JPS58225042A - 3",4'''-dihalogenophenyl 4-(trans-4'-trans-4"-alkylcyclohexyl) cyclohexyl)benzoate - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R is H or 1-10C alkyl; X and Y are F or Cl). EXAMPLE:3''-Chloro-4'''-fluorophenyl 4-[trans-4'-( trans-4''-propylcyclohexyl )cyclohexyl] benzoate. USE:A component in liquid crystal compositions, having a small positive dielectric anisotropy, exhibiting the liquid crystal phase in a wide temperature range to high temperature, and stable to moisture, heat, etc. with a low viscosity. PROCESS:A bromobenzene expressed by formula II is reacted with metallic magnesium to form a compound expressed by formula III, which is then reacted with a compound expressed by formula IV to afford a compound expressed by formula V. The resultant compound expressed by formula V is then hydrogenated in the presence of Raney nickel to give a compound expressed by formula VI, which is halogenated with HIO3, etc., cyanogenated with Cu(CN)2 and finally hydrolyzed in a system of an aqueous solution of KOH and diethylene glycol to afford a benzoic acid derivative. The resulant benzoic acid derivative is then converted into an acid chloride with SOCl2, and the resultant acid chloride is then reacted with a compound expressed by formula VII to afford the aimed compound expressd by formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel low-viscosity liquid crystal compound that has small positive dielectric anisotropy and exhibits a liquid crystal phase over a wide temperature range up to high temperatures, and a liquid crystal composition containing the same.

Liquid crystal display elements utilize optical anisotropy and dielectric anisotropy, which are the characteristics of liquid crystal materials, and their display method uses T.
There are N type (twisted nematic type), D8 type (dynamic scattering type), guest-host type, DAP type, etc., and the properties required of the liquid crystal material used differ depending on each type.

However, in any case, the liquid crystal materials used in these materials exhibit a liquid crystal phase over a wide temperature range, and are also sensitive to moisture, heat, and
It must be stable to air and light. However, at present, there is no single compound that satisfies these conditions, and the current situation is to obtain something that can be put to practical use by mixing several types of liquid crystal compounds and non-liquid crystal compounds. Furthermore, depending on the type of display element, the dielectric anisotropy Δe may need to be positive, negative, or somewhere in between, but in general A liquid crystal mixture having an arbitrary value of Δ6 can be obtained by appropriately mixing a liquid crystal mixture with a positive value of Δε and one with a negative value of Δsensity. In addition, recently there has been a demand for the development of liquid crystal display elements that operate over a wide temperature range from low to high temperatures, and to meet these demands, compounds that exhibit a liquid crystal phase over a wide temperature range from low to high temperatures have been developed. ing.

The compound of the present invention has such characteristics and satisfies the above-mentioned demands to some extent.

That is, the present invention provides 4-[trans-4'- (Trans-4“
-Alkylcyclohexyl)cyclohexyl]benzoic acid-3111,4#/-dihalogenophenyl ester and a liquid crystal composition containing the same.

This compound exhibits a liquid crystalline phase over a wide temperature range up to high temperatures, and its hemi(6) is as small as +1.0, and its viscosity is 60°C at 20°C.
Cp, and by adding a small amount of it as a component to a liquid crystal mixture, it exhibits a nematic phase up to high temperatures, and the viscosity does not increase significantly. It also has good stability against moisture, heat, light, etc.

