JP3249575B2 - Phenoxymethylcyclohexane derivative - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenoxymethylcyclohexane derivative which is useful as an electro-optical display material, and more particularly, to minimize the increase in viscosity of a nematic liquid crystal material by mixing the same with a nematic liquid crystal material. Further, the present invention relates to a phenoxymethylcyclohexane derivative useful for reducing the anisotropy (Δn) of the refractive index and a liquid crystal composition containing the compound.

[0002]

2. Description of the Related Art Liquid crystal display devices began to be used in displays such as watches and calculators, and are now widely used in pocket televisions, various displays and optoelectronic devices. However, most of such liquid crystal display elements are of a TN type display system, and a liquid crystal material belonging to a nematic phase is used.

[0003] Such a TN type display system is a light receiving element type, so that it does not tire eyes even when used for a long time, it can be small and thin, and it has low driving voltage and low power consumption. However, the characteristics required for liquid crystal materials have been diversified as the application fields have expanded, and the increase in viscosity has been minimized, and the anisotropy of the refractive index (Δ
There has been a demand for a liquid crystal material that reduces n).

Accordingly, an object of the present invention is to provide a novel compound capable of minimizing an increase in the viscosity of the liquid crystal material and reducing the anisotropy (Δn) of the refractive index by being mixed with the liquid crystal material. Is to provide.

[0005]

Means for Solving the Problems The present inventors have formulated a phenoxymethylcyclohexane derivative represented by the following general formula (I) of the following [formula 2] (the same as [formula 1]) into a liquid crystal material. As a result, the present inventors have found that an increase in the viscosity of the liquid crystal material can be suppressed to a minimum and the anisotropy (Δn) of the refractive index can be reduced.

[0006]

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That is, the present invention provides a phenoxymethylcyclohexane derivative represented by the above general formula (I) and a liquid crystal composition containing the compound.

Hereinafter, the phenoxymethylcyclohexane derivative of the present invention having the above-mentioned gist and the liquid crystal composition containing the compound will be described in detail.

In the above general formula (I), X, Y
And the halogen atom represented by Z include fluorine, chlorine, bromine and iodine, and the alkyl group represented by Y includes, for example, methyl, ethyl, propyl, isopropyl, butyl, amyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl and decyl groups are exemplified.

Accordingly, the phenoxymethylcyclohexane derivatives represented by the above general formula (I) include, for example, trans-1-chloromethyl-4- (4′-methylphenoxymethyl) cyclohexane, trans-1-chloromethyl- 4- (4'-ethylphenoxymethyl) cyclohexane, trans-1-chloromethyl-4-
(4'-n-propylphenoxymethyl) cyclohexane, trans-1-chloromethyl-4- (4'-n-butylphenoxymethyl) cyclohexane, trans-1
-Fluoromethyl-4- (4'-n-propylphenoxymethyl) cyclohexane, trans-1-fluoromethyl-4- (4'-n-butylphenoxymethyl) cyclohexane, trans-1-chloromethyl-4- (4 '
-Cyanophenoxymethyl) cyclohexane, trans-1-chloromethyl-4- (3 ′, 4′-difluorophenoxymethyl) cyclohexane, trans-1-fluoromethyl-4- (3 ′, 4′-difluorophenoxymethyl) cyclohexane And trans-1-chloromethyl-4- (4'-chloro-3'-fluorophenoxymethyl) cyclohexane.

The phenoxymethylcyclohexane derivative of the present invention represented by the above general formula (I) can be obtained, for example, by etherifying one hydroxyl group of trans-1,4-cyclohexanedimethanol with each substituted phenol. Further, it can be easily produced by halogenating the remaining hydroxyl groups.

By mixing the thus obtained phenoxymethylcyclohexane derivative of the present invention with a liquid crystal material (base liquid crystal), the anisotropy of the refractive index of the liquid crystal material composition (Δ
n) can be reduced.

Examples of the compound constituting the mother liquid crystal include compounds represented by the following formulas (II), (III) and (IV) of [Chemical Formula 3].

[0014]

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The mother liquid crystal is usually used by mixing several or more of these compounds.
The liquid crystal composition of the present invention is prepared by mixing 0 parts by weight of the phenoxymethylcyclohexane derivative of the present invention, preferably 1 to 30 parts by weight.

[0016]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by the following examples.

Example 1 Synthesis of trans-1-chloromethyl-4- (4'-n-butylphenoxymethyl) cyclohexane (compound 1 of the following chemical formula 4)

[0018]

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Trans-1,4-cyclohexanedimethanol 14.42 g, p-butylphenol 7.51 g
Then, 15.74 g of triphenylphosphine was dissolved in 100 ml of dichloromethane, and 12.13 g of diisopropyl azodicarboxylate was gently added dropwise at room temperature under an argon atmosphere. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours.

