JPH054944A - Optically active compound and liquid crystal composition containing the same compound - Google Patents

Abstract

PURPOSE:To obtain a new optically active compound having chemical stability and properties of inducing large spontaneous polarization by adding the compound to a SC liquid crystal composition. CONSTITUTION:An optically active compound shown by formula I [R is <=16C alkyl (one coincident with X is omitted) or alkoxy; R* is <=16C optically active alkyl; X is methyl, ethyl, F, Cl, CN and Y is COO, OCO or O; group shown by formula II is group shown by formula III to formula V, etc. (Z is H, halogen or CN); C* is optically active carbon; n is 0 or 1; n is 1 or 2; m+n>=2] such as (R)-2-n-hexyloxypropionic acid (S)-4-{4'-[4-(2-methyl)butyroyl]benzoyloxy-1,1'- biphenyl} ester. The compound is obtained by reacting an optical activator shown by formula VI with an optical activator shown by formula VII in the presence of a dehydrating agent such as dicyclohexylcarbodiimide. A new ferroelectric liquid crystal material having a wide temperature range of Sc* phase and high-speed response is obtained by using the compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel optically active compound and a chiral liquid crystal composition using the optically active compound.

[0002]

2. Description of the Related Art Liquid crystal display devices are characterized by low driving voltage, low power consumption, thinness and light weight, and are applied to calculators, watches, televisions and the like. Currently, nematic liquid crystals are widely used for these display materials, but the response speed is several tens of msec.
There was a drawback that it was slow. As one of attempts to improve this point, a display system using a ferroelectric liquid crystal has been proposed [N. A. Clark et al., Applied Phys. Lett.
36, 899 (1980)]. This method utilizes a chiral smectic C phase (hereinafter abbreviated as Sc ^* phase) of a ferroelectric liquid crystal, and the ferroelectric liquid crystal material exhibits the Sc ^* phase in a wide temperature range including room temperature. It is required that the polarization be large, have an appropriate tilt angle, have a small rotational viscosity, have a long helical pitch, be chemically stable, and the like. However, a ferroelectric liquid crystal compound satisfying all of these conditions is not known.
Therefore, when the ferroelectric liquid crystal is practically used as an electro-optical element, it is necessary to mix several kinds of ferroelectric liquid crystals or compounds that induce ferroelectricity and non-ferroelectric liquid crystals and use them as a composition. is there. To obtain a Sc ^* liquid crystal composition, a method of mixing a plurality of compounds having a Sc ^* phase is used ^.
Method for mixing non-ferroelectric liquid crystal with a compound exhibiting a phase, Sc
There is a method of adding an optically active compound to a non-optically active compound exhibiting a phase or a liquid crystal composition, and the final method is considered to be easy to obtain a low-viscosity and high-speed response. Therefore, it is becoming the mainstream at present. .

[0003]

The optically active compound to be added has such a property that it exhibits a large spontaneous polarization or induces a large spontaneous polarization in the composition, and that it gives a long helical pitch. Is desirable. The object of the present invention is to provide a novel optically active compound which is chemically stable and exhibits a large spontaneous polarization by itself or induces a large spontaneous polarization by being added to a Sc liquid crystal composition. An object of the present invention is to provide a novel ferroelectric liquid crystal material having a wide temperature range of Sc ^* phase using an optically active compound and responding at high speed.

[0004]

The present invention will be summarized as follows. The first invention of the present invention is represented by the general formula (Formula 1):

[0005]

[Chemical 1]

[Wherein R is a linear or branched alkyl group having 16 or less carbon atoms (excluding those corresponding to X) or an alkoxy group, R ^* is an optically active alkyl group having 16 or less carbon atoms, and X is A methyl group, an ethyl group, fluorine: chlorine, or a nitrile group, Y represents any one of —COO—, —OCO—, and —O—;

[0007]

[Chemical 2] The group represented by is represented by the following formula (Formula 3):

[0009]

[Chemical 3]

(Z is any one of hydrogen, halogen, and nitrile group), C ^* is optically active carbon, m is 0 or 1, n is 1 or 2, and m + n≤
It is represented by the optically active compound represented by 2].

A second invention of the present invention relates to a chiral liquid crystal composition, which is characterized by containing at least one component of the optically active compound of the first invention.

