JPH0733355B2 - Biphenylcarboxylic acid ester derivative and liquid crystal composition - Google Patents

Description

The present invention relates to a novel liquid crystal compound and a liquid crystal composition containing at least one compound thereof. The liquid crystal display element originated in the digitization of watches and is used in computers, games, etc., and the liquid crystal display in these products has already become technically completely established. At present, it has been used in pocket televisions and the like, but in these display systems, the TN (twisted nematic) type that utilizes the nematic phase in the liquid crystal is the mainstream.

Disadvantages of this method are that the response is slow and the display cannot be seen depending on the viewing angle (the viewing angle characteristic is poor). The liquid crystal display element has the excellent features that it is a light-receiving type that does not cause tired eyes, consumes extremely little power, and has good compatibility with ICs, and it is hoped that it will be used for a wider range of applications. The improvement of is an essential issue.

Various researches have been made to solve this problem. Among them, a display device using a ferroelectric liquid crystal (NAClark, S.
T. Lagerwall; Appl. Phys. Lett., 36 , 899 (1980)).

Ferroelectric liquid crystals were found by RB Meyer et al. (RBMeyer, J. Physique, 36 , L-69 (1975)) This display system is a chiral smectic C of a ferroelectric liquid crystal.
Phase (hereinafter abbreviated as SmC ^* ), chiral smectic H
The phase (abbreviated as SmH ^* ) is used, and the response speed is much faster than the TN type method, so research on practical application is actively being carried out in various fields. However, the number of ferroelectric liquid crystal materials used in this display method is still small, and they are practically problematic in terms of stability.

We have a chemically stable and wide SmC that can be put to practical use.
^The present invention has been achieved as a result of intensive research aimed at developing a liquid crystal compound having a phase and a liquid crystal compound useful as a composition component.

That is, the present invention has the general formula (In the formula, R ^* represents an alkyl group having an asymmetric carbon atom having 4 to 14 carbon atoms, n represents an integer of 1 to 12, and R represents
Represents an alkyl group having 1 to 12 carbon atoms, the number of n and R
The sum of the number of carbon atoms of is 14 or less), and a liquid crystal composition containing at least one compound of the biphenylcarboxylic acid ester derivative.

The novel ferroelectric liquid crystal compound according to the present invention is a chemically stable substance, and by itself, SmC ^{* in a} wide temperature range ^.
Although having a phase, the temperature range of the SmC ^* phase can be further extended by mixing them with each other or adding them to another liquid crystal composition, thereby extending the operating temperature range of the display device. Is effectively used for.

The synthetic routes of the compounds according to the present invention are shown below by formulas,
In addition, the manufacturing method and usage example thereof will be specifically described with reference to Examples. The symbols (i) to (x) shown in the diagram are:
Both are referred to as the corresponding compounds in the examples.

The abbreviations used in this specification have the following meanings.

mp: melting point Sm: smectic phase SmC ^* : chiral smectic phase C SmA: smectic phase A SmB: smectic phase B Sx: unidentifiable smectic phase Ch: cholesteric phase Iso: isotropic liquid Cryst: crystalline state as well as Example 1 (S) -P- (3-ethoxypropyl) phenyl 4'-
[(6-Methyloctyl) oxy] biphenyl-4 "
-Synthesis of carboxylate (v) (a) (S) -6-methyloctyl bromide (i)
Into a reaction vessel, 13.8 g of powdered magnesium and 160 cc of tetrahydrofuran (treated with lithium aluminum hydride and purified by distillation) were charged, and (S) -2-methylbutyl bromide (Mol.Cryst.Liq.Cryst., 48 , 37 ~ 5
A Grignard reagent was prepared by dropping 78 g of synthetic b.p123-124 ° C) according to the reaction example of 2,1978.

Separately, 123 g of 1,4-dibromobutane, 350 cc of tetrahydrofuran (THF) and 0.1 mol / dilithium tetrachlorocuprate-THF solution (Li ₂ CuCl ₄ / TH) were placed in a reaction vessel.
F) 18 cc was charged, and the above Grignard reagent was added dropwise at 0 ° C or lower.

