JPH06220074A - Liquid crystalline compound and liquid crystal composition containing the compound - Google Patents

Abstract

PURPOSE:To provide the subject new compound useful as a compounding component for ferroelectric liquid crystal composition. CONSTITUTION:The compound of formula I [R1 is (substituted) aliphatic hydrocarbon-group; R2 and R3 are (substituted) aliphatic hydrocarbon group or optically active aliphatic group; X is group of formula II, etc.; C* is optically active carbon atom; R is H, halogen, etc.; (1 is 0 or 1; m and n are 1 or 2; 1+m+n is 2 or 3; rings A and B are (substituted) 1,4-phenylene, pyrimidine-2,5, etc.], e.g. methyl-(R)-1-methylheptyl-4-[4'-{(S)-2- hexyloxypropanoyloxy}bisphenylcarboxy]phenyl-(R)-phosphine oxide. The compound of formula I can be produced by the successive (substituted) alkylation or (substituted) alkenylation of a compound of formula III with R3X and R3X, elimination of the protecting groups, demethylation of the product to obtain a compound of formula IV and esterification of the product with a compound of formula V.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel liquid crystal compound and a liquid crystal composition containing the same.

[0002]

2. Description of the Related Art Liquid crystal display elements are widely used as various display elements because they have many advantages such as low power consumption, thin display, and light receiving type display, which reduces eye fatigue. Has been done. Currently, the most widely used display system is a twisted nematic (TN) type, and a liquid crystal compound showing a nematic phase is used. However, the TN type display device has a drawback that its response speed is very slow as compared with other light emitting type display devices such as CRT, plasma display, and electroluminescence display. Therefore, it is desired to develop a liquid crystal display device having an improved response speed, and many studies have been conducted for that purpose. In order to meet the above demand, a liquid crystal display method using a ferroelectric liquid crystal compound has been proposed (NA Clark, ST Lagerwa
ll, Applied Phys. Lett., 36 899 (1980)). The display device using this ferroelectric liquid crystal is 100% of the TN type display device.
With a memory effect brought about by more than double the high speed response and bistability, large TV image, high speed shutter,
It is expected to be applied to optoelectronic materials such as printer heads, computer terminals, and nonlinear optical materials.

Ferroelectric liquid crystals belong to the tilt type chiral smectic phase as the liquid crystal phase, and among them, the practically desirable one is the chiral smectic C (abbreviated as Sc *) phase having the lowest viscosity. Is. As a liquid crystal material exhibiting ferroelectricity, a liquid crystal compound exhibiting a Sc * phase or a liquid crystal compound exhibiting a smectic C (hereinafter abbreviated as Sc) phase is compatible with a liquid crystal compound although it does not exhibit an Sc phase per se. It is possible to use a liquid crystal mixture having a good chiral compound and having an optically active compound. So far, liquid crystalline compounds exhibiting various Sc * phases or optically active compounds as blending components of liquid crystal mixtures have been studied, and many compounds have already been known. But,
Many of these compounds have an azomethine bond (-CH = N
It has a double bond (-) or a double bond (-CH = CH-), is prone to hydrolysis and photodegradation, and is colored. Further, in many cases, the Sc * phase is exhibited at a temperature higher than room temperature,
Ferroelectric liquid crystals exhibiting the Sc * phase near room temperature are desired. Moreover, a material having a response speed sufficient to exhibit practical characteristics has not yet been obtained.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a novel liquid crystalline compound which is useful as a compounding component of a ferroelectric liquid crystalline composition and is chemically stable, has no coloration and is excellent in light stability. It is an object of the present invention to provide a stable liquid crystal composition containing the compound as a member and having high responsiveness at around room temperature.

[0005]

As a result of various studies aimed at solving the above-mentioned problems, the present inventors have found that a compound having a phosphine oxide group in its molecular structure and an asymmetric atom at its opposite terminal. Found that the liquid crystal temperature is low and responds at high speed, and completed the present invention. That is, according to the present invention, a liquid crystal compound represented by the following general formula (1) and a liquid crystal composition containing the liquid crystal compound as a blending component are provided.