Next, a method for producing the compound of the present invention will be described. First, 2
．．・Phenyl from bromobenzene and metallic magnesium
□ Manufacture magnesium bromide and convert it into 4=(
Reaction with trans-4'-alkylcyclohexyl)cyclohexanone yields 4'-()trans-4#-alkylcyclohexyl)cyclohequitin-1-ol-benzene (1). Next, this was dehydrated using potassium hydrogen sulfate as a catalyst to obtain 4'-()lans-4"-alkylenechlorohexyl)cyclohexen-1'-yl-benzene (rin).
This is then hydrogenated using a Raney nickel catalyst to obtain trans-4'-()trans-4"-alkylcyclohexyl)cyclohexylbenzene+Ill. This is obtained by directly hydrogenating +11 using Raney nickel. can also be obtained.Next, by halogenating compound (■) with iodic acid or periodic acid, etc.
-(trans-4"-alkylcyclohexyl)k a
By cyanating this with cupric cyanide, we obtain 4-[trans-4'-()
lance-4"-alkylcyclohexyl[cyclohexyl]benzonitrile+ff) is obtained. Next, this compound 111 is hydrolyzed in an aqueous potassium hydroxide solution diethylene glycol system to obtain 4-()lance-4'-(trans-4 “-alkylcyclohexyl)cyclohexyl”
Manufacture benzoic acid. This benzoic acid derivative was converted into an acid chloride with thionyl chloride, and then reacted in 3,4-dihalogenophenol pyridine to form the desired 4-()trans-4'-(trans-4''-alkylcyclohexyl).
Cyclohexyl]benzoic acid-3#F,4///-dihalogenophenyl ester (1) is obtained. The above is represented by a chemical formula: (ff) (v) U (1) (In the above formula, R%X and Y are the same as above) The present invention will be explained in more detail with reference to Examples below.

Example 1 (4-() lance-4'-() lance-4-propylcyclohexyl)cyclohexyl]benzoic acid-3''-c
rColo-”-fluorophenyl turned magnesium3.
6 f (0,148 mol) into the third flask,
A solution of 23.2f (0,148 mol) of bromobenzene dissolved in tetrahydrofuran (50-) was slowly added dropwise while stirring in a N2 stream while keeping the reaction temperature at 30-35°C, and the reaction continued for 3 hours. The magnesium dissolves and becomes homogeneous, producing phenylmagnesium bromide.

To this, 26,2 t (0,118 mol) of 4-(trans-4'-propylcyclohexyl)cyclohexanone was dissolved in tetrahydrofuran to form 5O-1, and the reaction temperature was kept below 10°C. Drips quickly. After the dropwise addition, the temperature was raised to 35°C, stirred for 30 minutes, and then 3N hydrochloric acid (100°C) was added. The reaction solution was transferred to a separatory funnel and extracted three times with 100% of n-heptane.The combined n-hebutane group was washed with water until the washings became neutral, and then the n-heptane was distilled off under reduced pressure. leave The remaining oil was (4'-()lance-4"-furobylv-lylohexyl)cyclohexane-1'-ol]benzene, and 19f of potassium hydrogen sulfate was added to it, and the mixture was heated at 170°C in a N2 stream.
Dehydrate for 2 hours. After cooling, 200-h of n-hebutane is added, potassium hydrogen sulfate is separated from P, and the n-hebutane layer is washed with water in a separating funnel until the washing liquid becomes neutral. Then n-
Hebutane is distilled off under reduced pressure, and the remaining oil is recrystallized from n-hebutane and acetone to obtain (4-()lance-4).
“-propylcyclohexyl)cyclohexene-1'
-i/l/) benzene. This 7.52 was dissolved in 500 ml of ethanol, 3.2 f of Raney nickel catalyst was added, and catalytic reduction was carried out at 50° C. and atmospheric pressure by passing hydrogen through the solution. To raw materials
Both the reactant and the product were monitored by gas chromatography, and the reduction reaction was terminated when the starting material disappeared, that is, after 8 hours. The amount of hydrogen absorbed at this time was 800-.

After removing the catalyst, the solvent was distilled off under reduced pressure, and the remaining crystals were recrystallized from ethanol to form [trans-4'-()trans-
4#-propylcyclohexyl)cyclohexyl]benzene was obtained. Dissolve this 1.4 f in 50 f of acetic acid, 0.9 f of pure water, 1.0 f of concentrated sulfuric acid, and 0.20 f of iodic acid.
A mixture of 0.50 t% iodine and 0.4 t% carbon tetrachloride was refluxed at 80° C. for 5 hours. The reaction solution was cooled, the precipitated crystals were separated from P, and the crystals were recrystallized from n-hebutane to give 4-[trans-4'-(trans-4''-propylcyclohexyl)cyclohexyl] Iodobenzene (V).This substance exhibits a liquid crystal state and is C-8m
Point is 119.0℃, 8m -N point is 139.2℃, N-
Point I was 189.2°C. This 1.2f is N, N-
The mixture was dissolved in 50 g of dimethylformamide, 0.63 t of cupric cyanide was added, and the mixture was reacted at 130° C. for 4 hours. Add 100% of n-heptane, transfer to a separatory funnel, separate the liquid with 30% ammonia water, then wash with water, wash with 6N hydrochloric acid, and wash with water until the washing liquid becomes neutral. The solvent was distilled off under reduced pressure and the product obtained by recrystallizing with n-/<butane was 4-
It is [trans-4'-(trans-4"-propylcyclohexyl)cyclohexyl]benzonitrile. The yield is 0.4 fs. The yield is 45% for the cyanation reaction, and its C-8m point is 73%. 1°C, the Sm-N point was 81.1°C, and the N-I point was 242.5°C.