After stirring at 0 ° C or lower for 1 hour, at 10 ° C for 1 hour, and further at room temperature for 1 hour, the reaction solution was poured into dilute hydrochloric acid. The liberated organic layer was extracted with benzene, and the benzene layer was thoroughly washed with water. After drying the benzene layer with sodium sulfate, the solvent was distilled off,
The residue was distilled under reduced pressure to obtain 60 g of (S) -6-methyloctyl bromide (i). bp 102 to 114 ° C./27 mmHg (b) (S) -methyl-4 [(6 ″ -methyloctyl) oxy] biphenyl-4′-carboxylate (i
Synthesis of i) In a reaction vessel, methyl 4-hydroxybiphenyl-4'-
38 g of carboxylate, 38 g of (S) -6-methyloctyl bromide (i), 53 g of anhydrous sodium carbonate and 500 cc of cyclohexanone were charged, and the mixture was stirred at 130 to 140 ° C. for 5 hours. After allowing to cool, the reaction solution was poured into water and the liberated organic layer was extracted with benzene. The benzene layer was washed well with water and then dried with mirabilite. The solvent was distilled off, and the residue was recrystallized from acetone to obtain 50 g of (S) -methyl 4-[(6 ″).
-Methyloctyl) oxy] biphenyl-4'-carboxylate (ii) was obtained.

(C) Synthesis of (S) -4-[(6 ″ -methyloctyl) oxy] biphenyl-4′-carboxylic acid (iii) In a reaction vessel, (S) -methyl 4-[(6 ″ -methyloctyl) oxy is added. ] Biphenyl-4'-carboxylate (i
i) 50 g (dissolved in 200 cc of tetrahydrofuran), 200 cc of methanol and 15 g of 95% caustic soda (dissolved in 150 cc of water) were charged and stirred under reflux for 4 hours. Next, hydrochloric acid was added to the reaction solution to make it acidic, and then the precipitate was passed under reduced pressure. The collected crystals were dried by heating to obtain 45 g of (S) -4-[(6 ″ -methyloctyl) oxy] biphenyl-4′-carboxylic acid (iii).

(D) Synthesis of (S) -4-[(6 ″ -methyloctyl) oxy] biphenyl-4′-carbonyl chloride (iv) (S) -4-[(6 ″ -methyloctyl) oxy] in a reaction vessel. 45 g of biphenyl-4'-carboxylic acid (iii), 500 cc of benzene and a small amount of pyridine were charged, and 32 g of thionyl chloride was added dropwise with stirring under reflux. Then, after reacting at the same temperature for 10 hours, the solvent and excess thionyl chloride were distilled off to give 47 g of (S) -4-[(6 ″ -methyloctyl) oxy] biphenyl-4′-carbonyl chloride (iv ) Got.

(E) Synthesis of (S) -P- (3-ethoxypropyl) phenyl 4 ′-[(6-methyloctyl) oxy] biphenyl-4 ″ -carboxylate (v) In a reaction vessel, P- (3-ethoxy) was added. Propyl) phenol (synthesized according to the synthetic example of 4- (γ-methoxypropyl) phenol described in JP-A-58-85825, page 153)
1.7 g, 10 cc of benzene and 0.8 g of pyridine were charged, and 3.5 g of (S) -4-[(6 ″ -methyloctyl) oxy] biphenyl-4′-carbonyl chloride (iv) (dissolved in 20 cc of benzene) was stirred at room temperature. Was allowed to drip.
After reacting for 2 hours at room temperature and 3 hours under reflux,
The reaction solution was poured into water. The liberated benzene layer was washed well with water and dried with mirabilite. Benzene was distilled off, and the residue was recrystallized twice from acetone to give (S) -P- (3-ethoxypropyl) phenyl 4 '-[(6-methyloctyl).
Oxy] biphenyl-4 ″ -carboxylate (v) 1.
8g was obtained.

