JPS5927859A - Trans-4-alkyl-trans-4"-(4-cyanophenyl)-trans-octadecahydro-p- terphenyl - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R is H or 1-10C alkyl). EXAMPLE:trans-4-Butyl-trans-4''-(4-cyanophenyl)-trans-octadecahydro-p- terphenyl. USE:A liquid crystal composition having positive dielectric anisotropy. It has broad and high liquid crystal temperature range for its low viscosity, and has high transparency. The stability to moisture, heat and light is also high. PROCESS:The compound of formula I can be prepared by (1) reacting the compound of formula II with metallic Mg and then with the compound of formula III, (2) dehydrating the product in the presence of a KHSO4 catalyst, (3) catalytically reducing the resultant compound of formula IV, and demethylating with HBr in acetic acid, (4) catalytically reducing in the presence of a Ru/C catalyst to obtain the compound of formula V, (5) oxidizing the product with chromic anhydride, (6) reacting with benzene magnesium bromide converted to Grignard reagent, (7) dehydrating and catalytically reducing to obtain the compound of formula VI, and (8) iodizing the compound and cyanizing with cuprous cyanide.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel liquid crystal substance that has positive dielectric anisotropy and exhibits a liquid crystal phase over a wide temperature range, and a liquid crystal composition containing the same.

Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials, but depending on the display format, TN
It is divided into various types such as type (twisted nematic type), DS type (dynamic scattering type), guest-host type, and DAP type.
The properties of liquid crystal materials suitable for each use vary. However, it is common for all liquid crystal materials to be stable against moisture, air, heat, light, etc., and they are also required to exhibit a liquid crystal phase over as wide a temperature range as possible, centered around room temperature. It is being However, at present, there is no single compound that satisfies these conditions, and the current situation is to use liquid crystal compositions obtained by mixing several types of liquid crystal compounds and non-liquid crystal compounds. In particular, recently there has been a demand for liquid crystal display elements that operate over a wide temperature range of -20'C to 80'C. In order to satisfy such requirements, an effective means is to lower the viscosity, especially the viscosity at low temperatures. However, in general, those with a high clearing point (N-I point) have a high viscosity, and those with a low viscosity, such as alkylphenylcyclohexitine derivatives, have a low clearing point.

The present inventors have previously discovered that a liquid crystal compound having a low viscosity, a high clearing point, and a wide nematic temperature range has the following properties: 4-[)lance- 4'-() Lance-4"
Invented -alkylcyclohexyl)cyclohexyl]benzonitrile! Filed a patent application (Patent application 1973-1073)
82). However, recent advances in liquid crystal display element technology have been remarkable, and there is a demand for display elements that operate at lower to higher temperatures.

An object of the present invention is to provide a liquid crystal compound that meets these requirements.

That is, 1 the present invention relates to trans-4-alkyl-trans-4'' represented by the general formula (in the above formula, R represents a hydrogen atom or an alkyl group having 1 to 1 o carbon atoms).
-(4-cyanophenyl)-trans-octadecahydro-p-terphenyl and a liquid crystal composition containing at least one thereof.

The compound of formula +11 of the present invention has a wide and high liquid crystal temperature range despite its low viscosity, such as trans-4-butyl-trans-4''-(4-cyanophenyl)-, trans-octadecahyte E-1)- Terphenyl has a crystalline-smectic point (C-8 point) of 6o, 4℃, a smectic-nematic point (S-N point) of 2C, 17,6℃, a nematic-clearing point (N-, [point) of 300℃ or more, and a liquid crystal temperature. It has a wide range and a high clearing point, making it a very useful compound as a component of liquid crystal compositions used for liquid crystal display cells that operate in a wide temperature range from low to high temperatures.Also, the dielectric anisotropy Δε is 4
However, the threshold voltage and saturation voltage of the liquid crystal composition to which the compound of the present invention is added do not increase much compared to the composition to which the compound of the present invention is not added, and are about the same. Furthermore, it is stable against light, heat, air, moisture, etc., and has a wide range of applications.

Next, a method for producing the compound of the present invention will be described.

First, 4-methquine bromobenzene and metallic magnesium are reacted to form 4-methquine phenylmagnesium bromide, which is then converted into 4-(trans-4'-alkylene chlorohexyl)cyclohexanone (the corresponding cyclohexanol is reacted with chromic anhydride). 4-methoxy-[1'-hydrogine-4'-
(trans-4"-alkylcyclohexyl)cyclohexyl]benzentosul.

