JPH01135743A - Production of unsaturated dibasic acid diester - Google Patents

Abstract

PURPOSE:To readily obtain the present compound, useful for producing active compounds which are difficult to purify in high yield and selectivity and excellent in aspects of industry and cost, by reacting an unsaturated dibasic acid with a benzyl halide compound as raw materials in the presence of a tertiary amine. CONSTITUTION:An unsaturated dibasic acid, e.g., fumaric, maleic or itaconic acid, in an amount of 1mol. is reacted with 0.5-6mol. benzyl halide compound expressed by the formula (X is Cl, Br or I; Y is a group selected from halogen, 1-4C alkyl and alkenyl; l is 0-2), e.g., benzyl bromide or chlorostyrene, in the presence of 0.5-4mol. tertiary amine, e.g., triethylamine or benzylmethyl amine, preferably in water and/or an organic solvent, e.g., or benzene, at 30-150 deg.C for 0.5-24hr to carry out esterification and afford the aimed com pound, useful as a modifier for polymers, monomer having a high refractive index, intermediate for organic synthesis, etc., and having an ester residue.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing an unsaturated dibasic acid diester.

<Prior art and its problems> Conventionally, esters of unsaturated dibasic acids such as maleic acid, fumaric acid, and itaconic acid are esters having an alkyl group or an alkenyl group having about 1 to 8 carbon atoms. It is used as a copolymerizer for molecular modifiers or as an intermediate raw material for organic synthesis. In addition, methods for producing the esters include a method of esterifying an unsaturated dibasic acid and an alcohol in the presence of an acid catalyst, and a method of esterifying an alkali metal salt of an unsaturated dibasic acid with an alkyl halide or an alkenyl halide. A method of transesterifying an unsaturated dibasic acid ester and an alcohol in the presence of a basic catalyst is known. The conventional methods have industrial advantages such as easy availability of raw materials, high yields, and easy purification methods.

However, in the conventional method, when producing an unsaturated dibasic acid ester using a benzyl group having an aromatic ring as an ester, for example, when producing by esterification with alcohol or transesterification method, the use of Since it is difficult to obtain alcohol, it is necessary to hydrolyze the halide to obtain the alcohol, which has the drawback of requiring an extra manufacturing process. In the method of transesterification in the presence of a basic catalyst, ethers are easily produced as by-products, and the ether itself is a high-boiling liquid substance.
The drawback is that the purification method is difficult.

In order to solve the above drawbacks, 1, for example, an esterification reaction between an alkali metal salt of an unsaturated dibasic acid and a halide can be considered, but in this case, the disadvantages are that a special catalyst is required and the yield is low. Moreover, the presence of water as a solvent causes hydrolysis of the halides, and the purification method is difficult, making them difficult to use industrially.

<Objective of the Invention> An object of the present invention is to provide a method for easily producing an unsaturated dibasic acid diester having a benzyl-based ester group with high yield and high selectivity.

Another object of the present invention is to provide a method for producing an unsaturated dibasic acid diester that is industrially and cost-effective.

According to the present invention, the following general formula (I) (wherein, X represents a chlorine atom, a bromine atom, or an iodine atom; (represents a group selected from an alkyl group or an alkenyl group, and Q represents an integer of O to 2) and an unsaturated dibasic acid are reacted in the presence of a tertiary amine. A method for producing an unsaturated dibasic acid diester is provided.

The present invention will be explained in more detail below.

In the following general formula (I) used in the present invention, X in the formula represents a chlorine atom, a bromine atom, or an iodine atom. Atoms are preferred. Further, Y represents a group selected from a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkenyl group, and Q represents an integer of 0 to 2. At this time, Q
If it is 3 or more, it cannot be used because it becomes difficult to manufacture.

Examples of the halogenated benzyl compound represented by the general formula (I) used in the present invention include:

Benzyl chloride, benzyl bromide, benzyl iodide, p-fluorobenzyl chloride, p-chlorobenzyl chloride, 0-chlorobenzyl chloride, m-chlorobenzyl chloride, p-bromobenzyl bromide, p-bromobenzyl chloride, O+p
-dichlorobenzyl chloride, p-methylbenzyl chloride, 0-methylbenzyl chloride, p-methylbenzyl bromide, p-ethylbenzyl chloride,
0-ethylbenzyl bromide, p-isopropylbenzyl chloride, p-vinylbenzyl chloride, 0-
It is desirable to select one or more from the group consisting of vinylbenzyl chloride, P-allylbenzyl chloride, and the like.

Preferred examples of unsaturated dibasic acids used in the present invention include fumaric acid, maleic acid, itaconic acid, mesaconic acid, and citraconic acid.