The first feature of the present invention is to realize an optically active compound which induces a large spontaneous polarization by employing a partial structure in which a carbonyl group is directly bonded to the core portion. The spontaneous polarization of a liquid crystal compound is caused by a dipole perpendicular to the molecular axis of liquid crystal. Most of the ferroelectric liquid crystals reported so far use an ester group or ether group dipole. When the dipole sandwiched between the core and optically active carbon is changed from an ether group or an ester group to a carbonyl group, the spontaneous polarization increases almost in proportion to the group moment of these groups. A methylene group may be interposed between the carbonyl group and the optically active carbon, but the direct connection of the carbonyl group and the optically active carbon has a remarkable effect in increasing spontaneous polarization. Examples of the R ^* group having optically active carbon at the 1-position are 1-methylpropyl group, 1-methylbutyl group, 1-methylpentyl group, 1-
Methylhexyl group, 1-methylheptyl group, 1-methyloctyl group, 1-methylnonyl group, 1-methyldecyl group, 1-methylundecyl group, 1-methyldodecyl group,
Examples thereof include a 1,3-dimethylbutyl group and a 1,6-dimethylheptyl group. In order to improve liquid crystallinity, it is desirable to introduce a methylene group between the carbonyl group and the optically active carbon. Examples thereof include 2-methylbutyl group, 2-
Examples thereof include a methylpentyl group, a 2-methylhexyl group, a 3-methylpentyl group and a 4-methylhexyl group.

The second feature of the present invention is that the above-mentioned optically active group containing a carbonyl group (optically active alkanoyl group) and another optically active group are introduced into one molecule with the core portion sandwiched therebetween. Is. When the signs of spontaneous polarization caused by two optically active groups are the same, it is possible to obtain a compound exhibiting or inducing a larger spontaneous polarization than a compound having each optically active group alone. Further, when the directions of the helices caused by the two optically active groups are opposite to each other, it is expected that the helices cancel each other out to increase the helix pitch of the molecule as a whole.

In order to make the signs of the spontaneous polarization caused by the two optically active groups the same, the following combinations must be taken.

When the absolute configuration of the alkanoyl group having an R ^* group having an odd number of branches is (S), The absolute configuration of O- is (R) when R is an alkyl group, If it is an oxy group and X is a methyl group, it is (R).

When the absolute configuration of the alkanoyl group having an R ^* group having a branch at an odd number position is (R), The absolute configuration of O- is (S) when R is an alkyl group, If it is a xy group and X is a methyl group, it is (S).

When the absolute configuration of the alkanoyl group having an R ^* group having a branch at an even position is (S), The absolute configuration of O- is (S) when R is an alkyl group, If it is a xy group and X is a methyl group, it is (S).

When the absolute configuration of the alkanoyl group having an R ^* group having a branch at an even position is (R), The absolute configuration of O- is (R) when R is an alkyl group, If it is an oxy group and X is a methyl group, it is (R).

Among the combinations in which the signs of spontaneous polarization caused by two optically active groups are the same, R having a branch at the 1-position
A compound having a ^* group gives a particularly large spontaneous polarization.

To obtain a compound having a long helical pitch,
It is necessary to make the directions of the helix caused by the two optically active groups opposite to each other. A combination of an alkanoyl group having an R ^* group having a branch at the 1-position and having an absolute configuration (S) and an optically active group having an absolute configuration (R) in which R is an alkoxy group and X is a methyl group. The compounds are examples. Since this compound also has the same sign of spontaneous polarization, it is a very useful compound in that it also exhibits large spontaneous polarization.

In the general formula (Formula 1), R is a methyl group,
Linear alkyl groups such as ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group,
Linear alkoxy groups such as methoxy group, ethoxy group, propyloxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group,
Isopropyl group, 1-methylpropyl group, 1-methylbutyl group, 1-methylpentyl group, 1-methylhexyl group, 1-methylheptyl group, 1-methyloctyl group,
1,3-dimethylpentyl group, 2-methylbutyl group, 3
Examples include branched alkyl groups such as -methylhexyl group and 2,6-dimethylheptyl group, and corresponding alkoxy groups, but branched alkyl groups or alkoxy groups are preferable in order to obtain large spontaneous polarization. .

Introduction of a halogen or cyano group into the core is often used as a means for increasing liquid crystallinity and a means for increasing spontaneous polarization.
This method is also effective in the present invention. That is, the introduction of fluorine, chlorine, bromine or a cyano group enhances liquid crystallinity,
It is effective in increasing spontaneous polarization.

In the present invention, the other component of the chiral liquid crystal composition containing the optically active compound represented by the general formula (Formula 1) may be a ferroelectric liquid crystal compound, or a non-chiral liquid crystallinity. It may be a compound.

[Production Method of Compound] The optically active compound represented by the general formula (Formula 1) is, for example, the following general formula (Formula 4):

[0025]

[Chemical 4]

An optically active phenol derivative such as a compound represented by the following general formula (Formula 5):

[0027]

[Chemical 5]

It is obtained by reacting an optically active carboxylic acid such as a compound represented by the formula (I) with R, C ^* , X, and X in the presence of a dehydrating agent such as dicyclohexylcarbodiimide.
Y, R ^* , (Chemical Formula 2), m and n are the same as above].

