JP2788220B2 - Fluorinated biphenyl-based liquid crystal compound and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel fluorine-containing biphenyl liquid crystal compound and a method for producing the same. More specifically, the present invention relates to a biphenyl-based liquid crystal compound having a nitrogen-containing perfluoroalkyl group useful as a liquid crystal for a display, and a method for producing the compound in a simple and high yield.

[0002]

2. Description of the Related Art A high-performance liquid crystal compound is indispensable for improving the performance of a liquid crystal for a display. The introduction of a perfluoroalkyl group into a liquid crystal compound is expected to provide the liquid crystal compound with excellent properties such as thermal, chemical stability and low viscosity possessed by the perfluoroalkyl group, and to improve the performance as a liquid crystal. In particular, introduction of a nitrogen-containing perfluoroalkyl group is expected to be more effective than ordinary alkyl groups, and various studies have been made so far. However, as this type of compound, only an optically active nitrogen-containing perfluorocarboxylic acid having improved optical activity is known (Japanese Patent Publication No. 4-66060), and a liquid crystal having a nitrogen-containing perfluoroalkyl group introduced therein. The compound is not yet known.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel biphenyl-based liquid crystal compound having a nitrogen-containing perfluoroalkyl group, which is useful as a liquid crystal for a display.

[0004]

The present inventors have conducted intensive studies to obtain a liquid crystal compound having a nitrogen-containing perfluoroalkyl group, and as a result, have found that a fluoroacetic acid halide having a perfluorodialkylamino group at the 2-position or The present inventors have found that a novel biphenyl-based liquid crystal compound having a nitrogen-containing perfluoroalkyl group can be easily obtained by reacting a perfluoropropionic acid halide having a perfluorodialkylamino group at the 3-position. Was completed.

That is, the present invention provides a compound represented by the general formula

Embedded image (In the formula, Rf ¹ and Rf ² are each a perfluoroalkyl group having 1 to 5 carbon atoms, and these are bonded directly or via an oxygen atom or a nitrogen atom, and both are bonded. A heterocyclic ring may be formed together with the nitrogen atom, and n is 1 or 2).

According to the present invention, the compound represented by the general formula (I)
The fluorine-containing biphenyl liquid crystal compound represented by the general formula

Embedded image (X in the formula is a halogen atom, and Rf ¹ , Rf ² and n
Has the same meaning as defined above) and 4-hydroxy-4 '
By reacting with -methoxybiphenyl.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The fluorine-containing biphenyl-based liquid crystal compound of the present invention represented by the above general formula (I) is a novel compound which has not been described in any literature, but Rf ¹ and Rf in this general formula (I) ² is a perfluoroalkyl group having 1 to 5 carbon atoms, each of which may be the same or different. Further, they are bonded directly or via an oxygen atom or a nitrogen atom to form a heterocyclic ring such as a five-membered ring, a six-membered ring, and a seven-membered ring together with the nitrogen atom to which they are bonded. Is also good.

The group (Rf ¹ ) in the general formula (I)
Examples of (Rf ² ) N- include the following groups.

[0009]

Embedded image

The fluorinated biphenyl-based liquid crystal compound represented by the general formula (I) can be produced by various methods, but according to the method of the present invention shown below, the general formula (I)

Embedded image (X in the formula is a halogen atom, and Rf ¹ , Rf ² and n
Has the same meaning as defined above) and 4-hydroxy-4 '
-Methoxybiphenyl can be produced simply and in high yield.

The halogen atom represented by X in the general formula (II) is a fluorine atom, a chlorine atom, a bromine atom,
An iodine atom is mentioned, and among these, a fluorine atom is particularly preferable.

The nitrogen-containing perfluorocarboxylic acid fluoride in which X is a fluorine atom can be easily obtained by, for example, electrolytically fluorinating a corresponding ester or halide of a nitrogen-containing carboxylic acid in hydrogen fluoride. . Further, if necessary, as the nitrogen-containing perfluorocarboxylic acid halide represented by the general formula (II),
In the case where X is a halogen atom other than a fluorine atom, for example, the nitrogen-containing perfluorocarboxylic acid fluoride obtained by the electrolytic fluorination is hydrolyzed,
After generating the corresponding nitrogen-containing perfluorocarboxylic acid, a suitable acid halogenating agent may be reacted to derive the corresponding nitrogen-containing perfluorocarboxylic acid halide.

Examples of the nitrogen-containing perfluorocarboxylic acid halide represented by the general formula (II) include 2-
Perfluoroacetic acid halide having various groups represented by the above-mentioned (Rf ¹ ) (Rf ² ) N- at the 3-position and various kinds represented by the above-mentioned (Rf ¹ ) (Rf ² ) N- at the 3-position Perfluoropropionic halides having a group can be mentioned.

