JPH04128258A - Tolan derivative, liquid crystal composition containing the same derivative and liquid crystal element using the same composition - Google Patents

Abstract

NEW MATERIAL:A compound shown by formula I (R is 1-10C straight-chain alkyl; A is single bond or group shown by formula II or formula III; X is H or F; cyclohexane ring is in trans-configuration). EXAMPLE:4-Propyl-3'-fluoro-4'-cyanotolan. USE:A component of liquid crystal composition providing a liquid crystal display device having low drive voltage, high response speed and a wide temperature range of practical use. PREPARATION:A phenylacetylene compound shown by formula V derived from a benzaldehyde shown by formula IV is made to react with 1-cyano-2-fluoro-4- iodobenzene shown by formula VII obtained from an aniline derivative shown by formula VI to give a compound shown by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel tolan derivative used as an electro-optical display material, a liquid crystal composition containing the same, and a liquid crystal element using the same.

[Summary of the invention]

The present invention is based on the general formula (in the above formula, R represents a straight-chain alkyl group having 1 to 10 carbon atoms, A represents any one of a single bond, φΣ, -+,
X represents hydrogen or fluorine. The present invention also relates to a novel compound represented by (the cyclohexane ring has a trans configuration) and a liquid crystal composition containing the same. The compound of the present invention has the following characteristics.

1. The dielectric constant anisotropy (hereinafter referred to as Δε) is positive and extremely large.

2. The anisotropy of birefringence (hereinafter referred to as ○) is large.

3. Compounds 1-c, 1-d, 1-e, and 1-f have high nematic-isotropic liquid transition points (hereinafter referred to as N-1 points).

Therefore, by using a liquid crystal composition containing the compound (1) of the present invention, a liquid crystal display device having the following characteristics can be provided.

1. The driving voltage is low.

2. Fast response speed.

3゜Wide practical temperature range.

[Conventional technology]

Liquid crystal display devices utilize the electro-optic effect of liquid crystals, and the liquid crystal phases used therein include a nematic phase, a cholesteric phase, and a smectic phase. The currently widely used display method is the twisted nematic (hereinafter referred to as TN) type which utilizes a nematic phase.

liquid crystal display device 1. It is small and thin.

2. Low driving voltage and low power consumption.

3. Since it is a light-receiving element, your eyes won't get tired even if you use it for a long time.

Because of these advantages, it has been applied to watches, calculators, audio equipment, various measuring instruments, automobile dashboards, etc. Particularly recently, it has been applied to displays with a large number of pixels, such as personal computer and word processor displays, as well as monochrome or color pocket televisions, and is attracting attention as a display device that can replace CRTs. As described above, liquid crystal display devices are being applied in many fields, and it is thought that the fields of application will further expand in the future. It is thought that the characteristics required of liquid crystal materials will change along with this, but the characteristics shown below are basic and indispensable.

1. Must be non-colored and thermally, optically, electrically and chemically stable.

2. Wide practical temperature range.

3. Fast electro-optical response speed.

4. Drive voltage must be low.

5. The rise of the voltage-light transmission regression characteristic is steep, and the temperature dependence of the threshold voltage (hereinafter referred to as V 1H) is small.

6. Wide viewing angle range.

[Problem to be solved by the invention]

Among these characteristics, many liquid crystals that satisfy characteristic 1 are known, but no liquid crystal compound that satisfies characteristic 2 or less with a single component is known. Therefore, in order to obtain these characteristics, a liquid crystal composition in which several types of nematic liquid crystal compounds or non-liquid crystal compounds are mixed is used.

In order to satisfy the second characteristic, it is generally necessary to use a liquid crystal compound with a relatively low molecular weight and a crystal-nematic transition point (hereinafter referred to as the C-N point) or a melting point around room temperature, and a liquid crystal compound with a high molecular weight of N-1. Liquid crystal compounds with a point of 200°C or higher are used, and in order to obtain a liquid crystal composition with a wide practical temperature range,
A liquid crystal compound with as high an N-1 point as possible is required.

In addition, in order to satisfy characteristic 3, the response speed (hereinafter τ
There is the following relationship between the viscosity coefficient (hereinafter referred to as η) and the cell gap (hereinafter referred to as d), and in order to increase the response speed, it is necessary to make d small. By the way, in cells that are used for practical purposes, the value of 80-d is set to a constant value in order to prevent the generation of interference fringes on the cell surface that would cause damage to the cell appearance. By using a material with a large value of d, the value of d can be reduced and the response speed can be increased.