[0029]

[Chemical 6]

The optically active phenol derivative represented by the general formula (Formula 4) can be synthesized, for example, by the following route.

[0031]

[Chemical 7]

[0032]

[Chemical 8]

[0033]

[Chemical 9]

[In the formula, R, C ^* , X, Y, (Chemical Formula 2), and m are the same as above. R'represents a methyl group or an ethyl group, and Ts represents a p-toluenesulfonyl group.]

The optically active carboxylic acid represented by the general formula (Formula 5) can be synthesized, for example, by the following route (in the formula, R ^* and n are the same as above).

[0036]

[Chemical 10]

[0037]

[Chemical 11]

[0038]

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

Example 1 (R) -2-n-hexyloxypropionic acid (S)-
4- {4 '-[4- (2-methyl) butyroyl] benzoyloxy-1,1'-biphenyl} [In the general formula (1), R is n-hexyloxy group, X is methyl group, and Y is Wherein 1 is 1]

(1) Synthesis of (S) -2-methylbutyric acid chloride 40 g (0.39 mol) of (S) -2-methylbutyric acid and 70 g of thionyl chloride are mixed and gradually heated to 50-60. ℃
And reacted for 2 hours. After the reaction, the mixture was concentrated, and the residue was distilled under atmospheric pressure to obtain 42 g of (S) -2-methylbutyric acid chloride fraction having a bp of 116 to 118 ° C. as a colorless oil.

(2) (S) -4-amino (2-methyl)
36.2 g of (S) -2-methylbutyric acid chloride obtained in the synthesis (1) of butyrophenone
(0.3 mol) was poured into 27.0 g (0.2 mol) of acetanilide, 107 g of anhydrous aluminum chloride and 500 ml of 1,2-dichloroethane, and the mixture was stirred and refluxed for 3 hours. After cooling the reaction solution, it was poured into a dilute hydrochloric acid aqueous solution, the organic layer was separated, washed with water, and the solvent was distilled off to obtain a residue of 6
The mixture was stirred and refluxed in 200 ml of N hydrochloric acid for 4 hours. After cooling, the reaction solution was neutralized with a 20% caustic soda aqueous solution, extracted with methylene chloride (100 ml x 2), the organic layer was washed with water and concentrated, and the residue was separated by column (filler: Wakogel C-
200; Eluent: n-hexane / ethyl acetate = 3/1)
Then, 10.3 g of (S) -4-amino- (2-methyl) butyrophenone was obtained as a pale yellow oil. [Α] _D ²⁵ :
+ 21.5 ° (c = 0.98, CHCl ₃ ).

[0042]

[Chemical 12]

IR (neat): 3370, 3280, 29
40, 2850, 1660, 1605 cm ^-1 .

(3) Synthesis of (S) -4- (2-methylbutyroyl) benzoic acid (S) -4-amino- (2-methyl) butyrophenone obtained in (2) 8.9 g (0.05) Mol) was dissolved in 20 ml of concentrated hydrochloric acid and 20 ml of water, and a solution of 4.3 g (0.06 mol) of sodium nitrite in 10 ml of water was added dropwise at 0 to 5 ° C., and the mixture was stirred at the same temperature for 1 hour. After neutralizing the reaction solution,
CuCN 14.1 g (0.157 mol) in cold water 200
It was poured into a solution dissolved in ml and then stirred and refluxed for 30 minutes. After cooling the reaction mixture, 2 ml with 100 ml of ethyl ether.
It was extracted twice, the organic layer was separated, washed with water, then the solvent was distilled off, and the residue was refluxed in 100 ml of 40% aqueous sulfuric acid for 3 hours. After cooling, the precipitated crystals were collected by filtration, washed with water, and recrystallized from water-ethanol to obtain 4.6 g of (S) -4- (2-methylbutyroyl) benzoic acid as white crystals. mp. 1
01-103.5 ° C. [Α] _D ²⁵ : + 21.8 ° (c = 1.0, CHC
l ₃ ).

[0045]

[Chemical 13]

IR (KBr): 2950, 2870, 26
50, 2540, 1680, 1605 cm ^-1 .

(4) (R) -4-hydroxy-4'-
(2-n-hexyloxy) propanoyloxy-1,
Synthesis of 1'-biphenyl (R) -2-n-hexylpropionyl chloride 3.9 g
(20 mmol) was added to 4,4'-dihydroxy-1,1 '
-Biphenyl 3.9 g (20 mmol), pyridine 40
ml and methylene chloride 40 ml at room temperature, and the mixture was stirred at the same temperature for 2 hours. Dilute hydrochloric acid 15
Pour into 0 ml and extract twice with 100 ml methylene chloride,
The organic layer was washed 3 times with 100 ml of water and dried over anhydrous MgSO ₄ . After the solvent was distilled off, the residue was subjected to column purification (filler: Wakogel C-200; eluent: n-hexane / ethyl acetate = 5/1) and (R) -4-hydroxy-4 '-(2
-N-hexyloxy) propanoyloxy-1,1 '
3.2 g of biphenyl were obtained as white crystals. mp. 9
1-94.5 ° C. [Α] _D ²⁵ : + 39.4 ° (c = 0.97, CHC
l ₃ ).

