JPS58126821A - 1-(trans-4'-substituted cyclohexyl)-4-(trans-4"-(trans-4'''- substituted cyclohexyl)cyclohexyl)benzene - Google Patents

Abstract

NEW MATERIAL:A 1-(trans-4'-substituted cyclohexyl)-4-[trans-4''-(trans-4'''-substituted cyclohexyl)cyclohexyl]benzene expressed by formulaI(R and R' are H or 1-10C alkyl). EXAMPLE:1-( trans-4'-Methylcyclohexyl )-4-[ trans-4''-( trans-4'''-pentylcyclohexyl) cyclohexyl]benzene. USE:A liquid crystal display element exhibiting the liquid crystal phase in a wide temperature range with a low viscosity. PROCESS:p-Dibromobenzene is reacted with Mg, and then a 4-alkylcyclohexane to give a compound expressed by formula II, which is then dehydrated to afford a compound expressed by formula III. The resultant compound expressed by formula III is reacted with Mg and then a compound expressed by formula VI to give a compound expressed by formula IV, which is then dehydrated to afford a compound expressed by formula V. The resultant compound expressed by formula V is finally reduced to give the aimed compound expressed by formulaI.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel liquid crystal substances that exhibit a liquid crystal phase over a wide temperature range and have low viscosity, and compositions containing them.

Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials, and their display methods include TN type, Ds type, and guest-host type.

There are six methods, including the DAP type and the White Tiller type, and each method requires different properties for the liquid crystal material used. For example, depending on the type of display element, a liquid crystal material with a positive or negative dielectric anisotropy ΔC may be required, or a liquid crystal material with a value somewhere in between may be suitable. However, even if K is used, the liquid crystal material used exhibits a liquid crystal phase over a wide temperature range as much as possible.

It also needs to 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 type A liquid crystal compounds and non-liquid crystal compounds.

Recently, there has been an increasing demand for liquid crystal display elements that operate over a wide temperature range, ie, from low temperatures to high temperatures. In order to meet these demands, it is necessary to exhibit a liquid crystal phase over a wider temperature range.

There is a need for a liquid crystal compound that also has low viscosity.

The present invention satisfies these demands.

That is, the present invention is a general formula.

1-(trans-4'-substituted cyclohexyl")-4-()trans-4 //-() Lance-4”'
-substituted cyclohexyl)7chlorohexyl]benzene.

The compound Fi of the present invention has low viscosity and a wide crystal temperature range. For example, l-()? Trans-4'-Methylcyclohexyl) Ichiban-[Trans-4''-() Lance4''-
Pentylcyclohexyl)S/chlorohexyl]benzene is i! It shows a liquid crystal phase from the vicinity of the lagoon, the clearing point is 259℃, and when added in a small amount, it has a low activity with a wide range of 1 degree and 11 degrees.
It is the best compound for making Nemadec liquid crystal compositions.

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

First, from P-dibromobenzene and metallic magnesium, 4
- Bromobenzene magnesium bromide and 4
4-(4'-alkylcyclohexane-1'-ol)bromobenzene (1) is obtained by reacting with -alkyl 7-chlorohexanone. This was thoroughly dehydrated using aqueous potassium sulfate as a catalyst to form 4-(4'-alkylcyclohexeno-
1'-yl) promohenzene) is obtained. This product was made into 4-(4'-alcyclohexen-1'-yl)benzenemagnesium bromide with magnesium metal, and this was reacted with 4-(trans-4'-alkyl/chlorocyclohexanone). 1-(4'-alkyl7
1-(,t'-(trans-4''-alkylcyclohexyl)cyclohexane-1''-ol)benzene (2) is obtained.

Next, this was dehydrated using potassium hydrogen sulfate as a catalyst, and 1
-(4'-alkyl7chlorohexen-1'-yl) -
4-(4"-()lance-4"'-alkyl7chlorohexyl)cyclohexen-1"-yl]benzene (ma) is obtained. This is subjected to catalytic reduction in an autoclave using Raney nickel as a catalyst to obtain the product. By crystallization, the target product 1-(trans-4'-alkylcyclohexyl)-i-(?trans-4''-(1':7-4''-alkylcyclohexyl)cyclohexyl)benzene (1) is obtained. Obtained.

The above can be expressed as a chemical formula (1) The compounds of the present invention will be explained in more detail with reference to Examples below.

Example 1 1-Ct5/su4'-)tylcyclohexyl)-4-
[trans-4"-()lans-4"'-pentyl7chlorohexyl)cyclohexyl]Production method of benzene 3.
P-dibromobenzene 283.1
? (1,20 mol) of tetrahydrofuran 500111
The agitated solution was heated to a reaction temperature of 30 to 35 in a NI gas stream.
Keep at ℃ and slowly add dropwise while stirring. 3 hours later.

Reaction rl 1% completes yielding magnenium bromide.

