JPS5913737A - 3,4-dimethyl-1-(4'-(trans-4"-alkylcyclohexyl)-cyclohexen-1'- yl)benzene - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R is H or 1-10C alkyl). EXAMPLE:3,4-Dimethyl-1-[4'-(trans-4''pentylcyclohexyl)cyclohexen-1-yl] -benzene. USE:A component of liquid crystal composition. It exhibits liquid crystal phase over a wide temperature range from a low temperature (about -20 deg.C) to a high temperature (about 80 deg.C), and gives a liquid crystal substance having low viscoxity. PROCESS:The compound of formula I can be prepared by reacting 3,4-dimethyl- bromobenzene of formula II with Mg, reacting the resultant compound of formula III with the compound of formula IV to obtain the compound of formula V, and dehydrating the product with KHSO4.

Description

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

Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials, but their display method requires a
type, DS type, guest-host type, DAP type, white
There are various types such as Tiller type, and each type requires different properties of the liquid crystal material used. For example, depending on the type of display element, the dielectric anisotropy of the liquid crystal material may vary depending on the type of display element.
It may be necessary for ε to be positive or negative, or it may be appropriate to have an intermediate value. However, in any case, the liquid crystal material used must exhibit a liquid crystal phase over as wide a temperature range as possible and be stable against moisture, heat, air, light, etc. At present, there is no single compound that satisfies all of these conditions, and the current situation is to obtain compounds that can be put to practical use by mixing several types of liquid crystal compounds and non-liquid crystal compounds.

Recently, there has been a demand for liquid crystal display elements that can operate over a particularly wide temperature range, from low temperatures (about -20°C) to high temperatures (about 80 tl). There is a growing need for liquid crystal materials that also have low viscosity.

The compound of the present invention provides a novel liquid crystal compound useful as a component constituting a liquid crystal composition that satisfies such requirements.

That is, the present invention provides 3,4-dimethyl-1-(4'-() lance-4N-alkylcyclo xyl) cyclohexene
1'-yl]benzene.

The compound of formula (11) of the present invention has a nematic temperature range of 1 (f
If i is very wide, for example, C5H, then C-
The temperature at point 8 is 54.7°C, the temperature at point S-N is 105.2°C, and the temperature at point N-4 is 109.2°C.However, since it has a low viscosity, its application range is wide.

Next, a method for producing the compound of the present invention will be described. Commercially available 3,4-dimethylbromobenzene (75%) is reacted with metallic magnesium to form 3,4-dimethylbenzenemagnesium bromide, which is then converted into 4-(trans-4'-
3,4-dimethyl-1-44'-()lanse-4〃- by reacting with alkylcyclohexyl)cyclohexanone
alkyrnchlorohexyl)cyclohexane-1'-ol]benzene+11 and sul.

Next, this was dehydrated with potassium hydrogen sulfate to produce 3,4-dimethyl-1-(4'-(trans-4〃-alkylcyclohexyl)cyclohexen-1'-yl]benzene (1).
get.

The chemical formula for the above is as follows.

Hereinafter, the production method and usage examples of the compound of the present invention will be explained in more detail with reference to Examples.

Example 1 [3,4-dimethyl-1-(4'-()lance-4"-
Production of pentylcyclohexyl)cyclohexen-1'-yl]benzene] Commercially available 3,4-dimethylbromobenzene (75eIO)
A solution of 47.6 F (0,257 mol) of
Reacted with F (0,257 mol) in a nitrogen stream3,4
- Dimethylbenzene magnesium bromide. After the solution became homogeneous, 4-()lance-4'-pentylcyclohexyl)cyclohexanone 49.6 F (0,
90ml of a solution of 198mol) dissolved in tetrahydrofuran
1 was added dropwise so that the reaction temperature did not exceed 3°C. After the dropwise addition, the mixture was refluxed for 2 hours, then 150 mg of 3N hydrochloric acid was added, and the mixture was extracted with 500 portions of n-hebutane. The oil layer is washed with water until the washing liquid becomes neutral, and the solvent is distilled off under reduced pressure.

The remaining oil was 3,4-dimethyl-1-(4'-(trans-4''-pentylcyclohexyl)cyclohexane-1'-ol)benzene, and 15F potassium hydrogen sulfate was added thereto at 200°C under a nitrogen atmosphere. After cooling, 300 ml of n-hebutane is added, potassium hydrogen sulfate is separated with P, and the heptane layer is washed with water until the washings become neutral.Then, the solvent is distilled off under reduced pressure to remove the residue. The target 3, which is obtained by recrystallizing with n-hebutane and atocene,
4-dimethyl-1-(4'-()lannu-4"-pentylcyclohexyl)cyclohexen-1'-yl]benzene. Yield: 120 y.

Yield 29.4%. The C-8 score for this one is 54.7-55
．． 6°C, the SN point was 102 to 105.2°C, and the NI point was 109.2°C.

Similarly, in the above procedure, 4-(trans-4'-alkylclohexyl)cyclohexanone with a different alkyl group was used instead of 4-(trans-4'-pemburunchlohexyl)vtalohexanone. The following compound was produced in the same manner as above.

3.4-dimethyl-1-(4'-cyclohexene-1/,r)benzene3.4-dimethyl-1-[4'-(trans-4-methylcyclohexyl)cyclohexene-1'-yl]benzene3.4-dimethyl-1-(4'-(trans-4"-!
#7Chlohequinyl)cyclohexet-7-1'-yl]benzene3,4-dimethyl-1-(4'-()lans-4''-furobylcyclohexenyl)cyclohexen-1'-yl]
Benzene 3.4-dimethyl-1-(4'-(trans-4〃-butyrunclohexyl)cyclohexen-17-yl)benzene 3.4-dimethyl-1-(4'-()trans-4 “-cyclohexyl)cyclohexen-1′-yl]
Benzene 3.4-dimethyl-1-(4'-()lance-4''-heptylsicσhekynyl)sic-ahexen-1'-yl]
Benzene 3.4-dimethyl-1-(4'-()lance-4''-octylenchlorohequinyl)cyclohexen-1'-yl]
Benzene 3,4-dimethyl-1-(4'-()lannu-4"-nonylcyclohexynyl)cyclohexen-1'-yl]benzene3,4-dimethyl-1-(4'-()lannu-4"- Decylcyclohexynyl)cyclohexen-1'-yl]benzene Example 2 (Application example) The N-I point of Merck's liquid crystal composition S-1132 (phenylcyclohexane type) is 72.1°C, Δε is 11, 3
, Δn is 0.138. The viscosity at 20°C is 29 Cp
It is.

90 parts of this composition was added to 3,4-dimethyl-1-(
trans-4'-()trans-4"-pentylcyclohexyl)cyclohexene-1'-1l]benzene lo
The N-I point of the liquid crystal composition obtained by adding 50% is 76.3°C,
6 was +10.3 and Δn was 0.134.The viscosity at 20°C was 32Cp, and the N-I point could be raised without increasing the viscosity much.

that's all

Claims (1)

[Scope of Claims] 3,4-dimethyl-1-(4'-(trans-4"-alkylinchlorohexyl) represented by (in the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms) Cyclohexene
1'-yl]benzene. 3,4-dimethyl-1-(4'-(trans-4"-alkylenechlorohexyl)cyclohexene-
1. A liquid crystal composition comprising at least one type of 1'-yl]benzene.