[0048]

[Chemical 14]

IR (KBr): 3400, 2950, 28
60,1740,1605 cm ^-1 .

(5) (R) -2-n-hexyloxypropionic acid (S) -4- {4 '-[4- (2-methyl)
Synthesis of (butyroyl] benzoyloxy-1,1′-biphenyl} 1.1 g (5.3 mmol) of (S) -4- (2-methylbutyroyl) benzoic acid obtained in (3) and 1.3 g of dicyclohexylcarbodiimide (6.1 mmol) was dissolved in 50 ml of methylene chloride and (R) -4-hydroxy-4 '-(2-n-hexyloxy) propanoyloxy-1,1 obtained in (4) at 10 ° C or lower. ′ -Biphenyl 1.
A solution prepared by dissolving 7 g (5.0 mmol) in 25 ml of methylene chloride was added dropwise, and the mixture was stirred at room temperature for 24 hours. After the reaction, the precipitate was filtered off, the filtrate was concentrated under reduced pressure, and the residue was column-separated (filler: Wakogel C-200 [manufactured by Wako Pure Chemical Industries, Ltd.]; eluent: n-hexane / ethyl acetate = Two
The crude crystal 1.3 g obtained by 0/1} was recrystallized from ethanol to give (R) -2-n-hexyloxypropionic acid (S) -4- {4 ′-[4- (2-methyl)). Butyroyl] benzoyloxy-1,1′-biphenyl} 600
mg was obtained as white needles. mp. 74.0 to 76.0 ° C and 100.5 to 101.
5 ° C. [Α] _D ²⁵ : + 42.1 ° (c = 0.35, CHC
l ₃ ).

[0051]

[Chemical 15]

IR (KBr): 2950, 2870, 17
70, 1740, 1680, 1605 cm ^-1 . Elemental analysis (C ₃₃ H ₃₈ O ₆₎ Calculated: C% 74.69; H% 7.22 Found: C% 74.77; H% 7.04

Example 2 (R) -2- (1-methylbutoxy) propionic acid (S) -4- {4 '-[4- (2-methyl) butyroyl] benzoyloxy-1,1'-biphenyl} [In the general formula (Formula 1), R is a 1-methylbutoxy group,
X is a methyl group, Y is Compound that is 1]

(1) Synthesis of 4-bromobenzyl- (1-ethoxy) ethyl ether 11.2 g (60 mmol) of p-bromobenzyl alcohol, 5.4 g (75 mmol) of ethyl vinyl ether.
And 0.37 g of pyridinium p-toluenesulfonate were dissolved in 100 ml of methylene chloride and stirred at room temperature for 20 hours. After the reaction, it was washed twice with 150 ml of water, dried over anhydrous MgSO ₄ , and the solvent was distilled off to give the residue 4-bromobenzyl- (1-ethoxy) ethyl ether 15.4.
g was obtained as a colorless oil.

[0055]

[Chemical 16]

IR (neat): 2990 cm ^-1 .

(2) Synthesis of (S) -4- (2-methyl) butyroylbenzyl alcohol 0.64 g of metallic magnesium and 5.18 g of 4-bromobenzyl- (1-ethoxy) ethyl ether obtained in (1)
The Grignard reagent obtained by reacting (20 mmol) with tetrahydrofuran was cooled to -65 ° C, and (S) -2-methylbutyric acid chloride obtained in (1) of Example 1 was added thereto.
37 g (19.8 mmol) of methylene chloride solution (20
ml) was added dropwise at -70 to -65 ° C, and the mixture was stirred at the same temperature for 3 hours and then at room temperature for 1 hour. The reaction solution was cooled to 0 ° C., 30 ml of 1N hydrochloric acid was added dropwise, the mixture was stirred at the same temperature for 1 hour, extracted twice with 70 ml of ethyl acetate, and the organic layer was washed with 100 ml of water three times, and then dried over anhydrous MgSO ₄ . Dried. After the desiccant was filtered off, the solvent was distilled off and the residue (S) -4-
2.4 g of (2-methyl) butyroylbenzyl alcohol
Was obtained as a pale yellow oil. [Α] _D ²⁵ : + 24.1 ° (c = 2.0, CH ₂ C
l ₂ ).

[0058]

[Chemical 17]

IR (neat): 3450, 2970, 16
80 cm ^-1 .

