridine or triethylamine can be used in combination.

In this case, the amount of the condensing agent used is usually 1 to 1.2 equivalent times the 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. The reaction temperature in the reaction of the carboxylic acid compound (II) and the optically active phenol compound (III) is usually -30 ° C to 100 ° C.
However, it is 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 target optically active ester represented by the general formula (I) can be isolated from the reaction mixture by concentration or the like,
If necessary, it can be purified by column chromatography, recrystallization and the like.

The following compounds are specifically exemplified as the optically active esters thus obtained. 4-Alkyl 4-alkyl (3-20 carbon atoms) benzoic acid 4 '-[1-alkyl (1 carbon atom)
~ 20) Carbonyloxyethyl] phenyl ester, 4
-Alkyl (C3-20) oxybenzoic acid 4'-
[1-Alkyl (C1-20) carbonyloxyethyl] phenyl ester, 4-alkyl (C3-20)
) Benzoic acid 4 '-[1-alkyl (having 1 to 20 carbon atoms)
Carbonyloxyethyl] -4-biphenylyl ester, 4-alkyl (C3-20) oxybenzoic acid 4 '-[1-alkyl (C1-20) carbonyloxyethyl] -4-biphenylyl ester , 4-alkyl (C3-20) -4'-biphenylcarboxylic acid 4
-[1-alkyl (C1-C20) carbonyloxyethyl] phenyl ester, 4-alkyl (C3-C3)
20) Oxy-4′-biphenylcarboxylic acid 4- [1-
Alkyl (C1-C20 carbonyloxyethyl)
Phenyl ester, 4-alkyl (C3-20)-
4'-biphenylcarboxylic acid 4 '-[1-alkyl (C1-20) carbonyloxyethyl] -4-biphenylyl ester, 4-alkyl (C3-20) oxy-4-biphenylcarboxylic acid 4 '-[1-alkyl (C1-C20) carbonyloxyethyl] -4-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 exemplified are alkyl (or alkyloxy) benzoic acid alkyloxyalkylcarbonyloxyethyl phenyl ester (or biphenylyl ester), alkyl (or alkyloxy) biphenylcarboxylic acid alkyloxycarbonyloxyethyl phenyl ester (or biphenylyl ester) Can also be given.

4-Alkyl (C3-20) benzoic acid 4 '-[1
-Alkyloxyalkyl (C1-20) carbonyloxyethyl] phenyl ester, 4-alkyl (C3-20) oxybenzoic acid 4 '-[1-alkyloxyalkyl (C1-20) Carbonyloxyethyl] phenyl ester, 4-alkyl (C3-20)
) Benzoic acid 4 '-[1-alkyloxyalkyl (C1-20) carbonyloxyethyl] -4-biphenylyl ester, 4-alkyl (C3-20) oxybenzoic acid 4'-[ 1-alkyloxyalkyl (C1-C20) carbonyloxyethyl] -4-biphenylyl ester, 4-alkyl (C3-C20) -4 '
-Biphenylcarboxylic acid 4- [1-alkyloxyalkyl (C1-20) carbonyloxyethyl] phenyl ester, 4-alkyl (C3-20) oxy-4'-biphenylcarboxylic acid 4- [1 -Alkyloxyalkyl (having 1 to 20 carbon atoms) carbonyloxyethyl] phenyl ester, 4-alkyl (having 3 to 20 carbon atoms)
) -4'-biphenylcarboxylic acid, 4 '-[1-alkyloxyalkyl (C1-20) carbonyloxyethyl] -4-biphenylyl ester, 4-alkyl (C3-20) oxy -4-Biphenylcarboxylic acid 4 '-[1-alkyloxyalkyl (C1-20
) Carbonyloxyethyl] -4-biphenylyl ester.

Alkyloxyalkyl exemplified above (having 1 to 20 carbon atoms
Of) may be substituted with a halogen atom, and the alkyloxyalkyl optionally substituted with these halogen atoms 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.

<Effects of the Invention> Thus, according to the method of the present invention, a very useful optically active ester, 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) -4-
Hydroxybiphenyl (2.84 g, 10 mmol) is dissolved in 50 ml of anhydrous pyridine, and a solution of 3.22 g (12 mmol) of 4-octyloxybenzoic acid chloride in 10 ml of dichloromethane is added dropwise thereto.

After completion of dropping, stir at 40-50 ° C for 3 hours and then add the reaction solution
Pour into 200 ml of 3N hydrochloric acid water. To this is added 200 ml of toluene for extraction treatment, and the toluene layer is washed successively with 1N hydrochloric acid water, water, 5% aqueous sodium hydrogen carbonate and water. The toluene layer was concentrated under reduced pressure,
The white solid obtained was purified by silica gel column chromatography to obtain (+)-4-octyloxybenzoic acid 4 '.
4.85 g (yield 94.5%) of-(1-butyryloxyethyl) -4-biphenylyl ester was obtained.