In this reaction, 4-hydroxy-4'-
The use ratio of methoxybiphenyl and nitrogen-containing perfluorocarboxylic acid halide is usually selected in a molar ratio of 1: 1 to 1: 3, preferably 1: 1.2 to 1: 2.5. The reaction is advantageously carried out in a solvent, which is preferably inert to the reaction and capable of dissolving both components. Examples of such a substance include halogenated hydrocarbons such as methylene chloride, ethylene dichloride, chloroform, carbon tetrachloride, monochlorobenzene, and dichlorobenzene, and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene. Also,
The reaction is preferably carried out in the presence of a hydrogen halide scavenger. As the hydrogen halide scavenger, for example, organic bases such as pyridine and triethylamine are suitable.

[0015] The reaction temperature is usually selected in the range of 20 to 200 ° C, preferably 50 to 150 ° C. The pressure is not particularly limited, but the reaction is usually performed under normal pressure. The reaction time varies depending on the type of the nitrogen-containing perfluorocarboxylic acid halide, the reaction temperature, and other factors, and cannot be determined unconditionally, but usually about 10 minutes to 5 hours is sufficient.

After completion of the reaction, the reaction solution is washed, and then the desired product is separated and recovered by, for example, column chromatography, and if necessary, recrystallized using a suitable solvent to obtain a highly pure product. The fluorinated biphenyl-based liquid crystal compound of the invention is obtained.

[0017]

The biphenyl-based liquid crystal compound of the present invention having a nitrogen-containing perfluoroalkyl group introduced therein is a novel compound which has not been described in any literature, has a stable liquid crystal phase, and is useful as a display material. . According to the method of the present invention,
The biphenyl-based liquid crystal compound in which the nitrogen-containing perfluoroalkyl group has been introduced, using a readily available raw material,
It can be produced in a good yield by a simple operation.

[0018]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 4-methoxy-4 '-[perfluoro (dimethylaminoethanoyl) oxy] biphenyl

Embedded image In a 100 ml flask, 1.0 g (5.0 mmol) of 4-hydroxy-4'-methoxybiphenyl, 0.60 g (7.6 mmol) of pyridine and about 20 parts of chloroform were added.
and heated under an argon stream to 50-60 ° C.
Then, 3.6 g of perfluoro (dimethylaminoacetic acid) fluoride (purity 70%, 10 mmol, crude electrolytic fluorinated product) was added dropwise thereto, and the mixture was refluxed for about 30 minutes.
Allowed to react for minutes.

After completion of the reaction, the reaction solution
After addition of 1N, the solution was added with 3N hydrochloric acid (50 ml × 2).
Times), water (50 ml × 1 time), saturated aqueous sodium hydrogen carbonate solution (50 ml × 2 times), saturated saline (50 ml × 2 times)
) And dried over anhydrous magnesium sulfate. The mixture was allowed to stand for about 2 hours, and after filtering off magnesium sulfate, the solvent was distilled off under reduced pressure and concentrated to about 5 ml.

This solution was subjected to column chromatography [stationary phase: silica gel BW-200, developing solution: methylene chloride / n-hexane (volume ratio 1/1), column: inner diameter 2.0
cm, length 25 cm], and the column fraction was distilled off under reduced pressure. Then, the recovered solid was recrystallized from n-hexane to give 1.75 g of the purified product (4.07 mmol,
(81% yield).

With respect to this purified product, an infrared absorption spectrum (IR) and a nuclear magnetic resonance spectrum ( ¹ H-NMR, ¹⁹
F-NMR) was measured and identified. IR (KBr) (cm ^-1 ): 1801 (C = O), 16
^{_{09 (OCH 3) 1 H-}} NMR (TMS, CDCl 3) (ppm): 7.6
5~6.95 (8H), 3.87 (3H ) 19 F-NMR (CCl 3 F, CDCl 3) (ppm): -
65.2 (6F), -89.2 (2F) As a result of observation with a polarizing microscope or the like, a smectic A phase liquid crystal was shown in the range of 124 to 140 ° C.

Example 2 4-methoxy-4 '-[perfluoro (morpholinopropanoyl) oxy] biphenyl

Embedded image In a 100 ml flask, 0.96 g (4.8 mmol) of 4-hydroxy-4'-methoxybiphenyl, 0.50 g (6.3 mmol) of pyridine and about 20 m
and heated to 50 to 60 ° C. under an argon stream, and then 3.6 g of perfluoro (3-morpholinopropionic acid) fluoride (purity 70%, 7.8)
Mmol, electrolytic fluorination crude product) was added dropwise, and the reaction was carried out under reflux for about 1 hour and 30 minutes.