(3) Synthesis of (S) -4- (2-methyl) butyroylbenzoic acid 5.6 g (29.3) of (S) -4- (2-methyl) butyroylbenzyl alcohol obtained in (2). Mmol) and 6.9 g (43.5 mmol) of potassium permanganate were suspended in 400 ml of acetone and stirred at room temperature for 3 hours. After adding 4 g of sodium sulfite to the reaction solution and stirring the mixture, 200 ml of 1N hydrochloric acid was injected, the mixture was stirred, the insoluble matter was filtered off, and the solvent was distilled off. The residue is methylene chloride 10
Extracted twice with 0 ml, washed the organic layer three times with 200 ml of water,
After drying over anhydrous MgSO ₄ , the solvent was distilled off. Residue 5.
7 g was recrystallized from n-hexane-methylene chloride to give (S) -4- (2-methyl) butyroylbenzoic acid 4.1.
g was obtained as white crystals. mp. 101 to 103.5
° C. [Α] _D ²⁵ : + 21.8 ° (c = 1.0, CH ₂ C
l ₂ ).

[0061]

[Chemical 18]

IR (KBr): 2950, 1680 cm ^-1 .

(4) Synthesis of methyl (R) -2- (1-methylbutoxy) propionate 56 g (0.54 mol) of (R) -methyl lactate and 128 g (0.65 mol) of 2-iodopentane were added to 70%. After heating to ℃, add 9.3g (0.40mol) of silver oxide and add
Stirring reaction was carried out at 0 to 80 ° C. for 8 hours. After cooling, the precipitate was filtered off and the filtrate was distilled under reduced pressure to obtain a bp of 104 to 106 ° C / 9.
18.5 g of methyl (R) -2- (1-methylbutoxy) propionate of a 6 mmHg fraction was obtained as a colorless oil.
[Α] _D ²⁵ : + 54.4 ° (neat).

[0064]

[Chemical 19]

IR (neat): 2940, 1730 cm ^-1 .

(5) Synthesis of (R) -2- (1-methylbutoxy) propionic acid 17.5 g (0.1) of methyl (R) -2- (1-methylbutoxy) propionate obtained in (4) Mol) and formic acid 20 ml
And 10 ml of concentrated hydrochloric acid were mixed and agitated at 60 to 70 ° C. for 6 hours. After injecting 150 ml of water into the reaction solution, the mixture was extracted twice with 100 ml of ethyl acetate, the organic layer was washed with 200 ml of water three times, and dried over anhydrous MgSO ₄ . After the desiccant was filtered off, the solvent was distilled off to obtain 11.2 g of residual (R) -2- (1-methylbutoxy) propionic acid as a colorless oily substance.
[Α] _D ²⁵ : + 45.2 ° (neat).

[0067]

[Chemical 20]

IR (neat): 2940, 1700 cm ^-1 .

(6) (R) -4-hydroxy-4'-
[2- (1-methylbutoxy) propanoyloxy]-
Synthesis of 1,1'-biphenyl 4.65 g (29 mmol) of (R) -2- (1-methylbutoxy) propionic acid obtained in (5) and 6.9 g of thionyl chloride were dissolved in 25 ml of methylene chloride and stirred. The mixture was refluxed for 2 hours and then concentrated. Then, 4.4 g of the residue was dissolved in 20 ml of methylene chloride, and this was dissolved in a solution of 4.0 g (22 mmol) of 4,4'-dihydroxy-1,1'-biphenyl, 3.5 g of pyridine and 20 ml of methylene chloride at room temperature. Dropwise, and then treated in the same manner as in (4) of Example 1, 11 g of the residue was subjected to column purification (filler: Wakogel C
-200; Eluent: n-hexane / ethyl acetate = 10 /
1) and then (R) -4-hydroxy-4 '-[2- (1-
3.0 g of methylbutoxy) propanoyloxy] -1,1′-biphenyl was obtained as white crystals. mp. 107-115 ° C. [Α] _D ²⁵ : + 40.3 ° (
c = 2.03, CH ₂ Cl ₂ ).

[0070]

[Chemical 21]

IR (KBr): 3480, 2990, 17
50 cm ^-1 .

(7) Synthesis of (R) -2- (1-methylbutoxy) propionic acid (S) -4- {4 '-[(2-methyl) butyroyl] benzoyloxy-1,1'-biphenyl} 1.2 g (5.8 mmol) of (S) -4- (2-methyl) butyroylbenzoic acid obtained in (3) and (R) -4-hydroxy-4 ′-[2- (2) obtained in (6). (1-Methylbutoxy) propanoyloxy] -1,1′-biphenyl (1.9 g, 5.8 mmol) was used in the same manner as in (5) of Example 1 to obtain a crude product obtained after column separation. Recrystallize 1.0 g of crystals from ethanol to give (R) -2- (1
-Methylbutoxy) propionic acid (S) -4- {4'-
[(2-methyl) butyroyl] benzoyloxy-1,
610 mg of 1'-biphenyl} was obtained as white needle crystals.
mp. 59.0-61.0 ° C. [Α] _D ²⁵ : + 47.9 ° (c = 1.0, CHC
l ₃ ).