Furthermore, in order to satisfy characteristic 4, the threshold voltage must be lowered, but the following relationship exists between Vlh, the elastic constant (hereinafter referred to), and Δε: vlhCx-(K/
Δε)I/2 To lower vl, a liquid crystal compound with a large Δε and a small K is required.

Therefore, the present invention has been made to meet the demands under these circumstances, and its purpose is to lower the threshold voltage and reduce Δn by mixing it with one or more other nematic liquid crystal compounds or non-liquid crystal compounds. It is an object of the present invention to provide a novel liquid crystal compound that has a large value and can provide a liquid crystal composition that has a wide practical temperature range.

[Means to solve the problem]

The present invention is based on the general formula (in the above formula, R represents a linear alkyl group having 1 to 10 carbon atoms, A represents a single bond, -fqΣ, +,
X represents hydrogen or fluorine. The present invention also relates to a novel compound represented by (the cyclohexane ring has a trans configuration) and a liquid crystal composition containing the same. Compound of the present invention (1
) can be obtained by the following manufacturing method.

Step 1) Compound (2) is reacted with carbon tetrabromide and triphenylphosphine in dichloromethane to obtain compound (3).

Step 2) Compound (3) is reacted with butyllithium in tetrahydrofuran to obtain compound (4).

Step 3) Compound (5) is reacted with iodine chloride in acetic acid to obtain compound (6).

Step 4) Compound (6) or compound (7) is reacted with sodium nitrite and sulfuric acid in acetic acid to form a diazonium salt, and then reacted with sulfuric acid and potassium cyanide to obtain compound (8).

Step 5) Compound (4) and compound (8) are reacted in the presence of bis(triphenylphosphine)palladium(Il) chloride, cupric iodide, and diethylamine in N,N-dimethylformamide to produce compound (1). obtain.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 (Synthesis of compound 1-a) Production process of 4-propyl-3'-fluoro-4'-cyanotran 1) 60 mN of carbon tetrabromide into 180 mN of dichloromethane
Dissolve 93g of triphenylphosphine at below 0℃
added. Next, 22 g of 4-propylbenzaldehyde was dissolved in 150 mj of dichloromethane and added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour. After the reaction was completed, dichloromethane was distilled off, and 550 mN of hexane was added to the residue. The crystals were filtered off and washed three times with hexane. The hexane in the filtrate was distilled off, a small amount of hexane was added to the residue, the crystals were filtered off, and the hexane in the filtrate was distilled off. The residue was distilled under reduced pressure (120-b) to obtain 27 g of 4-propyl-β,β-dipromostyrene.

Step 2) 27 g of 4-propyl-β,β-dipromostyrene was dissolved in 44 mg of tetrahydrofuran under a nitrogen stream and cooled to -78°C. A 200 mN butyllithium hexane solution (1.6 mol/I) was added dropwise into the solution over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour and 30 minutes.

After the reaction was completed, 200 r+J of water was added, extracted with chloroform, and washed with water three times. After chloroform was distilled off, 3.5 g of phenyl acetylene was obtained by distillation under reduced pressure.

Step 4) Dissolve 27g of sodium nitrite in 205mg of sulfuric acid, cool to below 10°C, add 238ml of acetic acid,
65 g of 2-fluoro-4-iodinated aniline was added at 20-25°C, followed by stirring for 1 hour. Dissolve 83g of copper sulfate pentahydrate in 205mg of water and add 140g of ice into it.
I put it in. Additionally, 200mg of water and 88% potassium cyanide
A solution containing 500g of sodium bicarbonate, 500g of sodium bicarbonate, and 200rrl of Hensen were added. A henazonium salt sulfuric acid solution was added thereto. After stirring at room temperature for 3 hours, an aqueous sodium hydroxide solution was added to dissolve the crystals. After extraction with chloroform, it was washed three times each with 10% sodium hydroxide solution and water. After chloroform was distilled off, the residue was extracted with hexane and the hexane was distilled off.

The residue was distilled under reduced pressure (95~b) and further recrystallized from methanol to give 1-cyano-2
-20 g of -fluoro-4-iodinated benzene was obtained.