[Chemical 1]

A substituent may be bonded to the 1,4-phenylene group or the pyrimidine-2,5- or -5,2-diyl group constituting the ring A and the ring B of the general formula (1). The substituent in this case includes a halogen atom, a hydroxyl group, a nitro group, a cyano group and the like. In the compound represented by the general formula (1), the aliphatic hydrocarbon group which may have a substituent represented by R ₁ , R ₂ and R ₃ has 1 to 22 carbon atoms, preferably 3 carbon atoms. To 16 alkyl groups or 3 to 22 carbon atoms
Desirably, preferably 4 to 16 alkenyl groups.
In addition, a substituent may be bonded to R ₁ , R ₂ and R ₃ , and examples of such a substituent include a hydroxyl group, an alkoxy group, an ester group, a halogen atom, a nitro group and a cyano group. Can be mentioned. Specific examples of the aliphatic hydrocarbon groups represented by R ₁ , R ₂ and R ₃ described above include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and n-hexyl group. Group, isohexyl group,
Heptyl group, n-octyl group, isooctyl group, octenyl group, nonyl group, n-decyl group, isodecyl group, decenyl group, dodecyl group, dodecenyl group, tetradecyl group,
Tetradecenyl group, hexadecyl group, hexadecenyl group, octadecyl group, octadecenyl group, icosyl group,
Examples thereof include, but are not limited to, an icosenyl group. In the general formula (1), R ₂ and R ₃ are preferably an aliphatic group containing an asymmetric carbon atom, and such an aliphatic group is derived from an optically active compound having an asymmetric carbon atom. It

Illustrative examples of the optically active compound used as the raw material for introducing an optically active aliphatic group include optically active 2-methylbutanol, optically active 3-methylpentanol, and optically active 4-.
Methylhexanol, optically active 5-methylheptanol, optically active 6-methyloctanol, optically active citronellol, optically active 3,7-dimethyloctanol, optically active 2-butanol, optically active 2-pentanol, optically active 2-hexanol, Optically active 2-heptanol,
Optically active 2-octanol, optically active 2-nonanol,
Optically active 2-decanol, optically active 2-undecanol, optically active 2-dodecanol, optically active 2-methylheptanol, optically active 2-methylhexanol, optically active 2-alkyloxypropanol, optically active 3-alkyloxybutanol, optical Active 3-alkyloxypentanol, optically active lactic acid ester, optically active 3-hydroxy-2-methylpropanoic acid ester, optically active 3-
Hydroxybutanoic acid ester, optically active 3-hydroxypentanoic acid ester, optically active 2-halogenopropanol, optically active 2-halogenobutanol, optically active 2-halogenopentanol, optically active 2-halogenohexanol, optically active 2-halogenoheptanol , Optical activity 2-
Halogenooctanol, optically active 2-halogenononanol, optically active 2-halogenodedecanol, optically active 2-halogenoundecanol, optically active 2-halogenododecanol, optically active solketal, optically active glycidol,
Optical activity 2,3-dihalogenopropanol, Optical activity 3
-Alkyloxy-2-halogenopropanol, optically active 3-halogeno-2-alkyloxypropanol, optically active 3-alkyloxy-1-halogeno-2-propanol, optically active 1,3-dialkyloxy-2-propanol, optical Active 1,1,1-trifluoro-2-butanol, Optical activity 1,1,1-Trifluoro-2-pentanol, Optical activity 1,1,1-Trifluoro-2-hexanol, Optical activity 1,1,1- Trifluoro-2-heptanol, Optical activity 1,1,1-Trifluoro-2-octanol, Optical activity 1,1,1-Trifluoro-2-nonanol, Optical activity 1,1,1-Trifluoro-2-decanol, Optical activity 1,1,1-trifluoro-2-undecanol, optically active 1,1,1-trifluoro-2-dodecanol, optically active 2 Hydroxybutanenitrile, optically active 2-hydroxypentanenitrile, optically active 2-hydroxyhexanenitrile, optically active 2-hydroxyheptanenitrile, optically active 2-hydroxyoctanenitrile, optically active 2-hydroxynonanenitrile, optically active 2-hydroxydecane Nitrile, optically active 2-hydroxyundecane nitrile, optically active 2-hydroxydodecane nitrile, and the like.

As will be described later, when the compound of the general formula (1) is produced from a phosphorus-containing compound, R ₂ and R ₃ can be introduced by using a phosphorus-containing compound and R ₂ X or R ₃ X (X is a halogen atom). ) Is the usual method (Tables 3, 4, 5,
7), a halide containing an asymmetric carbon atom (R ₂ X,
R ₃ X) can be easily obtained by employing a conventionally known method, for example, a method of reacting the above-mentioned optically active alcohol with dry hydrogen halide in the presence of sulfuric acid. Liquid crystal compounds containing a phosphorus atom are often studied as lyotropic liquid crystals in which a phospholipid, which is a component of a biological membrane, exhibits a liquid crystal phase at a specific concentration. However, what can be applied to the display device is a thermotropic liquid crystal that exhibits a liquid crystal phase at a specific temperature, and an example of adding a compound containing a phosphorus atom to an existing thermotropic liquid crystal (K.Klose et al., Mol. Cry
St. Liq. Cryst. 150 201 (1987)) is known, but an example in which a phosphorus-containing compound is applied to the compounding component of the ferroelectric liquid crystal composition is not known.

