JPH0669997B2 - Amine derivative - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a compound exhibiting a novel liquid crystal, a method for producing the same, and a liquid crystal element using the compound.

[Conventional technology and its problems]

Many known liquid crystal compounds include a so-called nematic liquid crystal. Although this compound is the mainstream of compounds or compositions currently used in liquid crystal display devices, one of its disadvantages is its slow response speed,
It is said that only a response speed of the order of a few msec can be obtained, and as a result, it is said that the limit for increasing the size of the display is approaching.

In order to improve the drawbacks of such a conventional liquid crystal display device, the use of a liquid crystal having bistability has been proposed by Clark and Lagawell (JP-A-56-107216).
issue). This bistability liquid crystal is called a ferroelectric liquid crystal, and it has been noted that it can obtain a high-speed response and a memory property. Especially, in recent years, its practical application has been actively studied. There is an urgent need to develop phase materials.

Generally, a ferroelectric liquid crystal is a compound having an optically active site, and is expressed in a series of smectic phases having a molecular orientation in which the molecular long axis is tilted from the normal direction of the layer. Among them, the chiral smectic C (hereinafter abbreviated as S _C ^* ) phase is practically superior because of its relatively low voltage operability.

As described above, the ferroelectric liquid crystal has a very fast response speed due to its spontaneous polarization, can express a bistable state with a memory property, and has an excellent viewing angle. Suitable as a display material for large-capacity screens.

As such a ferroelectric liquid crystal, 4- (4-decyloxybenzylideneamino) cinnamic acid-2-methylbutyl ester (hereinafter abbreviated as DOBAMBC) synthesized by RB Meyer et al. In 1975 is known (J. .Physique 36 L-69
(1975)).

This DOBA MBC has a chemical stability because it contains a Schiff base in the structure. Therefore, various physically and chemically stable compounds were searched for as ferroelectric liquid crystal materials, and currently, 4- (4-nalkyloxyphenyl) -1-carboxylic acid-2-methylbutyl ester (hereinafter referred to as CN , Etc.) is the main focus of the search for ester compounds. However, the ester compounds such as CN do not show the S _C ^* phase, or if they do, the temperature range where the S _C ^* phase appears is narrow, and the phase sequence that differs when the liquid crystal is heated or cooled. Since it is a monotropic liquid crystal that shows, there are few that can withstand practical use (Liquid Crysta
ls and Ordered Fluids 4 (1984)).

On the other hand, many ferroelectric liquid crystal compounds containing a hetero atom are known, but as a compound containing a nitrogen atom, a compound containing a hetero ring such as a pyrimidine ring (Japanese Patent Application Laid-Open No. 61-22072,2).
4576,129170), and DOBAMBC and other Schiff bases and the like as binding groups.

Among the compounds containing a nitrogen atom as a bonding group, the Schiff base has poor chemical stability as described above. Further, compounds containing an amide bond generally have a high melting point, and it is difficult to exhibit liquid crystallinity, so that they cannot be said to be effective.

As an example of introducing a nitrogen atom in the form of an amine, first, an amine is introduced from a tranexamic acid as a raw material in an alkyl chain to provide an inexpensive liquid crystal compound having a wide liquid crystal temperature range (Japanese Patent Application No. -158993). Further, as an example of introducing as an aromatic amine, there is an example of introducing an aromatic secondary amine (JP-A-63-2961, JP-A-2-53756).

However, only the example showing a narrow temperature range showing liquid crystallinity and high temperature is disclosed, and it is not yet in a practical stage.

[Means for Solving the Problems]

An object of the present invention is to provide a novel amine derivative that is chemically stable and exhibits liquid crystallinity in a wide temperature range.

Furthermore, the present invention provides a method for producing a novel liquid crystal compound using an N, N-disubstituted amine derivative as an intermediate, which makes it easy to change the type of alkyl group. Further, the type and length of the alkyl group and the type of the ester group can be easily changed, and the type of the liquid crystal phase that develops in the liquid crystal state and the temperature range can be controlled, and at least one type of the liquid crystal compound is contained as a blending component. A liquid crystal composition is provided.

In the present invention, by using an N, N-disubstituted amine derivative as an intermediate and reacting it with a biphenyl derivative to effect esterification, a compound having stable liquid crystallinity over a wide temperature range was successfully synthesized. .