Step 5) Add 1- to 14 mg of N,N-dimethylformamide
Dissolve 2.1 g of cyano-2-fluoro-4-iodobenzene, and add 3 mg of Hebis (triphenylphosphine) palladium (II) chloride 1 cupric iodide 13
mg was added. Thereafter, 1.2 g of 4-propylphenylacetylene obtained in step 2 was added, and the mixture was heated to 50 to 60°C for 0.5 g. The reaction was allowed to proceed for 5 hours. After completion of reaction, 996 hydrochloric acid 35r
J was added to the reaction solution, extracted with chloroform, washed with water three times, and chloroform was distilled off. After the residue was purified by silica gel chloroform column chromatography, it was recrystallized from a mixed solvent of acetone and methanol to obtain 0.5 g of 4-propyl-3'-fluoro4'-cyanotolane. The melting point (hereinafter referred to as C-1 point) of this compound is 67.
The temperature was 2°C.

The following compounds were synthesized in a similar manner.

4-Methyl-3'-fluoro-4'-cyanotolan-4-ethyl-3'-fluoro-4'-cyanotolan-4-butyl-3'-fluoro-4'-cyanotolan-4-pentyl-3'-fluoro-4' -Cyanotran 4-hexyl-3'-fluoro-4'-cyanotran C-1 point 63.8°C 4-hebutyl-3'-fluoro-4'-cyanotran 4-octyl-3'-fluoro-4' - Cyanotran 4-nonyl-3'-fluoro-4'-cyanotran 4-decyl-3'-fluoro-4'-cyanotran Example 2 (synthesis of compound ib) 4-propyl-3'5'-difluoro-4 '-Cyanotran production process 1) 60 ml of carbon tetrabromide into 180 ml of dichloromethane
Dissolve 93g of triphenylphosphine at below 0℃
added. Next, 22 g of 4-propylbenzaldehyde was dissolved in 150 mN of dichloromethane and added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour. After the reaction was completed, dichloromethane was distilled off, and 500 rJ of hexane was added to the residue. The crystals were filtered off and washed three times with hexane. The hexane in the filtrate was distilled off, a small amount of hexane was added to the residue, the crystals were filtered, and the hexane in the filtrate was distilled off. The residue was distilled under reduced pressure (120-1.30° C./4 mmHg) to obtain 27 g of 4-propyl-β,β-dipromostyrene.

Step 2) 27 g of 4-propyl-β,β-dipromostyrene was dissolved in 44 mg of tetrahydrofuran under a nitrogen stream and cooled to -78°C. A butyl lithium hexane solution (1.6 mol)/Ω) (200 rJ) was added dropwise into the solution over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour and 30 minutes. After the reaction was completed, 200 m of water and Q were added, extracted with chloroform, and washed with water three times. After chloroform was distilled off, 3.5 g of phenyl acetylene was obtained by distillation under reduced pressure.

Step 3) Add 60 g of 2.6-cyfluoroaniline to 18 g of acetic acid.
0ml). A solution of 75 g of iodine chloride dissolved in 48 rrl of acetic acid was added dropwise thereto, and the mixture was stirred at 80° C. for 2 hours. Pour the reaction solution into water and filter the precipitated crystals.
I washed it with water. The product was recrystallized from methanol, distilled under reduced pressure (125° C./22 mmHg), and recrystallized again from methanol to obtain 57 g of 2,6-difluoro-4-iodide phosphorus.

Step 4) Dissolve 12 g of sodium nitrite in 91 mlJ of sulfuric acid, cool to below 10°C, add 100 np of acetic acid, add 39 g of 2,6-diphenol-olow-4-aniline iodide at 20-25°C, and dissolve. The mixture was stirred for 1 hour. 37 g of copper sulfate pentahydrate was dissolved in 91 ml of water, and 62 g of ice was placed therein. In addition, a solution of 39 g of potassium cyanide in 92 mN of water, and 221 g of sodium hydrogen carbonate.
, Ben 7〉91mj! added. A diazonium salt sulfur-resistant solution was added therein. After stirring at room temperature for 3 hours, an aqueous sodium hydroxide solution was added to dissolve the crystals. After extraction with chlorine juice, 10% sodium hydroxide solution, 3 ml each
Washed several times. After removing the chloroform, the residue was extracted with hexane and the hexane was distilled off.

The residue was recrystallized from methanol, and 6.7 g of 1,3-difluoro-2-cyano-5-iodobenzene was added thereto.

