JPH01294655A - Novel optically active ester compound and production thereof - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R is <=20C alkoxy; n is 1 or 2; * indicates asymmetric carbon atom). EXAMPLE:Optically active p'-[2.(4-methylcyclohexyl)-1)propoxy]phenyl p-n- decyloxybenzoate. USE:A liquid crystal material, especially suitable for optical switching methods with a high speed of response, chemically stable and exhibiting ferroelectricity. PREPARATION:p-[2-(4-Methylcyclohexyl-1)propoxy]phenol expressed by formula II is reacted with carboxylic acids or carboxylic acid halides expressed by formula III (n is 1 or 2; X is hydroxy or halogen) to afford the aimed compound expressed by formula I. In case the carboxylic acids are used, the reaction is carried out in the presence of a condensing agent (e.g. N,N' dicyclohexylcarbodiimide) in a solvent at ambient temperature. In the case of the carboxylic acid halides, the reaction is carried out in the presence of a base (e.g., pyridine) in a solvent at ambient temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a novel optically active ester compound useful as a liquid crystal material and a method for producing the same.

[Prior art]

Currently, liquid crystal materials are widely used in display elements.
Most of these liquid crystal display elements are of the TN (Ttsisted Nematic) type display system using nematic liquid crystal. However, this method has the disadvantage that the response speed is slow, and a response speed on the order of several Isec can be obtained at most.Therefore, various liquid crystal display methods based on different principles have been attempted in place of the TN display method. , one of them is a display method that uses ferroelectric liquid crystals (N, A, C1arks et al.; A
pplied Phys, Lett, 36.899
(1980)).

This method uses a ferroelectric chiral smectic phase.

In particular, it utilizes chiral smectic C phase and is attracting attention as a potential for high-speed optical switching.

Although some such ferroelectric liquid crystal materials are already known (for example, JP-A-60-32748), none exhibits sufficiently satisfactory properties.

〔the purpose〕

The purpose of the present invention is to provide a novel optically active ester compound having sufficiently satisfactory properties as a liquid crystal material suitable for optical switching methods, such as fast response speed and chemical stability, and a method for producing the same. be.

〔composition〕

The novel optically active ester compound of the present invention is represented by the general formula (I) (wherein, R is an alkoxy group having 20 or less carbon atoms, n is an integer of 1 or 2, and the car represents an asymmetric carbon atom). It is something.

Furthermore, the method for producing the optically active ester compound represented by the general formula (1) of the present invention includes p-(2-(4-methylcyclo) represented by the formula (n) (where * represents an asymmetric carbon atom). hexyl-1
) propoxyphenol and general formula (III) (however, R
is an alkoxy group having 20 or less carbon atoms, n I'i1 or 2
X represents a hydroxyl group or a halogen atom). The ceremony■
The compound is also a new compound.

The most significant feature of the ester compound represented by the general formula (1) of the present invention is that it contains a cyclohexyl group having an asymmetric carbon. Conventional ferroelectric liquid crystal compounds also contain asymmetric carbon, but in the case of conventional compounds, the asymmetric carbon source is an alkyl group such as activated amyl alcohol. By using a cyclohexyl group as an asymmetric carbon source as in the compound of the present invention, 1) a decrease in viscosity, 2) an increase in spontaneous polarization due to the steric effect of the asymmetric source, resulting in a dramatic improvement in response speed. be able to.

Specific examples of the optically active ester compound of general formula (1) as described above are shown in Table 1 in relation to the following general formula.

These compounds of the general formula (2) are generally p-(2) of the formula (II).
2-(4-methylcyclohexyl-1)propoxy]phenol and the carboxylic acids of the general formula (III),
The reaction is carried out in a solvent at room temperature using a condensing agent such as N,N'-dicyclohexylcarbodiimide, or the general formula (II
It is obtained by reacting I) with the carboxylic acid halide in a solvent at room temperature using a base catalyst such as pyridine. As a solvent, toluene, tetrahydrofuran,
Methylene chloride, 1,2-dichlorothane, etc. are used.

In addition, the ratio of the compound of formula (II) and the compound of general formula (III) may be stoichiometric.

In addition, the compound of formula (II) can be prepared, for example, according to the following reaction formula:
P-benzyloxyphenol (IV) and optically active P
-Toluenesulfonic acid-2-(4-methyl-3-cyclohexenyl-1)propyl ester (V) is reacted in the presence of a basic catalyst such as sodium hydride or potash to obtain optically active P. -(2-(4-methyl-3-cyclohexenyl-1)propoxy]phenylbenzyl ether (IV) is obtained.The above-mentioned P-toluenesulfonic acid-2-(4-methyl-3-cyclohexenyl-1) ) Propyl ester (V) can be prepared by the usual method, namely, P-toluenesulfonic acid chloride and commercially available (R,R) 2-(4-methyl-3-cyclohexenyl-1)propanol are added to a base such as pyridine. Zero-order optically active P-(2-(4-methyl-3
-Cyclohexenyl-1)propoxy]phenylbenzyl ether (VI) is obtained by reducing it in the presence of a reducing catalyst such as Pd-carbon.

