JPS59230084A - Liquid crystal compound - Google Patents

Abstract

NEW MATERIAL:A phenanthrene derivative shown by the formula I or formula II(R is H, or alkyl; A is alkyl, aliphatic acyl, p-alkoxybenzoyl). EXAMPLE:2-Phenanthryl-p-octyloxybenzoate. USE:A liquid crystal display element. PREPARATION:For example, phenanthrene is sulfonated, treated with barium chloride into a barium sulfonate, which is subjected to alkali fusion with KOH to give 2-hydroxyphenanthrene. This compound is reacted with a p-alkoxybenzoyl chloride, to give a 2-phenanthryl-p-alkoxybenzoate shown by the formula I (with the proviso that R is H; A is p-alkoxybenzoyl).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to liquid crystalline compounds, specifically phenanthrene derivatives.

In recent years, liquid crystal display elements have come to be used in many fields, and the required characteristics have also expanded to a wide variety. For example, a liquid crystal display element used at high temperatures must not only exhibit nematic liquid crystal at that temperature, but also be stable against heat, air, and the like. Furthermore, it is desirable for liquid crystal display elements used in calculators, digital watches, etc. to exhibit nematic liquid crystal over a wide temperature range around room temperature.

The present inventors have conducted various studies in order to meet such demands. As a result, the following general formula (I) or tn) (wherein R is hydrogen or an alkyl group, and A is an alkyl group, an aliphatic acyl group, or a p- The present invention was achieved by synthesizing novel phenanthrene derivatives represented by (representing an alkoxybenzoyl group) and discovering that these compounds have excellent liquid crystal performance.

The compound of the present invention represented by the general formula +1) or (It) exhibits excellent liquid crystal performance due to the introduction of a highly polar oxygen atom at the 2-position in addition to the elongated tabular structure ζ'''- of the phenanthrene skeleton. Also, because it has a phenanthrene skeleton, it has extremely high chemical stability.

In the liquid crystal compound represented by general formula (1) or (loss), R is preferably hydrogen or an alkyl group having 1 to 40 carbon atoms, and the alkyl group is preferably a linear or less branched alkyl group. A is a carbon number 1 to 20 alkyl groups, aliphatic acyl groups, or p-alkoxybenzoyl groups in which the alkoxy group has 1 to zO carbon atoms, and the alkyl group, aliphatic acyl group, or alkoxy group is linear or branched. It is preferable that there is a small amount of

The liquid crystalline compound represented by the general formula (1) can be produced, for example, by the following route when phenanthrene is used as a raw material.

That is, after sulfonating phenanthrene, it is made into a baricum sulfonate salt with barium chloride, which is then alkali-melted with potassium hydroxide, and then hydrolyzed with hydrochloric acid to give 2-hydroxyphenanthrene. 2-Hydroxyphenanthrene and p-alkoxybenzoyl chloride are reacted to obtain 2-phenanthryl-p-alkoxybenzoate.

Furthermore, 2-acyloxyphenanthrene is obtained by reacting 2-hydroquinphenanthrene with an aliphatic acid chloride. Alternatively, 2-alkoxyphenanthrene can be obtained by reacting 2-hydroxyphenanthrene and alkyl bromide in the presence of an alkali.

The liquid crystalline compound represented by the general formula (II) can be produced by the following route, for example, when phenanthrene is used as a raw material. .

That is, phenanthrene was added to Cu in syflonhexane.
-Hydrogenation in the presence of a CrO catalyst to give 9,10-dihydrophenanthrene, which was nitrated with fuming nitric acid in wood acetic acid and then reduced with hydrazine hydrate in the presence of a Pd(C) catalyst in ethanol. -Amino9.10-dihydrophenanthrene. The obtained 2-amino-9,10-
Dihydrophenanthrene is diazotized by reacting with sodium nitrite and then hydrolyzed to form 2-hydroxy-9,1
0-dihydrophenanthrene, which was reacted with an aliphatic acid chloride in the presence of Kl (J3 catalyst) in carbon disulfide to give 2-aziluf-hydroxy-9,10-dihydrophenanthrene, which was then reacted in diethylene glycol in the presence of KOH. Reduction with hydrazine hydrate gives 2-alkyl-7-hydroxy-9,10-dihydrophenanthrene.2-alkyl-7-hydroxy9,10
-dihydrophenanthrene is reacted with alkyl bromide in the presence of an alkali to produce 2-alkyl-7-alkoxy-9,10-dichodrophenanthrene, and
If aliphatic acid chloride is reacted, 2-alkyl-7-
Acyloxy-9,IO-dihydrophenanthrene is obtained.

