JPH0713039B2 - New liquid crystal compound - Google Patents

Description

The present invention relates to a novel compound having liquid crystallinity. More specifically, in the field of optoelectronics, in particular, digital display devices such as calculators and watches, electro-optical shutters, electro-optical apertures, optical modulators, optical communication optical path selector switches, memories, liquid crystal printer heads, focal length variable lenses, etc. The present invention relates to a novel compound having liquid crystallinity used as an electro-optical device.

[Conventional technology]

Liquid crystals have already been used as various electro-optical elements,
Widely used for digital displays such as calculators and clocks. Most conventional liquid crystal display elements use nematic liquid crystal or cholesteric liquid crystal,
These have problems in responsiveness, contrast, viewing angle characteristics, and the like. Therefore, recently, in order to solve these drawbacks, a display element using a ferroelectric chiral smectic C-phase (S _c ^* phase) liquid crystal capable of high-speed response has been proposed. However, even in these cases, there are problems that the temperature range in which the smectic C phase is exhibited is high and the chemical stability is lacking. There are known ones having a ferroelectric S _c ^* phase which has a relatively low temperature range and is capable of high-speed response (Japanese Patent Laid-Open Nos. 55-21479, 60-235885 and 60-235885). 6
No. 1-22072, JP-A No. 61-24576, etc.), these compounds are difficult to produce.

[Problems to be solved by the invention]

The present invention is to provide a novel liquid crystal compound which is a chemically stable liquid crystal compound and exhibits a ferroelectric S _c ^* phase capable of high-speed response in a wide temperature range around room temperature. ..

[Means for solving problems]

As a result of intensive studies to solve the above problems, the present inventors have found that a compound having a specific structure having an aromatic ring, an ester bond, and a group having two adjacent asymmetric carbon atoms in the molecule They have found that they can meet the purpose, and have completed the present invention based on this finding.

That is, the novel liquid crystal compound of the present invention has the general formula [I] (In the formula, R ¹ and R ⁵ represent an alkyl chain having 1 to ⁵ carbon atoms, and may be the same or different, and X ¹ and X ² are —O—, Which may be the same or different, each represents R ² -H or -CH ₃ , R ³ represents an alkylene chain having 1 to 20 carbon atoms, and R ⁴ represents Represents, X represents a halogen atom, and C ^* represents an asymmetric carbon atom. The present invention provides a novel liquid crystal compound represented by

An example of the method for producing the novel liquid crystal compound of the present invention will be described below.

[1] R ¹ and R ⁵ in the general formula (I) are the same,
X ¹ And R ⁴ is Of a compound of formula (II) As shown in the above reaction formula, first, 4-acetoxybenzoic acid is esterified with an optically active alcohol (III), and then the acetyl group which is a protecting group of the obtained ester body is hydrogen-substituted to obtain a hydroxy body. On the other hand, 4-hydroxybenzoic acid benzyl ester is reacted with α,ω-dibromoalkane (IV) to be etherified, and then hydrogenated to eliminate the benzyl group as a protecting group to obtain a carboxylic acid derivative. The carboxylic acid derivative is reacted with the previously obtained hydroxy form to be esterified to obtain a bromo form.
The bromo compound is reacted with the compound (V) to form an ester to obtain an alcohol compound. The alcohol compound and the acid anhydride (VI) are reacted to diesterify the compound to obtain the desired novel liquid crystal compound (II).

[1] R ¹ and R ⁵ in the general formula (I) are the same,
X ¹ And R ⁴ is Of a compound of formula (VII) This compound can be produced by performing the same procedure as in the above-mentioned production method [1] except that 4′-hydroxybiphenyl-4-carboxylic acid benzyl ester is used instead of 4-hydroxybenzoic acid benzyl ester. it can.

Examples of the optically active alcohol (III) used in the above production method include (2S,3S)-2-chloro-3
-Methyl-1-pentanol, (2S,3S)-2-fluoro-3-methyl-1-pentanol, (2S,3S)-2-
Bromo-3-methyl-1-pentanol, (3S,4S)-
3-chloro-4-methyl-1-hexanol, (4S,5
S)-4-chloro-5-methyl-1-heptanol, (5
S,6S)-5-Chloro-6-methyl-1-octanol,
(6S,7S)-6-chloro-7-methyl-1-nonanol is mentioned.

The α,ω-dibromoalkane (IV) used in the above production method is specifically dibromomethane, 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dibromobutane, 1,5- Dibromopentane, 1,6-dibromohexane, 1,7-dibromoheptane, 1,8-dibromooctane,
1,9-dibromononane, 1,10-dibromodecane, 1,11-
Dibromoundecane, 1,12-dibromododecane, 1,13-
Dibromotridecane, 1,14-dibromotetradecane, 1,
15-dibromopentadecane, 1,16-dibromohexadecane, 1,17-dibromoheptadecane, 1,18-dibromooctadecane, 1,19-dibromononadecane, and 1,20-dibromoeicosane.

