JPH0881410A - Production of methylsuccinic acid - Google Patents

Abstract

PURPOSE: To provide a method for producing methylsuccinic acid by which the methylsuccinic acid that is a branched α, ω-dicarboxylic acid can industrially and advantageously be produced to improve properties of polyester polyols, nylons, fibers, lubricating oils, plasticizers, etc. CONSTITUTION: The characteristic of this method for producing methylsuccinic acid comprises oxidizing a compound selected from the group consisting of α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, 2-hydroxy-4- methyltetrahydrofuran and 2-methyl-1,4-butanediol with oxygen in the presence of an oxidation catalyst and water.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing methylsuccinic acid. The methylsuccinic acid provided by the present invention is useful as a main raw material or additive for polyester polyol, nylon, fiber, lubricating oil, plasticizer, pharmaceutical intermediate, and the like.

[0002]

BACKGROUND OF THE INVENTION α, ω-dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and dodecadioic acid are industrially available. In particular, adipic acid is a polyester polyol, nylon, fiber, lubricating oil, plasticizer. It is used in large quantities as a raw material. All of these α, ω-dicarboxylic acids are linear.

Methylsuccinic acid is a branched α, ω-dicarboxylic acid and is a useful compound as a starting material for polyesters, polyurethanes, etc., but its industrial production method has not been established so far.

[0004] For example, conventionally known methods for synthesizing methylsuccinic acid include an oxidation method, a reduction method, an olefin carboxylation method, and a STOBBE reaction method. Are known. (1) Method of reacting nitric acid with a cyclohexanol and cyclohexanone derivative having a methyl group (Ropa
Uhlie, 14 (8), 401-16,1972 and J. Chem. Soc. , Perkin Tran
s. 2 (4), 605-11,1992) (2) γ-methyl-γ-butyrolactone with hydrogen fluoride-
Method for reacting antimony pentafluoride (Chem. Le
tt. , (6), 767-8, 1981) (3) Method by electrolytic reduction from citraconic acid and mesaconic acid (electrochemistry and industrial physical chemistry, 50 (6), 49
1-3, 1982) (4) Method by electrolytic reduction from itaconic acid (Che
m. Stosow. , 33 (1), 107-11, 19
89) (5) Method using propylene and carbon monoxide as raw materials (Japanese Patent Publication No. 46-16727 and J. Org. Che
m. , 44 (20), 3474-82, 1979) (6) Method for deriving methylsuccinic acid from succinate (J. Org. Chem., 37 (4), 555-).
9, 1972) However, in the method (1), nitric acid, which is cheaper than oxygen, is used as an oxidant, so it is of great practical value.
There is a high risk of explosion or explosion due to the corrosion of the reactor, the by-product of nitric oxide, and the rapid reaction of nitric acid with organic substances to cause a rapid increase in the internal pressure of the container. Moreover, the cyclohexanol and cyclohexanone derivatives having a methyl group used in this method are not industrially manufactured at low cost, and therefore it is not preferable to use them as starting materials.

In the above method (2), the oxidizing agent is special and expensive, and there is a concern that the oxidizing agent may corrode the reactor. Furthermore, γ-methyl-γ-used in this method
Butyrolactone is not industrially manufactured at low cost, and therefore it is not preferable to use it as a starting material.

The electrolytic reduction in the above methods (3) and (4) has the advantage that it can be carried out without the need for a particularly expensive catalyst, but carbon dioxide, carbon monoxide gas, hydrocarbons, etc. from the produced methylsuccinic acid. There is a risk of rupture and explosion due to a rapid increase in pressure inside the container due to an increase in decomposition loss due to the formation of. By the way, Kawaken Fine Chemicals Co., Ltd. has also proposed a method for producing methylsuccinic acid from citraconic acid using a hydrogenation reaction with a Raney catalyst instead of electrolytic reduction. ("Raney-catalyzed hydrogenation reaction", edited by Kawaken Fine Chemicals Co., Ltd., 1980) However, citraconic acid, mesaconic acid and itaconic acid used in these methods are not manufactured industrially at low cost. Therefore, it is not preferable to use it as a starting material.