Examples of the compound represented by the general formula (1) are shown in Tables 1 and 2. However, it is not limited to these compounds. In the following, C * represents an asymmetric carbon atom and P * represents an asymmetric phosphorus atom.

[Table 1]

[0010]

[Table 2]

The liquid crystalline compound of the present invention represented by the general formula (1) can be synthesized, for example, by the following method. Table 3 shows the reaction formula when (a) X is a single bond.

[Table 3]

That is, a phosphine oxide derivative having a hydroxyl group protected by a methyl group represented by the general formula (2) is
After sequentially (substituted) alkyl or (substituted) alkenylation with R ₂ X and R ₃ X, removing the protecting group with BBr ₃ to convert it into a hydroxy compound represented by the general formula (3), and deriving from this and a lactate ester The acid chloride derivative represented by the general formula (5) can be synthesized by an esterification reaction according to a conventional method. When R ₂ and R ₃ are different from each other in this reaction, the compound represented by the general formula (1-a) is obtained as a mixture of diastereomers having the configurations of R and S on the phosphorus atom. Therefore, a compound having an optically active phosphorus atom can be obtained by optically resolving the compound.

[0013]

[Table 4]

That is, instead of the phosphine oxide derivative of the general formula (2) shown in Table 3, a phosphine oxide derivative represented by the general formula (6) was used as a raw material, and this was used in the same manner as in the case of Table 3 for the general formula. After conversion to the hydroxy compound represented by (7), it can be synthesized by subjecting the compound of the general formula (8) to an esterification reaction according to a conventional method. The compound of general formula (8) can be synthesized from the compound of general formula (4) synthesized in reaction (2) of Table 3 according to a conventional method as shown in reaction (6). In addition, in this reaction, when R ₂ and R ₃ are different substituents from each other, general formula (1-
The compound represented by b) is obtained as a mixture of diastereomers of R and S with the configuration on the phosphorus atom. Therefore, by optically resolving this, a compound having an optically active substance on the phosphorus atom can be obtained. .

[0015]

[Table 5]

That is, instead of the phosphine oxide derivative of the general formula (2) shown in Table 3, a phosphine oxide derivative [compound of the general formula (9)] in which a carboxyl group was amidated and protected was used as a raw material. In the same manner as in the case of 3, the R ₂ group and the R ₃ group are introduced, and then hydrolyzed to convert the amide group into a carboxyl group to give a compound represented by the general formula (1
After obtaining a phosphine oxide derivative having a carboxyl group represented by 0), it can be synthesized by subjecting the compound of the general formula (11) to an esterification reaction in the presence of a condensing agent such as dicyclohexylcarbodiimide. The compound of general formula (11) can be synthesized from the compound of general formula (4) synthesized in reaction (2) of Table 3 according to a conventional method as shown in reaction (9). In addition, in the case where R ₂ and R ₃ are different substituents in this reaction, the compound represented by the general formula (1
In the compound represented by -c), the configuration on the phosphorus atom is R
And S as a mixture of diastereomers,
By optically resolving this, a compound having an optically active phosphorus atom can be obtained.

Table 6 shows the reaction formula when (d) X is --CH ₂ O--.

[Table 6]

That is, the compound of the general formula (1) synthesized from the compound of the general formula (4) obtained in the reaction (2) of Table 3 is used as a raw material.
The alcohol derivative of 2) is tosylated with p-toluenesulfonyl chloride to give a tosylate derivative of general formula (13), and the hydroxy compound of general formula (7) obtained in reaction (5) of Table 4 is obtained. , Can be synthesized by an etherification reaction according to a conventional method. When R ₂ and R ₃ are different from each other in this reaction, the compound represented by the general formula (1-d) is obtained as a mixture of diastereomers having R and S configurations on the phosphorus atom. Therefore, a compound having an optically active phosphorus atom can be obtained by optically resolving the compound.

Table 7 shows the reaction formula when (e) X is —OCH ₂ —.