Examples of the tertiary amines used in the present invention include trimethylamine, triethylamine, 1-linormal butylamine, triisopropylamine, trinorbutylamine, triisooctylamine, trioctylamine, triethanolamine, tribenzylamine, benzyl One or more compounds selected from the group consisting of dimethylamine, dibenzylmethylamine, benzyldiethylamine, dibenzylethylamine, benzyldinormalbutylamine, triphenylamine, etc. can be mentioned.

The unsaturated dibasic acid diesters obtained by the production method of the present invention include, for example, dibenzyl fumarate, diorthochlorobenzyl fumarate, diparachlorobenzyl fumarate, cibarabrombenzyl fumarate, and fumaric acid. Shibara methyl benzyl ester,
Diparavinylbenzyl fumarate ester, diorthovinylbenzyl fumarate, diparaallyl benzyl fumarate, dibenzyl maleate.

Diorthochlorobenzyl maleate, Shibara methyl benzyl maleate, Dipara vinylbenzyl maleate, Dibenzyl itaconate, Diorthochlorobenzyl itaconate, Shibara methyl benzyl itaconate, Dipara itaconate Examples include vinylbenzyl ester, mesaconate dibenzyl ester, mesaconate diorthochlorobenzyl ester, mesaconate diparavinylbenzyl ester, and citraconic acid dibenzyl ester.

The amount of raw materials used when producing the unsaturated dibasic diester of the present invention is, for example, 0.5 to 6 mol of the halogenated benzyl compound, 0.5 to 6 mol of the halogenated benzyl compound, 0.5 to 6 mol of the third
The amount of the secondary amine is preferably in the range of 0.5 to 4 moles.

If the amount of the halogenated benzyl compound is less than 0.5 mol, the yield will drop significantly, and if it exceeds 6 mol, it will be difficult to recover unreacted substances, which is not preferable. Furthermore, if the amount of the tertiary amine is less than 0.5 mole, the yield will be significantly lowered, and even if it exceeds 4 moles, it will be difficult to recover unreacted materials, and further post-treatment steps will be required, so this is not preferred. do not have.

The reaction temperature during the reaction in the production method of the present invention varies depending on the type or amount of raw materials, but is 30°C to 150°C.
A range of 50°C to 140°C is particularly desirable. If the reaction temperature is less than 30° C., it is not preferable because one reaction takes a long time. In addition, when the temperature exceeds 150°C, it is not preferable because by-products are noticeably generated due to coloring, etc. Furthermore, the reaction time varies depending on the reaction temperature, but it is preferably in the range of 0.5 to 24 hours. desirable.

The method for producing the unsaturated dibasic acid diester of the present invention includes:
A method in which an unsaturated dibasic acid, a halogenated benzyl compound, and a tertiary amine are simultaneously charged and reacted under the desired reaction conditions, and a method in which an unsaturated dibasic acid and a halogenated benzyl compound are first charged and the desired reaction is carried out. A method in which a tertiary amine is charged and reacted after the conditions are reached, and a method in which a halogenated benzyl compound and a tertiary amine are charged and after the desired reaction conditions are reached, an unsaturated dibasic acid is charged and reacted.

Alternatively, a method may be mentioned in which an unsaturated dibasic acid and a tertiary amine are first charged, and after the desired reaction conditions are reached, a halogenated benzyl compound is charged and the reaction is carried out.
Particularly preferred is a method in which an unsaturated dibasic acid and a tertiary amine are reacted in a first step, and then a benzyl halide is reacted in a second step under the desired reaction conditions.

In the present invention, in addition to carrying out the above reaction without a solvent, it is also possible to carry out the esterification reaction in the presence of a solvent such as water and/or an organic solvent. Examples of the organic solvent include aromatics such as benzene, toluene, xylene, cumene, and chlorobenzene, aliphatics such as pentane, hexane, petroleum ether, heptane, and hexane, and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. , halogenated hydrocarbons such as chloroform, carbon tetrachloride, and methylene chloride, esters such as ethyl acetate and butyl acetate, and ethers such as diethyl ether and diisopropyl ether. Compounds can be mentioned. The proportion of the solvent used is based on 100 parts by weight of the tertiary amine.

It is desirable that the amount is 10 to 10,000 parts by weight, preferably 50 to 1,000 parts by weight, and when water and an organic solvent are used as a mixture, they can be used in any mixing ratio.

As a method for purifying the unsaturated dibasic acid diester obtained by the production method of the present invention, for example, the reaction product is acid-washed or alkaline-washed with an acid aqueous solution such as hydrochloric acid or sulfuric acid, or an alkali aqueous solution such as sodium hydroxide or sodium carbonate. The oil layer can be purified by a method of carrying out this process and further neutralizing and washing.

