JPS5936642A - Trans-4-alkyl-trans-4"-(4-halogenobenzoyloxy)-octadecahydro- trans-p-terphenyl - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R is H or 1-10C alkyl; X is F or Cl). EXAMPLE:trans -4-Propyl- trans-4''-( 4-fluorobenzoyloxy )-octadecahydro- trans -p- terphenyl. USE:A liquid crystal substance exhibiting a liquid crystal phase over a wide temperature range, having high clear point, and nevertheless, low viscosiy and positive dielectric anisotropy. When the compound is used as a compound of a liquid crystal composition, the clear point of the composition can be raised without increasing the viscosity of the composition nor too much affecting the threshold voltage and saturation voltage. PROCESS:The compound of formula I can be prepared by (1) reacting 4-bromoanisole of formula II with metallic Mg, (2) reacting the product with 4-(trans-4'- alkylcyclohexyl)cyclohexanone to obtain the compound of formula III, (3) subjecting the compound successively to dehydration, reduction, demethylation, and reduction, and (4) reacting the resultant compound of formula IV with 4-halogenobenzoic acid chloride.

Description

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

Display elements using liquid crystals have come to be widely used in watches, calculators, etc. This liquid crystal display element utilizes the properties of optical anisotropy and dielectric anisotropy of liquid crystal materials, and liquid crystal phases include nematic liquid crystal phase, smectic liquid crystal phase, and cholesteric liquid crystal phase, among which nematic liquid crystal is used. The one that has been put into practical use is the most widely used. That is, they include TN (twisted nematic) type, DB type (dynamic scattering IJi), guest-host type, DAP type, etc., and the a-quality required for the liquid crystal material used for each type is different. However, in any case, it is desirable that the liquid crystal materials used in these display elements exhibit a liquid crystal phase over a wide range of natural phenomena. Currently, there is no material that can overcome this problem, and the current situation is to mix several types of liquid crystal materials and non-liquid crystal materials to obtain materials that can withstand practical use. In addition, these materials must of course be stable against moisture, light, heat, air, etc., and the threshold voltage and saturation voltage required to drive the display element must be as low as possible, and the response must be as low as possible. It is desirable for the viscosity to be as low as possible for faster rounding. By the way, in order to widen the liquid crystal temperature range toward high temperatures, it is necessary to use a liquid crystal substance with a high melting point as a component, but liquid crystal substances with a high melting point generally have a high viscosity, so liquid crystal compositions containing smudges may also be used. As the viscosity increases, the response speed of liquid crystal display devices that can be used at high temperatures, for example, up to 80°C, tends to be slow, especially at low temperatures. However, the present inventors have discovered a liquid crystal material that exhibits a liquid crystal phase over a wide temperature range, has a high clearing point, and has a low viscosity, leading to the present invention.

That is, the present invention provides trans-4-alkyl-tran '
-(4-halogenobenzoyloxy)-octadecahydro-trans-p-terphenyl and a liquid crystal composition containing the same.

The compounds of the invention have high clearing points, for example trans-4-propyl-trans-
The a-S point of 4'-(4-fluorobenzoyloxy)-octadecahydro-trans-p-terphenyl is 10
2℃, S-N point is 225.8℃, R-1 point is 297.0
It exhibits a liquid crystal phase in a wide range above .degree. C., and by adding it as a component of the composition, the clearing point can be raised without increasing the viscosity of the liquid crystal composition.

The enzymatic anisotropy value of the compound of the present invention is about +2,
The threshold voltage of the composition, the saturation voltage does not change by 4M, and the composition has good stability against moisture, heat, light, etc.

