JP2687022B2 - Optically active liquid crystalline compound - Google Patents

Description

The present invention relates to an optically active liquid crystalline compound useful for a display device or an electro-optical device.

[Conventional technology]

In recent years, ferroelectric liquid crystals have been characterized by having a higher response speed than conventional nematic liquid crystals, and thus have been actively researched.

Ferroelectricity refers to the chiral smectic C phase, the chiral smectic I phase, the chiral smectic F phase, the chiral smectic G phase and the chiral smectic H phase (hereinafter referred to as S _C ^* phase, S
_I ^* phase, S _F ^* phase, S _G ^* phase and S _H ^* phase are abbreviated, and the response based on ferroelectricity is expressed by the following equation [a] τ = η / Ps · E [a] (wherein τ is the response time, η is the viscosity of the liquid crystal material, Ps is the spontaneous polarization, and E is the electric field.
It is theoretically possible to obtain a display element capable of responding up to 1 μs.

On the other hand, a ferroelectric liquid crystal display material actually used is required to have many characteristics, and at present, it is difficult to give one characteristic to one liquid crystal compound. Therefore, it is necessary to mix several kinds of liquid crystal compounds. Attempts have been made to obtain practical display materials.

[Problems to be solved by the invention]

Therefore, as the ferroelectric optically active liquid crystal compound,
It is required to be stable in terms of heat, light and chemicals, and have a wide temperature range showing a chiral smectic C phase and be capable of being mixed with various liquid crystal compounds.

[Means for solving the problem]

As a result of earnest research from the above viewpoints, the present inventors have found a liquid crystal compound having excellent stability, a wide temperature range showing a chiral smectic C phase, and being well mixed with other smectic liquid crystal compounds, and arrived at the present invention. .

That is, the present invention provides a compound represented by the general formula [I]: (In the formula, R ^* is an optically active alkyl group having an asymmetric carbon atom having 4 to 13 carbon atoms, R is a linear alkyl group having 1 to 20 carbon atoms, X is a hydrogen atom or a fluorine atom, and Y is Y. And Z is an optically active liquid crystalline compound represented by the formula: when Y is a single bond, Z represents a group —CH ₂ CH ₂ —, and when Y is a group —CH ₂ CH ₂ —, Z represents a single bond. .

Typical examples of the compound represented by the general formula [I] can be classified into the following groups depending on the combination of Y and Z in the formula.

(In the formula, R ^* , R and X have the same meanings as described above.) The production method of the compound represented by the general formula [I] will be described in detail below, but an optically active alcohol is used as one of the production raw materials. It As the optically active alcohol, it can be inexpensively obtained from the viewpoint of industrial versatility, for example, 1-methylbutanol, 2-methylbutanol, 3-methylpentanol, 4-methylhexanol, 1-methylheptanol, 5-methyl. Heptanol, 6-methyloctanol, 1-methylpropanol and the like are used.

The outline of the method for producing the compound of the present invention is as follows.

[Action and Effect of the Invention] The compound of the present invention is a novel liquid crystal compound having the following actions and characteristics.

First, it does not have a group that easily decomposes even in an atmosphere containing water, and does not contain a group that is isomerized by light, so that it is very stable against moisture and light.

Next, most of the liquid crystalline compounds of the present invention have a wide temperature range in which they exhibit a smectic C phase, and therefore have high utility value as a liquid crystalline substance.

Furthermore, by mixing the compounds of the present invention with each other or the compound of the present invention with a compound having an existing smectic C phase, the temperature range showing the smectic C phase can be expanded to a wide range including room temperature.

〔Example〕

Hereinafter, the present invention will be described with reference to examples, but% in the examples means% by weight.

