JP2714852B2 - Liquid crystalline compound - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid crystal compound useful for a display element or an electro-optical element.

[Conventional technology]

In recent years, ferroelectric liquid crystals are characterized by a faster response speed than conventional nematic liquid crystals, and are being actively studied for application in various fields. For example, there are the compounds shown in Table 1.

[Problems to be Solved by the Invention] Ferroelectricity is a property manifested in the Sc ^* phase of the liquid crystal phase and several other phases, but the Sc ^* phase is important in practical use. First
As shown in the table, most of the conventional compounds are in the low temperature range of Sc ^*.
A smectic phase other than the Sc ^* phase often develops, which hinders securing a practical working temperature range.
Therefore, a liquid crystal compound which does not exhibit a smectic phase other than the Sc ^* phase in a low temperature region of the Sc ^* phase is desired.

[Means for solving the problem]

As a result of intensive studies from the above viewpoints, the present inventors have found a compound having no other smectic phase in the low temperature region of the Sc ^* phase, and have reached the present invention.

That is, the present invention relates to the general formula [I] (Wherein R ^* represents an alkyl group having an asymmetric carbon atom, R represents a straight-chain alkyl or alkoxy group, X represents a hydrogen atom or a halogen atom, Y represents a group —C≡C—, a group —CH ₂ CH ₂ -Or Z represents a group —C≡C—, a group —CH ₂ CH ₂ — or n represents 0 or 1).

In the present invention, it can be used as a liquid crystal composition containing at least one liquid crystal compound represented by the above general formula [I].

Specific examples of typical examples of the compound represented by the general formula [I] are as follows. Depending on the combination of Z and n, it can be divided into the following groups.

(In the formula, R ^* , R and X have the same meanings as described above.) As R ^* OH, any optically active alcohol having an asymmetric carbon atom can be used. Examples of the primary groups include 2-methylbutyl, 3-methylpentyl, 4-methylhexyl, 5-methylheptyl, 6-methyloctyl, and 3,7-dimethyloctyl. Examples of the secondary group include optically active alcohols having a 1-methylpropyl group, a 1-methylbutyl group, a 1-methylpentyl group, a 1-methylhexyl group, a 1-methylheptyl group, a 1-methyloctyl group, and the like. .

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

(In the formula, R ^* , R and X have the same meanings as described above, and m represents 0 or 1.) [Operation and Effect of the Invention] The compound of the present invention has another smectic phase in the low temperature region of the Sc ^* phase. Therefore, it is expected to be an important compound in obtaining a practical Sc ^* phase temperature range including room temperature.

〔Example〕

Hereinafter, the present invention will be described by way of examples. In the examples,% represents% by weight.

Production Example 1 Synthesis of 4-alkoxycarbonylphenylacetylene [B] In a 500 cc three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 64 mmol of 4-alkoxycarbonyl bromobenzene, 3-methyl- 5.91 g (70 mmol) of 1-butyn-3-ol, 270 mg of triphenylphosphine,
140 mg (0.20 mmol) of dichlorobis (triphenylphosphine) palladium catalyst and 60 ml of triethylamine were charged and dissolved by 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 raised to 80 ° C. in 30 minutes.
The reaction was performed at this temperature for 10 hours. After the reaction, the temperature was returned to room temperature, and triethylamine was distilled off under reduced pressure.
The mixture was washed with water and dried over anhydrous sodium sulfate. After that, ether was distilled off, and the residue was subjected to silica gel column chromatography (100 g of silica gel of 200 mesh, developing solvent: dichloromethane) to obtain a compound [A] of the following formula as an intermediate compound.

