JPS59161334A - Cyclohexanecarboxylic acid ester - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (n is 0 or 1; R is 1-15C alkyl or alkoxy; formula II and formula III are benzene ring, cyclohexane ring; * shows an asymmetric carbon atom). EXAMPLE:S-(+)-4-(2-Methylbutylphenyl)cyclohexanecarboxylic acid 4-propylphenyl ester. USE:A component of liquid crystal compositions. It has a spiral structure. Some of them show cholesteric-smectic liquid crystal with low viscosity. The addition of a small amount of the compound enable the production of liquid crystal compositions for a low-viscosity cholesteric-nematic phase transfer display elements or white-tailor type display elements. PREPARATION:The compound of formula IV is reduced with sodium metal in sioamyl alcohol to give a compound of formula V. Then, the product is converted into an acid chloride of formula VI with SOCl2. Then, a compound of formula VII is made to act on the chloride of formula VI in pyridiene to give the compound of formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optically active compound having a rotary molecular structure and a liquid crystal compound containing the same.

Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy that are the characteristics of liquid crystal materials, and there are various display methods, but the one currently in practical use is the twisted nematic phase (TN). type), dynamic scattering type (DS type), etc. Recently, other types of liquid crystal display methods have been actively developed, and representative examples include cholesteric nematic phase change display and white tiller color display. All of the liquid crystal compositions used in these display elements are modified by adding an optically active substance or the like to nematic liquid crystal so as to have cholesteric helical pitches suitable for each composition. It is desired that the molecules of the optically active substance to be added have a twisted shape, are short in shape, and are stable against heat, light, air, and water.

The present invention provides a compound having novel optical activity and a twisted molecular structure that is useful for two or more applications, and a composition thereof.

That is, the compound J of the present invention has the general formula % (in the above formula, n is 0 or 1, R represents an alkyl group or an alkoxy group having 1 to 15 carbon atoms, and ■ and ■ are respectively a benzene ring or These are esters of S-(t)-4-(2-methylbutylphenyl)cyclohexanecarboxylic acid represented by the formula (represents a cyclobegisan ring, and * represents an asymmetric carbon atom).

The compounds of the present invention have a helical molecular structure, some exhibit cholesteric smectic liquid crystals, and also have low viscosity, and by adding a small amount of this to nematic liquid crystals, a low viscosity cholesteric nematic phase transition type display element can be created. A liquid crystal composition for display devices or White-Taylor type display elements can be obtained. The helical group pinch of this compound itself, obtained from the helical pitch value obtained by adding 10% of this compound to a nematic liquid crystal and measuring it, is about 2 μm. Furthermore, when this compound is added to a nematic liquid crystal composition for a TN type display element, it is possible to reduce the occurrence of dotted lines (so-called reverse domains) on the display surface and improve its performance.

Next, the method for producing the compound according to the present invention will be described.
First, S-(+)-4-(2-methylbutyl)biphenylyl-4'-carboxylic acid was dissolved in amyl alcohol solvent.
S-(t)-4-(2) is reduced by the action of metallic sodium.
-methylbutylphenyl)cyclohexanecarbonrR
Tor-j-ru. This is reacted with thionyl chloride to form an acid chloride, which is then reacted with the corresponding phenol or cyclohexanol in the presence of pyridine. The above is expressed as a chemical formula as follows.

C) 13' 0 Product 30 CH30 CH30 (In the above formula, n, R+■, and ■ are the same as those described above.) The compounds and liquid crystal compositions of the present invention will be explained in more detail with reference to Examples below.

In the example, the crystal phase is C and the cholesteric phase is Ch.

*Structure of transparent phase (■), optically active smectinic phase (Sm) and cyclohexanecarboxylic acid 4-chloropylphenyl ester R'' C34L7] (Its -(+)-4-(2-methylbutylphenyl)cyclohexanecarboxylic acid) Production of S-(t)-4-(2-methylbutyl)biphenyl-4
'-carvone &31i', inamyl alcohol 15
Keyaki stirred with 00πe and heated to 90°C 5 then metallic sodium 10! i'i also asked for a violent reaction. Refluxing was continued as it was, and after 3 hours, an additional 1,001 liters of metallic sodium was added.

The reaction solution gradually became homogeneous. After the reaction is complete, let it cool for 10 minutes.
It was kept at 0°C. Isoamyl alcohol was distilled off while adding water little by little. Next, 1.54 g of water and 14 g of 6N hydrochloric acid were added to make it completely acidic, and the precipitate was concentrated, washed thoroughly with water, completely dried, and used as it was for the next reaction.

(1) Put 2.7 f of S-(+)-4-(2-methylbutylphenyl)cyclohexanecarboxylic acid obtained in re-esterification (1) into a flask with 10 yxt of thionyl chloride and heat at 60 to 70°.
When refluxed with C, the mixture became homogeneous in about 2 hours, and after further heating for 1 hour, excess thionyl chloride was distilled off under reduced pressure, leaving the acid chloride as an oil. In another flask, 1.4 g of 4-propylphenol was dissolved in 10 πt of pyridine, and the entire amount of the acid chloride was added thereto, and the mixture was stirred and reacted at room temperature.

50 ml of toluene was added to the solution, mixed well, left overnight, washed with a 2N aqueous sodium hydroxide solution, and then washed with water until neutral. After drying Sono'L over anhydrous sodium, toluene was distilled off under reduced pressure, and the remaining crystals were diluted with ethanol.
After recrystallization, 1.2 g of the desired S-(t)-4-(2-methylbutylphenyl)cyclohexanecarbonyl-4-propylphenyl ester was obtained. (Yield 32%
) The c-ch point of this is 98.7-99.3°C, C
h-I point], 05. It was OoC.

Examples 2 to 6 The desired compounds were produced by carrying out all operations according to Example 1, except that the corresponding phenol or cyclohexanol was used in place of 4-propylphenol in Example 1. The results are shown in Table 1 together with the results of Example 1.
I showed this.

Example 7 (Application example) 90 parts by weight of a liquid crystal composition called GR-68 (Chisso (commercially available nematic liquid crystal)) and a cell of the present invention having a cell thickness of 10.5 μη2 which had been vertically aligned with octadecyl-triethoxysilane were added. The operating threshold voltage of a cholesteric-nematic phase change display element sealed with a liquid crystal composition consisting of 10 parts of S-(t)-4-(2-methylbutylphenyl)cyclohexanecarboxylic acid R47-rohilphenyl ester is 10 g. .OV.

that's all

Claims (2)

[Claims] (1) General formula % Formula % (In the above formula, n is O or 1, R represents an alkyl group or an alkoxy group having 1 to 15 carbon atoms, and ■ and ■ represent a benzene ring or a cyclohexane ring, respectively. esters of S-(t)-4-(2-methylbutylphenyl)cyclohexanecarboxylic acid represented by: (2) General formula % Formula % (In the above formula, n is O or l υ, R represents an alkyl group or alkoxy group having 1 to 15 carbon atoms, and ■ and ■ each represent a benzene ring or a cyclohexane ring. * indicates an asymmetric carbon atom) A liquid crystal composition comprising at least one component of S-(t)-4-(2-methylbutylphenyl)cyclohexanecarboxylic acid noesters.