[0073]

[Chemical formula 22]

IR (KBr): 2950, 1765, 17
30, 1680 cm ^-1 . Elemental analysis value (C ₃₂ H ₃₆ O ₆ ) calculated value: C% 74.40; H% 7.02 measured value: C% 74.55; H% 6.99

Example 3 (S) -4- [4 '-(2-methyl) octanoyl-
1,1'-Biphenyl-4-carbonyloxy] benzoic acid (R) -1-methylheptyl Formula 2) is a phenyl group, R ^* is a 1-methylheptyl group, m
Is 0 and n is 2]

(1) 4'-acetyl-4-bromo-1,
Synthesis of 1'-biphenyl 2-bromo-1,1'-biphenyl 25.0 g (0.1
1 mol) and 17.2 g of anhydrous aluminum chloride are mixed in 130 ml of nitrobenzene to give 9.4 g of acetyl chloride.
(0.12 mol) was added dropwise at room temperature, and then the mixture was reacted by stirring at 70 ° C. for 4 hours. 70 ml of water and 2 ml of concentrated hydrochloric acid
Poured into a mixed solution of 5 ml, extracted twice with 150 ml of ethyl acetate, washed the organic layer 5 times with 100 ml of water, and dried over anhydrous MgS.
Dry with O ₄ . The desiccant was filtered off, the solvent was distilled off, and the residue was purified by column [filler: Wakogel C-200; eluent: n-hexane → n-hexane / ethyl acetate = 10 /
1] to obtain 24.9 g of 4'-acetyl-4-bromo-1,1'-biphenyl as slightly brown crystals. IR (KBr): 1684 cm ^-1 .

(2) Synthesis of 4'-bromo-1,1'-biphenyl-4-carboxylic acid 4'-acetyl-4-bromo-1,1'-obtained in (1)
After mixing 24.0 g (87 mmol) of biphenyl and 100 ml of 1,4-dioxane and cooling, an aqueous solution of sodium hypobromite [58 g of sodium hydroxide and 30 g of water was added thereto.
Bromine (57.9 g, 0.36 mol) was added to a 0 ml solution at 10 ° C.
The aqueous solution prepared by dropping below was added dropwise at 10 ° C. or lower, and the mixture was further stirred at 40 to 50 ° C. for 4 hours. After cooling, the reaction solution was treated with 12.5 g of sodium sulfite, and 6
300 ml of N hydrochloric acid was injected, and the mixture was stirred and crystallized under ice cooling. The precipitated crystals were collected by filtration, washed with water, washed with n-hexane, and dried to obtain 24.2 g of 4'-bromo-1,1'-biphenyl-4-carboxylic acid as light brown crystals. mp. 250
℃ or more.

[0078]

[Chemical formula 23]

IR (KBr): 1690 cm ^-1 .

(3) Synthesis of 4'-bromo-4-hydroxymethyl-1,1'-biphenyl 4'-bromo-1,1'-biphenyl-4 obtained in (2)
-12.0 g (43.3 mmol) of carboxylic acid was suspended in 80 ml of tetrahydrofuran, and 57.6 ml of 1M borane-tetrahydrofuran complex salt [tetrahydrofuran solution] was added dropwise at 5 ° C or lower under a nitrogen stream, and the mixture was added at 0-5 ° C at 1 ° C. The reaction was stirred for 2 hours and then at room temperature for 2 hours. The reaction solution was poured into 60 ml of water, extracted twice with 100 ml of ethyl acetate, the organic layer was washed once with 150 ml of water, and then dried with anhydrous MgS.
Dry with O ₄ . The desiccant is filtered off and the solvent is distilled off to 4'-
10.5 g of bromo-4-hydroxymethyl-1,1'-biphenyl was obtained as light brown crystals. mp. 163-166 ° C.

[0081]

[Chemical formula 24]

IR (KBr): 3350 cm ^-1 .

(4) Synthesis of 4'-bromo-4- (1-ethoxy) ethoxymethyl-1,1'-biphenyl 4'-bromo-4-hydroxymethyl-obtained in (3)
The same procedure as in Example 2 (1) was carried out using 9.5 g (36 mmol) of 1,1'-biphenyl and 3.3 g (45.8 mmol) of ethyl vinyl ether, and 4'-bromo-4- ( 12.0 g of 1-ethoxy) ethoxymethyl-1,1'-biphenyl was obtained as pale yellow crystals. mp. 49.0-50.0 ° C.

[0084]

[Chemical 25]

IR (KBr): 2950 cm ^-1 .