The content of this product was 99% or more by liquid chromatography and 1 spot by thin layer chromatography.

Moreover, according to the infrared absorption spectrum measurement, the characteristic value is 28
^{00~3000cm -1, 1720cm -1, 1270cm -1} , Atsuta at 1180cm ^-1. Further, in the mass spectrum analysis, a molecular ion peak was observed at 503 and a reference peak at 323, supporting the chemical structure of this.

This product was sandwiched between METTLER Hotstage FP-82 and the phase change was observed under a polarizing microscope. The results were as follows.

Example 2 (S) -P- (5-methoxypentyl) phenyl 4'-
[(6-Methyloctyl) oxy] biphenyl-4 "
-Synthesis of Carboxylate (vi) 1.5 g of P- (5-methoxypentyl) phenol (synthesized by the production method described below), 10 cc of benzene and 0.7 g of pyridine are charged into a reaction vessel and stirred at room temperature (S)- Four
-[(6 "-methyloctyl) oxy] biphenyl-
2.8 g of 4'-carbonyl chloride (iv) (benzene 20cc
Dissolved in) was added dropwise. After reacting at room temperature for 2 hours and further at reflux for 3 hours, the reaction solution was poured into water. The liberated benzene layer was washed well with water and dried with mirabilite. Benzene was distilled off, and the residue was recrystallized twice from acetone (S).
-P- (5-methoxypentyl) phenyl 4 '-[(6
1.7 g of -methyloctyl) oxy] biphenyl-4 "-carboxylate (vi) was obtained. The content of this product was 99% or more by liquid chromatography and 1 spot by thin layer chromatography. It was

According to infrared absorption spectrum measurement, the characteristic value is
^{2800~3000cm -1, 1730cm -1, 1270cm -1} , Atsuta at 1180cm ^-1. Also, in the mass spectrum analysis, a molecular ion peak was observed at 516 and a reference peak at 323, supporting the chemical structure of this.

This product was sandwiched between METTLER Hotstage FP-82, and the phase change was observed under a polarization microscope.

The P- (5-methoxypentyl) phenol used in this example was prepared as follows.

Synthesis of P- (5-methoxypentyl) phenol a) Synthesis of 3-benzoylbutyric acid A reaction vessel was charged with 2.5 g of benzene and 512 g of powdered anhydrous aluminum chloride. 200g of glutaric anhydride (dissolved in 500cc of benzene) was added to this mixture under stirring for 25
The mixture was added dropwise at -30 ° C and further stirred at the same temperature for 7 hours. The reaction solution was poured into dilute hydrochloric acid, and the precipitated crystals were separated. The crystals were dissolved in a caustic soda aqueous solution, insoluble materials were removed, and then hydrochloric acid was added to make the solution acidic. The precipitated crystals were collected to obtain 320 g of 3-benzoylbutyric acid. mp122-126 ° C b) Synthesis of 5-phenylvaleric acid In a reaction vessel, 320 g of 3-benzoylbutyric acid, 330 g of 80% hydrazine hydrate, diethylene glycol 2 and 85% caustic potash were added.
254 g (dissolved in 400 cc of water) was charged, and the mixture was stirred under reflux for 3 hours. Next, the temperature was raised to 220 ° C. while distilling water off, and the mixture was stirred at the same temperature for 6 hours.

After allowing to cool, the reaction solution was poured into water and hydrochloric acid was added to make the solution acidic.
The precipitated crystals were extracted with benzene, the benzene layer was washed with water and then dried with sodium sulfate.

Benzene was distilled off, and the residue was recrystallized from ligroin to obtain 5-phenylvaleric acid (260 g). mp57-59 ° C c) Synthesis of 5-phenylpentanol A reaction vessel was charged with 700 cc of ethyl ether and 62 g of lithium aluminum hydride, and 260 g of 5-phenylvaleric acid.
(Dissolved in ethyl ether 1) was added dropwise under stirring at 30 ° C or lower. After stirring at the same temperature for 2 hours, the reaction solution was poured into dilute hydrochloric acid. The liberated ethyl ether layer was washed with water and then dried with mirabilite.