◎-CH20-◎-OH(IV) The optically active ester compound represented by the general formula (1) of the present invention exhibits excellent performance as a ferroelectric liquid crystal material,
It has a fast response speed, exhibits very good orientation, and is chemically stable.

The novel optically active ester compound represented by the general formula (1) of the present invention can be used alone as a ferroelectric liquid crystal material, but it can be mixed with other liquid crystal materials, especially ferroelectric liquid crystal materials, to improve performance. It can be a thing. In addition, the liquid crystal composition containing the compound of the present invention can be used not only for display purposes, but also for display purposes.
It can be suitably used in the field of optoelectronics as various electro-optical devices such as electro-optical shutters, electro-optical diaphragms, optical modulators, optical communication optical path switching switches, memories, and variable focal length lenses.

Among other liquid crystal compounds that can be used in combination with the compound of the present invention, examples of those exhibiting a ferroelectric chiral smectic phase are shown in Table 2.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.The value of the three-phase transition degree in Example 1 may vary depending on the measurement method or It varies slightly depending on the purity of the compound.

Example 1 Compound &6 (optically active P-n-decyloxybenzoic acid-
Production A of P'-(2-(4-methylcyclohexyl-1)propoxy]phenyl ester), optically active P-(2-(4-methyl-3-cyclohexenyl-1)propoxy]phenylbenzyl ether (
VI) Preparation of P-benzyloxyphenol 22.03 g (0,
11 mol) in dry N,N-dimethylformamide 100
Dissolved in RIQ, add 6 g (0.15 mol) of 60% sodium hydride while cooling and stirring, then optically active p-toluenesulfonic acid-2-(4-methyl-3-cyclohexenyl-1) Propyl ester 30.84g (
After the completion of the reaction, 300 m of water and 20 m of toluene were added to the reactor and stirred at 50 to 60°C for 4 hours.
Add 0- and stir well, and add 6N- to the separated toluene layer.
Washing with HCl followed by water until neutral. The toluene layer was dried over anhydrous magnesium sulfate, the toluene was distilled off, and the residue was then subjected to silica gel column chromatography using toluene as a developing solvent to obtain 30.93 g of crude target product (VI).

B, optically active P-[2-(4-methylcyclohexyl-
1) Production of propoxy]phenol (n) P-(2-(4-methyl-3-cyclohexenyl-1)propoxy)phenylbenzyl ether obtained in above A
Dissolve 0.93 g in a mixed solvent of 200 m of 1.4-dioxane and 200 m of ethanol, and dissolve 4.53 g of Pd-carbon.
Catalytic hydrogenation was carried out at room temperature in the presence of g. Twice as many moles of hydrogen were required.

After the reaction, Pd-carbon was removed by filtration, the solvent was distilled off, and the residue was distilled under reduced pressure at 165°C to 167°C (11 hours).
) was fractionated to obtain 16.16 g of the desired product (If).

Properties of compound (■) Optical rotation [α)': (-) 1.21° (chloroform) H (phantom) 9.90 9.74 The structure of this compound was confirmed by infrared absorption spectrum. A spectrum diagram is shown in FIG.

Preparation of C4 compound (Nα6) P-(2-(4-methylcyclohexyl-
1) Propoxy]phenol 1.99 g (0,00
8 mol) was dissolved in 50-pyridine, and while cooling, 2.96 g of P-n-decyloxybenzoic acid chloride was added to the solution.
(0.01 mol) was added, the reaction was stirred at room temperature for 5 hours, and after being left overnight, 200 ml of water and 200 ml of toluene were added thereto, stirred well, and the separated toluene layer was The toluene layer was dried over anhydrous magnesium sulfate, then 1 heluene was distilled off, and the residue was then subjected to silica gel chromatography using toluene as a developing solvent.
The obtained crude target product was recrystallized with ethanol three times to obtain 1.53 g of pure target product [Compound (& 6)].

The structure of this product was also confirmed by infrared absorption spectroscopy.

Example 2 Compound (Nα4) (optically active P-n-octyloxybenzoic acid-P'-(2-(4-methylcyclohexyl-1)
2.69 g of P-n-octyloxybenzoic acid chloride instead of 2.96 g of P-n-decyloxybenzoic acid
1.59 g of the pure target product was obtained in the same manner as C of Example 1 except that (0.01 mol) was used. The structure of this substance was also confirmed by infrared absorption spectroscopy.