Step 5) 1 in 35 ml of N,N-dimethylformamide
．． 3-difluoro-2-cyano-5-iodinated benzene 5
．． 6 g was dissolved, and 7.3 mg of Hebis (triphenylphosphine) palladium (II) chloride and 34 mg of cupric iodide were added thereto.

Thereafter, 3 g of 4-propylphenylacetylene obtained in step 2 was added, and the mixture was reacted at 50 to 60°C for 0.5 hour. After the reaction was completed, 35 mj7 of 9% hydrochloric acid was added to the reaction solution, extracted with chloroform, washed with water three times, and chloroform was distilled off. After the residue was purified by silica gel-chloroform column chromatography, it was recrystallized from a mixed solvent of acetone and methanol to give 4-propyl-3'5.
1.6 g of '-difluoro-4'-cyanotolane was obtained. The melting point (hereinafter referred to as C-1 point) of this compound was 83.3°C.

The following compounds were synthesized in a similar manner.

4-Methyl-3'5'-difluoro-4'cyanotran4-ethyl-3'5'-difluoro-4'cyanotran4-butyl-3',5'-difluoro-4'cyanotran C-1 point 69.5 °C 4-pentyl-3', 5'-difluoro-4'
-Cyanotran 4-hexyl-3', 5'-difluoro-4'-cyanotran C-1 point 50.2°C 4-hebutyl-3', 5'-difluoro-4'
-cyanotolane 4-octyl-3', 5'-difluoro-4'-cyanotolane 4-nonyl-3', 5'-difluoro-4'cyanotolane 4-decyl-3', 5'-difluoro-4'cyanotolane Example 3 (Synthesis of compound 1-c) 4-(4'-butylphenyl)-3'-fluoro-4'
-Cyanotran production process 1) Dichloromethane 185mj! into carbon tetrabromide 6
Dissolve 0g of triphenylphosphine at below 0℃
Added 0g. Next, 22 g of 4'-butyl-4-biphenylaldehyde was dissolved in 9311 dichloromethane and added dropwise over 1 hour. After that, it was stirred at room temperature for 1 hour. After the reaction was completed, dichloromethane was distilled off and the residue was dissolved in 500 g of hexane.
m1 was added.

The crystals were filtered off and washed three times with hexane. The hexane in the filtrate was distilled off, a small amount of hexane was added to the residue, the crystals were filtered, and the hexane in the filtrate was distilled off.

The residue was recrystallized from hexane to obtain 9.6 g of 4-(4'-butylphenyl)-β,β-dipromostyrene.

Step 2) 9.6 g of 4-(4'-butylphenyl)-β,β-dipromostyrene was dissolved in 50 mp of tetrahydrofuran under a nitrogen stream and cooled to -78°C. Butyl lithium hexane solution (1,6 moj!/II) into it
A force of 100 mN was added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour and 30 minutes.

After the reaction was completed, 500 mjl of water was added, extracted with chloroform, and washed with water three times. After chloroform was distilled off, the solvent was completely removed to obtain 5 g of 4'-butyl-4-bifuronyl acetylene.

Step 4) 27 g of sodium nitrite was dissolved in 205 mg of sulfuric acid, and after cooling to below 10°C, 238 rrl of acetic acid was added, and 65 g of 2-fluoro4-aniline iodide was added at 20 to 25°C, followed by stirring for 1 hour. . Dissolve 82.5 g of copper sulfate pentahydrate in 20°5 ml of water and add 1 ice cube into it.
40g was added. Furthermore, a solution of 88 g of potassium cyanide in 207 ml of water, 500 g of sodium bicarbonate
g, and 206 ml of benzene were added. A hediazonium salt sulfuric acid solution was added thereto. After stirring at room temperature for 3 hours, an aqueous sodium hydroxide solution was added to dissolve the crystals. After extraction with chloroform, extract with 10% sodium hydroxide solution and water, respectively.
I purified 15 times each time. After chloroform was distilled off, the residue was distilled under reduced pressure (95 - mmHg) and further recrystallized from methanol to recover 20 g of 1-cyano-2-fluoro-4-iodobenzene.