5f of 4-[trans-4'-(trans-4"-brobylcyclohexyl)cyclohexyl]benzonitrile obtained as above was added to 10t of potassium hydroxide 5f.
Diethylene glycol 10 along with the solution of d in water.
0- and heated in a flask at 200°C for 7 hours. After the reaction, cool to room temperature and add 6NH (J50ml and water 10ml).
Add o-. Filter the precipitated crystals and wash thoroughly with water.

4-[trans-4'-(trans-4"-brobylcyclohekynyl]cyclohexyl) thus obtained
Heat benzoic acid (11l f) to 80°C with pyridine 0.1- and thionyl chloride 10-. The reaction mixture becomes homogeneous in 2 hours and the reaction is continued for an additional 1.5 hours. Excess thionyl chloride is removed under reduced pressure. The remaining oily substance is acid chloride.On the other hand, 3-chloro4-fluorophenol 1
After the acid chloride was added to a solution of f in pyridine, 100 ml of toluene was added, and the mixture was allowed to stand overnight.

Wash the toluene layer in a separatory funnel with 6N hydrochloric acid, then with 2N caustic soda solution, and finally with water until neutral. After drying it over anhydrous sodium sulfate, the toluene layer was distilled off under reduced pressure. The precipitated crystals are recrystallized with ethanol and then with acetone to obtain the desired 4-[trans-4'
-()lance-4#-propyrunchlorohexyl)cyclohexynyl]benzoic acid-3''-chloro-4#-fluorophenyl ester was obtained.

Yield o, 7t, yield 50%, its C-N point 124.
'i' ~ 125.6°C (unstable type 116.0 ~ 116.
9°C), and the N-I point was 242.3°C.

Example 2 In the same manner as in Example 1, 3,4-dichlorophenol was used in place of 3-chloro-4-fluorophenol to prepare 4-()trans-4/-[trans-4''-pro cyclohexylbenzoic acid-3
1.4111-dichlorophenyl ester was obtained. Yield o, s r , yield 56 chi. Its C-N is 126.
3-l 27,11:, N-I point was 287.8°C.

Example 3 (Usage example) Trans-4-propyl-(4'-cyanophenyl)cyclohexane 28% trans-4-pentyl-(4'-cyanophenyl)cyclohexane 42thitrans-4-hebutyl-(4' -cyanophenyl)V
The NI point of a liquid crystal composition having a composition of 30% chlorhexane is 53°C.

When this liquid crystal composition was sealed in a TN cell (twisted nematic cell) with a cell thickness of 10 μm, the operating threshold voltage was 1,
53 V, and the saturation voltage was 2.12 V. The viscosity was 23 cp at 20°C.

97 parts of this liquid crystal composition was added to 4-[trans-4'-()lance-4"-propyrunchlorohexyl)cyclohexyl]benzoic acid-3"'-chloro 4N produced in Example 1.
-N-I with 3 parts of fluorophenyl ester added
The point was 56° C., the threshold voltage was 1.5.5 V, and the saturation voltage was 2.14 V. Also, the viscosity is 2 at 20'C.
It was 5 cp.

Claims (2)

[Claims] (1) 4-[trans-4'-()trans- 4“
-Alkylclohexylbenzoic acid-3//l, 4/#-dihalogenophenyl ester. (2) 4-[trans-4'-()trans- 4“
A liquid crystal composition comprising at least one component of -alkylcyclohexynylbenzoic acid-3#, 4#Z-dihalogenophenyl ester.