[Table 7]

That is, a phosphine oxide derivative represented by the general formula (14) was used as a raw material in place of the compound represented by the general formula (6) in Table 4, and the phosphine having a hydroxyl group was prepared in the same manner as in the reaction (5) in Table 4. As an oxide derivative,
It is obtained by tosylating the compound of the general formula (15) and then reacting it with the compound of the general formula (11) obtained in the reaction formula (9) of Table 5. When R ₂ and R ₃ are different substituents in this reaction, the compounds of the general formula (1
In the compound represented by -e), the configuration on the phosphorus atom is R
And S as a mixture of diastereomers,
By optically resolving this, a compound having an optically active phosphorus atom can be obtained.

The compound of the general formula (1) of the present invention is
Alternatively, a ferroelectric liquid crystal compound or composition having an improved temperature range of the Sc * phase and excellent response characteristics can be obtained by using it in combination with another liquid crystal compound. Further, even if the compound according to the present invention has a poor liquid crystallinity, it is possible to improve the temperature range of the Sc * phase by mixing with the compound exhibiting the Sc phase or Sc * phase, and to improve the ferroelectricity with excellent response characteristics. Liquid crystal composition can be obtained.

[0022]

The compound of the present invention is colorless and has an azomethine bond (-CH = N-) or a double bond (-CH = CH-).
Since it does not have such properties, it is stable both chemically and to light and has a low liquid crystal temperature. Furthermore, it has good compatibility with other liquid crystals, and when used as a component of a ferroelectric liquid crystal composition, a liquid crystal display device exhibiting excellent high-speed response can be obtained. Further, since the liquid crystal composition of the present invention is an optically active compound and has good compatibility with nematic liquid crystal, it is for white Taylor type color display, cholesteric nematic phase transition type display, reverse domain generation prevention in TN type cell, etc. For the purpose of, it is also possible to add it to a conventional nematic liquid crystal and use it.

[0023]

EXAMPLES Next, the present invention will be described in more detail by way of examples. In the following, Cry, Sx, SA, N *, and Iso phases represent a crystal phase, a smectic phase that cannot be clearly identified, a smectic A phase, a chiral nematic phase, and an isotropic liquid phase, respectively.

Example 1 Methyl- (R) -1-methylheptyl-4- [4'-
Synthesis of {(S) -2-hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (R) -phosphine oxide Iodohexane 15.3 g (72 mmol) and (S)-
33 g (142 mmo) of Ag ₂ O prepared immediately before was mixed with 11.8 g (100 mmol) of ethyl lactate.
1) was added over 50 minutes, and the mixture was reacted for 16 hours at room temperature with stirring. Dilute with diethyl ether 150ml, A
After g ₂ O was filtered off, it was washed successively with a saturated NaHCO ₃ aqueous solution, water and a saturated saline solution, and dehydrated with anhydrous magnesium sulfate. After the solvent was distilled off, the residue was purified by silica gel column chromatography to obtain ethyl (S) -2-hexyloxypropionate (6.0 g, yield 45%).

Then, 4N was added to 6.0 g (32.1 mmol) of ethyl (S) -2-hexyloxypropionate.
16 ml of NaOH aqueous solution was added, the mixture was stirred at room temperature for 2 hours, 10 N hydrochloric acid was added until it became acidic, and the mixture was extracted with hexane. The hexane solution was dehydrated with anhydrous magnesium sulfate. When hexane is distilled off from the liquid after dehydration, (S) -2
-4.6 g of hexyloxypropionic acid (yield 83
%) Obtained. Then, to 4.4 g (25.3 mmol) of this (S) -2-hexyloxypropionic acid, 15 ml of thionyl chloride was added and stirred at room temperature for 2 hours, after which thionyl chloride was distilled off under reduced pressure and then methylene chloride. 5 ml was added. 5.4 g (25.3 mmo) of 4- (4'-hydroxyphenyl) benzoic acid prepared separately was prepared.
1), pyridine (15 ml) and methylene chloride (15 ml) were added dropwise to the mixture, and the mixture was stirred at room temperature for 16 hours. After washing this liquid with 80 ml of 10% HCl aqueous solution, the solvent of the organic layer was distilled off and then purified by silica gel column chromatography to give 4-{(S) -2-hexyloxypropanoyloxyphenyl} benzoic acid. 6 g (yield 71%) was obtained.

