JPH04198143A - Cyclohexanol derivative and production thereof - Google Patents

Abstract

NEW MATERIAL:Cyclohexanol derivatives represented by formula I (R is 1-5C alkyl which may contain asymmetric carbon; n is integer if 1-10). EXAMPLE:4-(1'-Methoxyethyl)-1-cyclohexanol. USE:A liquid crystal material capable of reducing the n value of a mixed liquid crystal and of raising the nematic-isotropic phase transition temperature, i.e., the upper limit of the temperature range showing nematic phase by addition to various kinds of mixed nematic liquids put to practical use as a host liquid crystal. PREPARATION:A benzene derivative represented by formula II (X is halogen or OSO2C6H4CH3) is condensed with an alcohol and subsequently subjected to ring hydrogenation to readily obtain the objective compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cyclohexanol derivative useful as a raw material for a liquid crystal material which is an electrochemical display material, and a method for producing the same.

[Prior Art] The currently mainstream liquid crystal display cell is a TN cell, which is a type of field effect cell. In this TN type cell, Mol by G. Bauer.

Cryst, Liq, Cryst, 63.45 f1
As reported in 9811, the anisotropy (△n) of the refractive index of the liquid crystal material filled in the cell is used to prevent the occurrence of interference fringes on the cell surface that would impair the cell appearance.
It is necessary to set the product of the thickness of the liquid crystal layer in the cell (d) μm to a specific value. The thickness of the liquid crystal layer in practically used liquid crystal display cells is usually 6 to 10 μm.
Since it is set to a value consisting of a limited range of m, △n−
When setting the value of d to 0.5, a liquid crystal material with a small value of △n is required, and the value of △n・d is set to 1.0, 1.6.
Alternatively, if it is set to 2.2, on the contrary, a liquid crystal material with a large value of Δn is required. Thus, depending on the display characteristics of the liquid crystal display cell, a liquid crystal material with a small value of Δn and a liquid crystal material with a large value of Δn are required.

On the other hand, most of the liquid crystal materials that can be used for practical purposes are usually prepared by mixing several or more components consisting of a compound that has a nematic phase near room temperature and a compound that has a nematic phase at a temperature higher than room temperature.

Many of the above-mentioned mixed liquid crystals that are currently in practical use are required to have a nematic phase over the entire temperature range of at least -30°C to +65°C. There is a need for a liquid crystal with a 1. All such useful liquid crystals are liquid crystals having a cyclohexane ring in their molecules; for example, Japanese Patent Publication No. 2-394
No. 98, Special Publication No. 2-39497, Special Publication No. 2-3733
3, Special Publication No. 64-935, Special Publication No. 63-55496
No., Special Publication No. 63-53178, Special Publication No. 63-4674
No. 2, JP 2-36153, JP 2-36133
No., JP-A-64-22835, JP-A-63-2877
Examples include No. 37.

[Problem to be Solved by the Invention] The problem to be solved by the present invention is to reduce the value of △n of the mixed liquid crystal by adding it to the nematic mixed liquid crystal, which is currently in practical use as a base liquid crystal, and to reduce the nematic liquid crystal. Provided is a cyclohexanol derivative useful as a raw material compound that can be used for a liquid crystal having a cyclohexane ring and capable of increasing the nematic phase/isotropic liquid phase transition temperature, which is the upper limit of the temperature range showing a phase. There is a particular thing.

[Means for Solving the Problems] That is, the present invention has the following features: (1) General formula (I): (In the formula, R is an alkyl group having 1 to 5 carbon atoms that may contain an asymmetric carbon, and n is an alkyl group having 1 to 10 carbon atoms. Cyclohexanol derivatives represented by (represents an integer) and ■General formula (■): (wherein, X is a halogen atom or
Represents H3. n is the same as above. 2. The method for producing a cyclohexanol derivative according to claim 1, wherein nuclear hydrogenation is performed after condensing the benzene derivative represented by the following formula with an alcohol.

The present invention will be explained in detail below.

The cyclohexanol derivative represented by Funazura (I) above can be synthesized, for example, from the phenol derivative represented by the compound (■): (where n is the same as above) by the following process. .