After adding 20 g of silica gel and filtering, the filtrate was concentrated under reduced pressure. Solvent removal residue is ethyl acetate / n-
A silica gel column treatment was performed using hexane (20/80) as a developing solvent, and trans-1-hydroxymethyl-4 was used.
7.74 g of-(4'-n-butylphenoxymethyl) cyclohexane was obtained.

3.67 g of trans-1-hydroxymethyl-4- (4'-n-butylphenoxymethyl) cyclohexane and 4.20 g of triphenylphosphine obtained above were dissolved in 15 ml of carbon tetrachloride and heated for 6 hours. Reflux was performed. After adding n-hexane to the reaction solution and filtering the precipitate, 15 g of silica gel was added and the mixture was filtered again.

The filtrate was desolvated under reduced pressure, the residue was subjected to silica gel column treatment using ethyl acetate / n-hexane (5/95) as a developing solvent, and further recrystallized from methanol / ethyl acetate to give a melting point of 47.1. 2.82 g of white crystals at a temperature of .degree. C. were obtained.

As a result of infrared spectroscopy, the obtained reaction product (white crystal) had the following characteristic absorption and was confirmed to be the desired product.

2920 cm ^-1 , 1609 cm ^-1 , 150
^{9cm -1, 1461cm -1, 1444cm -1} , 1238
^{cm -1, 1037cm -1, 826cm -1} , 811c
m ^-1, 719cm ^-1, 512cm ^-1

Example 2 Synthesis of trans-1-chloromethyl-4- (4'-ethylphenoxymethyl) cyclohexane (compound 2 of the following chemical formula 5)

[0026]

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Trans-1,4-cyclohexanedimethanol 16.22 g, p-ethylphenol 9.16 g
Then, 23.61 g of triphenylphosphine was dissolved in 150 ml of tetrahydrofuran, and 18.20 g of diisopropyl azodicarboxylate was gently added dropwise at room temperature under an argon atmosphere. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours.

After desolvating the solution under reduced pressure, the residue was subjected to silica gel column treatment using ethyl acetate / n-hexane (20/80) as a developing solvent to give trans-1-hydroxymethyl-4- (4'-ethyl). 9.79 g of phenoxymethyl) cyclohexane were obtained.

4.97 g of trans-1-hydroxymethyl-4- (4'-ethylphenoxymethyl) cyclohexane obtained above and triphenylphosphine 6.
29 g was dissolved in 20 ml of carbon tetrachloride, and the mixture was heated under reflux for 6.5 hours. N-Hexane was added to the reaction solution and the mixture was filtered. 10 g of silica gel was further added, and the mixture was filtered again.

The filtrate was desolvated under reduced pressure, and the residue was recrystallized from methanol / ethyl acetate to give 3.43 g of white crystals having a melting point of 64.7 ° C.

As a result of infrared spectroscopy, the obtained reaction product (white crystal) had the following characteristic absorption and was confirmed to be the desired product.

2932 cm ^-1 , 1608 cm ^-1 , 150
8 cm ^-1 , 1460 cm ^-1 , 1445 cm ^-1 , 1038
^{cm -1, 839cm -1, 811cm -1} , 713cm -1,
511 cm ^-1

Example 3 Synthesis of trans-1-chloromethyl-4- (4'-cyanophenoxymethyl) cyclohexane (compound 3 of the following chemical formula 6)

[0034]

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Trans-1,4-cyclohexanedimethanol 10.82 g, p-cyanophenol 5.96 g
Then, 15.74 g of triphenylphosphine was dissolved in 150 ml of tetrahydrofuran, and 12.13 g of diisopropyl azodicarboxylate was gently added dropwise at room temperature under an argon atmosphere. After completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour.

The precipitate was filtered, and the filtrate was desolvated under reduced pressure. The residue was treated with ethyl acetate / n-hexane (50/5
Silica gel column treatment was carried out using 0) as a developing solvent to obtain 7.31 g of trans-1-hydroxymethyl-4- (4′-cyanophenoxymethyl) cyclohexane.

1.10 g of trans-1-hydroxymethyl-4- (4'-cyanophenoxymethyl) cyclohexane obtained above and triphenylphosphine 1.
24 g was dissolved in 20 ml of carbon tetrachloride, and heated under reflux for 6 hours. Ethyl acetate / n-hexane (2
(0/80) was added, the precipitate was filtered, 5 g of silica gel was further added, and the mixture was filtered again.

The filtrate was desolvated under reduced pressure, and the residue was recrystallized from methanol to give 0.21 white crystals having a melting point of 58.7 ° C.
g was obtained.

As a result of infrared spectroscopy, the obtained reaction product (white crystal) had the following characteristic absorption and was confirmed to be the desired product.