Formula used in the above manufacturing method The compounds of are specifically 2,2-bis(hydroxymethyl)acetic acid and 2,2-bis(hydroxymethyl)propionic acid.

Further, the acid anhydride of the formula (VI) used in the above-mentioned production method is specifically acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, hexanoic anhydride and the like.

Examples Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to these examples.

The structure of the obtained compound was confirmed by NMR, IR, and elemental analysis, and the phase transition temperature was measured and the phase was confirmed by DSC and a polarizing microscope, respectively.

In the diagram showing the phase transition behavior, each phase is shown by the following abbreviations. The numbers in the diagram represent the phase transition temperature in units of °C.

[Cry: crystalline state, S _c ^* phase: chiral smectic C phase liquid crystal state, Iso: isotropic liquid state]

The spontaneous polarization value and the electric field response speed were measured as follows.

Measurement of Spontaneous Polarization Value A liquid crystal compound was sandwiched between two 20×10 mm ITO substrates to prepare a cell having a thickness adjusted to 10 μm. Frequency in this cell
The spontaneous polarization value was obtained from the polarization reversal current value generated by the reversal of the dipole of the molecule by applying the triangular wave of 10Hz and the maximum voltage of 200V.

Measurement of electric field response speed A liquid crystal compound is sandwiched between two 20×10 mm ITO substrates, the thickness is adjusted to 10 μm with a spacer and 200 V is applied, and the change in the amount of transmitted light (0→90%) response at that time The time was measured.

Example 1 Preparation of 4-[4'-{12-(2,2-bis-acetoxymethylpropionyloxy)dodecyloxy}benzoyloxy]benzoic acid 2-chloro-3-methylpentyl ester (1) 4-acetoxybenzoic acid Synthesis of acid 2-chloro-3-methylpentyl ester (ester form) After stirring 0.12 mol (21.6 g) of 4-acetoxybenzoic acid and 15 ml of thionyl chloride in 70 ml of toluene, the mixture was stirred at 80°C.
Excess thionyl chloride and toluene as a solvent were distilled under reduced pressure to concentrate the reaction solution to obtain an acid chloride. Next, (2S,3S)
2-chloro-3-methyl-1-pentanol 0.1 mol (13.6 g) and triethylamine 0.12 mol (12.1 g)
A 300 ml solution of THF (tetrahydrofuran) was stirred. The THF solution of the acid chloride obtained above was added dropwise to this, and the mixture was stirred for 8 hours. The reaction solution was extracted with ether, washed with diluted HCl water, concentrated, and then purified by column chromatography.
16.4 g of the target ester compound of the following formula was obtained. (Yield 5
5%, ▲[α] ²³ _D ▼＝+17.4° (CHCl ₃ )) (2) Synthesis of 2-chloro-3-methylpentyl ester of 4-hydroxybenzoic acid (hydroxy form) 50 mmol (14.9 g) of ether 300 obtained in (1)
The ml solution was stirred, 20 ml of benzylamine was added and stirred for 2 hours. The reaction solution was extracted with ether, dried and concentrated, and then purified by column chromatography to obtain 12.2 g of the target hydroxy compound of the following formula. (Yield 95
%, ▲ [α] ²³ _D ▼ = +12.8° (CHCl ₃ )) (3) Synthesis of 4-(12-bromododecyloxy)benzoic acid benzyl ester (ester form) 1,12-dibromododecane 150 mmol (49.2 g), 4-hydroxybenzoic acid benzyl ester 50 mmol (10.6
g), and 0.3 mol of potassium carbonate (41.5 g) of acetone 5
The 00 ml solution was refluxed for 6 hours. The reaction solution was filtered and concentrated, and then purified by column chromatography to obtain 18.8 g of the target ester compound of the following formula. (Yield 82%) (4) Synthesis of 4-(12-bromododecyloxy)benzoic acid (carboxylic acid derivative) 100 mmol of ester obtained by the method of (3) (45.
A solution of 2.0 g of palladium carbon (5% catalyst) in 150 ml of ethyl acetate was stirred in the presence of hydrogen gas for 5 hours. The reaction solution was filtered and concentrated, and then purified by column chromatography to obtain 36.2 g of the desired carboxylic acid derivative of the following formula. (Yield 98%) (5) Synthesis of 4-[4'-(12-bromododecyloxy)benzoyloxy]benzoic acid 2-chloro-3-methylpentyl ester (bromo form) 80 mmol of the carboxylic acid derivative obtained in (4) (29.5
To a solution of g) in 30 ml of toluene, add 10 ml of thionyl chloride,
The mixture was stirred at 0°C for 2 hours. After the reaction, excess thionyl chloride and toluene as a solvent were distilled under reduced pressure and the reaction solution was concentrated to obtain an acid chloride. Next, 90 mmol (23.1 g) of the hydroxy compound obtained by the method (2) and 100 of triethylamine
A 200 ml solution of mmol (10.1 g) in THF was stirred, the THF solution of the acid chloride obtained above was added dropwise, and the mixture was stirred for 8 hours. After the reaction, extraction with ether, washing with diluted HCl water, drying, and concentration were performed, followed by purification by column chromatography,
39.4 g of the desired bromo compound of the following formula was obtained. (Yield 81
%, ▲ [α] ²³ _D ▼ = +10.5° (CHCl ₃ )) (6) Synthesis of 4-[4'-{12-(2,2-bis-hydroxymethyl bromopionyloxy)dodecyloxy}benzoyloxy]benzoic acid 2-chloro-3-methylpentyl ester (alcohol) 2 18.0 mmol (2.4 g) of 2,2-bis(hydroxymethyl)propionic acid and 20.0 mmol (3.6 g) of tetramethylammonium hydroxide (pentahydrate) were stirred in 150 ml of DMF (dimethylformamide) for 2 hours. Next, (5)
Add 18 mmol (11.0 g) of the bromo compound obtained in step 6,
Stir for hours. After the reaction, the mixture was extracted with ether, dried, and concentrated, and then purified by column chromatography to obtain 7.4 g of a desired alcohol compound of the following formula.
(Yield 62%, ▲[α] ²³ _D ▼=10.3° (CHCl ₃ )) (7) Synthesis of 4-[4'-{12-(2,2-bis-acetoxymethylpropionyloxy)dodecyloxy}benzoyloxy]benzoic acid 2-chloro-3-methylpentyl ester Obtained in (6) A solution of 7.5 mmol (5.0 g) of the alcohol compound and 45 mmol (4.6 g) of acetic anhydride in 5 ml of pyridine was stirred at room temperature for 12 hours. The reaction solution is extracted with ether, washed with diluted HCl water, dried, and concentrated, and then purified by column chromatography to obtain a target novel liquid crystal compound of the following formula 4.
Obtained 6 g. (Yield 82%, ▲[α] ²³ _D ▼＝+10.0° (CHC
l ₃ )) The phase transition behavior of this compound was as follows.