On the other hand, 15.6 g (0.1 mol) of 4-methoxyphenylphosphine oxide and sodium bis (2-methoxyethoxy) aluminum hydride (Red-Al: 3.4M solution manufactured by Aldrich) 2
9.4 ml (0.1 mol) of tetrahydrofuran 2
It was dissolved in 00 ml and cooled to 0 ° C., and 14.2 g (0.1 mol) of methyl iodide was added to 10 ml of tetrahydrofuran.
What was dissolved in 0 ml was added dropwise, and at the room temperature after completion of the addition 8
Stir for hours. In addition to this, 3.4M Red-Al
29.4 ml was added and the mixture was cooled to 0 ° C. again, and then 28.4 g (0.1%) of ((R) -1-methylheptyl tosylate) was obtained.
(mol) was dissolved in 100 ml of tetrahydrofuran, and the mixture was stirred at room temperature for 8 hours after the addition was completed. Water was added to this solution to stop the reaction, and the solution extracted with ethyl acetate was dehydrated with anhydrous sodium sulfate. The solvent was evaporated, each diastereomer was separated and purified by silica gel column chromatography, and methyl- (R) -1-methylheptyl-4-methoxyphenyl- (R) -phosphine oxide 11.9 g (yield 38%), and methyl-
(R) -1-Methylheptyl-4-methoxyphenyl-
10.0 g of (S) -phosphine oxide (yield 32
%) Was obtained. For each diastereomer, using methylene chloride as a solvent, 10 equivalents of BBr ₃ were added at −78 ° C. to perform a reaction for converting a methoxy group into a hydroxy group, and the mixture was returned to room temperature and water was added to decompose BBr _3. After stopping the reaction with ethyl acetate, the desired product was extracted with ethyl acetate to obtain methyl- (R) -1-methylheptyl-4-m almost quantitatively.
Hydroxyphenyl- (R) -phosphine oxide,
And methyl- (R) -1-methylheptyl-4-hydroxyphenyl- (S) -phosphine oxide were obtained.

Next, 1.1 g of 4-{(S) -2-hexyloxypropanoyloxyphenyl} benzoic acid (3 m
mol), 10 ml of thionyl chloride and a few drops of dimethylformamide were added, the mixture was heated at 50 ° C. for 2 hours, and thionyl chloride was distilled off under reduced pressure. What melt | dissolved this in methylene chloride 5ml mixed methyl- (R) -1-methylheptyl-4-hydroxyphenyl- (R) -phosphine oxide 0.57g (1.9 mmol), pyridine 3ml, and methylene chloride 3ml. Add to solution, room temperature 15
Stir for hours. The liquid after stirring was extracted with ethyl acetate, the extract was washed successively with water and a saturated sodium sulfate aqueous solution, and then dehydrated with anhydrous sodium sulfate. Purification by silica gel column chromatography after distilling off the solvent removes methyl- (R) -1-methylheptyl-4- represented by the following formula.
0.92 g (yield 78%) of [4 ′-{(S) -2-hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (R) -phosphine oxide was obtained.

[Chemical 2]

The ¹ H-NMR and phase transition temperature of this compound were as follows. NMR, δ (ppm, CDCl ₃ ): 0.84 to 0.9
4 (6H, m), 1.09 (3H, d), 1.19 ~
1.91 (24H, m), 3.51 (1H, m), 3.
61 (1H, m), 3.88 (1H, m), 4.22
(1H, m), 7.25 (2H, m), 7.40 (2
H, d), 7.52 to 7.78 (4H, m), 7.82.
(2H, m), 8.27 (2H, d) Cry ← Sx ← Iso <-10 ° C 41 ° C As described above, the compound of the present invention showed a stable smectic phase in a wide temperature range including room temperature. 4-decyloxybenzoic acid-4 '-{(S) -4-, a known Sc compound
The phase transition temperature of the liquid crystal mixture obtained by adding 10 mol% of this synthesized compound to methylhexyloxy} phenyl was as follows. Sc * ← SA ← Iso 61 ℃ 70 ℃

This mixture was sealed between the rubbing-oriented glass transparent electrodes with a spacing of 2 μm, and spontaneous polarization and response time were measured. Triangular wave method (± 30V, 10H)
z), measured at 24 ° C. was 39.3 nC / c
It was a very large value of m ² . Also ± 30V, 10H
When a rectangular wave of z was applied, clear optical switching was observed. The response time was 125 μsec at 24 ° C., which was very fast. In addition, it is a known Sc compound, 5
When the response speed of a liquid crystal mixture obtained by adding 15 mol% of this synthesized compound to -nonyl-2- (4-octyloxyphenyl) pyrimidine was measured by the same method, 2
It was a very high speed of 24 μsec at 5 ° C. As described above, the compound of the present invention exhibits excellent fast response at room temperature.