2912 cm ^-1 , 2208 cm ^-1 , 159
^{5cm -1, 1500cm -1, 1460cm -1} , 1251
^{cm -1, 1011cm -1, 838cm -1} , 800c
m ⁻¹ , 713 cm ⁻¹ , 541 cm ⁻¹

Example 4 Synthesis of trans-1-chloromethyl-4- (3 ', 4'-difluorophenoxymethyl) cyclohexane (compound 4 of the following formula 7)

[0042]

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10.82 g of trans-1,4-cyclohexanedimethanol, 6.50 g of 3,4-difluorophenol and 15.74 g of triphenylphosphine
Was dissolved in 100 ml of tetrahydrofuran and diisopropyl azodicarboxylate was added at room temperature under an argon atmosphere.
13 g was dripped gently. After completion of the dropwise addition, the mixture was stirred at room temperature for 7 hours.

The precipitate was filtered, and the filtrate was desolvated under reduced pressure. The residue was treated with ethyl acetate / n-hexane (30/7).
Silica gel column treatment was performed using 0) as a developing solvent, and 9.24 g of trans-1-hydroxymethyl-4- (3 ′, 4′-difluorophenoxymethyl) cyclohexane was obtained.
I got

1.28 g of trans-1-hydroxymethyl-4- (3 ′, 4′-difluorophenoxymethyl) cyclohexane and 1.97 g of triphenylphosphine obtained above were dissolved in 10 ml of carbon tetrachloride, and the solution was dissolved for 2 hours. The mixture was heated to reflux. After the precipitate was filtered, the solvent was removed, and the residue was subjected to silica gel column treatment using ethyl acetate / n-hexane (20/80) as a developing solvent. Further Kugelrohr distillation was performed to obtain 1.06 g of a colorless liquid.

As a result of infrared spectroscopy, the obtained reaction product (colorless liquid) had the following characteristic absorption and was confirmed to be the desired product.

2920 cm ^-1 , 2858 cm ^-1 , 160
^{0cm -1, 1510cm -1, 1445cm -1} , 1250
^{cm -1, 1210cm -1, 1160cm -1} , 1031c
m ⁻¹ , 778 cm ⁻¹ , 724 cm ⁻¹

Example 5 Effect of Using 4-n-Alkylcyclohexanecarboxylic Acid Alkoxyphenyl Ester Liquid Crystal Composition as Mother Liquid Crystal

A commercially available 4-n-alkylcyclohexanecarboxylic acid alkoxyphenyl ester-based liquid crystal composition [4
- (C ₃ -C ₅ alkyl) cyclohexanecarboxylic acid -
72% by weight of a 4 ′-(C ₁ -C ₅ alkoxy) phenyl ester mixture, 4-amylcyclohexanecarboxylic acid
12% by weight of 4'-amylphenyl ester and 4-
(C ₃ -C ₅ alkyl) cyclohexanecarboxylic acid -
4 ′-(4 ″ -methylphenoxycarbonyl) phenyl ester mixture (16% by weight)], the phenoxymethylcyclohexane derivative of the present invention was added, and the refractive index anisotropy (Δ
n) and viscosity (η) were measured. The results are shown in the following [Table 1].

[0050]

[Table 1]

Example 6 The refractive index anisotropy (Δn) and viscosity (η) were measured when 3 parts by weight of the phenoxymethylcyclohexane derivative of the present invention were added to 97 parts by weight of the mother liquid crystal as in Example 5.
The results are shown in the following [Table 2].

[0052]

[Table 2]

From the results of the above examples, it can be seen that the phenoxymethylcyclohexane derivative of the present invention has an excellent effect of reducing the anisotropy of the refractive index of the mother liquid crystal, has the advantage of having a wide viewing angle, and has a minimum increase in viscosity. Can be minimized. Therefore, it is clear that the liquid crystal composition containing the phenoxymethylcyclohexane derivative of the present invention is extremely useful as a liquid crystal material of a TN display mode.

[0054]

The phenoxymethylcyclohexane derivative of the present invention can be added to a liquid crystal material to minimize the increase in viscosity of the liquid crystal material and to reduce the refractive index anisotropy (Δn). You can do it.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-4724 (JP, A) JP-A-4-282354 (JP, A) JP-A-5-58925 (JP, A) 501575 (JP, A) WO 91/8184 (WO, A2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 43/225 C07C 255/54 C09K 19/30 C09K 19/42 CA ( STN) REGISTRY (STN)

Claims (2)

(57) [Claims] A phenoxymethylcyclohexane derivative represented by the following general formula (I): Embedded image 2. A liquid crystal composition comprising at least one phenoxymethylcyclohexane derivative according to claim 1.