To explain the method for producing the compound of the present invention, first, 4-bromoanisole and metal magne are reacted to form 4-methquinphenylmagnesylano-bujjmide, which is then
Reacting with '4-()rance-l-alcyclo\xyl)cyclohexanone (obtained by oxidizing cyclohexanone with chromic anhydride)
-MeI xy-[1'-hydroxy-1-(trans-
41-alkylcyclohexyl)cyclohexyl]benzene. Then, this was dehydrated using potassium hydrogen sulfate as a catalyst to give 4-methoxy-(4'-()lance-41)
-alkylcyclohexyl)cyclohexene-1'-1
[le] benzene and 5-. This is then reduced using a Raney nickel catalyst in an ethanol solvent at normal pressure and 30°C to yield 4-methoxy-(4'-()lans-4'-alkylcyclohexyl)cyclohexyl]benzene. Since this is a mixture of trans isomer and trans isomer, it is recrystallized from ethanol and 4-methoxy-[trans-4'-()/par41-
Alkylcyclohexyl)cyclohexyl]benzene is obtained. Then, it was demethylated with bromic hydric acid to give 4-[
trans-4'-()trans-4I-alkylcyclohexyl)cyclohexyl]phenol is obtained. Using a ruthenium catalyst in an ethanol solvent, 180
Catalytic reduction was carried out at 5'0 Kri/aj to give trans-4-alkyl-l'-hydroxycutorans-octadecahy)'o-p-terphenyl. This product was recrystallized from acetone to give trans-4-alkyl-
Trans-C-hydroxy7-trans-octadecahydro-p-terphenyl was separated. This was reacted with 4-halogenobenzoic acid chloride in the presence of pyridine to obtain the desired trans-4-alkyl-trans-4'-(4-halogenobenzoyloxy)-octadecahydo-trans-p-terphenyl t. - Manufactured. The above is represented by a chemical formula: (1) Hereinafter, the manufacturing method and usage examples of the compound of the present invention will be explained in more detail with reference to Examples.

Example 1 [Production of trans-4-propyl-trans-41-(4-fluorobenzoyloki7)-octadecahydro-trans-p-terphenyl] 1.2 t (0,049 mol) of magnesium turnings Put 3 of them into a Lough flask and add 4-bromoanisole 9.2
30 ml of a solution of f (0,049 mol) dissolved in tetrahydrofuran was heated to a reaction temperature of 30 to 35' in a nitrogen stream.
When the temperature is maintained at C and the mixture is slowly added dropwise with stirring, the reaction occurs, and in 3 hours, the magnesium dissolves and becomes homogeneous to produce 4-methoxyphenylmagnesium bromide. 4-
(trans-4'-7" lovylcyclohegycyl) cyclohexanone l O,9t (0,049 mol) was dissolved in tetrahydrofuran to make 50 m as quickly as possible while keeping the reaction temperature at 5 to 10°C. After the dropwise addition, the temperature was raised to 35°C, stirred for 30 minutes, and then 311 hydrochloric acid 50- was added.

The reaction solution was placed in a separatory funnel, extracted three times with 200-g of toluene, and 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 was 4-methoxy-[1'-hydokuchi-4'-()lance-41-propylcyclohexyl)cyclohexyl]pentene, and 6f of potassium hydrogen sulfate was added to it, followed by nitrogen flow at 160°C. Dehydrate for 2 hours. After cooling, 200 ml of toluene is added, and the potassium hydrogen sulfate is removed separately, and the toluene layer is washed with water until the washing liquid becomes neutral. Next, toluene was distilled off under reduced pressure, and the remaining oil was recrystallized from ethanol to obtain 4-methoxy-(4'-()lanse-41).
-propylcyclohexyl)cyclohexen-1'-yl)ben7ane. The total amount obtained here, 7.02, was added to the Raney nickel catalyst 1. ○T and ethanol 120mK
500Mt of hydrogen was melted and subjected to catalytic reduction at normal pressure of 50℃.
was absorbed. The catalyst is sent door to door and recrystallized as is.

Since the obtained product is a mixture of cis and trans forms, recrystallization is repeated with ethanol to isolate the trans form.