After distilling off the ethyl ether, the residue was distilled to obtain 200 g of 5-phenylpentanol.

bp97-103 ° C / 0.1mmHg d) Synthesis of 1-chloro-5-phenylpentane In a reaction vessel, 290g of thionyl chloride, 20g of pyridine and 500cc of benzene are charged, and 200g of 5-phenylpentanol.
Was added dropwise with stirring under reflux. After stirring at the same temperature for 4 hours, the reaction solution was poured into water.

The benzene layer was washed with a caustic soda aqueous solution, further washed with water, and then dried with Glauber's salt. After distilling off benzene, the residue was distilled to obtain 195 g of 1-chloro-5-phenylpentane. bp139-140 ° C / 18mmHg e) Synthesis of 1-methoxy-5-phenylpentane Methanol 1 was charged into a reaction vessel and metallic sodium was added.
50 g was dissolved. Next, 195 g of 1-chloro-5-phenylpentane was added dropwise with stirring under reflux, and the mixture was further stirred at the same temperature for 32 hours.

The reaction solution was poured into water, and the released oil was extracted with benzene. The benzene layer was washed well with water and then dried with mirabilite. Benzene was distilled off, and the residue was distilled to obtain 181 g of 1-methoxy-5-phenylpentane. bp127-133 ° C / 1
9mmHgf) P- (5-methoxypentyl) acetophenone synthesis In a reaction vessel, methylene chloride 2, anhydrous aluminum chloride
295 g and 1-methoxy-5-phenylpentane 180 g were charged. Then add 158 g of acetyl chloride with stirring to 0-5
The mixture was added dropwise at 0 ° C, and the mixture was stirred at the same temperature for 4 hours.

The reaction solution was poured into diluted hydrochloric acid, the separated methylene chloride layer was washed with water, and then dried with sodium sulfate.

After distilling off methylene chloride, the residue was distilled to obtain P- (5
202 g of -ethoxypentyl) acetophenone were obtained. bp
128 ° C / 0.6mmHg-136 ° C / 0.4mmHg g) Synthesis of P- (5-methoxypentyl) phenol 200g of P- (5-methoxypentyl) acetophenone, 88% formic acid 1.6, acetic anhydride 0.8, concentrated Sulfuric acid 10cc
And, 300cc of 35% hydrogen peroxide water was charged, and it was 8 at 40-50 ° C.
Stir for hours. The reaction solution was poured into water, and the aqueous solution was extracted with ether. The ether layer was washed with an aqueous sodium carbonate solution, washed with water, and then dried with mirabilite. After the ether was distilled off, the residue was distilled (bp 130-150 ° C / 0.4mmHg, 74g). Distillate 74g, methanol 200cc, caustic soda in another reaction vessel
32 g (dissolved in 100 cc of water) was charged, and the mixture was stirred under reflux for 2 hours. The reaction solution was poured into dilute hydrochloric acid, and the released oil was extracted with ether. The ether layer was washed with water and dried with sodium sulfate.

After the ether was distilled off, the residue was distilled to obtain 54 g of P- (5-methoxypentyl) phenol. bp128-150 ℃ / 0.
3mmHg <Reaction path> Examples 3 to 5 Based on Examples 1 and 2, various derivatives were synthesized in the same manner and the phase transition temperature was measured. The results are shown below.

[In the table, R ^* and (CH ₂₎ nOR are both R ^* and (CH ₂₎ nOR in the general formula (I), show it by the compounds.