That is, the general formula (I) [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those partially substituted with halogen, R ₂ represents a methyl or ethyl group, and R ₃ represents the number of carbon atoms. 1 to 20 straight-chain alkyl groups, X represents COO or OCO, and m and n each represent 0 or 1. ] By varying the combination of the values of R ₁ , R ₂ , R ₃ , m, n, and X of the compound represented by the above formula, compounds having various liquid crystallinity can be obtained.

The amine derivative of the present invention is a N, N-disubstituted amine derivative moiety having adjacent aromatic rings, And biphenyl derivative part And two are linked by an ester bond represented by X.

With respect to R ₁ , it is an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those in which a part thereof is halogen-substituted, and preferably having 3 to 8 carbon atoms. Specific examples of R ₁ include 2-octyl group, 2-chloropropyl group, (S) -2
-Methylbutyl group and the like can be mentioned, and (S) -2-methylbutyl group is preferable because it can be obtained at a low cost.

By introducing an optically active group with R ₁ in this way, the compound is made to have ferroelectricity.

R ₂ is a methyl group or an ethyl group. A preferable result is obtained with a methyl group, and a similar effect is obtained with an ethyl group. When the carbon number of R ₂ is 3 or more, the liquid crystallinity is deteriorated, which is not preferable.

R ₃ represents a linear alkyl group having 1 to 20 carbon atoms, preferably 7 to 18 carbon atoms, and when the carbon number is 6 or less or 19 or more, the temperature range of the smectic phase tends to be narrowed.

X represents COO or OCO, and when X is COO, the cholesteric property tends to increase, and when X is OCO, the smectic property tends to increase.

m and n each represent 0 or 1, but 0 when m is 1.
Compared with the above case, the tendency to exhibit enantotropic liquid crystallinity is stronger (see Examples 1 to 7 and Examples 8 and 9). Furthermore n
When 1 is 1, the melting point tends to be lower than when 0, and it is preferable in terms of practical use (see Example 1 and Examples 2 to 9).

The compound of the present invention can be produced according to the following production method.

First, in the general formula (I), the production method differs depending on whether the ester bond represented by X is COO or OCO. When X = COO (represented by general formula (Ia)), a carboxyl group is attached to the para position of the phenyl group of the tertiary amine derivative moiety (represented by general formula (II)).
And a biphenyl derivative having a hydroxyl group at the 4-position (represented by general formula (III)) are reacted. In the case of X = OCO (represented by the general formula Ib), it can be obtained by reacting the above-mentioned compounds (represented by the general formulas (IV) and (V) in which the carboxyl groups are replaced with the hydroxyl groups in the same manner. That is, when X is a compound represented by COO, the compound of the general formula (II) And a salt thereof and a compound represented by the general formula (III) By esterifying the compound represented by the general formula (Ia), the general formula (Ia) [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those partially substituted with halogen, R ₂ represents a methyl or ethyl group, and R ₃ represents the number of carbon atoms. It represents a linear alkyl group of 1 to 20, and m and n each represent 0 or 1. ] The compound represented by this is obtained.

When X is a compound represented by OCO, the compound represented by the general formula (IV) And a salt thereof and a compound represented by the general formula (V) By esterifying the compound represented by the general formula (Ib) [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those partially substituted with halogen, R ₂ represents a methyl or ethyl group, and R ₃ represents the number of carbon atoms. It represents a linear alkyl group of 1 to 20, and m and n each represent 0 or 1. ] The compound represented by these can be obtained.

Esterification is performed by dicyclohexylcarbodiimide (hereinafter
DCC) or thionyl chloride.

The amine intermediates represented by the general formulas (II) and (IV) are
It can be obtained by attaching a protecting group to the corresponding active hydroxyl group and then N-alkylating an alkyl halide having an alkyl group corresponding to R ₁ and R ₂ with a base such as sodium hydride.

That is, in the compound represented by the general formula (II), first, a corresponding commercially available primary amine is used as a raw material, and a t-butyloxycarbonyl group or the like is introduced as a protecting group of the amine, and R ₂
By carrying out N-alkylation with an alkyl halide corresponding to and simultaneously esterifying, a protective group for the carboxyl group can be formed (see FIG. 1 (A)). Then, the compound (II) can be obtained by deprotecting with hydrochloric acid, N-alkylating with an alkyl halide corresponding to R ₁ and finally hydrolyzing the ester (see FIG. 1 (B)).