This was then dehydrated using potassium hydrogen sulfate catalyst to give 4-
When methquin-(4'-()lans-4"-alkylcyclohexyl)cyclohexen-1'-yl]benzene is reduced using a Raney nickel catalyst in an ethanol solvent at normal pressure and 30°C, 4-methoxy- (4'-
() lance-4"-alkylcyclohexyl) nclohexyl]benzene. Since this is a mixture of trans isomer and trans isomer, it is recrystallized from ethanol to produce 4-methquine-[trans-4'-() lance- 4"-Alkylcyclohexyl)cyclohexyl]benzene is obtained. This was subjected to a demethylation reaction with hydrobromic acid in acetic acid, and 4-
Hydroxy-[trans-4'-()trans-4"-alkylcyclohexyl)n-σhekynyl]benzene is obtained. Next, this is dissolved in ethanol and brought into contact at 180°C in the presence of a ruthenium catalyst at 50*q/cnt. Originally,
4-[trans-4'-()trans-4"-alkylcyclohexyl)-cyclohexanol]cyclohexanol is obtained. This is dissolved in acetone and oxidized with chromic anhydride to give 4-[trans-4"-(trans- 4#-Alkylcyclohexyl)cyclohequinyl]cyclohexanone is obtained. Dissolve this product in tetrahydrofuran and add the solution to a tetrahydrofuran solution of benzenemagnesium bromide using metallic magnesium as a Grignard reagent.
-alkylcyclohexyl)cyclohexyl]cyclohexane-1'-o/lz)benzene is obtained. This was dehydrated with potassium hydrogen sulfate, 1-(4'-, (:
Trans-4"-(trans-4"-alkylcyclohexyl)cyclohexyl]cyclohexen-1'-yl]benzene is obtained. This product was subjected to catalytic reduction in the presence of a Raney nickel catalyst to produce trans-4-alkyl-
Trans-4"-phenyl-trans-octadecahydro-p-terphenyl is isolated. It is then dissolved in acetic acid,
Perform an iodination reaction with iodine and iodic acid to form a trans-
4-Alkyl-trans-4"-(4-iodophenyl)-trans-octadecahydro-p-terphenyl is obtained. When this is subjected to a cyanation reaction with cupric cyanide in dimethylformamide, the desired product is obtained. Trans-4-argyl-trans-4"-(4-cyanophenyl)-trans-octadecahydro-p-terphenyl is obtained.

The above is expressed as a chemical formula as follows.

Br伽CH3 ↓・Mg BrMg伽C)ta ↓ KHSO3 ↓ H2+IdoNi ↓ HBr AcOH ↓ I2. Ru/C ↓ CrO3, acetone ↓ BrMgno↓ )G(804 ↓ I2.R, -Nl ↓ I2.I(IO3 acetic acid ↓ Cu2(CN)z, DMF Below, the compounds of the present invention will be explained in more detail through Examples. explain.

Example 1 [Production of trans-4-butyl-trans-4''-(4-cyanophenyl)-trans-octadecahydro-p-terphenyl] 1.2 f (0
, 049 mol) was placed in a third flask, and a solution of 9.2 t (0,049 mol) of 4-bromoanisole dissolved in tetrahydrofuran (30°C) was heated to a reaction temperature of 3o~35°C in a nitrogen stream. When the magnesium is maintained and slowly added dropwise while stirring, the magnesium reacts and dissolves in 3 hours to produce homogeneous sil-methoxyphenylmagnesium bromide. ) of cyclohexanone 11.6 f (0,049
mol) dissolved in tetrahydrofuran and added dropwise as quickly as possible while maintaining the reaction temperature at 5 to 10°C. After the dropwise addition, the temperature was raised to 35°C and stirred for 30 minutes, and then 50° of 3N hydrochloric acid was added. Separate the reaction solution into a liquid separator and p2
After extraction three times with 00 rnl of toluene, the combined toluene layers were washed with water until the washings became neutral, and then the toluene was distilled off under reduced pressure. The remaining oil is 4-methoxy-[1'
-Hydroxy-4'-()lance-4"-butyrunchlorohexyl)cyclohexyl] Add 6f of potassium hydrogen sulfate to this and dehydrate at 160°C for 2 hours in a nitrogen stream. After cooling, add 200% of toluene. After that, the potassium hydrogen sulfate is removed separately, and the toluene layer is washed with water until the washing liquid becomes neutral.Then, the toluene is distilled off under reduced pressure, and the remaining oil is recrystallized with ethanol to obtain 4-methoxy-( 4'-()lannu-4"-butyrunchlorohexyl)cyclohexen-1'-yl]benzene. The total t7. of Raney nickel catalyst i, o
It was dissolved in 120 ml of ethanol together with t and subjected to catalytic reduction at normal pressure at 50° C. to absorb 500 − of hydrogen. V the catalyst
Separate and recrystallize as is. Since the obtained product is a mixture of cis and trans forms, recrystallization is repeated with ethanol to isolate the trans form. This is 4-methoxy-[trans-4'-()trans-4"-butylcyclohexyl)cyclohexyl]benzene. 40f of this product was dissolved in 400 m7 of acetic acid, and hydrobromic acid (
Add 450me (47%) and reduce for 30 hours. After cooling, a large amount of water is added to separate the precipitate, and this residue is recrystallized from ethanol. 8. Of ethanol 400
7! Ruthenium/carbon 1. Add Of, 18
Catalytic reduction is carried out at 0°C and 50 Kf/c7it for 5 hours. After separating the catalyst 11, the solvent was distilled off under reduced pressure and 4-[trans-4'
-()lance-4"-butercyclohexyl)cyclohexylconclohexanol is obtained. Dissolve this in 41 parts of acetone and add 20 parts of a mixture of chromic anhydride and concentrated sulfuric acid dropwise at a reaction temperature of 0 to 3°C. The reaction solution turns orange,
The reaction is terminated when the color no longer disappears, and the reaction solution is neutralized with sodium bicarbonate. After filtering the solution under reduced pressure, the solvent is distilled off, extracted with toluene, washed with water, the toluene is distilled off under reduced pressure, and recrystallized from toluene. Remove the solvent etc. by vacuum drying and store. This thing is 4-[trans-4
'-[trans-4"-butercyclohexyl)cyclohexyl]cyclohexanone. Magnesium piece 0
．． When a solution of bromobenzene 4.7F dissolved in tetrahydrofuran is added dropwise to 73F, the magnesium reacts to produce 4-fluorobenzenemagnesium bromide. Add the previously prepared 4-[trans-4'-(
) Lance-4"-butylcyclohexyl)cyclohexylcocyclohexanone 4.02 dissolved in 50% tetrahydrofuran is added. At this time, make sure the temperature does not exceed 30°C and reflux for 1 hour after the dropwise addition. Cool. rear,
3N hydrochloric acid 5.0++! ! and extracted with 200% of toluene. After washing with water, the solvent is distilled off, and potassium hydrogen sulfate 12 is added to the remaining oil, followed by dehydration at 160° C. for 2 hours in a nitrogen stream. After cooling, dissolve potassium hydrogen sulfate in 200 ml of toluene and wash with water. The solvent is removed under reduced pressure and recrystallized from fresh toluene. The obtained crystal is 1-(4'
-()trans-4''-(trans4#j thylcyclohexyl)cyclohexyl]cyclohexen-1'-yl]benzene.

