JPH0653708B2 - Phenanthrene carboxylic acid ester compound - Google Patents

Description

TECHNICAL FIELD The present invention relates to the provision of a liquid crystal compound or a novel compound that can be used as a liquid crystal composition, and as such or as a blend with another liquid crystal compound. Then, it can be used for producing a liquid crystal display device by improving its performance.

(Prior Art) Most liquid crystal compounds used in liquid crystal display devices are liquid crystals having a nematic phase. However, in terms of electro-optical response speed, it is far inferior to that of the light-emitting display element, and improvement is attempted. In recent years, a ferroelectric liquid crystal compound is one of the liquid crystal compounds that has been attracting attention due to its high response speed. The first ferroelectric liquid crystal compound developed was dodecylbenzylidene-p-amino-.
It is 2-methylbutyl cinnamate and was synthesized in 1975. Although this compound has a chiral smectic C phase, it has a high transition temperature and therefore cannot be used in a wide temperature range including room temperature. In addition, since it contains a Schiff base, it lacks chemical stability. Have problems such as. After that, many compounds have been synthesized and their properties have been investigated, but theoretics have not been successful, and a liquid crystal compound having a chiral smectic C phase in a wide temperature range including room temperature has not yet been known.

The general method adopted in the field of nematic liquid crystals for lowering the transition temperature of the liquid crystal phase or expanding the temperature range,
There is a method of mixing several liquid crystal compounds.

Similar methods have been studied in the field of ferroelectric liquid crystals and are in the trial and error state. What kind of skeleton should be selected, what kind of substituent should be introduced to improve the compatibility with other liquid crystal compounds, and what kind of liquid crystal phase should be taken to affect the phase transition temperature. It's no exaggeration to say that you can't expect at all unless you test each compound.

A liquid crystal compound having a skeleton similar to that of the compound according to the present invention has been studied, and for example, Chemistry and Industr
y, 3 Aug.1974 p. 615, we synthesized compounds in which an acyl group with various carbon chain lengths was introduced into one of the phenanthrene skeletons and an alkyl group with various carbon chain lengths was introduced into the other,
There are only reports that they have investigated their thermal properties.

(Problems to be Solved) The present invention seeks for a novel liquid crystal compound having a phenanthrene skeleton.

(Means for Solving the Problem) In the present invention, a target compound was synthesized according to the method described below, without providing a novel ferroelectric chiral smectic liquid crystal having a phenanthrene skeleton.

First, the skeleton 7-hydroxy-2-carboxy-9,10-dihydrophenanthrene of the object compound of the present invention is 9,1.
It is prepared from 0-dihydrophenanthrene according to a known method (JP-A-57-146737). The thus-obtained 7-hydroxy-2-carboxy-9,10-dihydrophenanthrene is RX (R has 4 to 1 carbon atoms).
2 shows a straight chain alkyl group. The same applies hereinafter to an alkyl halide or alkyl sulfonic acid ester represented by the formula (1) in a solvent, and converted to 7-aruxy-2-carboxy-9,10-dihydrophenanthrene. Here, as the alkyl halide represented by RX, butyl halide, pentyl halide, hexyl halide, heptyl halide, octyl halide, nonyl halide, decanyl halide, undecanyl halide,
Such as dodecanyl halide, chloride, bromide, iodide is used for the halide. When used in the form of an alkyl sulfonate, the above-mentioned alkyl p-toluene sulfonate, benzene sulfonate, methane sulfonate, etc. are used.

The reaction is carried out a) using water or alcohol-water as a solvent and using an alkali hydroxide such as potassium hydroxide or sodium hydroxide, or b) dimethylformamide, alcohol, dimethylsulfoxide, diglyme, tetrahydrofuran, toluene. Alkali metals such as sodium and potassium, using xylene, acetone, etc. as solvents,
Alternatively, a salt of potassium carbonate, sodium carbonate or the like is used to alkylate the hydroxyl group at the 7-position, at the same time alkylate the carboxyl group at the 2-position, and then hydrolyze the alkyl ester at the 2-position. Thus, 7-alkoxy-2-carboxy-9,10-dihydrophenanthrene is obtained.