Example 2 Methyl- (R) -1-methylheptyl-4- [4'-
Synthesis of {(S) -2-hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (S) -phosphine oxide Methyl- (R) -1-methylheptyl-4-of Example 1
Instead of hydroxyphenyl- (R) -phosphine oxide, methyl- (R) -1-methylheptyl-4-
Hydroxyphenyl- (S) -phosphine oxide was used, and methyl- (R)-was used in exactly the same manner as in Example 1.
1-Methylheptyl-4- [4 '-{(S) -2-hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (S) -phosphine oxide 0.88
g (yield 75%) was obtained. The phase transition temperature of this compound was as follows. Cry ← Sx ← Iso 46 ° C. 81 ° C. 4-decyloxybenzoic acid, which is a known Sc compound-
The phase transition temperature of the liquid crystal mixture obtained by adding 5 mol% of this synthesized compound to 4 '-{(S) -4-methylhexyloxy} phenyl was as follows. Sx ← Sc * ← SA ← Iso 29 ° C. 64 ° C. 72 ° C. When the response time of this mixture was measured by the same method as in Example 1, it was 180 μsec at 30 ° C., which was very high speed.

Example 3 Methyl- (R) -1-methylheptyl-4- [4'-
Synthesis of {(R) -2-hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (R) -phosphine oxide Using (R) -methyl lactate in place of (S) -ethyl lactate in Example 1 In the same manner as in Example 1, methyl-
(R) -1-Methylheptyl-4- [4 '-{(R)-
0.92 g (yield 78%) of 2-hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (R) -phosphine oxide was obtained. The phase transition temperature of this compound was as follows. Cry ← Sx ← Iso 43 ° C. 102 ° C. Thus, the compound of the present invention showed a stable smectic phase in a wide temperature range including room temperature. 4-decyloxybenzoic acid-4 '-{(S) -4-, a known Sc compound
The phase transition temperature of the liquid crystal mixture obtained by adding 5 mol% of this synthesized compound to methylhexyloxy} phenyl was as follows. Sx ← Sc * ← SA ← N * ← Iso 28 ° C. 65 ° C. 70 ° C. 72 ° C. Spontaneous polarization and response time of this mixture were measured by the same method as in Example 1 and found to be 7.2 nC / c at 30 ° C., respectively.
m ^{2 was} 179 μsec, which was a very high speed.

Example 4 Methyl- (R) -1-methylheptyl-4- [4'-
{(R) -2-Hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (S) -phosphine oxide synthesis Methyl- (R) -1-methylheptyl-4-of Example 3.
Instead of hydroxyphenyl- (R) -phosphine oxide, methyl- (R) -1-methylheptyl-4-
Hydroxyphenyl- (S) -phosphine oxide was used, and methyl- (R)-was used in exactly the same manner as in Example 3.
1-Methylheptyl-4- [4 '-{(R) -2-hexyloxypropanoyloxy} biphenylcarboxy] phenyl- (S) -phosphine oxide 0.85
g (yield 72%) was obtained. This compound was a liquid at room temperature. The phase transition temperature of a liquid crystal mixture obtained by adding 5 mol% of the synthesized compound to 4 '-{(S) -4-methylhexyloxy} phenyl 4-decyloxybenzoate, which is a known Sc compound, is shown below. Sx ← Sc * ← SA ← Iso 29 ° C. 63 ° C. 70 ° C. When the response time of this mixture was measured by the same method as in Example 1, it was 167 μsec at 30 ° C., which was a very high speed.

Example 5 Methyl- (R) -1-methylheptyl-4- [4'-
Synthesis of {(S) -2-propyloxypropanoyloxy} biphenylcarboxy] phenyl- (R) -phosphine oxide Iodopropane was used in place of iodohexane in Example 1, and otherwise the same as in Example 1. Methyl- (R) -1-methylheptyl-4- [4'- represented by the following formula
0.90 g (yield 82%) of {(S) -2-propyloxypropanoyloxy} biphenylcarboxy] phenyl- (R) -phosphine oxide was obtained.

[Chemical 3] 4-decyloxybenzoic acid, which is a known Sc compound-
The response time of a liquid crystal mixture obtained by adding 5 mol% of this synthesized compound to 4 ′-{(S) -4-methylhexyloxy} phenyl was measured by the same method as in Example 1 and found to be 107 μsec at 30 ° C. Yes, it was very fast.