Of the above methods (5), Japanese Patent Publication No. 46-16
The method for producing 2-methylsuccinic acid using propylene and carbon monoxide as raw materials described in Japanese Patent No. 727 is a method in which carbon tetrachloride and a catalyst are reacted under high pressure conditions of 200 atm and then treated with concentrated sulfuric acid. Therefore, there is a risk of hydrogen chloride by-product, corrosion of reactor, explosion and explosion due to high pressure. Also, J. Org. Chem. , 44 (20), 3
The production method described in 474-82, 1979 is a method in which propylene and carbon monoxide are reacted in the presence of a palladium catalyst and methanol.
As in the method described in JP-A-6-16727, there is a concern that hydrogen chloride may be a by-product and the reaction apparatus may be corroded, and a large-scale process is required to recycle an expensive palladium catalyst.

Further, the above method (6) is not only unsatisfactory because the reaction step is long and the operation is complicated, and neither the purity nor the yield of the target compound is bad.

[0009]

If a branched α, ω-dicarboxylic acid can be industrially advantageously provided, the properties of conventional polyester polyols, nylons, fibers, lubricating oils, plasticizers, etc. can be improved. . An object of the present invention is to make it possible to industrially produce methylsuccinic acid which is a branched α, ω-dicarboxylic acid.

[0010]

The present inventors attach great importance to these problems of the prior art and favorably produce methylsuccinic acid starting from a raw material that can be industrially mass-produced in Japan and is easily available. As a result of intensive studies on the method, the present invention has been completed.

That is, the present invention relates to α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, 2-
Hydroxy-4-methyltetrahydrofuran and 2-
The present invention relates to a method for producing methylsuccinic acid, which comprises oxidizing a compound selected from the group consisting of methyl-1,4-butanediol with oxygen in the presence of an oxidation catalyst and water.

Oxygen of a compound selected from the group consisting of α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, 2-hydroxy-4-methyltetrahydrofuran and 2-methyl-1,4-butanediol in the present invention. Oxidation is carried out by contacting these compounds with oxygen gas or oxygen-containing gas in a water solvent. As the oxygen-containing gas at that time, air, a mixed gas of nitrogen and oxygen at an arbitrary ratio, or a mixed gas of these with helium gas, argon gas, carbon dioxide gas, or the like is used.

The reaction raw materials α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, 2-hydroxy-4-methyltetrahydrofuran, 2-methyl-
The 1,4-butanediol can be used alone or in combination of two or more.

These reaction raw materials can be produced by a usual method. For example, α-methyl-γ-butyrolactone hydroformylates methyl methacrylate with hydrogen / carbon monoxide mixed gas in the presence of a rhodium complex catalyst, and the resulting methyl 3-formyl-2-methylpropionate is catalyzed. It is obtained by hydrogenation in the presence and then demethanolation in the presence of a catalyst.

2-Hydroxy-4-methyltetrahydrofuran can be obtained by hydroformylating methallyl alcohol with a hydrogen / carbon monoxide mixed gas in the presence of a rhodium complex catalyst.

Further, β-methyl-γ-butyrolactone can be obtained by dehydrogenating 2-hydroxy-4-methyltetrahydrofuran in the presence of a catalyst.

Further, 2-methyl-1,4-butanediol is catalyzed by a compound selected from the group consisting of 2-hydroxy-4-methyltetrahydrofuran, α-methyl-γ-butyrolactone and β-methyl-γ-butyrolactone. It can be obtained by hydrogenation in the presence.

The reaction in the present invention is carried out in the presence of an oxidation catalyst. One example of the catalyst is a catalyst in which a metal is supported on a carrier. That is, examples of the metal include platinum, palladium, ruthenium, and the like, which may be carried alone on the carrier, or may be carried on two or more kinds in combination on the carrier. Examples of the carrier include activated carbon, alumina, calcium carbonate, barium carbonate and the like. Further, the catalyst in which these metals are supported on the carrier may be partially modified with another metal component selected from tin, lead, bismuth, selenium, tellurium, cerium and the like. Since these catalysts are commercially produced, they can be easily obtained.