Production Example 1 Synthesis of 4-alkoxyphenylacetylene [B] In a 500 cc three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 4-alkoxybromobenzene (or 4-alkoxy-3-) in a nitrogen stream. Fluorobromobenzene) 0.234 mol, 2-methyl-3-butyn-2-ol 2
9.57 g (0.352 mol), triphenylphosphine 1.00 g (3.
81 mmol), dichlorobis (triphenylphosphine) palladium 0.52 g (0.730 mmol) and triethylamine 200 m
l was charged, dissolved with stirring, and 160 mg of copper iodide was added. After stirring at room temperature for 3 hours, gradually heat the mixture to an internal temperature of 90 minutes.
° C. The reaction was performed at this temperature for 20 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 300 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After filtration, ether was distilled off, and the residue was subjected to silica gel column chromatography (200 g of silica gel 400 g, developing solvent: benzene) to obtain the following compound [A] as an intermediate.

Next, in a 500 cc three-necked flask equipped with a stirrer, a thermometer and a distillation apparatus, the above compound [A]
mmol, anhydrous toluene 120 ml and sodium hydride (6%
Nujol dispersant) (310 mg) was added, and the mixture was stirred at room temperature for 30 minutes. The mixture was gradually heated, and the internal temperature was set to 70 ° C. over 30 minutes.
Reflux of acetone (by-product) started, and distillation started with toluene. The reaction was continued by further heating until the distillation temperature reached the boiling point of toluene. It took 2 hours during this time, and the distilled solvent was 60 ml. After completion of the reaction, return to room temperature,
100 ml of benzene was added, washed with water, and dried over anhydrous sodium sulfate. After filtration, the organic solvent was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 150 g, developing solvent: hexane) to obtain 4-alkoxyphenylacetylene [B] (X = H, F). Its structure was confirmed by IR and ¹ H-NMR spectra.

The results are shown in Table 1.

Production Example 2 Synthesis of 4-alkyloxycarbonylphenylacetylene [D] In a 500 cc three-necked flask equipped with a stirrer, thermometer and reflux condenser, alkyl p-bromobenzoate 64 mmol, 2-methyl-in a nitrogen stream. 3-butyn-2-ol 5.
91g (70mmol), triphenylphosphine 270mg (1.03mm
ol), 140 mg (0.20 mmol) of dichlorobis (triphenylphosphine) palladium and 60 ml of triethylamine were charged and dissolved with stirring, and 45 mg of copper iodide was added. After stirring at room temperature for 3 hours, the mixture was gradually heated, and the internal temperature was brought to 80 ° C over 30 minutes. The reaction was performed at this temperature for 10 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 300 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After filtration, the ether was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 100
g, developing solvent: dichloromethane) to obtain the following compound [C] as an intermediate.

Next, in a 300 cc three-necked flask equipped with a stirrer, a thermometer and a distillation device, the above compound [C] 57.8 mm was placed in a nitrogen stream.
ol, 120 ml of anhydrous toluene and 200 mg of sodium hydride (60% Nujol dispersant) were charged, and the mixture was stirred at room temperature for 30 minutes. The mixture was gradually heated, and the internal temperature was set to 70 ° C. over 30 minutes. Reflux of acetone (by-product) started, and distillation started with toluene. The reaction was continued by further heating until the distillation temperature reached the boiling point of toluene. It took 2 hours during this time, and the distilled solvent was 60 ml. After the reaction was completed, the temperature was returned to room temperature, 100 ml of benzene was added, washed with water, and dried over anhydrous sodium sulfate. After filtration, the organic solvent was evaporated and the residue was subjected to silica gel column chromatography (200 mesh silica gel 100 g, developing solvent: benzene) to obtain 4-alkyloxycarbonylphenylacetylene [D]. Its structure was confirmed by IR and ¹ H-NMR spectra.

 The results are shown in Table 2.

Example 1 4-alkyloxycarbonyl-4 ′-[2
-(4-Alkoxyphenyl) ethyl] biphenyl [I
Synthesis of a] In a 100 cc three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 4-alkyloxycarbonyl-4′-
Bromobiphenyl [E] 3.46 mmol, obtained in Preparation Example 1
Alkoxyphenylacetylene [B] (X = H, F) 3.56m
mol, triphenylphosphine 21.2 mg (0.081 mmol), dichlorobis (triphenylphosphine) palladium 9.5 m
g (0.014 mmol) and 20 ml of triethylamine were charged under a nitrogen atmosphere, dissolved by stirring, and 5 mg of copper iodide was added. After stirring for 3 hours at room temperature, gradually heat the mixture to an internal temperature of 80 for 30 minutes.
° C. The reaction was carried out at this temperature for 8 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 50 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After filtration, the ether was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 5
0 g, developing solvent: benzene / hexane = 1/1) to obtain the following compound [ F ] as an intermediate.