Field response speed 2℃ 100μSec Spontaneous polarization value 49nc/cm ² Elemental analysis values of this compound are shown in the table below.

The ¹ H-NMR spectrum chart and IR spectrum chart of this compound are shown in FIG. 1 and FIG. 2, respectively.

Example 2 4-[4″-{12-(2,2-bis-acetoxymethylpropionyloxy)dodecyloxy}biphenyl-4′
-Carbonyloxy]benzoic acid 2-chloro-3-methylpentyl ester production (1) Synthesis of 4-acetoxybenzoic acid 2-chloro-3-methylpentyl ester (ester form) By the method of (1) of Example 1. An ester compound of the following formula was obtained.

(2) Synthesis of 4-Hydroxybenzoic acid 2-chloro-3-methylpentyl ester (hydroxy form) The hydroxy form represented by the following formula was obtained by the method of (2) of Example 1.

(3) Synthesis of 4'-hydroxybiphenyl-4-carboxylic acid benzyl ester (hydroxy form) 0.1 mol (21.4 g) of 4'-hydroxybiphenyl-4-carboxylic acid and tetramethylammonium hydroxide (5
A solution of 0.11 mol (19.9 g) of hydrate) in 200 ml of DMF was stirred for 2 hours. Next, 0.1 mol (17.1 g) of benzyl bromide was added to the reaction solution.
Was added and stirred for 6 hours. After the reaction, ether extraction, drying, and concentration were performed, followed by purification by column chromatography to obtain the desired hydroxy compound of the following formula: 23.1
got g. (Yield 76%) (4) Synthesis of 4'-(12-bromododecyloxy)biphenyl-4-carboxylic acid benzyl ester (ester form) 70 mmol of hydroxy form obtained in (3) (21.3
g), 1,12-dibromododecane 0.21 mmol (68.9
G) and a 1 mol solution of 0.4 mol (55.3 g) of potassium carbonate in acetone were refluxed for 6 hours. The reaction solution was filtered and concentrated, and then purified by column chromatography to obtain 34.4 g of the target ester compound of the following formula. (Yield 89
%) (5) Synthesis of 4'-(12-bromododecyloxy)biphenyl-4-carboxylic acid (carboxylic acid derivative) 60 mmol (33.1 g) of the ester obtained in (4) and 2.0% palladium carbon (5% catalyst) g ethyl acetate
The 500 ml solution was stirred for 24 hours under hydrogen gas atmosphere. After the reaction, the mixture was filtered and concentrated, and then purified by column chromatography to obtain 27.1 g of the desired carboxylic acid derivative of the following formula. (Yield 98%) (6) Synthesis of 4-[4″-(12-bromododecyloxy)biphenyl-4′-carbonyloxy]benzoic acid 2-chloro-3-methylpentyl ester (bromo) Carboxylic acid derivative obtained in (5) 50 mmol (23.1
A mixture of g), 20 ml of toluene, 10 ml of chloroform, and 10 ml of thionyl chloride was stirred at 80°C for 2 hours. After the reaction
Excess thionyl chloride and the solvents toluene and chloroform were distilled off under reduced pressure to obtain an acid chloride. Next, a solution of 55 mmol (14.1 g) of the hydroxy compound obtained in (2) and 60 mmol (6.1 g) of triethylamine in 200 ml of THF was stirred, and the THF solution of the acid chloride obtained above was added dropwise for 8 hours. It was stirred. After the reaction, the mixture was extracted with ether, washed with diluted HCl water, dried, and concentrated, and then purified by column chromatography to obtain 28.7 g of a target bromo compound of the following formula. (Yield 82%, ▲[α] ²³ _D ▼＝+10.8° (CHCl ₃ )) (7) 4-[4″-{12-(2,2-bis-hydroxymethylpropionyloxy)dodecyloxy}biphenyl-4′-carbonyloxy]benzoic acid 2-chloro-3-