In a 300 cc three-necked flask equipped with a stirrer, a thermometer and a distillation apparatus, 57.8 mmol of the above compound [A] was placed in a nitrogen stream.
120 ml of anhydrous toluene and sodium hydride (60%
(Nujur dispersant) 200 mg was stirred and stirred at room temperature for 30 minutes. The temperature was gradually increased, and the internal temperature was raised to 70 ° C in 30 minutes. Reflux of acetone (by-product) started, and distillation with toluene started, but the reaction was continued by further heating until the distillation temperature reached the boiling point of toluene. It took 2 hours during this time to distill off 60 ml of the solvent. 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 that, the organic solvent was distilled off, and the residue was subjected to silica gel column chromatography (silica gel 100 mesh of 200 mesh).
g, developing solvent: benzene) to give 4-alkoxycarbonylphenylacetylene [B] in Table 3 in a yield of 85 to 88%. Its structure was confirmed by IR and NMR spectra.

 The results are shown in Table 2.

Production Example 2 Synthesis of alkyl-6-chloronicotinic acid ester and 4'-alkoxycarbonylphenyl-6-chloronicotinic acid ester [D] Optical activity was measured in a 100 cc three-necked flask equipped with a stirrer, thermometer and reflux condenser. 15 mmol of alcohol or optically active alkoxycarbonylphenol and 10 ml of pyridine were added and dissolved. To this pyridine solution, add dichloroethane 20ml
Was added under ice-cooling, and the mixture was stirred at room temperature for 24 hours. Dichloroethane and pyridine were distilled off under reduced pressure, and the residue was dissolved in 100 ml of ether, washed with a 10% aqueous NaOH solution, and dried over anhydrous sodium sulfate. After that, ether was distilled off, and the residue was subjected to silica gel column chromatography (100 g of 200-mesh silica gel, developing solvent: dichloromethane) to obtain an alkyl-6-chloronicotinic acid ester or 4'-alkoxycarbonylphenyl-6- as shown in Table 3. Chlornicotinic acid ester [D] was obtained in a yield of 90 to 98%.

 The results are shown in Table 3.

Production Example 3 p-Alkoxy (or alkyl) phenyl-
Synthesis of 6-chloronicotinic acid ester [E] (X = H) In a 100 cc three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 30 mmol of p-alkoxy (or alkyl) phenol and 20 ml of anhydrous pyridine were charged. Dissolved with stirring. To this pyridine solution, 50 ml of a dichloroethane solution containing 35 mmol of 6-chloronicotinyl chloride was added under ice cooling. After returning the reaction temperature to room temperature, the mixture was heated to 40 ° C. and stirred for 8 hours. After completion of the reaction, benzene was added, and the mixture was washed with water, washed with 10% caustic soda in alkaline water, washed with water in that order, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, the residue was isolated and purified from ethanol, and the p-alkoxy (or alkyl) phenyl-6-chloronicotinic acid ester [E] shown in Table 4 was obtained at a yield of 72 to 95%. Obtained.

Production Example 4 4'-Alkoxy-3'-chlorophenyl-
Synthesis of 6-chloronicotinic acid ester [E] (X = Cl) Except that 30 mmol of p-alkoxy (or alkyl) phenol was used instead of 30 mmol of 4-alkoxy-3-chlorophenol, the same conditions as in Production Example 3 were used. Synthesize, 4th
4'-Alkoxy-3'-chlorophenyl-6-chloronicotinic acid ester [E] in the table was obtained in a yield of 83%.

 Table 4 shows the above results.

Production Example 5 Synthesis of 4-alkoxy-3-fluorophenylacetylene [F] (X = F) Production Example 1 except that the reaction temperature was 90 ° C. and the starting material halide was 4-alkoxy-3-fluorophenyl bromide. Under the same conditions as described above to obtain a compound [G] of the following formula as an intermediate compound.

