JP2569732B2 - Ester derivative and method for producing the same - Google Patents

Description

The present invention relates to an intermediate of an organic electronic material such as a liquid crystal compound.

<Prior art> Various compounds have been conventionally developed as liquid crystal compounds.However, there are very few liquid crystal compounds having excellent characteristics such as high-speed response and memory properties. Has not yet been sufficiently developed, and an intermediate and an industrially advantageous production method thereof have been desired.

<Problems to be Solved by the Invention> The present invention provides an ester derivative useful as an intermediate of a liquid crystal compound having excellent properties as described above, an alcohol as an intermediate thereof, and a method for producing the same.

<Means for Solving the Problems> The present invention provides a compound represented by the general formula (I): (Wherein, X is -COO -, - OCO -, - CH 2 O- or -OCH
_2- , A represents an alkyl group or an alkoxyl group having 5 to 20 carbon atoms, R 'represents a lower alkyl group, and l and m are 1 or 2, respectively. ) An ester derivative represented by the general formula (III): (Wherein, X is -COO -, - OCO -, - CH 2 O- or -OCH
_2- , A represents an alkyl group or an alkoxyl group having 5 to 20 carbon atoms, and 1 and m are each 1 or 2. ) And their production methods.

Such a novel ester derivative can be produced through the following two steps.

The first step is the general formula (II) (Wherein, X is -COO -, - OCO -, - CH 2 O- or -OCH
_2- and A represents an alkyl group or an alkoxyl group having 5 to 20 carbon atoms, respectively. 1 and m are each 1 or 2. The ketones represented by the general formula (III) (Wherein, X is -COO -, - OCO -, - CH 2 O- or -OCH
_2- , A represents an alkyl group or an alkoxyl group having 5 to 20 carbon atoms, and 1 and m are each 1 or 2. The second step is a step of acylating the alcohol represented by the general formula (III) with a lower alkyl carboxylic acid to obtain an ester derivative represented by the general formula (I). is there.

 Hereinafter, the present invention will be described in detail.

Ketones (II), which are raw materials in the first step, can be easily produced, for example, by the following reaction depending on the type of the substituent -X-.

i) In the case of X: -COO-, -OCO- It is produced by an esterification reaction generally used widely.

[Example]

ii) X: —CH ₂ O—, —OCH ₂ — In the case of X: —CH ₂ O—, —OCH ₂ — is produced by a generally widely used etherification reaction.

[Example]

The reduction reaction for obtaining alcohols (III) from ketones (II) is performed using a reducing agent that can reduce ketones to alcohols.

When the substituent X in the starting ketones (II) is -COO- or -OCO-, sodium borohydride, lithium-tri-t-butoxyaluminum hydride, lithium-tri- S- butylboron hydride, borane are also substituents X is -CH ₂ O-
Or in the case of —OCH ₂ —, sodium borohydride, lithium borohydride, zinc borohydride, lithium aluminum hydride, aluminum isopropoxide, lithium tri-t-butoxyaluminum hydride, lithium tri-S -Butyl borohydride, borane, alkali metal-ammonia and the like are preferably used.

Such a reducing agent is required to be at least 1 equivalent or more times the amount of the starting ketone (II), and is usually used at 1 to 10 equivalents.

The reduction reaction is usually performed in a solvent, and examples of the solvent include tetrahydrofuran, dioxane, ethyl ether, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, ethers such as toluene, benzene, chloroform, and dichloromethane, and halogenated hydrocarbons. A single solvent or a mixture of solvents inert to the reaction, such as aromatic hydrocarbons and alcohols, is appropriately selected and used.

The reaction temperature is optional in the range of -30 ° C to 100 ° C, but is preferably in the range of -20 ° C to 90 ° C.

From the reaction mixture thus obtained, alcohols (III) are obtained by operations such as liquid separation, concentration, distillation and crystallization.
Can be obtained in good yield, but the ester derivative (I)
It is not always necessary to isolate the alcohols (III) in order to produce the compound, and the reaction mixture may proceed to the next step.

In the acylation reaction of the second step, the lower alkyl carboxylic acids which are acylating agents include lower alkyl carboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, acid anhydrides and acid halides thereof (for example, , Acid chloride, acid bromide, etc.).

