JPS62129251A - Trans-4-alkylcyclohexane-1-carboxylic acid ester - Google Patents

Abstract

NEW MATERIAL:A trans-4-alkylcyclohexane-1-carboxylic acid ester expressed by formula I [R1 is alkyl; X is H or halogen; R2 is formula II (R3 is H or methyl; m is 0 or 1), formula III (n is 1 or 2), -OR4 (R4 is alkyl in which at least one H is substituted by F) or cyano, provided that R2 is a group other than cyano when X is H]. EXAMPLE:A compound expressed by formula IV. USE:A compound useful for preparing liquid crystal compounds. PREPARATION:For example, a trans-4-alkylcyclohexane-1-carboxylic acid expressed by formula V is reacted with a halogenating agent in the presence or absence of a solvent to give a compound expressed by formula VI (Y is Cl or Br), which is then reacted with a phenolic derivative expressed by formula VII in a basic solvent to afford the aimed compound expressed by formula I.

Description

[Detailed description of the invention] Industrial applications The present invention relates to novel ester compounds.

More specifically, the present invention relates to natrans-4-alkylcyclohexane-1-carboxylic acid ester compounds useful in preparing liquid crystal mixtures.

BACKGROUND OF THE INVENTION Liquid crystal compounds, particularly nematic liquid crystals, are widely used as display elements by utilizing their electro-optical effects.

Many electro-optical effects of woodmatic liquid crystals are known up to now, but to enumerate the important ones from the viewpoint of application to liquid crystal 1 display elements, the first is based on the dielectric constant anisotropy of liquid crystals (phase transition (PhaseChange: PC) Effect, Guest-Host (Guest-I (ost: GH)
Effect, twisted nematic
tic: TN) effect, birefringence control (Electri
CallyControlled Birefring
ence: ECB) effect, and based on dielectric anisotropy and conduction variation (dynamic scattering).
There are effects such as scattering (DS).

Display elements that utilize these electro-optical effects are used in watches,
Widely used for calculators, electronic games, etc. - Ndbelt computer (HHCJ, etc.) portaple end Sung characters, came to be used for graphic display panels, and further for image display panels such as small TVs and viewfinders for video cameras Applications are also being considered, and demand is expected to increase rapidly.

For example, as a nematic liquid crystal, X (coo
()y (In the above formula, X is an alkyl group having 1 to 10 carbon atoms,
(Y represents a nitro group, a cyan group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group) The compounds shown are known. (East German Patent 105
701) Problems to be Solved by the Invention In order to use it as a liquid crystal display element, it must have a low melting point and a high clearing point, colorlessness, and stability against light, heat and chemicals, and low viscosity at low temperatures. It is necessary to have excellent sharp threshold values, etc., but at present no nematic liquid crystal has been found that satisfies these conditions alone, so two or more types of nematic liquid crystals are required. are used in combination.

The above-mentioned nematic liquid crystals are insufficient in these properties, especially the properties of low melting point (and high transparency), but it is desired to develop o-matic liquid crystals with a wider liquid crystal range.

Means for Solving the Problems The present invention aims to improve the drawbacks of the conventional nematic liquid crystal as described above (the present invention was achieved as a result of intensive research. That is, the present invention is based on the formula (1) In formula (J), R+ represents an alkyl group having 1 to 5 carbon atoms,
is a hydrogen atom or a halogen atom, R2 is 0 (CI-12
CH20)mCI-12CI=CHR3,0(CI-1
2) n@.

-0R4 or a cyan group, R3 is a hydrogen atom methyl group, R4 is an alkyl group having 2 to 5 carbon atoms in which at least one of the hydrogen atoms is substituted with a fluorine atom, m is 0 or l , n represents 1 or 2. (However, when X is a hydrogen atom, R2 represents the above-mentioned group other than a cyan group.) Trans-4-alkylcyclohexane-1 represented by
- providing a carboxylic acid ester compound.

The ester compound of the present invention is colorless.

The stability against light, heat and chemicals is good, some of the ester compounds are used to widen the liquid crystal temperature range, some to obtain low viscosity, and others to obtain sharp thresholds. It is a useful compound for

The ester compound of the general formula (1) of the present invention can be synthesized, for example, by the method described below.