The above-mentioned 4- (4'-alkoxy-3'-fluorophenyl) -2-methyl-3-butyn-ol [G] 37.9 was placed in a 200-cc three-necked flask equipped with a stirrer, a thermometer and a distillation apparatus in a nitrogen stream. mmol, 100 ml of anhydrous toluene and 100 mg of sodium hydride (60% Nujol dispersant) were charged and stirred at room temperature for 30 minutes. The temperature was gradually increased, and the internal temperature was raised to 70 ° C in 30 minutes. Reflux of acetone (by-product) started, and distillation with toluene started, but 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 50 ml. After the completion of the reaction, the temperature was returned to room temperature, 100 ml of benzene was added, washed with water, and dried over anhydrous sodium sulfate. After that, the organic solvent was distilled off, and the residue was subjected to silica gel column chromatography (20
The mixture was passed through 100 g of 0-mesh silica gel (developing solvent: hexane) to obtain 4-alkoxy-3-fluorophenylacetylene [F] shown in Table 5 in a yield of 80 to 97%. Its structure is IR
And NMR spectra.

Table 5 shows the results together with the properties and physical properties of each compound obtained.

Example 1 Synthesis of alkyl-6- (p-alkoxyphenylethynyl) nicotinic acid ester [Ia] (X = H) Manufactured in a 100 cc three-necked flask equipped with a stirrer, thermometer and reflux condenser in a nitrogen stream. Optically active alkyl-6-chloronicotinic acid ester obtained in Example 2 [D] 23.3
mmol, 4-substituted phenylacetylene 23.3 mmol, triphenylphosphine 100 mg, dichlorobis (triphenylphosphine) palladium catalyst 60 mg and triethylamine 50 ml were charged, stirred and dissolved, and copper iodide 20 mg was added. 2 at room temperature
After stirring for an hour, the mixture was gradually heated, and the internal temperature was raised to 80 ° C. in 30 minutes. The reaction was carried out at this temperature for 16 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 100 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After that, ether was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 100).
g, developing solvent: dichloromethane).
After recrystallization from petroleum ether, the alkyl-6-
(P-Alkoxyphenylethynyl) nicotinic acid ester [Ia] (X = H) was obtained in a yield of 71 to 80%. The structure of each compound was confirmed by IR and NMR spectrum data.

Example [Compound No. 8] Yield 80% Example 2 Alkyl-6- (4'-alkoxy-3'-
Fluorophenylethynyl) nicotinic acid ester [Ia]
Synthesis of (X = F) Synthesis was performed under the same conditions as in Example 1 except that 4-alkoxy-3-fluorophenylacetylene [F] obtained in Production Example 4 was used instead of 4-substituted phenylacetylene. Alkyl-6- (4'-alkoxy-3 'in Table 6
-Fluorophenylethynyl) nicotinic acid ester [I
a] in 79% yield.

Example. [Compound No. 5] Yield 79% Table 6 shows the phase transition temperatures of the compounds obtained in Examples 1 and 2 above.

Example 3 p-Alkoxy (or alkyl) phenyl-
Synthesis of 6- (p-alkoxycarbonylphenylethynyl) nicotinic acid ester [Ib] (X = H) In a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, the p-alkoxy ( Or alkyl) phenyl-6-chloronicotinic acid ester 4.8 mmol,
5.0 mmol of 4-alkoxycarbonylphenylacetylene obtained in Production Example 1, 60 mg of triphenylphosphine, dichlorobis (triphenylphosphine) palladium catalyst 30
mg and 30 ml of triethylamine were charged and dissolved by stirring, and 6 mg of copper iodide was added. After stirring at room temperature for 2 hours in a nitrogen atmosphere, the mixture was heated and reacted at 80 ° C. for 16 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After that, ether was distilled off, and the residue was isolated and purified by silica gel column chromatography (100 g of 200 mesh silica gel, developing solvent: dichloromethane). Recrystallization from hexane gave the p-alkyl or alkoxyphenyl-6- (p-alkoxycarbonylphenylethynyl) nicotinic acid esters [Ib] in Table 7 in 71-82% yield. The structure of each compound was confirmed by IR and NMR spectrum data.