(5) Synthesis of (S) -2-methyloctanoic acid chloride 5.0 g (32 mmol) of (S) -2-methyloctanoic acid and 11.3 g of thionyl chloride were dissolved in 40 ml of methylene chloride to give 3 parts. After stirring and refluxing for a period of time, the mixture was concentrated under reduced pressure to obtain 5.6 g of residual (S) -2-methyloctanoic acid chloride as a pale yellow oil.

[0087]

[Chemical formula 26]

IR (neat): 2940, 1800 cm ^-1 .

(6) (S) -4-hydroxymethyl-
Synthesis of 4 '-(2-methyl) octanoyl-1,1'-biphenyl 4'-Bromo-4- (1-ethoxy) ethoxymethyl-1,1'-biphenyl obtained in (4) 7.0 g (21 (5 mmol) and 3.5 g (20 mmol) of (S) -2-methyloctanoic acid chloride obtained in (5) were carried out in the same manner as in (2) of Example 2 to obtain crude crystal 7. Column purification (filler: Wakogel C-200; eluent: methylene chloride) of 3 g of (S) -4-hydroxymethyl-4 '
3.1 g of-(2-methyl) octanoyl-1,1'-biphenyl was obtained as white crystals. mp. 81.0-8
4.0 ° C. [Α] _D ²⁵ : + 3.0 ° (c = 2.0, CH ₂ C
l ₂ ).

[0090]

[Chemical 27]

IR (KBr): 3500, 2930, 16
82 cm ^-1 .

(7) Synthesis of (S) -4 '-(2-methyl) octanoyl-1,1'-biphenyl-4-carboxylic acid (S) -4-hydroxymethyl-4' obtained in (6) −
2.5 g (7.7 mmol) of (2-methyl) octanoyl-1,1'-biphenyl was used to prepare (2) of Example 2.
2.5 g of the crude crystals obtained were subjected to column purification [filler: Wakogel C-200; eluent: methylene chloride] to give (S) -4 ′-(2-methyl) octanoyl-1, 1.9 g of 1'-biphenyl-4-carboxylic acid was obtained as white crystals. mp. 190-198 ° C.

[0093]

[Chemical 28]

IR (KBr): 2940, 1690 cm ^-1 .

(8) Synthesis of 4-benzyloxybenzoic acid 200 g (1.2 mol) of ethyl 4-hydroxybenzoate
190 g (1.5 mol) of benzyl chloride and 165 g of potassium carbonate were stirred and refluxed in 1.2 liter of acetone for 12 hours. After cooling, the precipitate was filtered off and the solvent was distilled off. Next, 400 g of the residue was dissolved in 500 ml of ethanol, 60 g of sodium hydroxide and 1 liter of water were added thereto, and a stirring reaction was carried out at 60 to 70 ° C. for 4 hours. After cooling, 200 ml of concentrated hydrochloric acid was poured into the reaction solution, and the precipitated crystals were collected by filtration, washed with water, washed with ethanol, and dried to obtain 195 g of 4-benzyloxybenzoic acid as white crystals. mp. 191.2-192.6 ° C. IR (KBr): 1695 cm ^-1 .

(9) Synthesis of 1-methylheptyl (R) -4-benzyloxybenzoate 16.0 g of 4-benzyloxybenzoic acid obtained in (8)
(70 mmol) and thionyl chloride (16.7 g) were dissolved in methylene chloride (75 ml), stirred and refluxed for 3 hours, and then concentrated. Then, the concentrated residue was added dropwise to a solution of 9.1 g (70 mmol) of (R) -2-octanol, 10.1 g of pyridine and 60 ml of methylene chloride at room temperature, and treated in the same manner as in (4) of Example 1 below. Thus, 13.3 g of 1-methylheptyl (R) -4-benzyloxybenzoate was obtained as a pale yellow oil. [Α] _D ²⁵ : -31.6 ° (c = 2.06, CH ₂ Cl
₂ ).

[0097]

[Chemical 29]

IR (neat): 3020, 2920, 17
05 cm ^-1 .

(10) Synthesis of 1-methylheptyl (R) -4-hydroxybenzoate (R) -4-benzyloxybenzoic acid 1-obtained in (9)
5.0 g (14.7 mmol) of methylheptyl was dissolved in methanol and subjected to catalytic reduction under atmospheric pressure with a 5% palladium carbon catalyst, the catalyst was filtered off, and the solvent was distilled off to give (R) -4-hydroxybenzoic acid. 3.6 g of 1-methylheptyl was obtained as a pale yellow oil. [Α] _D ²⁵ : -34.4 ° (c = 2.01, CH ₂ Cl
₂ ). IR (neat): 3350, 2940, 1705 cm ^-1 .