Example 6 (S) -P- (5-methoxypentyl) phenyl 4'-
[(4-Methylhexyl) oxy] biphenyl-4 "
-Synthesis of carboxylate (x) (a) (S) -methyl 4-[(4 "-methylhexyl) oxy] biphenyl-4'-carboxylate (vi
Synthesis of i) 67.5 g of methyl 4-hydroxybiphenyl-4'-carboxylate and (S) -4-methylhexyl bromide (synthesized according to the reaction example of Mol.Cryst.Liq.Cryst. 114 237-247 1984) in a reaction vessel. Bp 71-72 ° C / 23.5 mmHg) 58.5 g, anhydrous potassium carbonate 82 g and cyclohexanone 750 cc were charged, and the mixture was stirred at 130-140 ° C for 5 hours.

After allowing to cool, the reaction solution was poured into water and the liberated organic layer was extracted with benzene. The benzene layer was washed well with water and then dried with mirabilite. The solvent was distilled off, and the residue was recrystallized from acetone to obtain 75 g of (S) -methyl 4-[(4 "-methylhexyl) oxy] biphenyl-4'-carboxylate (vii). When the phase change of the thing was observed under the polarization microscope, it was as follows.

(B) Synthesis of (S) -4-[(4 ″ -methylhexyl) oxy] biphenyl-4′-carboxylic acid (viii) In a reaction vessel, (S) -methyl 4-[(4 ″ -methylhexyl) [Oxy] biphenyl-4'-carboxylate (vii) 75 g (dissolved in tetrahydrofuran 200 cc), methanol 200 cc and 95% caustic soda 30 g (water 15
(Dissolved in 0 cc) was charged and stirred under reflux for 4 hours.

Next, hydrochloric acid was added to the reaction solution to make it acidic, and then the precipitate was subjected to reduced pressure. The collected crystals were dried by heating to obtain 67 g of (S) -4-[(4 ″ -methylhexyl) oxy] biphenyl-4′-carboxylic acid (viii).

(C) Synthesis of (S) -4-[(4 ″ -methylhexyl) oxy] biphenyl-4′-carbonyl chloride (ix) In a reaction vessel, (S) -4-[(4 ″ -methylhexyl)
Oxy] biphenyl-4′-carboxylic acid (viii) 67 g,
Benzene (600 cc) and a small amount of pyridine were charged, and thionyl chloride (51 g) was added dropwise with stirring under reflux. Then, after reacting at the same temperature for 10 hours, the solvent and excess thionyl chloride were distilled off to remove (S) -4-[(4 ″ -methylhexyl) oxy] biphenyl-4′-carbonyl chloride (ix).
I got 70g.

(D) Synthesis of (S) -P- (5-methoxypentyl) phenyl 4 ′-[(4-methylhexyl) oxy] biphenyl-4 ″ -carboxylate (x) In a reaction vessel, the composition described in Example 2 was used. P- manufactured in this way
(5-methoxypentyl) phenol 2g, benzene 10c
c, Pyridine 0.8g was charged and stirred at room temperature (S)
3.4 g of -4-[(4 "-methylhexyl) oxy] biphenyl-4'-carbonyl chloride (ix) (benzene 20
(dissolved in cc) was added dropwise. After reacting at room temperature for 2 hours and further at reflux for 3 hours, the reaction solution was poured into water.
The liberated benzene layer was washed well with water and dried with mirabilite.
Benzene was distilled off, and the residue was recrystallized twice from acetone to give (S) -P- (5-methoxypentyl) phenyl 4 '.
-[(4-methylhexyl) oxy] biphenyl-
2.1 g of 4 "-carboxylate (x) was obtained.

The content of this product was 99% or more by liquid chromatography and 1 spot by thin layer chromatography.

According to infrared absorption spectrum measurement, the characteristic value is 28
^{00~3000cm -1, 1730cm -1, 1270cm -1} , Atsuta at 1180cm ^-1. Moreover, in the mass spectrum analysis, a molecular ion peak was observed at 488 and a reference peak was observed at 295, supporting the chemical structure of this.

Scissor this with METTLER Hotstage FP-82,
Observation of the phase change under a polarizing microscope revealed the following.