Example. [Compound No. 16] Yield 77% Example 4 4'-Alkoxy-3'-chlorophenyl-
Synthesis of 6- (p-alkoxycarbonylphenylethynyl) nicotinic acid ester [Ib] (X = Cl) 4 ′ obtained in Production Example 4 instead of p-alkoxy (or alkyl) phenyl-6-chloronicotinic acid ester
All the compounds were synthesized under the same conditions as in Example 3 except that -alkoxy-3'-chlorophenyl-6-chloronicotinic acid ester was used, and 4'-alkoxy-3'-chlorophenyl-6- (p- Alkoxycarbonylphenylethynyl) nicotinic acid ester [Ib] was obtained in a yield of 77%. The structure of the compound was confirmed by IR and NMR spectral data.

Example. [Compound No. 19] Yield 77% Table 7 shows the phase transition temperatures of the compounds obtained in Examples 3 and 4 above.

Example 5 4 '-(p-Alkoxycarbonylphenyl) oxycarbonylphenyl-6- (p-alkoxyphenylethynyl) nicotinic acid ester [Ic] (X =
Synthesis of H) In a three-necked flask equipped with a stirrer, thermometer and reflux condenser, 4.8 mmol of 4'-alkoxycarbonylphenyl-6-chloronicotinic acid ester, 5.0 mmol of 4-alkoxyphenylacetylene, 60 mg of triphenylphosphine, and 60 mg of dichlorobis (Triphenylphosphine) palladium catalyst 30mg
And 30 ml of triethylamine were charged and dissolved by stirring, and 6 mg of copper iodide was added. After stirring for 2 hours at room temperature under a nitrogen atmosphere,
The mixture was heated to 80 ° C and reacted for 16 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After that, ether was distilled off, and the residue was isolated and purified by silica gel column chromatography (100 g of 200 mesh silica gel, developing solvent: dichloromethane). Recrystallized from hexane to give 4 '-(p-alkoxycarbonylphenyl) oxycarbonylphenyl-6- (p
-Alkoxyphenylethynyl) nicotinic acid ester [Ic] was obtained in 65-84% yield. The structure of each compound was confirmed by IR and NMR spectrum data.

Example. [Compound No. 32] Yield 69% Example 6 Synthesis of 4 '-(p-alkoxycarbonylphenyl) oxycarbonylphenyl-6- (4 "-alkoxy-3" -fluorophenylethynyl) nicotinic acid ester [Ic] (X = F) 4-alkoxyphenylacetylene Production example 5 instead of
Were synthesized under the same conditions as in Example 5 except that the 4-alkoxy-3-fluorophenylacetylene obtained in the above was used, and 4 ′-(p-alkoxycarbonylphenyl) oxycarbonylphenyl-6- (4 "-Alkoxy-3" -fluorophenylethynyl) nicotinic acid ester [Ic] was obtained in a yield of 65-71%. Compound structure is IR
And NMR spectrum data.

Example. [Compound No. 33] Yield 65% Table 8 shows the phase transition temperatures of the compounds obtained in Examples 5 and 6 above.

Example 7 Alkyl-6- [p-alkoxy (or 4 '
Synthesis of -alkoxy-3-fluoro) phenylethyl] nicotinic acid ester [Id] (X = H or F) In a flask equipped with a stirrer, a thermometer, a reflux condenser and a rubber balloon containing hydrogen gas. 4 mmol of alkyl-6- [p-alkoxy (or 4'-alkoxy-3'-fluoro) phenylethynyl] nicotinic acid ester [Ia] obtained in Example 1 or 2, 200 mg of 5% palladium-carbon catalyst, 10 ml of benzene and acetic acid After 30 ml of ethyl was charged and the atmosphere was replaced with hydrogen gas, the mixture was reacted at room temperature. The progress of the reaction was checked with a bed chromatograph. The reaction was almost completed in about 1.5 hours, but was continued in a hydrogen atmosphere for another 0.5 hour. After the reaction, the catalyst was removed with a glass filter covered with a super-aid, and the solvent was distilled off under reduced pressure. The reaction crude product was purified by silica gel column chromatography (silica gel of 200 mesh, 50 g, developing solvent: dichloromethane), and the alkyl-6- [p-alkoxy (or 4'-alkoxy-) in Table 9 was purified.
3-Fluoro) phenylethyl] nicotinic acid ester [Id] was obtained in a yield of 90 to 97%. The structure of each compound was confirmed by IR and NMR spectra.