This reaction is carried out by applying a normal esterification condition and reacting with a catalyst in the presence or absence of a solvent.

In this reaction, the amount of the lower alkyl carboxylic acid used must be at least 1 equivalent times the alcohol (III), and the upper limit is not particularly limited, but is preferably 4 equivalent times.

When a solvent is used in this reaction,
For example, aliphatic or aromatic hydrocarbons such as tetrahydrofuran, ethyl ether, acetone, methyl ethyl ketone, toluene, benzene, chloroform, chlorobenzene, chlorobenzene, dichloromethane, dichloroethane, carbon tetrachloride, dimethylformamide, hexane, pyridine, ether, halogenated A solvent or a mixture of solvents inert to the reaction, such as hydrocarbons and organic amines, is used,
The amount used is not particularly limited.

Examples of the catalyst include dimethylaminopyridine, triethylamine, tri-n-butylamine, pyridine,
Organic or inorganic basic substances such as picoline, imidazole, sodium carbonate, sodium methylate, potassium bicarbonate, etc., are used, and the amount used varies depending on the type of lower alkyl carboxylic acids used, the combination of catalysts used, and the like. Although not necessarily specified, for example, when an acid halide is used as a lower alkyl carboxylic acid, the amount is 1 to 5 equivalents to the acid halide.

When an organic amine is used as a solvent, the amine may act as a catalyst.

Further, acids such as toluenesulfonic acid, methanesulfonic acid, and sulfuric acid can be used as the catalyst.

When lower alkylcarboxylic acids are used as lower alkylcarboxylic acids, alcohols (II
The ester derivative (I) can be obtained by dehydrating and condensing in the presence of a condensing agent using a lower alkylcarboxylic acid in an amount of 1 to 2 equivalents relative to I).

As the condensing agent, carbodiimides such as N, N'-dicyclolhexylcarbodiimide and N-cyclohexyl-N '-(4-diethylamino) cyclohexylcarbodiimide are preferably used. A sex base is used in combination.

In this case, the amount of the condensing agent used is usually 1 to 1.2 equivalent times relative to the lower alkylcarboxylic acid, and when a base is used in combination, the amount of the base used is 0.01 to 1 equivalent times based on the condensing agent.

The reaction temperature is usually -80C to 100C, preferably -20C to 90C.

The reaction time in the acylation reaction is not particularly limited, and the time when the alcohol (III) as the raw material disappears can be the end point of the reaction.

After completion of the reaction, usual separation means such as extraction, liquid separation,
The target ester derivative represented by the general formula (I) can be isolated from the reaction mixture by concentration, recrystallization, or the like, and can be purified by column chromatography or the like, if necessary.

<Effect of the Invention> Thus, according to the method of the present invention, the novel ester derivatives and alcohols represented by the general formulas (I) and (III) can be produced industrially and advantageously in high yield, The derivative undergoes two steps of asymmetric hydrolysis and esterification (or etherification), (In the formula, R ″ represents an alkyl group, an alkoxyalkyl group, an alkylcarbonyl group, an alkoxyalkylcarbonyl group, or the like, and * represents an asymmetric carbon atom.
A, X, l and m have the same meaning as described above. ).

Further, the above ester derivatives can also be used as intermediates for pharmaceuticals, agricultural chemicals and the like.

<Example> Hereinafter, the present invention will be described with reference to examples.

Example 1 A four-necked flask equipped with a stirrer and a thermometer was charged with 40.2 g (0.1 mol) of 4'-acetyl-4-biphenylyl ester of 4-pentyloxybenzoic acid, 100 ml of ethanol and 100 ml of chloroform. At 80 ° C., 1.9 g (0.05 mol) of sodium borohydride are added over 10 minutes.

After keeping at the same temperature for 3 hours, the mixture is poured into ice water and extracted twice with 200 ml of chloroform.

The organic layer was washed with water and concentrated under reduced pressure to obtain 40.1 g (yield 99.1%) of 4 '-(1-hydroxyethyl) -4-biphenylyl ester of 4-pentyloxybenzoic acid.