Halogenating trans-4-alkylcyclohexane-1-carboxylic acid represented by the formula (IIl R1 C0OH (II) [In the formula l, R1 represents the same meaning as above] without a solvent or in the presence of a solvent. By reacting with the agent, the formula lNOR, (TOCOY (ur) [In the formula (III), Y represents a chlorine atom or a bromine atom, and R
1 represents the same meaning as above. ] Trans-4-alkylcyclohexane-1 represented by
-carboxylic acid halide, then formula ([V) [In formula (IV), R2 and X represent the same meanings as above. ]
It can be synthesized by reacting with a phenol derivative represented by in a basic solvent.

Examples of solvents used when synthesizing a compound of formula CE from a compound of formula (■) include organic solvents such as benzene, toluene, xylene, monochlorobenzene, and dichlorobenzene; Examples include thionyl chloride, phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphorus pentabromide, etc.The amount of halogenating agent used is 1 to 5 times the theoretical amount, or even if used in large excess as a solvent. Also, the reaction temperature is preferably 30 to 100°C.

Next, triethylamine, pyridine, dimethylformamide, etc. can be mentioned as basic solvents that can be used when reacting (fV) with formula (fV).

5. The ester compound of formula (D) of the present invention either exhibits liquid crystallinity itself or does not exhibit liquid crystallinity itself, but
It is a novel compound that can create a useful liquid crystal mixture by mixing it with a liquid crystal compound, and by mixing one or more of these compounds with other liquid crystal compounds, it can be used as a liquid crystal mixture in display elements.

Example The present invention will be explained in detail below with reference to Examples.

Example 1 8.5 g of trans-4-n-propylcyclohexane-1-carbone and 15 g of thionyl tetrahydride were added to 50 cc of toluene and reacted at 65 to 70°C for 1 hour. Then, excess thionyl chloride was added. After distillation, this reaction solution was mixed with p-allylphenol 8 g'a = pyridine containing 30 c
Add dropwise into the solution of c at 20°C or below.

After dropping, stir at 50-55°C for 1 hour, cool to room temperature,
Pour into ice water. Next, the target product was extracted with toluene, the toluene layer was washed twice with water, and then dried with sodium sulfate.
Toluene was distilled off. The residue was dissolved in chloroform and purified by column chromatography (developing solvent: chloroform) to obtain 7.5 g of the compound of the following formula.

The melting point and clearing point of this product are shown in Table 1 along with comparative examples.

Table 1. - 1*East German Patent No. 105701 Example 3 From Table 1, it is clear that the liquid crystal phase of the compound of the present invention is broader than that of the conventional known compound (Comparative Example-1).

Example 2゜9.9 gL of trans-r+ -4-pentylcyclohexane-1-carboxylic acid was added to 50 g of thionyl chloride 65
The reaction was allowed to proceed for 1 hour at ~70°C. After the reaction was completed, excess thionyl chloride was distilled off, 30 cc of toluene was added, and a solution of pyridine 3 containing 8 g of p-allylphenol was obtained.
It was dropped into 0 cc of MW at 20°C or lower. After completion of the dropwise addition, the compound 8.3 of the following formula is purified in the same manner as in Example 1.
g was obtained.

The melting point and clearing point of this product are shown in Table 2 along with comparative examples.

Table 2 * East German Patent No. 105701 Example 18 From Table 2, it is clear that the liquid crystal phase of the compound of the present invention is broader than that of the conventional known compound (Comparative Example-2).

Examples 3 to 13゜The melting point and clearing point of the ester compound represented by the formula [) synthesized in the same manner as in Examples 1 to 2 are shown in Table 3. Effect of the Invention Is the ester compound of the present invention itself liquid crystalline? It is a compound that exhibits liquid crystal properties or does not exhibit liquid crystal properties itself, but can be mixed with a liquid crystal compound to produce a useful liquid crystal mixture.

Claims (1)

[Claims] 1 Formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (I) [In formula (I), R_1 is an alkyl group having 1 to 5 carbon atoms, and X is a hydrogen atom or a halogen atom. , R_2 is -O(C
H_2CH_2O)_m-CH_2CH=CH-R_3
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -OR_4 or a cyano group, R_3 is a hydrogen atom or a methyl group, and R_4 is a carbon number of 2 to 5 in which at least one of the hydrogen atoms is replaced with a fluorine atom. an alkyl group, m is 0 or 1
, n represents 1 or 2. (However, when X is a hydrogen atom, R_2 represents the above-mentioned group other than a cyano group.)] trans-4-alkylcyclohexane-1-carboxylic acid ester compound