K2CO3, C5HsCHJr Reducing agent Halogenated or tosyl esterified aOR Ho<E)-+cH2). Ol'l (I)-
After protecting the phenolic hydroxyl group of the compound represented by Funazou (IV) with benzyl bromide, the ester group in the compound is reduced to the alcohol represented by -8 formula (V) using a reducing agent. . The reducing agent used at this time is not particularly limited,
Various known substances capable of reducing ester groups can be used, such as LiAlH4, NaAIHz fOcHzcHzO
cH3) 2 , LiBH, etc. are economically advantageous. The amount of the reducing agent used is about 1 to 4 mol, preferably 2.0 mol, per 1 mol of the substrate represented by the general formula (TV).
0 to 35 mol is used. The solvent used in the reduction reaction is not particularly limited as long as it is not an alcoholic solvent, but benzene, ether, toluene, xylene, tetrahydrofuran, and hexane are preferred.

Next, the alcohol represented by -8 formula (V) is treated by a known method, for example, P, Hodge, et, al, JC5, P
erkinl (19841, 195, R, T,
Hrubiec, J., Org., Chew.
.

Compound (II) can be derived by converting it into a tosyl ester by halogenation or tosyl chloride according to the method described in [9841, 49].

Next, compound (II) is condensed in the presence of an alcohol and a basic substance described below to form compound (III).
) can be manufactured. The basic substances used in the above reaction include alkali metal hydrides such as potassium hydride and sodium hydride, lithium, sodium,
Alkali metals, such as sodium ethylate,
Alkali metal alcoholades such as sodium methylate,
Examples include alkali metal carbonates such as sodium carbonate and potassium carbonate. In addition, alcohols used in the above reaction include methanol, ethanol, propatool,
Examples include butanol, (Si2-butanol, (R)-2-butanol, (S)-2-pentanol, (R)-2-pentanol, fsl-2-methyl-1-butanol. The amount of sexual substance used is usually at least one equivalent to the alcohol used, and in addition, tuf
f is not particularly limited, but is preferably 3(g
It is about an equivalent amount. The above alcohols and compound (II)
The equivalent ratio of the amount used is about 1:5 to 5:1, preferably 1:3 to 3:1. In the above reaction, the reaction temperature is usually about -50°C to 120°C, preferably about 0°C.
℃ to too''c. As the reaction temperature medium, inert solvents can be used alone or in mixtures during the reaction, such as tetrahydrofuran, diethyl ether, acetone, methyl ethyl ketone, toluene, benzene, chloroform, and dimethylformamide. , there is no particular restriction on the amount used.

Next, the target compound, cyclohexanol derivative (I), can be obtained by subjecting the obtained compound (III) to a catalytic hydrogenation reaction. In addition, the compound (IIT
), depending on the catalyst used, the debenzylation reaction occurs preferentially, and the phenol derivative (
Although the formation of Vl) was also observed, by proceeding the reaction without isolating it, the compound (I) which is the object of the present invention was obtained.
) can be obtained.

The catalyst used in the hydrogenation reaction is not particularly limited, and any conventional hydrogenation catalyst can be used. Preferred hydrogenation catalysts include those in which metals such as palladium, platinum, ruthenium, and rhodium are supported on various carriers such as carbon powder, zeolite, silica, and alumina. The amount of catalyst to be used is about 1 to 40% by weight, preferably 5 to 20% by weight, based on 1 equivalent of compound (■).
Heavy! % range. The catalytic hydrogenation reaction is performed in an autoclave at a hydrogen pressure of 5 Kg/cm2 to 200 Kg/cm.
”, preferably 40Kg/cm2 to 150Kg
/ cm2, and the presence or absence of a solvent is not a problem.

The solvent to be used is not particularly limited, but ethyl acetate, tetrahydrofuran, ethanol, dioxane, etc. are preferred. After the catalytic hydrogenation reaction is completed, the desired cyclohexanol derivative can be obtained by distillation under reduced pressure.

EXAMPLES The present invention will be explained in more detail based on Examples below, but the present invention is not limited thereto.