Especially when m = 0 and when R ₂ is methyl, it is possible to shorten the one-step reaction by using commercially available N-methylaminobenzoic acid and esterifying with methanol or ethanol (Fig. 1). (See (C)). The compound represented by (IV) leads to an amine site by reduction of a nitrile when m = 1 and reduction of a nitro group when m = 0 (second
(See Figures (D) and (E)), and after attaching a protecting group to the phenolic hydroxyl group and the amine moiety in almost the same manner as in (II),
It can be obtained by N-alkylation with an alkyl halide corresponding to R ₁ and R ₂ (see FIG. 2 (F)). At this time,
A protective group for the phenolic hydroxyl group is required, but by using a p-toluenesulfonyl group when m = 1 and a benzyl group when m = 0, the reduction reaction and deprotection reaction can be performed in good yield. it can.

1 and 2 show reaction routes of the compounds represented by the general formulas (Ia) and (Ib) via the amine intermediates (II) and (IV).

The compound produced by the above method is purified by column chromatography and recrystallization.

The compound represented by the general formula (III) is disclosed in Japanese Patent Application No. 1-158993.
It can be obtained in the same manner as the method shown in. As the compound represented by the general formula (V), a commercially available product can be used.

[Action]

General formula (I) in the present invention [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those partially substituted with halogen, R ₂ represents a methyl or ethyl group, and R ₃ represents the number of carbon atoms. 1 to 20 straight-chain alkyl groups, X represents COO or OCO, and m and n each represent 0 or 1. The compound [] is an amine derivative having a low melting point and exhibiting very stable liquid crystallinity.

In particular, a compound having an amino group existing across a methylene group (a compound of m = 1 in the general formula (I)) exhibits enantiotropic liquid crystallinity, which means that the amino group promotes polarization of the molecule, It is presumed that the liquid crystal array is easily taken. Further, in the compound having an amino group existing in the form of an aromatic amine (the compound of m = 0 in the general formula (I)), the liquid crystallinity greatly varies depending on the value of X in the general formula (I). (See Examples 8 and 9). It is considered that this is because the conjugated system via the benzene ring is greatly involved in the polarization state of the molecule and the liquid crystal alignment state.

From these, the compound having an amine in the molecule is
It was found that it has an effect of improving liquid crystallinity unlike an amide bond having a strong intermolecular hydrogen bond.

Furthermore, the introduction of asymmetric carbon in the vicinity of the nitrogen atom has the effect of exhibiting ferroelectricity in a stable and wide temperature range.

The compound of the present invention is a novel amine derivative having applicability to a liquid crystal display device having excellent responsiveness and memory property for the above reasons.

Further, the compound of the present invention, by blending with the already known strong fusible liquid crystal, to widen the temperature range showing strong fusible property up and down,
Responsiveness can be improved, and it can be compounded with a liquid crystal which is not optically active so as to have a strong melting point.

[Examples] Hereinafter, the compounds of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Hereinafter, Cry, Ch, S _A , S _C ^* , Iso phases are crystals, cholesteric phase, smectic A phase, chiral smectic C phase,
It shows an isotropic liquid, and S _X shows a higher-order structure of a smectic phase.

The compound of the present invention was purified by silica gel chromatography and recrystallization with alcohol, hexane and the like.

The measured values of the phase transition points shown below may be slightly affected by the purity of the substance.

Example 1 4- [N- (S) -2-Methylbutyl-N-methylaminomethyl] -benzoic acid 4 ″ -heptyloxycarbonyl-4 ′
-Synthesis of biphenyl ester.

(1-1) Synthesis of 4- (Nt-butyloxycarbonylaminomethyl) benzoic acid.