Example 3 Compound (Nn2) (optically active P-n-hexyloxybenzoic acid P'-[2-(4-methylcyclohexyl-1)
) Preparation of 2.96 g of P-n-hexyloxybenzoic acid chloride instead of 2.96 g of P-n-decyloxybenzoic acid chloride (propoxy]phenyl ester).
1.81 g of the pure target product was obtained in the same manner as in Example 1 C, except that 41 g (0.01 mol) was used.

The structure of this product was also confirmed by infrared absorption spectroscopy.

Example 4 Compound (NQ 19) (Optically active P-hexadecyloxy-P'-biphenylcarboxylic acid-P"-(2-(4
-Production of P-(2-(4-methylcyclohexyl-1)propoxy]phenyl ester) obtained in step B above
1) Propoxy]phenol 1.49 g (0,00
6 mol), P-n-hexadecyloxy-P'-biphenylcarboxylic acid 2.90 g (0,0066 mol),
N,N'-dicyclohexylcarbodiimide 1.37g
and 0.15 g of 4-dimethylaminopyridine were reacted in 100 mQ of methylene chloride at room temperature with stirring for 5 hours, and then left overnight. After filtering the crystals and distilling off the methylene chloride, the residue was subjected to silica gel column chromatography using toluene as the developing solvent, and the resulting crude target product was crystallized three times from a mixed solvent of ethanol and ethyl acetate to obtain the pure target product [ 1.09 g of compound (Nn19)) was obtained. The structure of this product was confirmed by infrared absorption spectrum. A diagram of this infrared absorption spectrum is shown in FIG.

Example 5 Preparation of compound (Nn18) optically active (P-n-tetradecyloxy-P'-biphenylcarboxylic acid 2) propoxy]phenyl ester P-n-hexadecyloxy-P'-biphenylcarboxylic acid 2 2.71 g (0.90 g) of P-n-tetradecyloxy-P'-biphenylcarboxylic acid instead of 0.90 g.
2.04 g of the pure target product was obtained in the same manner as in Example 4, except that 0066 mol) was used. The structure of this product was confirmed by infrared absorption spectrum.

Example 6 Compound (Nα17) (optically active P-n-dodecyloxy-P'-biphenylcarboxylic acid-P''- (2- (4
-Production of methylcyclohexyl-1) propoxy]phenyl ester) P-n-dodecyloxy-
P'-biphenylcarboxylic acid 2.52 g (0.00
66 mol) was used in the same manner as in Example 4 to obtain 1.8 g of the pure target product. The structure of this product was confirmed by infrared absorption spectrum.

Example 7 Compound (&16) (optically active P-n-decyloxy-P
'-Biphenylcarboxylic acid-P''-(2-(4-methylcyclohexyl-1)propoxy]phenyl ester)
Preparation of 2.34 g of P-n-decyloxy-P'-biphenylcarboxylic acid (0,
0066 mol) was used in the same manner as in Example 4 to obtain 1.55 g of the pure target product. The structure of this product was confirmed by infrared absorption spectrum.

Example 8 Compound (Nα15) (optically active P-n-nonyloxy-
Preparation of p'-biphenylcarboxylic acid-P''-(2-(4-methylcyclohexyl-1)propoxy]phenyl ester) P-n-hexadecyloxy-P'-biphenylcarboxylic acid 2.90 g -n-nonyloxy-P'-biphenylcarboxylic acid 2.25 g (0
, 0066 mol) was used in the same manner as in Example 4 to obtain 1.40 g of the pure target product. The subsequent structure was confirmed by infrared absorption spectroscopy.

Example 9 Compound (&14) (optically active P-n-octyloxy-
Preparation of P′-biphenylcarboxylic acid-P”-(2-(4-methylcyclohexyl-1)propoxy]phenyl ester) Instead of 2.90 g of P-n-hexadecyloxy-P′-biphenylcarboxylic acid P-n-octyloxy-
P'-biphenylcarboxylic acid 2.2 g (0,006
6 mol) was used in the same manner as in Example 4 to obtain 1.17 g of the pure target product. The structure of this product was confirmed by infrared absorption spectrum.

Example 10 Compound (&13) (optically active P-n-hebutyloxy-
Preparation of P′-biphenylcarboxylic acid-P”-(2-(4-methylcyclohexyl-1)propoxy]phenyl ester) P-instead of 2.90 g of Pn-hexadecyloxy-P′-biphenylcarboxylic acid n-hebutyloxy-P
'-Biphenylcarboxylic acid 2.06 g (0,006
6 mol) was used in the same manner as in Example 4 to obtain 1.70 g of the pure target product. The structure of this product was confirmed by infrared absorption spectrum.