This was added to 4-methylcyclohexanone 107.11 (1,
0O-r-R) to Tetrahy)o7200m1K%
The dissolved solution was quickly added dropwise while keeping the reaction temperature below 30°C. After dropping, the mixture was allowed to stand for 20 minutes, and then 3N hydrochloric acid was added. The reaction solution was diluted with n-hebutane (300 ml of
After extraction with gJ), the combined n-hebutane layer was washed with water, and #
The solvent is removed under reduced pressure. The remaining oil is 4 + < , /-
To this was added 307 g of potassium hydrogen sulfate, and the mixture was dehydrated at 200° C. for 2 hours in a N gas stream.

After cooling, 11 portions of n-heptane was added, potassium hydrogen peachate was filtered off, the n-hebutane layer was washed with water, and the 1i8 medium was distilled off under reduced pressure. The residue was distilled under reduced pressure and its main fraction, i.e. 170-1
The 73°C/9ml fraction was collected and recrystallized from xl/l to obtain 4-(4'-methylcyclohexen-1'-yl)bromobenzene. 6.1 (0,024 mol) of this material was added to 20 mol of tetrahydrofuran.
Dissolved in 111/, N, Magnesium A O, in an air stream.
58t (0,024-e-nyl) to form 4-(4'
-Methicinchlorohexen-1'-yl)benzene 7umbromide, and 4-(trans-4'-hentylcyclohexyl)cyclohexanone 4.8? (
Add 20 ml of tetrahydrofuran (0,019 mol) and extract with 300 ml of n-hebutane. The oily layer is washed with water and the solvent is distilled off under reduced pressure. Add 2 tons of potassium hydrogen sulfate to the residue.

Dehydrate for 2 hours at 200°C in a stream of air. After cooling 20011/
of toluene was added, and potassium hydrogen sulfate was filtered off.

Wash the toluene layer with water. The solvent was distilled off under reduced pressure, and the residue was recrystallized from toluene to obtain 1-(4'-methylcyclohexen-1'-yl)-4-(4/A ()
lance-4″′-pentylcyclohexyl)!
Fuclohexen-1″-yl]benzene.
(7) '1.2 #wo) Chef 20ml 1VC melted, Raney nickel 1. Add Ot and perform catalytic reduction in an autoclave. Follow the reaction with gas chromatography.

When the raw material disappears, the catalyst is filtered off and recrystallization is repeated with toluene to obtain 1-(trans-4'-methane chlorohexyl)-4-()trans-4''-()2ns4.
″′-hentylcyclohexyl)cyclohexyl]benzene was isolated (yield fi O, 1t′).

The crystal-smectic point (c-am point) of this is 30
Below ℃, the smectic-nematic point (Elm-1 point) is 256℃, and the nematic-clearing point (N, -I point) is 259
It was ℃.

Examples 2 to 5 In the same manner as in Example 1, various substituents with different substituents were synthesized. This is shown in Table 1 together with the results of Example 1.

The chemical structures of these were confirmed by NMR and the like.

Higashi Jllll1 Example 6 Trans-Ichiban-globyl-(4'-cyanophenyl)cyclohexane 28-trans-Ichiban-benchyl-(4'-cyanophenyl)cyclohexane 431 trans-4-hebutyl-(4'-cyanophenyl)cyclohexane 29-thi The nematic temperature range of the liquid crystal composition having the composition is 13 to 5.
2℃, s-electrotropy value Δt i;j + 10.5 T
L threshold voltage is 1.53V, saturation voltage is 2,127.2
The viscosity at 0°C is 230p.

Add 95 parts of this liquid crystal mixture to this liquid crystal mixture? , l-(trans-47-nitylcyclohexyl)- obtained in Example 3 of Ming.
i-(12th first //-() Lance-4///-;
By adding 5 parts of 7'rovircuchlorhexyl)cuclohexyl]-benzene, the nematic liquid crystal temperature range of the mourning liquid crystal composition expanded from -lO to 60.3°C, and Δε was +1a, e,
L threshold voltage is 1,70V, saturation voltage is 2.5V, 20
The viscosity at °C was 30.30p.

As described above, it can be seen that the compound of the present invention is effective in widening the nematic temperature range when added in a small amount.

Patent applicant Chisso Co., Ltd., agent Patent attorney Sasa Yatabe Sasaki

Claims (2)

[Claims] (1) 1-(trans-4'-substituted 7-chlorohekiflu)-4- represented by the general formula (in the above formula, R and R' each represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms) [Trans-4″-(Trans-4///
-[cyclohexyl]cyclohexyl]benzene, (2) 1-(trans-4'-substituted cyclohexyl)-4"-1' represented by the general formula (in the above formula, R and R' each represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms) ) Lance-4''- (Trans-4'''
A liquid crystal composition comprising at least one type of -substituted 7-chlorohexyl)7-chlorohexyl]benzene.