Example 7 (S) -P- (5-methoxypentyl) phenyl 4'-
[(2-Methylbutyl) oxy] biphenyl-4 "-
Synthesis of Carboxylate In Example 6, (S) -2-methylbutyl bromide was used in place of (S) -4-methylhexyl bromide, and (S) -P- (5-methoxypentyl) was used in the same manner. Phenyl 4 '-[(2-methylbutyl) oxy] biphenyl-4 "-carboxylate was obtained.

The content of this product was 99% or more by liquid chromatography and 1 spot by thin layer chromatography.

In addition, according to infrared absorption spectrum measurement, the characteristic value is 2800 ~
^{3000cm -1, 1730cm -1, 1270cm -1} , Atsuta at 1190cm ^-1. In the mass spectrum analysis, the molecular ion peak at 460, 2
A reference peak was found at 67, supporting the chemical structure of this.

This product was sandwiched between METTLER Hotstage FP-82, and the phase change was observed under a polarization microscope.

Example 8 A liquid crystal cell was assembled by sandwiching a Mylar film with a glass substrate having two transparent electrodes which were coated with a polyimide polymer film on the surface and rubbed. The two substrates are arranged so that their rubbing directions are parallel to each other, and the cell spacing is 9 μm. Such a liquid crystal cell was prepared, each compound having the SmC ^* phase obtained in each of the Examples was encapsulated, and the isotropic liquid was gradually cooled to the SmC ^* phase.

This liquid crystal cell is sandwiched between two polarizing plates, voltage is applied,
The display state changed when the polarity was reversed. The SmC ^* phase of each compound obtained in each example exhibits ferroelectricity and can be used as an electro-optical element.

Example 9 Existing ferroelectric liquid crystal (S) -p-octyloxyphenyl 4-[(2 ″ -methylbutyl)] biphenyl-4′-
Carboxylate (Mol.Cryst.Liq.Cryst. 37 189 197
In (6), the (S) -p- (3-ethoxypropyl) phenyl 4 '-[(6 "-methyloctyl) obtained in Example 1 is obtained.
20% of [oxy] biphenyl-4 ″ -carboxylate
(Weight ratio) The temperature range of the SmC ^* phase when added is shown in the table.

(S) -p- (3-ethoxypropyl) phenyl 4'-
[(6 "-methyloctyl) oxy] biphenyl-4"
-By adding 20% of carboxylate (S)-
The temperature range of the SmC ^* phase of p-octyloxyphenyl 4-[(2 ″ -methylbutyl)] biphenyl-4′-carboxylate extended from 12.6 ° C to 33 ° C.

The compound according to the present invention is chemically stable and is useful as a component for extending the temperature range of a ferroelectric liquid crystal composition.

Claims (4)

[Claims] 1. A general formula (In the formula, R ^* represents an alkyl group having an asymmetric carbon atom having 4 to 14 carbon atoms, n represents an integer of 1 to 12, and R represents
Represents an alkyl group having 1 to 12 carbon atoms, the number of n and R
The sum of the number of carbon atoms in is 14 or less). 2. In the above formula [I], R ^* is a general formula. (In the formula, m represents an integer of 0 to 10, n represents an integer of 1 to 12, R represents an alkyl group having 1 to 12 carbon atoms, and the sum of the number of n and the number of carbon atoms of R is The biphenyl carboxylic acid ester derivative according to claim 1, which is an alkyl group represented by 14 or less). 3. General formula (In the formula, R ^* represents an alkyl group having an asymmetric carbon atom having 4 to 14 carbon atoms, n represents an integer of 1 to 12, and R represents
Represents an alkyl group having 1 to 12 carbon atoms, the number of n and R
The sum of the number of carbon atoms of is 14 or less), at least one kind of the biphenylcarboxylic acid ester derivative is contained, and the liquid crystal composition is characterized by the above. 4. In the formula [I], R ^* is a general formula. (In the formula, m represents an integer of 0 to 10, n represents an integer of 1 to 12, R represents an alkyl group having 1 to 12 carbon atoms, and n represents the number of carbon atoms of R. The liquid crystal composition according to claim 3, wherein the sum is 14 or less).