Example 1. [Compound No. 38] 90% yield Example 2. [Compound No. 37] Yield 92% Table 9 shows the phase transition temperatures of the obtained compounds.

Example 8 p-Alkoxy (or alkyl) phenyl-
Synthesis of 6- (p-alkoxycarbonylphenylethyl) nicotinic acid ester [Ie] (X = H) Alkyl-6- [p-alkoxy (or 4'-alkoxy-3'-fluoro) phenylethynyl] of Example 7 Instead of nicotinic acid ester [Ia], the p-alkoxy (or alkyl) phenyl-6- (p-
Synthesized under the same conditions as in Example 7 except that alkoxycarbonylphenylethynyl) nicotinic acid ester [Ib] was used, and p-alkoxy (or alkyl) phenyl-6- (p-alkoxycarbonylphenylethyl) nicotine shown in Table 10 was used. The acid ester [Ie] was obtained in 90-97% yield. The structure of each compound was confirmed by IR and NMR spectrum data.

Example. [Compound No. 46] Yield 95% Example 9 4'-Alkoxy-3'-chlorophenyl-
Synthesis of 6- (p-alkoxycarbonylphenylethyl) nicotinic acid ester [Ie] (X = Cl) Alkyl-6- [p-alkoxy (or 4'-alkoxy-3'-fluoro) phenylethynyl] of Example 7 Instead of nicotinic acid ester [Ia], 4'-alkoxy-3'-chlorophenyl-6- (p-
All compounds were synthesized under the same conditions as in Example 7 except that alkoxycarbonylphenylethynyl) nicotinic acid ester [Ib] was used, and 4'-alkoxy-3'-chlorophenyl-6- (p-alkoxycarbonylphenylethyl) shown in Table 10 was used. ) Nicotinic acid ester [Ie] was obtained in 92-93% yield. The structure of the compound was confirmed by IR and NMR spectral data.

Example. [Compound No. 49] Yield 93% Table 10 shows the phase transition temperatures of the compounds obtained in Examples 8 and 9 above.

Example 10 4 '-(p-Alkoxycarbonylphenyl) oxycarbonylphenyl-6- [p-alkoxy (or 4 "-alkoxy-3" -fluoro) phenylethyl] nicotinic acid ester [If] (X = H or F Example 5 or 6 in place of the alkyl-6- [p-alkoxy (or 4'-alkoxy-3'-fluoro) phenylethynyl] nicotinic acid ester [Ia] of Example 7.
Performed except that the 4 '-(p-alkoxycarbonylphenyl) oxycarbonylphenyl-6- [p-alkoxy (or 4 "-alkoxy-3" -fluoro) phenylethynyl] nicotinic acid ester [Ic] obtained in the above was used. The compound was synthesized under the same conditions as in Example 7 and 4 '-(p-alkoxycarbonylphenyl) oxycarbonylphenyl-6- [p-alkoxy (or 4 "-alkoxy-3") in Table 11.
-Fluoro) phenylethyl] nicotinic acid ester [I
f] in 91-95% yield. The structure of each compound is IR and N
Confirmed by MR spectrum data.

Example 1. [Compound No. 62] 94% yield Example 2. [Compound No. 63] Yield 93% Table 11 shows the phase transition temperatures of the obtained compounds.

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Claims (1)

(57) [Claims] 1. A compound of the formula [I] (Wherein R ^* represents an alkyl group having an asymmetric carbon atom, R represents a straight-chain alkyl or alkoxy group, X represents a hydrogen atom or a halogen atom, Y represents a group —C≡C—, a group —CH ₂ CH ₂ -Or Z represents a group —C≡C—, a group —CH ₂ CH ₂ — or n represents 0 or 1, respectively).