Example 6 Methyl- (R) -1-methylheptyl-4- [4'-
Synthesis of {4 ″-(S) -2-hexyloxypropanoyloxyphenyl} benzyloxy] phenyl- (R) -phosphine oxide Instead of 4- (4′-hydroxyphenyl) benzoic acid of Example 1, 4 Using 4- (4'-hydroxyphenyl) benzyl alcohol, in the same manner as in Example 1, 4- [4 '
-{(S) -2-hexyloxypropanoyloxy}
Phenyl] benzyl alcohol 3.6 g (yield 40%)
Got Next, 3.6 g (10 mmol) of 4- [4 '-{(S) -2-hexyloxypropanoyloxy} phenyl] benzyl alcohol and 1.2 g (1
5 mmol) was dissolved in 50 ml of ether and cooled to 0 ° C., and 1.9 p-toluenesulfonic acid chloride was added thereto.
What melt | dissolved g (10 mmol) in 50 ml of ether was dripped, and after completion | finish of dripping, it stirred at room temperature for 2 hours. The precipitate was filtered off, the solvent was distilled off, and tosylic acid 4- [4'-
4.5 g (yield 89%) of {(S) -2-hexyloxypropanoyloxy} phenyl] benzyl was obtained.

Next, this tosylic acid 4- [4 '-{(S)
-2-hexyloxypropanoyloxy} phenyl]
2.5 g (5 mmol) of benzyl and methyl- (R) -1-methylheptyl-4-hydroxyphenyl- (R) -phosphine oxide obtained by the method of Example 1.1.
6 g (5 mmol) and 0.3 g of potassium hydroxide (5 m
mol) in 50 ml of dimethylformamide,
The mixture was heated and stirred at 00 ° C for 3 hours. The solvent was distilled off, followed by extraction with ethyl acetate. This solution was washed successively with water and a saturated sodium sulfate aqueous solution and then dried over anhydrous sodium sulfate. After the solvent was distilled off, the residue was purified by silica gel column chromatography to obtain methyl- (R) -1-methylheptyl-4- [4 '-{4 "-(S) -2-hexyloxypropanoyloxy represented by the following formula. Phenyl} benzyloxy] phenyl- (R) -phosphine oxide (2.0 g, yield 66%) was obtained.

[Chemical 4] 4-decyloxybenzoic acid, which is a known Sc compound-
The response time of a liquid crystal mixture obtained by adding 5 mol% of this synthesized compound to 4 ′-{(S) -4-methylhexyloxy} phenyl was measured by the same method as in Example 1 and found to be 102 μsec at 30 ° C. Yes, it was very fast.

Example 7 Methyl- (R) -1-methylheptyl-4 ', 2 "-
Synthesis of [5 ″-{(S) -2-hexyloxypropanoyloxy} pyrimidyl] phenyl- (R) -phosphine oxide Instead of 4-methoxyphenylphosphine oxide of Example 1, 4,2 ′-(5 ′ -Methoxypyrimidyl)
Using phenylphosphine oxide, methylation and (R) -1-methylheptylation were carried out in the same manner as in Example 1, and the obtained diastereomer was separated and purified, and further (S) -2-hexyloxypropion By carrying out an esterification reaction with an acid chloride, methyl- (R) -1-methylheptyl-4 ', 2 "-represented by the following formula:
0.73 g (yield 77%) of [5 ″-{(S) -2-hexyloxypropanoyloxy} pyrimidyl] phenyl- (R) -phosphine oxide was obtained.

[Chemical 5] 4-decyloxybenzoic acid, which is a known Sc compound-
When the response time of a liquid crystal mixture obtained by adding 5 mol% of this synthesized compound to 4 ′-{(S) -4-methylhexyloxy} phenyl was measured by the same method as in Example 1, it was 97 μsec at 30 ° C. Was very fast.