4-Aminomethylbenzoic acid 7.6 g in dioxane-water (2: 1) 1
Dissolve in 50 ml and under ice cooling 1 molar aqueous sodium hydroxide solution 50
ml and di-t-butyl dicarbonate 12.0 g dioxane (2
5 ml) solution was added dropwise over 10 minutes. Return to room temperature, 2.5
After stirring for an hour, the reaction solution was concentrated under reduced pressure to about 1/3 on an aqueous solution at an external temperature of 50-60 ° C, and about 40 ml of 1N hydrochloric acid was added dropwise under ice cooling,
Adjusted to H3-4. Extract with ethyl acetate (40ml x 3),
The organic layer was washed with purified water (30 ml) and saturated saline (30 ml), dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The obtained crude crystals were washed with isopropyl ether and then recrystallized from ethyl acetate to give 4- (Nt-
Butyloxycarbonylaminomethyl) benzoic acid 9.9g
(Yield 79%) was obtained.

(1-2) Synthesis of 4- (Nt-butyloxycarbonyl-N-methylaminomethyl) benzoic acid methyl ester.

DM compound of 8.8 g of the compound obtained in (1-1) and 17.4 ml of methyl iodide
Dissolve in F (80 ml), 60% with slow stirring under ice cooling
4.2 g of sodium hydride was added little by little.

After returning to room temperature and continuing stirring overnight, the mixture was diluted with 80 ml of ethyl ether, and 5 ml of purified water was added dropwise under ice cooling. The organic layer is purified water (20 ml x 3), saturated aqueous sodium hydrogencarbonate solution (20 m
l), washed with saturated saline (20 ml) successively, dried over magnesium sulfate, and evaporated under reduced pressure to give crude oily methyl 4- (Nt-butyloxycarbonyl-N-methylaminomethyl) benzoate. 12.2 g of ester (100% yield) was obtained.

(1-3) Synthesis of 4- (N- (S) -2-methylbutyl-N-methylaminomethyl) benzoic acid methyl ester.

To 12.2 g of the compound obtained in (1-2), 20 ml of 4N hydrochloric acid-ethyl acetate solution was added under ice-cooling, and the mixture was stirred for 1 hour, and then the resulting crystals were collected and methyl 4- (N-methylaminomethyl) benzoate was added. 6.8 g (90% yield) of ester hydrochloride was obtained. Crystals obtained 6.
Dissolve 5 g in DMF 30 ml, and under ice cooling, triethylamine 4.2 ml,
5.0 g of (S) -2-methylbutyl bromide was added. 60%
Sodium hydride (1.3 g) was added little by little, and the mixture was heated at 80 ° C for 1 to 2 hours. After cooling, it was diluted with 80 ml of ethyl ether, and 5 ml of purified water was slowly added dropwise. The organic layer is purified water (20m
l), a saturated aqueous solution of sodium hydrogencarbonate (20 ml) and a saturated aqueous solution of sodium chloride (20 ml) were successively washed, dried over magnesium sulfate and the solvent was distilled off under reduced pressure.

Column chromatography was performed using 80 g of the obtained yellow oily silica gel, and ethyl acetate-hexane (1:
A colorless oily 4- (N- (S) -2-methylbutyl-N-methylaminomethyl) benzoic acid methyl ester from the fraction of 6) 3.
9 g (yield 52%) was obtained.

(1-4) Synthesis of 4- (N- (S) -2-methylbutyl-N-methylaminomethyl) benzoic acid hydrochloride.

Dissolve 3.9 g of the compound obtained in (1-3) in 10 ml of 6N hydrochloric acid,
The mixture was stirred at 0 ° C for 6 hours. After distilling off the solvent under reduced pressure, it was recrystallized from isopropanol-ether to give 4- (N-
3.4 g (80% yield) of (S) -2-methylbutyl-N-methylaminomethyl) benzoic acid hydrochloride was obtained.

(1-5) Synthesis of target compound.

147 mg of the compound obtained in (1-4) and 4 obtained by a conventional method
-Hydroxy-4'-biphenylcarboxylic acid heptyl ester 185 mg was dissolved in dichloromethane 3 ml, dicyclohexylcarbodiimide 134 mg and 4-pyrrolidinopyridine 8 mg
Was added, and the mixture was stirred at room temperature overnight. The solvent was distilled off under reduced pressure, 20 mg of ethyl acetate was added, and the mixture was stirred for a while and passed. The obtained crystals were dissolved in 30 ml of a saturated aqueous solution of sodium hydrogen carbonate to remove insoluble matter, and then extracted with ethyl acetate (20 ml × 3).
The organic layer was washed with saturated brine (20 ml), dried over magnesium sulfate, and the solvent was evaporated under reduced pressure.