After completion of the reaction, 20 ml of toluene was added to the reaction solution, and the insoluble matter was removed by filtration.
After washing with hydrochloric acid (50 ml × 1 time), water (50 ml × 1 time), saturated aqueous solution of sodium hydrogencarbonate (50 ml × 1 time), and saturated saline solution (50 ml × 1 time), anhydrous magnesium sulfate is added and dried. did. After allowing to stand for 5 hours and filtering off magnesium sulfate, the solvent was distilled off under reduced pressure, concentrated to about 5 ml and allowed to stand.

This solution was subjected to column chromatography [stationary phase: silica gel BW-200, developing solution: 3.0% by volume.
Isopropanol / n-hexane, column: inner diameter 2.0
cm, length 25 cm], and the column fraction was distilled off under reduced pressure. Then, the recovered solid was recrystallized from n-hexane to give 2.02 g of the purified product (3.62 mmol,
Yield 76%).

With respect to this purified product, an infrared absorption spectrum (IR) and a nuclear magnetic resonance spectrum ( ¹ H-NMR, ¹⁹
F-NMR) was measured and identified. IR (KBr) (cm ^-1 ): 1790 (C = O), 16
^{_{10 (OCH 3) 1 H-}} NMR (TMS, CDCl 3) (ppm): 7.6
6~6.96 (8H), 3.86 (3H ) 19 F-NMR (CCl 3 F, CDCl 3) (ppm): -
87.1 (4F), -91.9 (4F), -92.2
(2F), -119.5 (2F) In addition, as a result of observation by a polarizing microscope or the like, a smectic A phase liquid crystal was shown in the range of 110 to 125 ° C.

Example 3 A 100 ml flask was charged with 10.0 g of phthalic acid dichloride and 30 ml of toluene, and refluxed with perfluoro-
After dropping 3.5 g of 3-morpholinopropionic acid,
The reaction was carried out under reflux for about 3 hours. After completion of the reaction, the reaction solution was distilled off under reduced pressure to obtain perfluoro-3-morpholinopropionyl chloride (boiling point: 68.0 to 70.0 ° C./55 torr).
r) 3.0 g were obtained.

A 100 ml flask was charged with 4-hydroxy-4'-methoxybiphenyl (1.0 g, 5.0 mmol), pyridine (0.60 g, 7.6 mmol) and chloroform (about 20 ml).
After the temperature was raised to 60 ° C, the perfluoro-3
-3.0 g (7.6 mmol) of morpholinopropionic acid chloride was added dropwise and reacted under reflux for about 30 minutes.

After completion of the reaction, the same operation as in Example 2 was carried out, and 2.50 g of 4-methoxy-4 '-[perfluoro (morpholinopropanoyl) oxy] biphenyl (4.4 g)
9 mmol, yield 90%).

This product has an infrared absorption spectrum (IR)
And nuclear magnetic resonance spectra ( ¹ H-NMR, ¹⁹ F-NM
The measurement of R) was consistent with the compound obtained in Example 2. Further, as a result of observation with a polarizing microscope and the like, the liquid crystal temperature range was also consistent with the compound obtained in Example 2.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C07D 207/10 C07D 207/10 211/38 211/38 223/04 223/04 G02F 1/13 500 G02F 1/13 500 (72) Inventor Haruhiko Fukaya 5-187-1 Kyosai-cho, Obu-shi, Aichi Prefecture Company Taizo Ono 6-324 Onada-cho, Tajimi-shi, Gifu (72) Inventor Kota Omori 3-6-1, Ibarjima, Akita-shi, Akita Inside Tochem Products Co., Ltd. (72) Hiroyuki Yayanagi, Akita-shi, Akita No. 3-6 Ibarjima Examiner, Tokumu Products Co., Ltd. Motohiro Okubo (58) Field surveyed (Int. Cl. ⁶ , DB name) CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A compound of the general formula (In the formula, Rf ¹ and Rf ² are each a perfluoroalkyl group having 1 to 5 carbon atoms, and these are bonded directly or via an oxygen atom or a nitrogen atom, and both are bonded. A fluorine-containing biphenyl-based liquid crystal compound represented by the formula (1), which may form a heterocyclic ring together with a nitrogen atom, and n is 1 or 2. 2. A compound of the general formula (In the formula, Rf ¹ and Rf ² are each a perfluoroalkyl group having 1 to 5 carbon atoms, and these are bonded directly or via an oxygen atom or a nitrogen atom, and both are bonded. A heterocyclic ring may be formed together with a nitrogen atom, X is a halogen atom, and n is 1 or 2), and 4-hydroxy-4'-methoxybiphenyl is reacted with a nitrogen-containing perfluorocarboxylic acid halide represented by the formula: A general formula characterized by the following: (Wherein Rf ¹ , Rf ² and n have the same meaning as described above)
A method for producing a fluorinated biphenyl-based liquid crystal compound represented by the formula: 3. The method according to claim 2, wherein the nitrogen-containing perfluorocarboxylic acid halide is nitrogen-containing perfluorocarboxylic acid fluoride.