At this time, when an organic solvent is used, the unreacted raw material and the solvent can be purified, and when no solvent is used, the unreacted raw material can be purified by removing the unreacted raw material by a method such as distillation. Further, in the case of a substance having a high melting point of ester, it can be purified by a recrystallization method. Furthermore, if necessary, it is also possible to use a separation method using a column such as chromatography.

<Effects of the Invention> According to the production method of the present invention, unsaturated dibasic acid diesters can be easily obtained in high yield and high selectivity, and can also be used in the production of viscous compounds that are difficult to purify. Furthermore, it is possible to produce unsaturated dibasic acid diesters having ester residues that can be used as polymer modifiers, high refractive index monomers, organic synthesis intermediates, etc., since they are industrially and economically superior.

<Examples> The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Examples 1 to 4 In an IQ flask equipped with a stirrer, a thermometer, a dropping funnel, and a reflux device, 1 mol of fumaric acid and 20% benzene as a solvent were added.
Add 0 cc of triethylamine or tributylamine while stirring and raising the temperature from room temperature to 60°C.
After 0 drops, benzyl bromide was added as a halogenated benzyl compound.

1.1 mol of 0-chlorobenzyl chloride, p-bromobenzyl bromide, or chlorostyrene was added, the temperature was raised to 80°C, and the mixture was reacted for 6 hours.

After the reaction is completed, the reaction product is transferred to a separating funnel, washed with water,
After washing with a 5% aqueous hydrochloric acid solution and a 5% aqueous sodium hydroxide solution, washing with neutralized water was performed.

Furthermore, benzene was distilled off from the obtained oil layer using a rotary evaporator to obtain a crystalline crude ester product. Purification was performed by a recrystallization method using the ester methanol. Table 1 shows the yield of each ester and the remaining by-products.

Dog 115-8 Using the same reactor as Examples 1-4, itaconic acid 1'
mol and 200 cc of toluene were added as a solvent, and 1 mol of triethylamine or benzylmethylamine L was added dropwise while stirring and raising the temperature to 60°C. After the dropwise addition, 1.1 mol of benzyl chloride, 0-chlorobenzyl chloride, p-methylbenzyl chloride, or chloromethylstyrene was added as a halogenated benzyl compound, and the mixture was heated to 85° C. and reacted for 6 hours. After the reaction was completed, washing and solvent removal were performed in the same manner as in Examples 1 to 4. Since the obtained ester was in a liquid state, it was purified by distilling the crude ester under reduced pressure to remove unreacted substances, rather than by recrystallization. Table 1 shows the yield and residue of each ester.

Furthermore, maleic acid was prepared in exactly the same manner as in Examples 1 to 4, mesaconic acid and citraconic acid were prepared in exactly the same manner as in Examples 5 to 9,
Under the conditions shown in Table 1, various esters were obtained. The yield and residue are shown in Table 1.

Double squeezed Fumaric acid, maleic acid, itaconic acid, mesakonmi 1 layer o
Using 1 winter clothes and 2.5 mol of alcohol, 3 g of para-toluenesulfonic acid as a catalyst and 200 cc of toluene as a solvent, IQ equipped with a stirrer, thermometer, nitrogen bubbler and water distiller.
The reaction was carried out with stirring at 120 to 130°C in a flask, and the reaction was terminated after 6 hours while continuously removing water. Purification was carried out in exactly the same manner as in the examples.

Claims (1)

[Claims] 1) The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (I) (In the formula, X represents a chlorine atom, a bromine atom, or an iodine atom, and Y represents a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkenyl group, and 1 is an integer of 0 to 2.) and an unsaturated dibasic acid, A method for producing an unsaturated dibasic acid diester, which comprises reacting in the presence of a tertiary amine. 2) Claim 1, wherein the unsaturated dibasic acid is selected from one or more of the group consisting of fumaric acid, maleic acid, itaconic acid, mesaconic acid, and citraconic acid. A method for producing the unsaturated dibasic acid diester described. 3) The tertiary amine is one or two selected from the group consisting of trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisooctylamine, trioctylamine, tribenzylamine, and triphenylamine. A method for producing an unsaturated dibasic acid diester according to claim 1, which is characterized in that it is selected from the above. 4) The unsaturated dibasic acid and the tertiary amine are reacted in the first step, and then, in the second step, the general formula (I
2. A method for producing an unsaturated dibasic acid diester according to claim 1, which comprises reacting a benzyl halide represented by: 5) The method for producing an unsaturated dibasic acid diester according to claim 1 or 4, wherein the reaction is carried out in the presence of a solvent such as water and/or an organic solvent.