=9- This was obtained as 4-methquin-[trans-4'-()trans-4'-furobylcyclohexyl)cyclohexyl]benzene in a yield of 28'' and a 1'R rate of 1 B%.

15f of this is refluxed for 20 hours with hydrobromic acid (47%) 2001Rt and vinegar tR200-. 5 after reaction completion
00- water is added and the precipitated crystals are filtered. After thoroughly washing with water, it was recrystallized from an acetone-ethanol mixed solvent. This is 4-[trans-4'-() lance-41-
pentylcyclohexyl)cyclohexyl]phenol.

Yield 114. Yield 77%0 4-[trans-4/-(trans-4'-pentylcyclohexyl)cyclohexyl] produced in this way
Dissolve 8 tons of phenol in 400 mK of ethanol, add ruthenium/carbon catalyst 1. Add Of, 180℃, 50Kf/
- Catalytic hydrogen reduction was carried out for 5 hours. After the reaction is completed, the catalyst is separated and the solvent is distilled off under reduced pressure. 1 of the remaining crystals
Recrystallize with acetone in Step 7. This is trans-10--4'-propyl-trans-41-hydroxy-octadecahydro-trans-p-terphenyl. Yield: S, 8t, yield 47mm, melting point 232-237℃
. Next, add 1 t of pyridino to 50 m of pyridino and add it to the solution.
Add 4-fluorobenzoic acid chloride 1-' l f ,
- Add 200 TIt and add the toluene layer in a separatory funnel, first soak in 6N salt, then soak in 200 TIt.
Wash with 1N caustic soda solution and water until neutral. After drying it over anhydrous sodium sulfate, the toluene layer was distilled off under reduced pressure. When the precipitated crystals are recrystallized with acetone, the desired trans-4-propyl-trans-4'=
(4-fluorobenzoyloxy)-octatekahi)'
0-trans-■)-terphenyl was obtained. settlement (),
fJf% yield 57%, 〇-day point of this is l 02
C% 11-N point is 225.8℃, N-i point is 297
．． It was on.

Example 2 ~ 4-[trans-4'-(
4-(trans-4#-furoylcyclohexyl) with another alkyl group instead of cyclohexane
The compounds shown in Examples 2 to 4 in Table J11 were prepared in exactly the same manner using 4'-() lance-41-alkylcyclohexyl)cyclohexanone and 4-fluorobenzoic acid chloride when X was (J). Their physical properties are shown in ill! along with the results of Example 1.

Table 1 Example 5 (Usage example) Trans-4-propyl-(4'-cyanophenyl)cyclohexane 28% Trans-4-pentyl-(4'-cyanophenyl)cyclohexane 42 Thitrans-4-heptyl-(4' -cyanophenyl)cyclohexane The oil leak composition 1-ON-■ point of the composition 30 is 52°C. This liquid crystal composition was sealed in a DTN cell (twisted nematic cell) with a diameter of 410 μm, but the operating voltage was 1.
53 V, and the saturation voltage was 2.12 V. Further, the viscosity was 23 CI at 20°C.

To 1197 parts of this liquid crystal composition l1th, 3 parts of trans-4-propyl-trans-4'-(4-fluorobenzoyloxy)-octadecahydro-trans-p-terphenyl produced in Example 1 were added. The N-1 point of the cell rises to 58°C, and when this is made into a TN cell similar to the above, the threshold voltage is 1.55V and the saturation voltage is 2.
．． It was 14V.

The viscosity was 26 cp at 20°C.

that's all 13-

Claims (2)

[Claims] (1) Trans-4-alkyl-trans-4' represented by the general formula (in the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms, and X represents either 1 or C)
-(4-halogenobenzoyloxy)-octadecahydro-trans-p-terphenyl. (2) trans-4-alkyl-trans-4' represented by the general formula (in the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms, and X represents either F or 07)
A liquid crystal composition containing at least one type of -(4-halogenobenzoyloxy)-octadecahydro-trans-p-terphenyl.