 Further purification was by recrystallization from ethanol.

Optical rotation ▲ [α] ²⁰ _D ▼ + 61 ° (c = 1, CHCl ₃ ) Example 2 (+)-4 ′-(1-butyryloxyethyl) -4-
Reaction and post-treatment were carried out in the same manner as in Example 1 except that 3.12 g (10 mmol) of (+)-4 '-(1-pentylcarbonyloxyethyl) -4-hydroxybiphenyl was used instead of hydroxybiphenyl (+ ) -4-Octyloxybenzoic acid 4 '-(1-pentylcarbonyloxyethyl) -4-biphenylyl ester (5.12 g, yield 94%) was obtained.

Optical rotation ▲ [α] ²⁰ _D ▼ + 56 ° (c = 1, CHCl ₃ ) Example 3 (+)-4 ′-(1-butyryloxyethyl) -4-
The reaction and post-treatment were carried out in the same manner as in Example 1 except that 3.4 g (10 mmol) of (+)-4 '-(1-heptylcarbonyloxyethyl) -4-hydroxybiphenyl was used instead of hydroxybiphenyl (+ ) -4-Octyloxybenzoic acid 4 '-(1-heptylcarbonyloxyethyl) -4-biphenylyl ester 5.3 g (yield 92%) was obtained.

This was further recrystallized with ethanol for purification.

▲ [α] ²⁵ _D ▼ + 49.4 ° (c = 1, CHCl ₃ ) Phase transition point (℃) According to the above method, various optically active esters shown in Table 1 were produced.

The optical rotation and the phase transition point of the obtained compound are shown in Table 1.

Example 18 4-octyloxybenzoic acid 3.0 g (12 mmol),
(+)-4- (1-Pentylcarbonyloxyethyl)
Phenol 2.36 g (10 mmol), N, N'-dicyclohexylcarbodiimide 2.47 g (12 mmol), 4-pyrrolidinopyridine 0.13 g and dichloromethane 30 ml were added to 25-30 parts.
Incubate for 15 hours at ℃. After completion of the reaction, N, N'-dicyclohexylurea is removed by filtration, and the filtrate is concentrated to obtain a residue. The obtained concentrated residue was purified by silica gel column chromatography to obtain (+)-p-octyloxybenzoic acid 4- (1-pentylcarbonyloxyethyl) phenyl ester.

▲ [α] ²⁵ _D ▼ ＝ ＋ 51 ° (c = 1, CHCl ₃ ) Example 19 (+)-4- (1-Pentylcarbonyloxyethyl) phenol (+)-4- (1-Acetylcarbonyloxyethyl) phenol 1.8 g (10 mmol)
Was reacted in the same manner as in Example 18 except that the above compound was used, and post-treated to give (+)-p-octyloxybenzoic acid 4- (1-acetylcarbonyloxyethyl) phenyl ester (3.85 g).
(Yield 93.5%) was obtained.

[Α] ²⁵ _D ▼ = + 60 ° (c = 1, CHCl ₃ ) Various optically active esters 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.

Reference Example 1 Table 3 shows the measured values of the spontaneous polarization of the optically active ester derivative.

All the measured values are values at a temperature 10 ° C lower than the S _C ^* upper limit temperature.

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 (S _C ^* ) at 38 ° C. or lower, and the spontaneous polarization at 25 ° C. was 40 nC / cm ² .

Incidentally, an equimolar mixture of the above-mentioned two kinds of known compounds showed an S _C ^* 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 Example 3 except that the optically active benzene derivative of the present invention, which alone did not exhibit the S _C ^* phase, was used instead of the compound No. 1 of the present invention. , And spontaneous polarization was measured for each. The results are shown in Table-4.

As a result, these compounds of the invention by themselves have S _C ^*
It can be seen that even if the phase is not shown, it is effective for expanding spontaneous polarization by blending with a known compound.

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 represented by: 2. General formula (Wherein A represents an alkyl group or an alkoxyl group having 3 to 20 carbon atoms, R'represents a hydroxyl group or a halogen atom, and l is 1 or 2), and a general formula (In the formula, R is an alkyl group or an alkyloxyalkyl group which may be substituted with a halogen atom having 1 to 20 carbon atoms, m is 1 or 2, and * is an asymmetric carbon atom. A general formula characterized by reacting an optically active phenol compound represented by (Wherein A, R, l, m and * have the same meanings as described above).