Dissolve 0.9 f of this product in 150 toluene, add 0.4 t of Raney nickel, perform catalytic reduction at room temperature and normal pressure, and recrystallize the resulting reduced product with toluene to obtain trans-4-butyl-trans-4"-phenyl. -trans-octadecahydro-p-terphenyl is obtained.
Dissolve 5 f in acetic acid 200-, sulfuric acid l-, iodine 0.1
Add 0.09 f of 7 f% iodic acid and reflux for 15 hours.

After cooling, the crystals were separated and recrystallized from toluene. What was obtained was trans-4-butyl-trans-4"-(4-iodophenyl)-trans-octadecahydro-p-terphenyl. 0.2f of this product was dissolved in 200 ml of dimethylformamide. Copper cyanide 0゜02
Add t and reflux for 10 hours. After cooling, ammonia water 10
Add 0 mA, extract with 200ml of toluene, wash with acid, and then wash with water. The solvent was distilled off under reduced pressure and recrystallized from toluene. The obtained crystals are the target trans-4-butyl-trans-4"-(4-cyanophenyl)-trans-octadecahydro-p-terphenyl.
lfoThis C-8 point is 60.4℃, 8-N point is 207.
6°C, the N-N point was 300°C or higher.

Example 2 (Usage example) Trans-4-propyl-(4'-cyanophenyl)cyclohexane 28% Trans-4-pentyl-(4'-cyanophenyl)cyclohexane 42% Trans-4-hebutyl-(4'- The nematic liquid crystal temperature range of a liquid crystal composition with a composition of cyanophenyl) cyclohexane 30
~52°C. This liquid crystal composition was applied to a T cell with a cell thickness of 10 μm.
When sealed in an N cell (twisted nematic cell), the operating threshold voltage is 1.5V and the saturation voltage is 2. It was OV.

The viscosity was 23 CI) at 20°C.

In addition to 97 parts of the above liquid crystal composition, f shown in Example 1 of the present invention,
*) The N-N point of the liquid crystal composition to which 3 parts of trans-4-butyl-trans-4"-(4-cyanophenyl)-trans-octadecahydro-p-terphenyl was added was 58.9.
℃, and when this cell was sealed in the above cell, the operating threshold voltage was 1.5 V, and the saturation voltage was 2.5 V. It did not change much from IV. Also, the viscosity at 20℃ is 26c
p did not increase that much. As mentioned above, by adding the compound of the present invention, liquid crystal yarn ■ has a wide nematic range without deteriorating the viscosity or voltage value! I was able to compose an object.

that's all

Claims (2)

[Claims] (1) Trans-4-alkyl-trans-4" represented by the general formula (the middle of the above formula represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms)
-(4-cyanophenyl)-trans-octadecahydro-p-terphenyl. (2) trans-4-alkyl-trans-4'' represented by the general formula (in the above formula, R represents a hydrogen atom or an alkyl group having 1 to 1° of carbon atoms)
A liquid crystal composition containing at least one type of -(4-cyanophenyl)-trans-octadecahydro-p-terphenyl.