The obtained crude crystals were recrystallized twice from hexane to obtain 43 mg (yield 15%) of the title compound as a colorless powder.

The structure of the obtained compound was confirmed by ¹ H-NMR and IR.

Next, the results of measuring the phase transition temperature of this substance are shown in Table 1. The phase transition temperature was determined by visual observation using a polarization microscope and a differential scanning calorimeter.

Further, Table 1 also shows the values of spontaneous polarization. The spontaneous polarization was measured by the following method.

(Measurement of Spontaneous Polarization) After heating a compound to form an isotropic liquid, the compound is injected into a 3.3 μm-thick cell made of a glass plate with a transparent electrode coated with polyimide and subjected to rubbing treatment, and The temperature was gradually lowered from the state to orient the smectic phase. Than the temperature of expressing the S _C ^* phase the temperature is lowered from this state further
Applying a triangular wave voltage at a temperature 10 ° C lower (Miyasato et a
l., Japanese Journal of Applied Physics, Vol.22, No.1
0, p.L661, 1983) was used to measure the spontaneous polarization value (applied voltage 30 Vp _- p, 50 Hz).

Examples 2 to 6 Synthesis of 4- (N- (S) -2-methylbutyl-N-methylaminomethyl) benzoic acid 4 ″ -alkoxy-4′-biphenyl ester.

In the general formula (I), X is COO, m is 1, and R ₁ , R ₂ , R ₃ and n are groups shown in Table 1, respectively. Synthesized.

The structures of the obtained compounds were confirmed by ¹ H-NMR and IR, respectively.

Table 1 shows the results of measuring the phase transition temperature and spontaneous polarization of these compounds by the methods described in Example 1.

[Example 7] 4-tetradecyloxy-4'-biphenylcarboxylic acid 4-
[N- (S) -2-methylbutyl-N-methylaminomethyl]
Synthesis of phenyl ester.

(7-1) Synthesis of 4-aminomethylphenyl tosylate.

3.64 g of p-cyanophenol was dissolved in 60 ml of dichloromethane, 4.2 ml of triethylamine and a dichloromethane solution (10 ml) of p-toluenesulfonyl chloride were added dropwise under ice cooling, and the mixture was stirred at room temperature for 2 hours. The reaction solution was washed successively with purified water (10 ml × 2) and saturated saline (10 ml), dried over magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain 8.0 g of crude 4-cyanophenyltosylate crystals.

Lithium aluminum hydride (2.28 g) was suspended in THF (200 ml), concentrated sulfuric acid (3.1 g) in THF (20 ml) was added dropwise under ice-cooling, and the solution was stirred at room temperature for 1 hour. 4-cyanophenyltosylate (8.0 g in THF (80 ml) ) The solution was added dropwise and heated at 50 ° C. for 2 hours. The mixture was ice-cooled again, 30 ml of THF-purified water (1: 1) was slowly added dropwise, and the mixture was stirred until gas evolution stopped, and 50 ml of 10% aqueous sodium hydroxide solution was added. The organic layer is separated,
The aqueous layer was extracted with ether (50 ml x 2). The organic layers were combined, washed with purified water (30 ml × 2) and saturated saline (30 ml), dried over magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain crude crystals of 4-aminomethylphenyl tosylate (8.8 g, yield). 100
%) Was obtained.

(7-2) Synthesis of 4- [N- (S) -2-methylbutyl-N-methylaminomethyl] -phenyl tosylate.

Using the compound obtained in (7-1), (1-1) to (1-
N-alkylated by the method described in 3) to give 4- [N-
(S)-(2) -methylbutyl-N-methylaminomethyl] -phenyl tosylate was obtained.

(7-3) Synthesis of 4- [N- (S) -2-methylbutyl-N-methylamino] -phenol hydrochloride.