Example 1 Synthesis of 4-fl'-methoxyethyl)-1-cyclohexanol (first stage) 150 g of rose hydroxyphenylacetic acid methyl ester
(0.9 mol), odor pencil (188 g fl, 1 mol)) and 248 g (18 mol) of anhydrous potassium carbonate were added to acetone lI2 and heated under reflux for 10 hours. After the reaction was completed, the precipitate was filtered off, thoroughly washed with acetone, and combined with the mother liquor and concentrated under reduced pressure. The remaining amount was purified by silica gel chromatography (CHCI3) to obtain 196 g of rosebenzyloxyphenylacetic acid methyl ester (yield: 76
%) was obtained. NMR (CDC1,); δfpp+ml
=3.51fs, 2H), 4.38(s, 3H)
, 5. IHs.

2H1, 6, 98fd, 2H1, 7, 35fm, 5H1
,7,98[d,2H1 (2nd stage) 15 g (0.4 mol) of lithium aluminum hydride in tetrahydrofuran (THF 1800 mQ)
and 50 g (o, z mol) of parabenzyloxyphenylacetic acid methyl ester was added to THF 200 ra under stirring.
12, and added dropwise. At this time, the reaction temperature was carefully controlled so as not to exceed 10°C, and after the completion of the dropwise addition, the reaction was further continued at room temperature for 15 hours. Then, after distilling off THF under reduced pressure, 500 mQ of diethyl ether was added, and 10 mQ of diethyl ether was added.
% aqueous hydrochloric acid solution, water, and saturated brine in this order. Concentrate the organic layer and dilute with parabenzyloxyphenylethanol 35
g (yield 76%) was obtained.

NMR (CDCl2); δfppml: 1.6
Q(s, It(l, 2.85(t, 2H), 3.5
3 (t, 2H), 5.12 (s, 2H), 6.
68fd, 2H), 7.35 fm, 5H1, 7,
98fd, 2H) (3rd stage) B→Benzyloxyphenylethanol 50g (0,2
1 mol) in 500 nu of carbon tetrachloride, -10
Phosphorous tribromide was added dropwise at °C. While keeping the same temperature 10
After reacting for an hour, the reaction mixture was condensed under reduced pressure, 300 mρ of diethyl ether was added, and the mixture was thoroughly washed with water. Concentrate the organic layer and add 4-benzyloxy-(lo-bromoethyl)
43.5 g (yield 71%) of benzene was obtained. NMR (
cnci, ) ; δfppm) ” 2.78 (
t.

2H1, 3, 65ft, 2H1, 5, 12 (s, 2H)
, 6.96fd, 2H], 7.35 (m, 5H
), 7.98 fd, 2H) (4th stage) 4-benzyloxy-[+'-
30 g (0.1 mol) of bromoethylbenzene, 21 g (0.15 mol) of methyl iodide, and 7.5 g (0.15 mol) of sodium methylate were added, and after heating under reflux for 15 hours, the reaction mixture was concentrated under reduced pressure. did. The remaining amount was purified by silica gel chromatography (CI (C18)) to obtain 4-benzyloxy-1fl'-methoxyethyl)benzene 2.
1 g (yield 87%) was obtained. NMR (CDCI!)
; δfppm) -2,78ft, 2H1,3,3
5fs, 3H), 3.58ft, 2H1,5, lHs,
2 old.

6.96fd, 2H1,7,35 (Ql, 5H1,7,
98fd, 2H1 (5th stage) 4-benzyloxy-1-(l-methoxyethyl)benzene 5 (1 g (0.2 mol)) was dissolved in ethanol 100 a + ρ containing 0.5% fw/w acetic acid. , 5%Ru
- Add 5g of carbon powder and place in an autoclave at 80% hydrogen pressure.
Kg/cm", and reacted at 70°C for 5 hours. After filtering off the catalyst, the mother liquor was distilled and the fraction at 97-98°C was collected at 4 mmHg to obtain 4-(1°-methoxyethyl)-1- 27 g (yield 86%) of cyclohexanol was obtained. NMR (C
DCl2) : δfppml ・0.98(m,
lHl, 1.15-1.80fm, 10H), 1.
95 im, IH], 3.30 (s, 3H
1,3,37(m, 2H1,3,52(m, G5H
1, 3,94in, 0.5H1 Example 2 The same procedure as in Example] was carried out except that 5% Rh-carbon powder was used as the catalyst instead of 5% Ru-carbon powder, and the reduction reaction was carried out at room temperature and normal pressure. 29 g of 4-fl'-methoxyethyl)-1-cyclohexanol (yield 92%)
) was obtained. The NMR analysis results were the same as in Example 1.