Example 11 Production of compound (Nα12) (optically active P-n-hexyloxy-P'-biphenylcarboxylic acid-P''-(2-(4-methylcyclohexyl-1)propoxy]phenyl ester) P-n-hexyloxy P-n-hexyloxy-
P'-biphenylcarboxylic acid 1.84 g (0,00
66 mol) was used in the same manner as in Example 4 to obtain 1.50 g of the pure target product. The structure of this product was confirmed by infrared absorption spectrum.

Table 3 shows the melting point and elemental analysis results of the compound obtained as described above.

! 1-3 Table 4 also shows the phase transition temperature of one or more compounds.

C: Crystalline solid state S X: Smectic phase SmA that cannot be clearly identified
: Smectic A phase SsC": Ferroelectric Smectic C phase Ch: Cholesteric phase: Isotropic liquid [Usage example] Usage example 1 After coating the surface of each electrode with polyvinyl alcohol (PVA), the surface is rubbed. Two transparent electrodes subjected to parallel alignment treatment were placed facing each other at an interval of 3 μm with the PVA film inside, and the optically active ester compound [compound (Nα17)] prepared in Example 7 was injected into the formed cell. Afterwards, when we placed it between two orthogonal polarizers to create a liquid crystal display element and applied a voltage of 20V between the electrodes, we found that the display was clear, had very good contrast, and had a fast response speed (approximately 10
0μ5ec) Switching behavior was observed.

Use Example 2 A composition was prepared by mixing the compound (Nα4) prepared in Example 2 with 23.6 vt% of P-octyloxybenzoic m-p'-n-hexyloxyphenyl ester. The phase transition point of this composition was as follows.

53°C 61°C 75°C ←5llC*←→S, A+-+Ch←→I [Effect] Most of the compounds where n=2 among the optically active ester compounds represented by the general formula (1) of the present invention It exhibits a ferroelectric smectic C phase as a single substance, and has a fast response time (approximately 100 μs).
Moreover, since extremely good alignment can be obtained, these compounds can be said to be particularly excellent ferroelectric liquid crystal materials.

In addition, as shown in Table 3, compounds with n=1 in general formula (1) preferably have a low melting point, but as shown in Table 4, chiral smectic C phase is not observed when used alone. As shown in 2, when this compound is mixed alone with a compound exhibiting an SmC phase, it exhibits a ferroelectric smectic C phase, so it can be said that it potentially possesses ferroelectricity.

Furthermore, since the compound of general formula (I) has an optically active carbon atom, it has the ability to induce a twisted structure by adding it to a nematic liquid crystal.

Since nematic liquid crystals having a twisted structure, that is, chiral nematic liquid crystals, do not generate so-called reverse domains of TN type display elements, the compound of general formula (1) can be used as an inhibitor for reverse domain formation. Can be used.

Furthermore, since the compound of general formula (1) of the present invention exhibits a chiral smectic C phase over a wide temperature range, it can also be used as an effective blend material for obtaining ferroelectric compositions.

[Brief explanation of the drawing]

FIG. 1 shows the optically active P-(2-(
Figure 2 shows the infrared absorption spectrum of 4-methylcyclohexyl-1)propoxyphenol. FIG. 2 is an infrared absorption spectrum diagram of (4-methylcyclohexyl-1)propoxy]phenyl ester.

Claims (4)

[Claims] (1) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R is an alkoxy group having 20 or less carbon atoms, n is an integer of 1 or 2, and * is an asymmetric carbon An optically active ester compound represented by (representing an atom). (2) Formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (However, * represents an asymmetric carbon atom.) p-[2-(4-methylcyclohexyl-1)
) Propoxy] Phenol. (3) Formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (However, * represents an asymmetric carbon atom) P-[2-(4-methylcyclohexyl-1)
) Propoxy] Phenol and general formula (III) ▲Mathematical formulas, chemical formulas, tables, etc.▼(III) (However, R is an alkoxy group with 20 or less carbon atoms, n is an integer of 1 or 2, and X is a hydroxy group or halogen General formula (I) characterized by reacting with carboxylic acids or carboxylic acid halides represented by (representing atoms) A method for producing an optically active ester compound represented by the following alkoxy group, n represents an integer of 1 or 2, and * represents an asymmetric carbon atom. (4) General formula (I) ▲Mathematical formula, chemical formula, table, etc.▼(I) (However, R is an alkoxy group having 20 or less carbon atoms, n is an integer of 1 or 2, and * is an asymmetric carbon A liquid crystal composition containing an optically active ester compound represented by (representing an atom).