In the oxygen oxidation reaction in the method of the present invention, water is used as a solvent, and in the presence of the above-mentioned metal-supported catalyst, oxygen gas or oxygen-containing gas is usually used, as well as α-methyl-γ-butyrolactone and β-methyl. It is carried out by continuously or intermittently supplying a compound selected from the group consisting of -γ-butyrolactone, 2-hydroxy-4-methyltetrahydrofuran and 2-methyl-1,4-butanediol. The reaction temperature at that time is 50-
Temperatures in the range of 200 ° C, especially 80-150 ° C, are preferred.

The amount of water used is selected from the group consisting of α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, 2-hydroxy-4-methyltetrahydrofuran and 2-methyl-1,4-butanediol. A molar amount of 1 to 200 times that of the compound is usually suitable, and a molar amount of about 2 to 75 times is preferable.

The reaction in the present invention can be carried out by adding a third component such as acid or alkali in addition to the oxidation catalyst and water.

In the method of the present invention, the reactor is
A general-purpose stirring reactor, bubble column reactor, perforated plate column reactor and the like are used in ordinary gas-liquid contact reaction. Although the optimum range of the reaction pressure varies depending on the oxygen concentration in the oxygen-containing gas, the reaction temperature, the catalyst concentration, etc., it cannot be uniquely determined, but it is usually selected from the range of 1 to 30 absolute atmospheric pressure. The obtained methylsuccinic acid exhibits acidity, so that metal ions are eluted from the reactor depending on the material of the reactor. In some cases, transition metal ions such as iron ions eluted from the reactor interact with methylsuccinic acid to induce coloration. Therefore, the material of the reactor or the like that comes into contact with the produced methylsuccinic acid is a material having good corrosion resistance, such as glass in the case of a small-scale reactor,
If it is an industrial scale reactor, JIS standard is SUS
304, SUS316, and other stainless steel ropes are preferable.

The oxidation reaction in the present invention can be carried out either continuously or batchwise.

Methylsuccinic acid can be separated and obtained by crystallization after removing the oxidation catalyst from the reaction mixture after the reaction by a usual method and distilling off most of the water.

The crude methylsuccinic acid thus obtained has a sufficiently high purity by itself, but can be further purified by recrystallization from the aqueous solvent solution or distillation if necessary.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 A pressure resistant reactor having a content of 300 ml equipped with a thermometer, a pressure gauge, an electromagnetic stirrer, an air inlet and an outlet gas line was filled with water 1
80 ml (10 mol), 15 g (0.15 mol) of α-methyl-γ-butyrolactone, a catalyst in which activated carbon is loaded with 5% platinum and 1% bismuth (manufactured by Degussa Japan Co., Ltd., water content: about 50 wt. %) 0.9 g was charged,
Warming was performed while pressurizing with air to 5 absolute pressure. When the temperature inside the reactor became constant at 130 ° C., the contents were stirred at a rotation speed of 1000 rpm, and the gas was discharged at a speed of 10 liters / hr to carry out an oxidation reaction for about 60 hours.

The autoclave was left to cool, the air was released, the reaction mixture was taken out, and the catalyst was filtered off. further,
Most of the water was distilled off from the filtrate using an evaporator and then the mixture was cooled to 10 ° C. When white crystals began to precipitate, they were separated by filtration. A total of 13 g of white crystals was collected. From various analyzes, it was concluded that this white crystal was methylsuccinic acid. The acquisition rate of methylsuccinic acid after recrystallization was 59% based on the mol of the added α-methyl-γ-butyrolactone.

Example 2 A pressure resistant reactor having a content of 300 ml equipped with a thermometer, a pressure gauge, an electromagnetic stirrer, an air inlet and an outlet gas line was filled with water 1.
80 ml (10 mol), β-methyl-γ-butyrolactone 50 g (0.5 mol), 5% platinum and 5 on activated carbon.
% Bismuth supported catalyst (Degussa Japan Co., Ltd.)
1.3 g of water content (about 50% by weight) and 1 g of activated clay (manufactured by Mizusawa Chemical Industry Co., Ltd.) were charged and heated while being pressurized with air to 10 absolute atmospheric pressure. The temperature in the reactor is 12
When the temperature became constant at 0 ° C, the contents were rotated at 800 rpm.
Stirring at the rotation speed of 10 liters / hr
The oxidation reaction was carried out for about 50 hours while being discharged at the rate of.