The liquid crystalline compound of the present invention produced by the above synthetic route can be used alone or in a mixture of two or more for liquid crystal display devices if it exhibits properties as a nematic liquid crystal. Liquid crystalline compounds can also be used for various purposes.

Compounds exhibiting nematic liquid crystal that can be used in combination with the liquid crystal compound of the present invention include various conventionally known liquid crystal compounds, such as azomethine compounds, other ester compounds or their oxycarboxylic acid derivatives, biphenyl derivatives, Examples include phenyl derivatives, stilbene compounds, azooxy compounds, and azo compounds.

By mixing these, the nematic liquid crystal temperature range is lowered.

When using the liquid crystalline compound of the present invention for display purposes, an electro-optical display element is filled with nematic liquid crystal and a voltage is applied. Other additives can be added.

Examples of the present invention will be shown below.

Example 1 Using 2-hydroxyphenanthrene obtained by the above method C2, 2-phenanthryl-p-alkoxybenzoate was synthesized.

2-Hydroxyphenanthrene log (0,00
52mo)) and dissolve in acetone 60mj+.

Next, 0.26 g of NaOH was ground with a milk pestle (
0,0066 mob ) and heated under stirring under reflux for 8 hours to obtain a sodium salt. To this was added 2 g of p-octyloxybenzoic acid chloride, (0,00
A solution of 72 moj) dissolved in 5 mj+f of acetone was added dropwise, and after the dropwise addition was completed, the mixture was heated under stirring and refluxed for 8 hours. Then stop the reaction and leave it for a while. After being left to stand, it is immersed in water at about 113°C to precipitate the final product. Filter this,
After drying, unreacted 2-hydroxyphenanthrene and octyloxybenzoic acid are separated by heating under reflux with ethanol and filtering under heat. Thereafter, the composition was recrystallized with benzene, and since compounds with a large number of carbon atoms have low solubility in benzene and other solvents, the composition was refluxed with ethanol and filtered with heat, which were repeated until the melting point became constant.

Yield: 631 cm.

The obtained 2-phenanthryl-p-octyloxybenzoate was a colorless crystal, and its structure and purity were confirmed by melting point measurement, infrared absorption spectrum analysis, etc. Furthermore, the liquid crystallinity was determined using a polarizing microscope with a heating plate and thermal analysis.

In addition, compounds in which the number of carbon atoms in the alkoxy group of the p-alkoxybenzoyl group differed were synthesized in the same manner. The properties of these compounds were as shown in Table 1.

Table 1 Ne: Temperature at which the transition to the nematic liquid crystal phase occurs (temperature at which the transition occurs to the diisotropic liquid phase): Monotropic phase Example 2 2-Alkyl-7-hydroxy- obtained by the method described above
Using 9,1O-dihydrophenanthrene as a raw material? -alkyl-7-alkoxy-9110-dihydrophenanthrene and 2-alkyl-7-acyloxy-9,10
-Dihydrophenanthrene was synthesized.

2-hexyl-7-hydroxy-9,10-dihydrophenanthrene 1.0g, hexyl bromide 1.28g
and potassium carbonate were dissolved in cyclohexanone solvent, and the reaction was carried out in one step under heating and reflux conditions.

Obtained 2-hexyl-7-hexyloxy-9゜10
-Dihydrophenanthrene was purified in the same manner as in Example 1. Colorless crystals, yield 51 cm.

In addition, 10 g of 2-hexyl-7-hydroxy-9,1°-dihydrophenanthrene was added in the same manner as in Example 1.
After making sodium salt with OH, c8H,,C0CA
A reaction was carried out with 1.16 g of the product in an acetone solvent under heating and reflux conditions.

The obtained 2-alkyl-7-acyloxy-9°IO-dihydrophenanthrene was purified in the same manner as in Example 1. Colorless crystals, yield 80.
3 chi.

The structure and purity of each product were confirmed in the same manner as in Example 1, and the liquid crystallinity was determined in the same manner.

Similarly (2-alkyl-7- with a different number of carbon atoms)
Alkoxy-9,10-dihydrophenanthrene and 2-alkyl-7-acyloxy-9°lO-dihydronoenanthrene were synthesized.

The properties of these compounds were as shown in Tables 2 and 8.

Table 2 Table 8 Patent applicant Yoshio Nagai

Claims (1)

[Claims] A liquid crystalline compound represented by the general formula +1) or (II). (In the formula, R represents hydrogen or an alkyl group, and A represents an alkyl group, an aliphatic acyl group, or a p-alkoxybenzoyl group).