785 mg of the compound obtained in (7-2) was dissolved in 100 ml of an ethanol-0.5N sodium hydroxide aqueous solution mixture (1: 1), and the mixture was heated under reflux for 2 hours. The reaction mixture was ice-cooled, neutralized with acetic acid and then extracted with ether (50 ml × 3). The organic layer was washed successively with saturated aqueous sodium hydrogen carbonate solution (50 ml) and saturated brine (50 ml), dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. To the residue was added 10 ml of 4N hydrochloric acid-ethyl acetate solution, the solvent was distilled off under reduced pressure again, and 4- [N- (S) -2-methylbutyl-
N-methylamino] -phenol hydrochloride 350 mg (yield 66
%) Was obtained.

(7-4) Synthesis of target compound 350 mg of the compound obtained in (7-3) and 4 obtained by a conventional method
-Tetradecyloxy-4'-biphenylcarboxylic acid 687
200 mg of the title compound by the method described in (1-5) using mg.
(Yield 24%) was obtained.

The structure of the obtained compound was confirmed by ¹ H-NMR and IR. Further, Table 1 shows the results of measuring the phase transition temperature and the spontaneous polarization by the method shown in Example 1.

Example 8 Synthesis of 4- [N- (S) -2-methylbutyl-N-methylamino] benzoic acid 4-octyloxy-4'-biphenyl ester.

(8-1) Synthesis of 4- [N- (S) -methylbutynyl-N-methylamino] benzoic acid hydrochloride.

20 ml of methanol was cooled to -10 ° C, 3 ml of thionyl chloride was added dropwise, and after stirring for 10 minutes, commercially available 4-methylaminobenzoic acid 4.0 g
Was added, and the mixture was stirred at room temperature overnight. The solvent was distilled off under reduced pressure and Et ₂ O was added.
(10 ml) was added and the resulting crystals were collected to give 5.0 g of 4-methylaminobenzoic acid hydrochloride (yield 93%.
-2), using the method described in (1-3), 4- [N-
4- (N- (S) -2-Methylbutyl-N-methylamino] benzoic acid hydrochloride was obtained through (S) -2-methylbutyl-N-methylamino] benzoic acid methyl ester.

(8-2) Synthesis of target compound.

221 mg of the compound obtained in (8-1) was dissolved in 5 ml of carbon tetrachloride, and 0.2 ml of thionyl chloride and N, N-dimethylformamide 1 were dissolved.
A drop was added and the mixture was heated under reflux for 1 hour. The solvent was distilled off under reduced pressure and the obtained residue was dissolved in toluene (5 ml) and added to a toluene (5 ml) -pyridine (1 ml) solution of 4-octyloxy-4'-hydroxybiphenyl obtained by a conventional method under ice cooling. The mixture was added dropwise, and the mixture was heated under reflux for 1 hour.

After cooling, dilute with ethyl acetate (30 ml) and purify water (10 ml x
2), washed successively with saturated saline (10 ml), dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue obtained
Column chromatography was performed using 30 g of silica gel, the 10% ethyl acetate-hexane fraction was concentrated, and recrystallized from hexane to give 120 mg of the title compound as colorless needles (yield 24
%) Was obtained.

The structure of the obtained compound was confirmed by ¹ H-NMR and IR.
Further, Table 1 shows the results of measuring the phase transition temperature by the method described in Example 1.

[Example 9] 4-octyloxy-4'-biphenylcarboxylic acid 4- [N-
Synthesis of (S) -2-methylbutyl-N-methylamino] phenyl ester.

(9-1) Synthesis of 4-benzyloxyaniline hydrochloride.

Dissolve 4.17 g of p-nitrophenol in 40 ml of ethanol,
Add 2.5 g of potassium carbonate and 3.9 ml of benzyl bromide to 1.5
Heated to reflux for hours.

The reaction solution was cooled, the precipitated crystals were collected, and washed with purified water. The obtained crude crystals were recrystallized from ethanol and colorless needle-shaped p-nitrophenol benzyl ether 6.4 g (yield
94%).

2.3 g of the obtained p-nitrophenol benzyl ether was suspended in 20 ml of acetic acid, 2.0 g of zinc powder was added, and the mixture was stirred at room temperature overnight. After removing the insoluble matter and concentrating the reaction mixture, ethyl acetate
After adding 50 ml, the mixture was washed successively with 10% aqueous sodium hydroxide solution (20 ml) and saturated saline (2 ml), dried over magnesium sulfate, and the solvent was evaporated. The residue was again dissolved in 20 ml of 4N acid salt-ethyl acetate solution and the solvent was distilled off to obtain 1.5 g of crude crystals of 4-benzyloxyaniline hydrochloride (yield 63%).