Step 5) Add 1- to 15 ml of N,N-dimethylformamide
Dissolve 2.1 g of cyano-2-fluoro-4-iodobenzene, and add 3 mg of Hebis(triphenylphosphine)palladium(II) chloride 1 cuprous iodide 14
mg was added. Then, after adding 2 g of 4'-butyl-4-biphenylacetylene obtained in step 2,
The reaction was carried out at 0'C for 0.5 hour. After the reaction, 9% hydrochloric acid 3
5 ml) was added to the reaction solution, extracted with chloroform, washed with water three times, and chloroform was distilled off. After purifying the residue by silica gel-chloroform column chromatography,
Recrystallize from a mixed solvent of acetone and methanol to obtain 4-(4″-butylphenyl)3′-fluoro-4′.
-0.4 g of cyanotran was obtained. The C-N point of this compound was 99.4°C, and the N-1 point was 214.5°C.

The following compounds were synthesized in a similar manner.

4-(4'-methylphenyl)-3'-fluoro-4'
-cyanotran 4-(4'-ethylphenyl)-3'-fluoro-4'
-cyanotran-4-(4'-propylphenyl)-3'-fluoro-4
' ~ Cyanotran C-N point 129.4℃ N-1 point 232.8℃ 4-(
4'-pentylphenyl)-3'-fluoro-4' -
Cyanotran 4-(4'-hexylphenyl)-3'-fluoro-4
' -Cyanotran C-N point 64.2℃ N-1 point 198.4℃4-(
4'-hebutylphenyl)-3'-fluoro-4'-cyanotran C-N point 72.5℃ N-1 point 190.3℃4-(
4'-octylphenyl)-3'-fluoro-4' -
Cyanotran 4- (4'-nonylphenyl)-3'-fluoro-4
'-Cyanotran 4-(4'-decylphenyl)-3'-fluoro-4'
-Cyanotrane Example 4 (Synthesis of compound 1-d) Production process of 4-(4'-butylphenyl)-3'5'difluoro-4'-cyanotrane 1) Dissolve 60 g of carbon tetrabromide in 185 mfi of dichloromethane. ,0℃
Below, 1.00 g of triphenylposphine was added.

Next, 22 g of 4'-butyl-4-biphenyl aldehyde was dissolved in 93 ml of dichloromethane and added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour. After the reaction was completed, dichloromethane was distilled off and 500 ml of hexane was added to the residue.

The crystals were filtered off and washed three times with hexane. The hexane in the filtrate was distilled off, a small amount of hexane was added to the residue, the crystals were filtered, and the hexane in the filtrate was distilled off.

The residue was recrystallized from hexane to obtain 9.6 g of 4-(4'-butylphenyl)-β,β-dipromostyrene.

Step 2) 9.6 g of 4-(4'-butylphenyl)-β,β-dibromostyrene was dissolved in 50 mg of tetrahydrofuran under a nitrogen stream and cooled to -78°C. Butyl lithium hexane solution (1.6 mol) II)
A force of 100 mN was added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour and 30 minutes.

After the reaction was completed, 500 ml of water was added, extracted with chloroform, and washed with water three times. After chloroform was distilled off, the solvent was completely removed to obtain 5 g of 4'-butyl-4-biphenylacetylene.

Step 3) 2,6-difluoro-
4-Aniline iodide was obtained.

Step 4) 1,3-difluoro-
2-cyano-5-iodinated benzene was obtained.

Step 5) N,N-dimethylformamide 19nd! to 1
．． 3-difluoro-2-cyano-5-iodinated benzene 3
To the solution were added 4 mg of Hebis (triphenylphosphine) palladium (II) chloride and 18 mg of cupric iodide. Then the 4 obtained in step 2
After adding 3 g of '-butyl-4-biphenylacetylene, the mixture was reacted at 50 to 60°C for 0.5 hour. 9% after reaction completion
After adding 35 mN of hydrochloric acid to the reaction solution and extracting with chloroform,
Washing with water was performed three times and chloroform was distilled off. After the residue was purified by silica gel-chloroform column chromatography, it was recrystallized from a mixed solvent of acetone and methanol to obtain 0.4 g of 4-(4'-butylphenyl)3'5'-difluoro-4' -cyanotran. . The C-N point of this compound is 101. 0°C, and the N-1 point was 165.7°C.

The following compounds were synthesized in a similar manner.