Then, 7-alkoxy-2-carboxy-9,10-
Dihydrophenanthrene is as it is or an acid halide (made from thionyl chloride, phosphorus tribromide, etc.),
Optically active alcohols (R ^* OH) that have asymmetric carbon atoms in their molecular chains are made into reactive derivatives such as active esters.
[R ^* is Asymmetric carbon atom Represents an alkyl group having n (n is an integer of 0 to 6). The same shall apply hereinafter)) to esterify. Here, as the optically active alcohol having an asymmetric carbon atom in the molecular chain, 1-methylpropyl alcohol,
2-methylbutyl alcohol, 3-methylpentyl alcohol, 4-methylhexyl alcohol, 5-methylheptyl alcohol, 6-methyloctyl alcohol, 7
Examples include optically active forms such as methylnonyl alcohol.

When the 2-position carboxyl group of 7-alkoxy-2-carboxy-9,10-dihydrophenanthrene is allowed to react, dimethylformamide, ethyl acetate, n
The reaction may be carried out by heating in a solvent such as hexane, benzene, toluene, dimethylsulfoxide, pyridine, or in the presence of a condensing agent such as dicyclohexylcarbodiimide, phosphorus oxychloride, thionyl chloride. When using an acid halide, triethylamine,
It is advisable to coexist with a tertiary amine such as pyridine or dimethylaniline.

Thus, the formula (I) (Wherein R and R ^* are the same as above), the compound of the present invention can be obtained. A compound of the formula (I) in which R and R ^* are interchanged can be easily prepared, and in such a case, the compound is 7-hydroxy-2-carboxy-9,10-dihydrophenanthene. First, an optically active alcohol having an asymmetric carbon atom in the molecular chain, as exemplified above, is introduced into a halide or sulfonic acid ester to react with len, and then reacted, and then a linear alkyl alcohol exemplified above as an alkyl halide. It is made by reacting.

(Effect of the present invention) Since the compound of the present invention is an optically active alkyl ester in a carboxyl group, it was expected to take a chiral smectic C phase as an intermediate phase. It shall take mesophase to a temperature considerably lower, including room temperature but was not (seen as S _a phase), such as those that have the effect of widening the range of transition temperatures of the other liquid crystal temperature side was obtained.

The present invention will be described in more detail with reference to the following examples.

Example 1 (1) Synthesis of 9,10-dihydro-7-n-octyloxyphenanthrene-2-carboxylic acid: 0.66 g of 50% sodium hydroxide, 30 ml of dry dimethylformamide, 9,10-dihydro-7. -Hydroxyphenanthrene-2-carboxylic acid 3 g at 80 ° C
Mix and stir for minutes. Then, octyl silate 7.8
g dissolved in 15 ml of dimethylformamide and added,
The mixture was stirred at 0 ° C for 8 hours. The reaction mixture was poured into ice water, acidified with hydrochloric acid and then extracted with ethyl acetate. The extract was washed with water, dried and concentrated to give 7 g of an oily substance. This was mixed with 49 g of an aqueous sodium hydroxide solution (8 ml) and methanol (250 ml) and refluxed for 4 hours. After completion of the reaction, the solvent was distilled off, the mixture was acidified with hydrochloric acid and extracted with chloroform to obtain the title compound from the chloroform layer. Obtained amount 0.88 g IRν _max cm ⁻¹ : 3600 to 3200 (—OH) 169
0 (C = 0) (2) (S) -2-Methylbutyl-9,10-dihydro-7-octyloxyphenanthrene-2-carboxylate synthesis: 0.88 g of the oil obtained in (1), 0.22 g of 2- (S) -methylbutyl alcohol, 0.57 g of dicyclohexylcarbodiimide, 15 m of 4-dimethylaminopyridine
g and 25 ml of ethyl acetate were mixed and stirred at room temperature for 9 hours.
The reaction mixture was poured into ice water, acidified with hydrochloric acid, and extracted with ethyl. The ethyl acetate layer was washed with water and dried, and then the solvent was distilled off. Silica gel column chromatography (3 cmφ x 4)
Purification with 0 cm, developing solvent: chloroform) gave the title compound. Yield 0.4 g IRv _max cm ^-1 : 1720, 1610, 1280, 12
_{^{40,1115,775 1 H-NMR (CDCl 3}} ) δ (ppm): 0.6~2.10 (m, 24H) 2.85 (s, 4H) 3.95 (t, 2H) 4.10 ( d, 2H) 6.0-8.0 (m, 6H) This showed the following phase transition temperatures.

Maintaining the S _A phase at -20 ° C., it was not -70 ° C. even crystallization.