The autoclave was allowed to cool, the air was released, the reaction mixture was taken out, and the catalyst and activated clay were separated by filtration. Further, most of the water was distilled off from the filtrate using an evaporator and then cooled to 10 ° C. When white crystals were precipitated, they were separated by filtration. 42 white crystals in total
g collected. From various analyzes, it was concluded that this white crystal was methylsuccinic acid. The acquisition rate of methylsuccinic acid after recrystallization was 58% based on the mol of added β-methyl-γ-butyrolactone.

Example 3 A pressure resistant reactor having a content of 1 liter equipped with a thermometer, a pressure gauge, an electromagnetic stirrer, an air inlet and an outlet gas line was provided with 4 parts of water.
00 ml (22.2 mol), 2-hydroxy-4-methyltetrahydrofuran 51 g (0.5 mol), a catalyst in which 4% platinum and 1% palladium and 5% lead are supported on activated carbon (Degussa Japan Co., Ltd. ) Water content of about 5
2.5 g (0% by weight) was charged and heated while being pressurized to 5 absolute pressure with air. When the temperature inside the reactor became constant at 125 ° C., the contents were stirred at a rotation speed of 800 rpm, and the gas was discharged at a rate of 10 liters / hr to carry out an oxidation reaction for about 100 hours.

The autoclave was left to cool, the air was released, the reaction mixture was taken out, and the catalyst was filtered off. further,
Most of the water was distilled off from the filtrate using an evaporator, and then the mixture was cooled to 7 ° C. When white crystals began to precipitate, they were separated by filtration. A total of 38 g of white crystals was collected.
From various analyzes, it was concluded that this white crystal was methylsuccinic acid. The acquisition rate of methylsuccinic acid after recrystallization was calculated by adding 2-
It was 53% on the molar basis of hydroxy-4-methyltetrahydrofuran.

Example 4 A pressure resistant reactor having a content of 1 liter equipped with a thermometer, a pressure gauge, an electromagnetic stirrer, an air inlet and an outlet gas line was charged with 4 parts of water.
00 ml, 2-methyl-1,4-butanediol 35
g, 6 g of a catalyst in which activated carbon has 5% platinum and 1% bismuth supported (a moisture content of about 50% by weight manufactured by Degussa Japan Co., Ltd.), and the mixture was heated while being pressurized to 20 absolute atmospheric pressure with air. When the temperature inside the reactor became constant at 110 ° C., the contents were stirred at a rotation speed of 1000 rpm, and the gas was discharged at a rate of 10 liters / hr to carry out an oxidation reaction for about 100 hours.

The autoclave was allowed to cool, the air was released, the reaction mixture was taken out, and the catalyst was filtered off. further,
Most of the water was distilled off from the filtrate using an evaporator, and then the mixture was cooled to around 7 ° C. When white crystals were precipitated, they were separated by filtration. A total of 25 g of white crystals was collected. From various analyzes, it was concluded that this white crystal was methylsuccinic acid. The acquisition rate of methylsuccinic acid after recrystallization was 52 based on the molar amount of added 2-methyl-1,4-butanediol.
%Met.

[0035]

According to the method of the present invention, branched α, ω-
Methylsuccinic acid, which is a dicarboxylic acid, can be produced industrially advantageously, and the properties of polyester polyol, nylon, fiber, lubricating oil, plasticizer and the like can be improved.

Claims (1)

[Claims] 1. α-Methyl-γ-butyrolactone, β-
Methyl amber characterized by oxygen-oxidizing a compound selected from the group consisting of methyl-γ-butyrolactone, 2-hydroxy-4-methyltetrahydrofuran and 2-methyl-1,4-butanediol in the presence of an oxidation catalyst and water. Method for producing acid.