4-(4'-methylphenyl)-3', 5'difluoro-4'-cyanotran 4-(4'-ethylphenyl)-3', 5'difluoro-4'-cyanotran 4-(4'-propylphenyl ) -3', 5'-difluoro-4'-cyanotran C-N point 142.8°C N-1 point 182.8°C 4-(
4'-pentylphenyl) -3', 5'difluoro-4'-cyanotran 4-(4'-hexylphenyl) -3', 5'
-difluoro-4'-cyanotran C-N point 52.0℃ N-1 point 152.5℃4-(
4'-hebutylphenyl) -3', 5'-difluoro-41-cyanotran C-N point 6069°C N-1 point 149.2°C 4-(
4'-octylphenyl)-3', 5'-difluoro-4'-cyanotran 4-(4'-nonylphenyl)-3', 5'difluoro-4'-cyanotran 4-(4'-decylphenyl)- 3',5'difluoro-4'-cyanotrane Example 5 (synthesis of compound 1-e) 4-(trans-4'-ethylcyclohexyl)-3'
-Production process of fluoro-4'-cyanotrane 1) Dissolve 148 g of carbon tetrabromide in 450 rJ of dichloromethane,
93 g of triphenylphosphine was added below 0°C. Next, 48.6 g of 4-(trans-4'-ethylcyclohexyl)benzaldehyde was dissolved in 225 mN of dichloromethane and added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour. After the reaction was completed, dichloromethane was distilled off, and 500 nJ of hexane was added to the residue. The crystals were filtered off and washed three times with hexane. The hexane in the filtrate was distilled off, a small amount of hexane was added to the residue, the crystals were filtered, and the hexane in the filtrate was distilled off. The residue was recrystallized from hexane to obtain 52 g of 4-(trans-4'-ethylcyclohexyl)-β,β-dipromostyrene.

Step 2) Tetrahydrofuran 2xyl)-β. Dissolve 52g of β-dipromostyrene at -78°C.
It was cooled to Butyl lithium hexane solution (1
．． 6moj! II) 300mj! was added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour and 30 minutes. After the reaction was completed, 500 mII of water was added, extracted with chloroform, and washed with water three times. After distilling off chloroform, vacuum distillation (1
10~b/30mmHg)L, 4-(trans-4'
20 g of -ethylcyclohexyl)acetylene were obtained.

Step 4) Dissolve 27 g of sodium nitrite in 205 mp of sulfuric acid, cool to below 10°C, add 238 ml of acetic acid, add 65 g of 2-fluoro-4-aniline iodide at 20-25°C, and then stir for 1 hour. did. 82.5 g of copper sulfate pentahydrate and 20 g of water.

It was dissolved in 5 mg and 140 g of ice was added thereto. Furthermore, a solution of 88 g of potassium cyanide dissolved in 207 mN of water,
500 g of sodium hydrogen carbonate and 206 mg of benzene were added. A hediazonium salt sulfuric acid solution was added thereto. After stirring at room temperature for 3 hours, an aqueous sodium hydroxide solution was added to dissolve the crystals. After extraction with chloroform, it was washed three times each with 10% sodium hydroxide solution and water. After chloroform was distilled off, the residue was distilled under reduced pressure (95 - mmHg) and further recrystallized from methanol to obtain 20 g of 1-cyano-2-fluoro-4-iodobenzene.

Step 5) Add 1- to 25 ml of N,N-dimethylformamide.
3.8 g of cyano-2-fluoro-4-iodobenzene was dissolved, and 5.3 mg s of hebis(triphenylphosphine) palladium (II) chloride and 25 mg of cupric iodide were added thereto. Then the 4 obtained in step 2
After adding 3.2 g of -(trans-4'-ethylcyclohexyl)acetylene, the mixture was reacted at 50 to 60°C for 0.5 hour. After the reaction was completed, 35 mN of 9% hydrochloric acid was added to the reaction solution.
After extraction with chloroform, washing with water was performed three times and chloroform was distilled off. After the residue was purified by silica gel-chloroform column chromatography, it was recrystallized from a mixed solvent of acetone and methanol to give 4-(trans-4'-
0.8 g of ethylcyclohexyl)-3'fluoro-4'-cyanotrane was obtained.

The C-N point of this compound was 129.3°C, and the N1 point was 201.3°C.

The following compounds were synthesized in a similar manner.