(9-2) Synthesis of 4- [N- (S) -2-methylbutyl-N-methylamino] phenol benzyl ether.

Using the compound obtained in (9-1), (1-1) to (1-
N-alkylated by the method described in 3) to give 4- [N-
(S) -2-Methylbutyl-N-methylamino] phenol benzyl ether was obtained.

(9-3) Synthesis of 4- [N- (S) -2-methylbutyl-N-methylamino] phenol.

1.0 g of the compound obtained in (9-2) and 100 m of palladium black
g was dissolved in 10 ml of ethanol, 2 ml of cyclohexene was added, and the mixture was heated under reflux for 1 hour. After removing unnecessary substances, the solvent was distilled off under reduced pressure to give 4- [NS) -2-methylbutyl-N as a pale yellow oil.
-Methylamino] phenol 610 mg (yield 86%) was obtained.

(3-4) Synthesis of target compound.

Using octyl 4-octyloxy-4'-biphenylcarboxylic acid 652 mg obtained by a conventional method and the compound 290 mg obtained in (9-3), the title compound 580 mg (yield 77 %) Was obtained.

The structure of the obtained compound was confirmed by ¹ H-NMR and IR. Further, the results of measuring the phase transition temperature and the spontaneous polarization by the method shown in Example 1 are shown in Table 1. Table 1 shows ¹ H-NMR and IR data of the compounds obtained in Examples 1 to 9.

[Effect of the Invention] As exemplified above, the compound of the present invention exhibits ferroelectricity in an extremely wide temperature range. Therefore, a novel compound useful as a material for a liquid crystal display device that applies an electro-optical effect in a practical temperature range alone or appropriately mixed with another nematic, smectic or ferroelectric liquid crystal can be easily and inexpensively prepared. Can be provided.

[Brief description of drawings]

FIG. 1 shows a reaction route of a compound represented by the general formula (Ia), and FIG. 2 shows a reaction route of a compound represented by the general formula (Ib).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C07C 229/60 C09K 19/20 9279-4H G02F 1/13 500 9225-2K

Claims (4)

[Claims] 1. A general formula (I) [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those partially substituted with halogen, R ₂ represents a methyl or ethyl group, and R ₃ represents the number of carbon atoms. 1 to 20 straight-chain alkyl groups, X represents COO or OCO, and m and n each represent 0 or 1. ] The amine derivative represented by these. 2. General formula (II) [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, a part of which is substituted with halogen, R ₂ represents a methyl or ethyl group, and m is 0 or 1 Represents ] The compound or its salt represented by the following general formula (III) [In the formula, R ₃ represents a linear alkyl group having 1 to 20 carbon atoms, and n
Represents 0 or 1. ] The compound of general formula (Ia) characterized by reacting a compound represented by [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those partially substituted with halogen, R ₂ represents a methyl or ethyl group, and R ₃ represents the number of carbon atoms. It represents a linear alkyl group of 1 to 20, and m and n each represent 0 or 1. ] The manufacturing method of the amine derivative represented by these. 3. General formula (IV) [In the formula, R ₁ represents an alkyl group having 4 to 12 carbon atoms and having an asymmetric carbon atom, including those in which a part thereof is substituted with halogen, R ₂ represents a methyl or ethyl group, and m is 0 or 1 Represents ] The compound or its salt represented by these, and general formula (V) [In the formula, R ₃ represents a linear alkyl group having 1 to 20 carbon atoms, and n
Represents 0 or 1. ] The compound represented by the general formula (Ib) characterized by reacting [In the formula, R ₁ represents an alkyl group having an asymmetric carbon atom having 1 to 12 carbon atoms, including those partially substituted with halogen, R ₂ represents a methyl or ethyl group, and R ₃ represents the number of carbon atoms. It represents a linear alkyl group of 1 to 20, and m and n each represent 0 or 1. ] The manufacturing method of the amine derivative represented by these. 4. A liquid crystal device comprising a composition containing at least one amine derivative according to claim 1 as a blending component.