Example 2 (1) Synthesis of 9,10-dihydrolo-7-n-undecyloxyphenanthrene-2-carboxylic acid: 50% sodium hydride 0.06 g, dry dimethylformamide 3 ml, 9,10-dihydro. 0.28 g of -7-hydroxyphenanthrene-2-carboxylic acid was added at 80 ° C.
The mixture was stirred for 1 hour. Then, 0.84 of n-undecyl tosylate was dissolved in 2 ml of dimethylformamide and added, and the mixture was stirred at 80 ° C. for 8 hours. The reaction mixture was poured into ice water and extracted with ethyl acetate. After washing with water, drying, and concentration, 0.7 g of an oily substance was obtained. This was refluxed with 49 g of sodium hydroxide aqueous solution 0.8 ml and methanol 25 ml for 3 hours. After cooling, the mixture was acidified with hydrochloric acid and extracted with chloroform.
The chloroform layer was washed with water, dried and concentrated to give the title compound.
Yield 0.73 g IRv _max cm ^-1 : 3450 to 2350, 1680, 16
10, 1470, 1430, 1300, 1280, 12
40 ¹ H-NMR (D ₆ -DMSO) δ (ppm): 0.6 to 2.10 (m, 21H) 2.88 (s, 4H) 4.00 (t, 2H) 6.6 to 8. 35 (m, 6H) (2) (S) -4-Methylhexyl-9,10-7-undecynyloxyphenanthrene-2-carboxylate synthesis: 20 ml of ethyl acetate, compound 1 obtained in (1) .88g,
0.6 g of 4- (S) -methylhexanol, 1.08 g of dicyclohexylcarbodiimide and 60 mg of 4-dimethylaminopyridine were mixed and stirred at room temperature for 15 hours. The title compound was obtained by the same procedure as in Example 1 (2). Gain 1.
3g IRν _max cm ^-1 : 1720, 1470, 1285, 11
90, 1115, 775 ¹ H-NMR (CDCl ₃ ) δ (ppm): 0.6 to 2.10 (m, 34H) 2.85 (s, 4H) 3.95 (t, 2H) 4.28 ( t, 2H) 6.60 to 8.10 (m, 6H) The obtained compound showed the following phase transition temperatures.

This compound has a stable _SA phase under supercooling, and when blended with other liquid crystal compounds, it has the effect of expanding the phase transition temperature to the low temperature side.

Example 3 (2) -2-Methylbutyl-9,10-dihydro-7-
Synthesis of n-undecyloxyphenanthrene-2-carboxylate: 9,10-dihydro-7-n-undecyloxyphenanthrene-2-carboxylic acid 1 g obtained in Example 2 (1),
0.25 g of 2- (S) -methylbutyl alcohol, 10 ml of ethyl acetate, dicyclohexylcarbodiimide.
58 g, 4-dimethylaminopyridine 34 mg at room temperature 1
The mixture was stirred for 5 hours. The reaction mixture was treated similarly to that in Example 2 (2) to give the title compound. Yield of ^{_{0.45g IRν max cm -1: 1710,1603,1280,}} 1240,1190,1110, 775 1 H-NMR (CDCl 3) δ (ppm): 0.6~2.10 (m, 30H) 2 .87 (s, 4H) 3.98 (t, 2H) 4.17 (d, 2H) 6.6 to 8.10 (m, 6H) The obtained compound showed the following phase transition temperatures.

This compound had a stable S _A phase even at low temperatures.

Example 4 The compounds of Examples 1 to 3 were blended with the phenylpyrimidine liquid crystal composition A shown below in a weight ratio of 5: 1, and the transition temperature thereof was measured.

Here, the composition A has the following composition.

As described above, in the phenylpyrimidine-based liquid crystal composition,
By blending the compound of the present invention, the lower limit of S _C ^* can be greatly widened.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masaaki Taguchi 6-31-1, Kameido, Koto-ku, Tokyo Seiko Electronics Co., Ltd. (72) Takamasa Harada 6-31-1, Kameido, Koto-ku, Tokyo Seiko Electronics Industry Co., Ltd.

Claims (1)

[Claims] 1. A formula [Wherein R represents a linear alkyl group having 4 to 12 carbon atoms, and R ^* represents Asymmetric carbon atom Represents an alkyl group having n (n is an integer of 0 to 6)], which is an optically active 9,10-dihydrophenanthrenecarboxylic acid ester compound.