4-(trans-41-methylcyclohexyl)3'
-fluoro-4' -cyanotolane 4-(trans-4
'-propylcyclohexyl)-3'-fluoro-4'
-Cyanotran C-N point 113.3℃ N-1 point 21
3.8℃4-(trans-41-butylcyclohexyl)3'-fluoro-4'-cyanotolane4-(trans-41-pentylcyclohexyl)-3'-fluoro-4'-cyanotolane4-(trans-4'-hexylcyclohexyl)-3'-fluoro-4'-cyanotolane4-(trans-4'-hebutylcyclohexyl)-3'-fluoro-4'-cyanotolane4-(trans-4'-octylcyclohexyl)-3'-Fluoro-4'-cyanotolane4-(trans-4'-nonylcyclohexyl)3'-Fluoro-4'-cyanotolane4-(trans-41-decylcyclohexyl)3'
~Fluoro4'-cyanotrane Example 6 (Synthesis of compound 1-f) 4-(trans-45-propylcyclohexyl)-3
',5'-difluoroni-4'-cyanotrane production process 1) 26 carbon tetrabromide into 82 mjJ of dichloromethane
．． Dissolve 9g of triphenylphosphine 4 at below 0°C.
2.6g was added. Next, 10 g of 4-(trans-4'-propylcyclohexyl)benzaldehyde was dissolved in 41 m9 of dichloromethane and added dropwise over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour. After the reaction was completed, dichloromethane was distilled off, and 500 ml of hexane was added to the residue. The crystals were filtered off and washed three times with hexane. The hexane in the filtrate was distilled off, a small amount of hexane was added to the residue, the crystals were filtered off, and the hexane in the filtrate was distilled off. The residue was recrystallized from hexane to obtain 16 g of 4-(trans-4'propylcyclohexyl)-β,β-dipromostyrene.

Step 2) 76ml of tetrahydrofuran + under nitrogen stream
Dissolve 16 g of 4-(trans-4'-propylcyclohexyl)-β,β-dipromostyrene in 4J and -7
Cooled to 8°C. 100 mg of butyllithium hexane solution (1,6 mo#/II) was added dropwise into the solution over 1 hour. Thereafter, the mixture was stirred at room temperature for 1 hour and 30 minutes. After the reaction was completed, 200 mN of water was added and extracted with chloroform.
Washing with water was performed three times.

After distilling off the chloroform, it was recrystallized from methanol to give 4-
2.45 g of (trans-4'-propylcyclohexyl)acetylene was obtained.

Step 3) 2,6-difluoro-
4-Aniline iodide was obtained.

Step 4) 1,3-difluoro-2-cyano-5-iodinated benzene was obtained in the same manner as in Example 2.

Step 5) 15mj of N,N-dimethylformamide! to 1
．． 3-difluoro-2-cyano-5-iodobenzene 2
．． 5 g was dissolved, and 3.3 mg of hebis (triphenylphosphine) palladium (II) chloride and 15 mg of cupric iodide were added thereto.

Then, after adding 2.45 g of 4-(trans-4'propylcyclohexyl)acetylene obtained in step 2,
The reaction was carried out at ~60°C for 0.5 hour.

After the reaction is complete, 9% hydrochloric acid 29rl! was added to the reaction solution, extracted with chloroform, and washed twice in the following order: water, 1096 hydrochloric acid, 5% aqueous hydrogen carbonate solution, and water. After that, chloroform was distilled off, and after purification by column chromatography, 4-(trans-41-propylcyclohexyl)-3 '5'difluoro-4'
-0.3 g of cyanotran was obtained.

The C-N point of this compound was 105.2°C, and the N-1 point was 175.0°C.

The following compounds were synthesized in a similar manner.

4-(trans-45-methylcyclohexyl)-3'
5'-difluoro-4'-cyanotolane 4-(
trans-41-ethylcyclohexyl)-3'
5'-difluoro-4'-cyanotran C-N point 12
1.8℃ N-1 point 150.4℃4-(Trans-4
1-Butylcyclohexyl)-3'5'-difluoro-4'-cyanotran C-N point 146.2°C
N-1 point 170.4℃ 4-(trans-4'-pentylcyclohexyl)-3',5'-difluoro-4
'-Cyanotran C-N point 99.5℃ N-1 point 172.4℃4-(
trans-4'-hexyl (1cyclohexyl)-3'
, 5'-difluoro-4'-cyanotran-4-(trans-4'-hebutylcyclohexyl)-3
',5'-difluoro-41-cyanotolane 4-(trans-41-octylcyclohexyl)-3
' , 5'-difluoro-4'-cyanotran4-(trans-4'-nonylcyclohexyl)-3'
, 5'-difluoro-4'-cyanotolane 4-(trans-4'-decylcyclohexyl)-3', 5'
-difluoro-4'-cyanotolane 4-(trans-4
1-propylcyclohexyl)-3',5'-difluoro-4'-cyanotrane Examples 7 to 12 (Usage examples) Commercially available mixed liquid crystal ZLI-1565 (Merck product, N-
1 point 89.3℃) is used as the base liquid crystal, and currently - v for boat fishing.
4-butylbenzoic acid, 4'-cyanophenyl ester, which is used for the purpose of lowering The characteristics of the compounds of the present invention were compared.