(11) Synthesis of (R) -1-methylheptyl (R) -1- (S) -4- [4 ′-(2-methyl) octanoyl-1,1′-biphenyl-4-carbonyloxy] benzoate (7) (S) -4 '-(2-methyl) octanoyl-1,1'-biphenyl-4-carboxylic acid obtained in 1.5 g
(4.4 mmol) and 1.1 g (4.4 mmol) of 1-methylheptyl (R) -4-hydroxybenzoate obtained in (10) were used and the same procedure as (5) of Example 1 was carried out. Then
After column separation, 2.5 g of the crude crystals obtained were recrystallized from ethanol to give (S) -4- [4 '-(2-methyl) octanoyl-1,1'-biphenyl-4-carbonyloxy] benzoic acid. 1.65 g of (R) -1-methylheptyl was obtained as white short needle crystals. mp. 82.0-83.0 ° C.

[0101]

[Chemical 30]

IR (KBr): 2940, 1740, 1720, 1680 cm ^-1 . [Α] _D ²⁵ : −22.7 ° (c = 2.02, CH ₂ Cl ₂ ). Elemental analysis value (C ₃₇ H ₄₆ O ₅ ) calculated value: C% 77.86; H% 8.12 measured value: C% 77.94; H% 8.00

The phase transition temperatures of the compounds of Examples 1 to 3 were measured by a differential scanning calorimeter (DSC) measurement and observation with a polarizing microscope equipped with a temperature controller. Further, the spontaneous polarization of these compounds at 10 ° C. below the Sc ^* phase maximum temperature was measured by the triangular wave method. The results are shown in Table 1.

[0104]

[Table 1]

Note 1) Cr: crystal, Sc ^* : chiral smectic C, S _A : smectic A, I: isotropic liquid Note 2) · indicates that the phase exists. The parentheses indicate that it is a monotropic transition. Note 3) Value at 5 ° C below the upper limit of Sc ^* phase

Examples 4 to 6 10% of the compounds of Examples 1 to 3 were added to the smectic C liquid crystal composition ZLI3234B manufactured by Merck & Co., Inc., and the phase transition temperature was measured. Further, these liquid crystal compositions were used in a test liquid crystal cell (a polyimide film was provided on a glass plate on which ITO was vapor-deposited and rubbed in a certain direction, and two substrates were bonded together by using glass beads having a diameter of 2 μm as a spacer). Then, a test element was manufactured. When a voltage of ± 10 V was applied to this test device and observed with a polarization microscope, a change in transmitted light intensity was observed. The response time was calculated from the intensity change. Moreover, the spontaneous polarization was measured by the triangular wave method. The results are shown in Table 2 (measurement temperature: 25 ° C).

[0107]

[Table 2]

[0108]

INDUSTRIAL APPLICABILITY The compound group represented by the general formula (Formula 1) of the present invention is an optically active compound having a chemically stable molecular structure, and includes not only those which exhibit extremely large spontaneous polarization, By mixing with another liquid crystal compound, a ferroelectric liquid crystal composition that induces large spontaneous polarization and operates at high speed can be obtained. In addition, since the compound has a plurality of asymmetric carbon atoms in the molecule, when the directions of the spirals that cause the respective asymmetric centers are different, the ferroelectric liquid crystal composition has a long spiral pitch.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication C07C 255/22 8519-4H 255/41 8519-4H C07D 213/30 6701-4C 213/63 6701-4C 239 / 26 7038-4C 239/32 7038-4C C09K 19/20 6742-4H 19/30 6742-4H 19/34 6742-4H G02F 1/13 500 (72) Inventor Shigeki Ishibashi 1-chome, Uchiyuki-cho, Chiyoda-ku, Tokyo No. 6 Nihon Telegraph and Telephone Corporation (72) Inventor Fumiyoshi Urano 1633 Matoba, Kawagoe City, Saitama Prefecture Wako Pure Chemical Industries, Ltd. Tokyo Research Laboratory (72) Inventor Takaaki Negishi 1633 Matoba, Kawagoe City, Saitama Prefecture Wako Pure Chemical Industries, Ltd. Tokyo Research Center

Claims (2)

[Claims] 1. The following general formula (Formula 1): [In the formula, R is a linear or branched alkyl group having 16 or less carbon atoms (excluding those corresponding to X) or an alkoxy group, R
^* Is an optically active alkyl group having 16 or less carbon atoms, X is a methyl group, an ethyl group, fluorine, chlorine or a nitrile group,
Y is any of -COO-, -OCO-, and -O-, and is represented by the formula (Formula 2): The group represented by is represented by the following formula (Formula 3): (Z is any of hydrogen, halogen, and nitrile group), C ^* is optically active carbon, and m is 0.
Or 1, and n is 1 or 2, but m + n ≦ 2]. 2. A chiral liquid crystal composition comprising at least one component of the optically active compound according to claim 1.