Synthesis of methyl pentyl ester (alcohol) 2,2-bis(hydroxymethyl)propionic acid 18.0 mmol (2.4 g) and tetramethylammonium hydroxide (pentahydrate) 20.0 mmol (3.6 g) in DMF 150 ml solution 2
Stir for hours. Next, 18.0 of the bromo compound obtained in (6)
Mmol (12.6 g) was added, and the mixture was stirred for 8 hours. After the reaction
After extraction with ether, drying, and concentration, purification by column chromatography was performed to obtain 10.8 g of the target alcohol compound of the following formula. (Yield 80%, ▲ [α] ²³ _D ▼
= +10.3° (CHCl ₃ )) (8) 4-(4″-{12-(2,2-bis-acetoxymethylpropionyloxy)dodecyloxy}biphenyl-4′-carbonyloxy]benzoic acid 2-chloro-3-
Synthesis of methylpentyl ester A solution of 7.5 mmol (5.6 g) of the alcohol derivative obtained in (7) and 45 mmol (4.6 g) of acetic anhydride in 5 ml of pyridine was stirred at room temperature for 12 hours. The reaction liquid is extracted with ether, washed with diluted HCl water, dried, and concentrated, and then purified by column chromatography to obtain a target novel liquid crystal compound of the following formula 4.
I got 9g. (Yield 78%, ▲[α] ²³ _D ▼＝+10.4° (CHC
l ₃ )) The phase transition behavior of this compound was as follows.

Field response speed 97℃ 73μSec Spontaneous polarization value 55nc/cm ² Elemental analysis values of this compound are shown in the table below.

The ¹ H-NMR spectrum chart and IR spectrum chart of this compound are shown in FIGS. 3 and 4, respectively.

〔The invention's effect〕

The novel liquid crystal compound of the present invention is a liquid crystal compound having a chemically stable chemical structure.
It shows the S _c ^* phase in a wide temperature range including room temperature or lower, has a spontaneous polarization value larger than that of a conventional liquid crystal compound, and is extremely excellent in electric field response. Therefore, the novel liquid crystal compound of the present invention can be used in various applications such as digital displays for calculators and watches, electro-optical shutters, electro-optical diaphragms, optical modulators, optical communication optical path selector switches, memories, liquid crystal printer heads, focal length variable lenses, etc. It has high utility as an electro-optical element for an electro-optical device, and its industrial value is great.

[Brief description of drawings]

FIG. 1 is a chart of ¹ H-NMR spectrum of the liquid crystal compound obtained in Example 1. FIG. 2 is a chart of the IR spectrum of the liquid crystal compound obtained in Example 1. FIG. 3 is a chart of ¹ H-NMR spectrum of the liquid crystal compound obtained in Example 2. FIG. 4 is a chart of the IR spectrum of the liquid crystal compound obtained in Example 2.

Claims (1)

[Claims] 1. A general formula (In the formula, R ¹ and R ⁵ represent an alkyl chain having 1 to ⁵ carbon atoms and may be the same or different, and X ¹ and X ² are —O—, R ² may represent the same or different, R ² represents —H or —CH ₃ , R ³ represents an alkylene chain having 1 to 20 carbon atoms, and R ⁴ represents Represents, X represents a halogen atom, and C ^* represents an asymmetric carbon atom. ) A new liquid crystal compound represented by.