Compositions shown in Table 1, Comparative Examples A and B, and Examples 7 to 12 were prepared. Next, as shown in FIG. 1, an electrode 3 made of a transparent conductive film (for example, an ITO film) is formed on the glass substrate 1.2, and an alignment material made of polyimide or the like is applied thereon and rubbed to form an alignment control layer. 4, and further a glass substrate 1
．． 2 were placed facing each other with a sealant 6 interposed therebetween to prepare a liquid crystal cell, and the liquid crystal composition was injected between the glass substrates.

Note that the cell thickness was 8 μm, and a TN type liquid crystal cell was used. The voltage-luminance characteristics of the thus manufactured liquid crystal cell were measured at 20° C. under AC static driving. Table 2 shows the results.
Shown below.

In addition, VIO in the table is the voltage value when the transmittance is 10%, and TNN
This is a measurement value from the cell measurement direction -90@.

Further, α and β are factors representing viewing angle characteristics and threshold characteristics, respectively, and are defined as follows.

a-090'Vqo/θ50'' V,.

β-θ90° V+o/θ90” V2O table Although a TN type liquid crystal cell was used in the above example, the same effect can be obtained even if applied to a super twisted nematic type (STN) liquid crystal cell. .

〔Effect of the invention〕

As mentioned above, the compound of the present invention can be mixed with a general liquid crystal composition to improve electro-optical properties (β value, β value).
The threshold 11t voltage can be significantly lowered without worsening the
It has the effect of increasing 80.

Furthermore, the compounds 1-c, 1-d, 1-e, and 1-f have the effect of widening the practical temperature range. In these respects, the present invention is extremely useful as a basic acid component of liquid crystal compositions for super twisted nematic displays, which are currently the mainstream of liquid crystal display devices.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a liquid crystal element manufactured in an example of the present invention. 1.2, 31, 4, 1, 5, cloudy, 6, glass substrate, electrode, alignment control layer, polarizing plate, sealant and above Applicant Seiko Epson Corporation Representative Patent attorney Kizobe Suzuki (1 other person) Figure 1

Claims (9)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (In the above formula, R represents a straight chain alkyl group having 1 to 10 carbon atoms, A is a single bond, ▲ Numerical formula, chemical formula, A tolan derivative characterized by being represented by either ▼, ▲mathematical formula, chemical formula, table, etc.▼, where X represents hydrogen or fluorine, and the cyclohexane ring has a trans configuration. . (2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1-a) (In the above formula, R represents a straight chain alkyl group having 1 to 10 carbon atoms). The tolan derivative according to claim 1. (3) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1-b) (In the above formula, R represents a straight chain alkyl group having 1 to 10 carbon atoms). The tolan derivative according to claim 1. (4) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1-c) (In the above formula, R represents a straight chain alkyl group having 1 to 10 carbon atoms). The tolan derivative according to claim 1. (5) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1-d) (In the above formula, R represents a straight-chain alkyl group having 1 to 10 carbon atoms). The tolan derivative according to claim 1. (6) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1-e) (In the above formula, R represents a straight-chain alkyl group having 1 to 10 carbon atoms, and the cyclohexane ring is in the trans configuration.) The tolan derivative according to claim 1, characterized in that it is represented by: (7) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1-f) (In the above formula, R represents a straight-chain alkyl group having 1 to 10 carbon atoms, and the cyclohexane ring is in the trans configuration) The tolan derivative according to claim 1, characterized in that it is represented by: (8) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (In the above formula, R represents a straight chain alkyl group having 1 to 10 carbon atoms, A is a single bond, ▲ Numerical formula, chemical formula, At least one of the tolan derivatives represented by A liquid crystal composition containing a tolan derivative, characterized in that the composition contains a tolan derivative. (9) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (In the above formula, R represents a straight chain alkyl group having 1 to 10 carbon atoms, A is a single bond, ▲ Numerical formula, chemical formula, At least one of the tolan derivatives represented by 1. A liquid crystal element using a liquid crystal composition containing a tolan derivative, characterized in that the liquid crystal composition contains the tolan derivative.