Next, in a flask equipped with a stirrer, a thermometer, and a rubber balloon filled with hydrogen gas, 1.0 mmol of the above compound [ F ], 5%
50 mg of palladium-carbon catalyst and 15 ml of tetrahydrofuran
Was charged, the atmosphere was replaced with hydrogen, and the mixture was reacted at room temperature for 2 hours. After completion of the reaction, the catalyst was filtered off, the solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 20 g, developing solvent: benzene) to isolate. Further, it was recrystallized from hexane to give 4-alkyloxycarbonyl-4 '-[2- (4-alkoxyphenyl) ethyl] biphenyl [Ia] (X = H, F) in a yield of 50-9.
Obtained at 0%. Its structure was confirmed by IR and ¹ H-NMR spectra.

Example 1 [Compound No. 15 ] Yield 85% Example 2 [Compound No. 23 ] Yield 73% Example 2 4-alkoxy-4 ′-[2- (4-alkyloxycarbonylphenyl) ethyl] biphenyl [I
Synthesis of b] In a 100 cc three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 4-alkyloxycarbonylphenylacetylene [D] 3.0 mmol obtained in Production Example 2, 4-alkoxy-4'- was obtained. 3.0 mmol of bromobiphenyl, 19.9 mg (0.086 mmol) of triphenylphosphine, 8.0 mg (0.011 mmol) of dichlorobis (triphenylphosphine) palladium and 20 ml of triethylamine were charged under a nitrogen atmosphere and dissolved by stirring, and 5 mg of copper iodide was added. After stirring at room temperature for 3 hours,
The mixture was heated gradually and the internal temperature was brought to 80 ° C over 30 minutes. The reaction was carried out at this temperature for 8 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 50 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After filtration, ether was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 50 g, developing solvent: benzene / hexane = 1/1) to obtain the following compound [ G ] as an intermediate.

Next, in a flask equipped with a stirrer, a thermometer and a rubber balloon filled with hydrogen gas, 1.0 mmol of the above compound [ G ], 5%
50 mg of palladium-carbon catalyst and 15 ml of tetrahydrofuran
Was charged, the atmosphere was replaced with hydrogen, and the mixture was reacted at room temperature for 2 hours. After completion of the reaction, the catalyst was filtered off, the solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 20 g, developing solvent: benzene) to isolate. Further recrystallized from hexane to give 4-alkoxy-
4 '-[2- (4-Alkyloxycarbonylphenyl) ethyl] biphenyl [Ib] was obtained with a yield of 80-90%.
Its structure was confirmed by IR and ¹ H-NMR spectra.

Example 3 [Compound No. 25 ] Yield 80% Table 3 shows the phase transition temperatures of the compounds [Ia] and [Ib] obtained in Examples 1 and 2.

Claims (2)

(57) [Claims] 1. A compound of the formula [I] (In the formula, R ^* is an optically active alkyl group having an asymmetric carbon atom having 4 to 13 carbon atoms, R is a linear alkyl group having 1 to 20 carbon atoms, X is a hydrogen atom or a fluorine atom, and Y is Y. And Z is an optically active liquid crystalline compound represented by the formula: when Y is a single bond, Z represents a group —CH ₂ CH ₂ —, and when Y is a group —CH ₂ CH ₂ —, Z represents a single bond. 2. In the general formula [I], R ^* is the general formula [II]. The optical according to claim 1, which is an optically active alkyl group represented by the formula (1 is an integer of 1 to 5, m is an integer of 0 to 5, and * is an asymmetric carbon atom). Active liquid crystalline compound.