Next, 20.2 g (0.05 mol) of the above 4-pentyloxybenzoate obtained above was dissolved in a mixed solution of 100 ml of pyridine and 200 ml of chloroform.
5.5 g (0.07 mol) are added over 1 hour at 10-15 ° C. Thereafter, it is kept at 40 to 50 ° C. for 2 hours.

After completion of the reaction, 200 ml of water is added at 10 ° C. or lower, and the organic layer is separated. The organic layer was washed successively with 3N hydrochloric acid, water, 7% sodium hydrogen carbonate and water, concentrated under reduced pressure, and concentrated to 4 '-(1-acetoxyethyl) -4-biphenyl of 4-pentyloxybenzoic acid as white crystals. Lil ester 21.6 g (Yield 97
%).

mp. 106-107 ° C. Examples 2-10 The reaction and post-treatment were carried out according to the method of Example 1 except that the ketones (II) shown in Table 1 were used as starting materials, and the results shown in Table 1 were obtained. Obtained.

Example 11 In a four-necked flask equipped with a stirrer and a thermometer, 4-
(P-acetylbenzyloxy) -4 ″ -octyloxybiphenyl 12.9 g (0.03 mol), 200 ml of ethanol and 50 ml of chloroform are charged, and 0.76 g (0.02 mol) of sodium borohydride is required at 20 to 30 ° C. for 10 minutes. And add.

After keeping at the same temperature for 3 hours, the mixture is poured into ice water and extracted twice with 200 ml of chloroform.

The organic layer was washed with water and concentrated under reduced pressure to give 4- ｛p- (1-
12.9 g (yield 99.5%) of hydroxyethyl) benzyloxy {-4 "-octyloxybiphenyl (III-11) was obtained.

Next, 10.8 g (0.025 mol) of the obtained III-11 was dissolved in 70 ml of dichloromethane, and 3.0 g (0.05 mol) of acetic acid, 7.1 g (0.035 mol) of dicyclohexylcarbodiimide and 0.1 g of 4-pyrrolidinopyridine were added thereto. And stirred at room temperature for 20 hours. After the completion of the reaction, 300 ml of water and 200 ml of dichloromethane are added, and the organic layer is separated. 5% organic layer
After washing sequentially with acetic acid, water, 5% aqueous sodium hydrogen carbonate and water, the mixture was concentrated under reduced pressure, and white crystals of 4- {p- (1-acetoxyethyl) benzyloxy} -4 ″ -octyloxybiphenyl 10.5 were obtained.
g (89% yield).

mp. 122 to 124 ° C Examples 12 to 13 Using ketones (II) shown in Table 2 as starting materials,
The reaction and post-treatment were carried out according to the method of Example 11 except that butanoic acid was used as the lower alkylcarboxylic acid, and the results shown in Table 2 were obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C07C 69/94 9546-4H C07C 69/94

Claims (4)

(57) [Claims] 1. The compound of the general formula (I) (In the formula, X, -COO -, - OCO -, - CH 2 O- or -O
A represents CH ₂ —, A represents an alkyl group or an alkoxyl group having 5 to 20 carbon atoms, R ′ represents a lower alkyl group,
And m are 1 or 2, respectively. ) An ester derivative represented by the formula: 2. A compound of the general formula (III) (In the formula, X, -COO -, - OCO -, - CH 2 O- or -O
A represents CH ₂ —, A represents an alkyl group or an alkoxyl group having 5 to 20 carbon atoms, and 1 and m each represent 1 or 2
It is. A method for producing an ester derivative represented by the general formula (I), wherein the alcohol represented by the formula (I) is reacted with a lower alkylcarboxylic acid. 3. A compound of the general formula (II) (In the formula, X, -COO -, - OCO -, - CH 2 O- or -O
A represents CH ₂ , A represents an alkyl group or an alkoxyl group having 5 to 20 carbon atoms, and 1 and m are each 1 or 2. The ketones represented by the formula (I) are reduced by using a reducing agent to obtain an alcohol represented by the formula (III), and then reacted with a lower alkyl carboxylic acid. A method for producing an ester derivative. 4. A ketone represented by the general formula (II):
A method for producing an alcohol represented by the general formula (III), wherein the alcohol is reduced by using a reducing agent.