Example 3 The same operation as in Example 1 was carried out except that 84 g (0.5 mol) of parahydroxyphenylpropionate methyl ester was used instead of parahydroxyphenylacetic acid methyl ester, and 4-(1- methoxypropyl)-1-cyclohexanol 29 g (overall yield 3
5%).

NMR (CDC1,); δfppm) = 0.9
2hm, 1Hl, 1.13~J, 78hm, 12H
1,1,92 (m, IH), 3.28fs, 3H1,3
,33(+n,2H1,3,48f+i,0.5H1,
3,91hm, 0.5H1 Example 4 The same operation as in Example 3 was performed except that 5% Rh-carbon powder was used instead of 5% Ru-carbon powder and the reduction reaction was carried out at room temperature and normal pressure. and 30 g of 4-(I-methoxypropyl)-1-cyclohexanol (overall yield 3
6%). The NMR analysis results were the same as in Example 3.

Example 5 The same operation as in Example 3 was carried out except that 5% PT-carbon powder was used instead of 5% Ru-carbon powder and the reduction reaction was carried out at room temperature and normal pressure. methoxypropyl)-1-cyclohexanol 25 g (overall yield 3
Obtained 0% n. The NMR analysis results were the same as in Example 3.

Example 6 In Example 1, instead of sodium methylate,
The same operation was performed except that sodium ethylate was used to obtain 18 g (total yield: 20%) of 411'-ethoxyethyl)-1-cyclohexanol. NMR (CD
Cl2); 6 fppml = 0.98h, l
Hl.

1.20ft, 3H), 1.21-1.80hm, l
0H1,1,95 (+1.IHI.

3.37hm, 2H), 3.47 fq, 2H1,3
, 52hm, 0.5H), 3.941rr+, 0
．． 5)11 Example 7 In Example 1, instead of sodium methylate,
4-[1-11''-
28 g of methylbutyloxyethyl]-]1-cyclohexanol (total yield 25%) was obtained.

NMR (CDC1,); δfppm) = 0.8
1111t, 3) 1).

0.98hm, IH), 1.15-1.811n, l
7H), 1.9Hm, 1 old.

3.371m, 2H), 3.52hm, 0.5H1,3
, 94in+, 0.5H), 4.40hm, iH) Example 8 Synthesis of 4-11°-methoxyethyl)-1-cyclohexanol parabenzyloxyphenylethyl tosylate 38.2
g (0.1 mol) wo THF 200 m9 niB
Sodium methylate (0.15 mol) (7)
A 100 ++ l THF solution was added dropwise at 20 to 25°C, and after the dropwise addition was completed, the mixture was further stirred at 40 to 50°C for 5 hours. After the reaction was completed, it was concentrated under reduced pressure and the residue was dissolved in chloroform. After washing the organic layer with O and IN sodium hydroxide drops and water in this order, the organic layer was concentrated under reduced pressure. 18 g of the obtained 4-benzyloxy-1-(1-methoxyethyl)benzene (yield 75%) was subjected to catalytic reduction according to Example 1 to give 4-(]]'-methoxyethyl-1-cyclohexanol. 9.5 g (yield 85%) was obtained.N
The MR analysis results were the same as in Example 1.

[Effects of the Invention] According to the present invention, by adding it to various nematic mixed liquid crystals that have been put into practical use as base liquid crystals, the value of Δn of the mixed liquid crystal can be reduced, and at the upper limit of the temperature range in which the nematic phase is exhibited. A great effect can be achieved in that a cyclohexanol derivative useful as a liquid crystal raw material having a cyclohexane ring capable of raising a certain nematic phase/isotropic liquid phase transition temperature can be easily provided.

Patent applicant: Arakawa Chemical Industry Co., Ltd.

Claims (2)

[Claims] (1) General formula (I): ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R is an alkyl group with 1 to 5 carbon atoms that may contain an asymmetric carbon, and n is 1 to 10 Cyclohexanol derivative represented by (representing an integer of ). (2) General formula (II): ▲Mathematical formulas, chemical formulas, tables, etc.▼(II) (In the formula, X is a halogen atom or -OSO_2C_6H
Represents _4CH_3. n is the same as above. 2. The method for producing a cyclohexanol derivative according to claim 1, wherein nuclear hydrogenation is performed after condensing the benzene derivative represented by () with the alcohol.