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[Procedure amendment]

[Submission date] May 21, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

A substituent may be bonded to the 1,4-phenylene group or the pyrimidine-2,5- or -5,2-diyl group constituting the ring A and the ring B of the general formula (1). The substituent in this case includes a halogen atom, a hydroxyl group, a nitro group, a cyano group and the like. In the compound represented by the general formula (1), the aliphatic hydrocarbon group which may have a substituent represented by R ₁ , R ₂ and R ₃ has 1 to 22 carbon atoms, preferably 3 carbon atoms. To 16 alkyl groups or 3 to 22 carbon atoms
Desirably, preferably 4 to 16 alkenyl groups.
In addition, a substituent may be bonded to R ₁ , R ₂ and R ₃ , and examples of such a substituent include a hydroxyl group, an alkoxy group, an ester group, a halogen atom, a nitro group and a cyano group. Can be mentioned. Specific examples of the aliphatic hydrocarbon groups represented by R ₁ , R ₂ and R ₃ described above include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and n-hexyl group. Group, isohexyl group,
Heptyl group, n-octyl group, isooctyl group, octenyl group, nonyl group, n-decyl group, isodecyl group, decenyl group, dodecyl group, dodecenyl group, tetradecyl group,
Tetradecenyl group, hexadecyl group, hexadecenyl group, octadecyl group, octadecenyl group, icosyl group,
Examples thereof include, but are not limited to, an icosenyl group. In the general formula (1), R ₂ and R ₃ are preferably an aliphatic group containing an asymmetric carbon atom, and such an aliphatic group is derived from an optically active compound having an asymmetric carbon atom. .

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

As will be described later, when the compound of the general formula (1) is produced from a phosphorus-containing compound, R ₂ and R ₃ can be introduced by using a phosphorus-containing compound and R ₂ X or R ₃ X (X is a halogen atom). ) Is the usual method (Tables 3, 4, 5,
7), a halide containing an asymmetric carbon atom (R ₂ X,
R ₃ X) can be easily obtained by employing a conventionally known method, for example, a method of reacting the above-mentioned optically active alcohol with dry hydrogen halide in the presence of sulfuric acid. Liquid crystal compounds containing a phosphorus atom are often studied as lyotropic liquid crystals in which a phospholipid, which is a component of a biological membrane, exhibits a liquid crystal phase at a specific concentration. However, can be applied to the display element is a thermotropic liquid crystal exhibiting a liquid crystal phase at a specific temperature, examples of adding a compound containing a phosphorus atom to existing thermotropic liquid crystal (G .Klose et al., Mol . Cry
St. Liq. Cryst. 150 201 (1987)) is known, but an example in which a phosphorus-containing compound is applied to the compounding component of the ferroelectric liquid crystal composition is not known.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

Table 6 shows the reaction formula when (d) X is --CH ₂ O--.

[Table 6]

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

On the other hand, 15.6 g (0.1 mol) of 4-methoxyphenylphosphine oxide and sodium bis (2-methoxyethoxy) aluminum hydride (Red-Al: 3.4M solution manufactured by Aldrich) 2
9.4 ml (0.1 mol) of tetrahydrofuran 2
It was dissolved in 00 ml and cooled to 0 ° C., and 14.2 g (0.1 mol) of methyl iodide was added to 10 ml of tetrahydrofuran.
What was dissolved in 0 ml was added dropwise, and at the room temperature after completion of the addition 8
Stir for hours. In addition to this, 3.4M Red-Al
29.4 ml was added and the mixture was cooled to 0 ° C. again, and then 28.4 g (0.1% ) of ((S) -1-methylheptyl tosylate ) was obtained.
(mol) was dissolved in 100 ml of tetrahydrofuran, and the mixture was stirred at room temperature for 8 hours after the addition was completed. Water was added to this solution to stop the reaction, and the solution extracted with ethyl acetate was dehydrated with anhydrous sodium sulfate. The solvent was evaporated, each diastereomer was separated and purified by silica gel column chromatography, and methyl- (R) -1-methylheptyl-4-methoxyphenyl- (R) -phosphine oxide 11.9 g (yield 38%), and methyl-
(R) -1-Methylheptyl-4-methoxyphenyl-
10.0 g of (S) -phosphine oxide (yield 32
%) Was obtained. For each diastereomer, using methylene chloride as a solvent, 10 equivalents of BBr ₃ was added at −78 ° C. to carry out a reaction for converting a methoxy group into a hydroxy group, and the mixture was returned to room temperature and water was added to decompose BBr _3. After stopping the reaction with ethyl acetate, the desired product was extracted with ethyl acetate to obtain methyl- (R) -1-methylheptyl-4-m almost quantitatively.
Hydroxyphenyl- (R) -phosphine oxide,
And methyl- (R) -1-methylheptyl-4-hydroxyphenyl- (S) -phosphine oxide were obtained.

Claims (2)

[Claims] 1. A liquid crystal compound represented by the following general formula (1). [Chemical 1] 2. A liquid crystal composition containing a compound represented by the following general formula (1). [Chemical 1]