JPH054938A - Method for oxidizing unsaturated carboxylic acid - Google Patents

Abstract

PURPOSE:To produce a corresponding saturated mono and di-carboxylic acid in high yield by oxidation reaction of an unsaturated carboxylic acid. CONSTITUTION:An unsaturated carboxylic acid selected from oleic acid, erucic acid, linolic acid, linolenic acid or ricinolic acid and catalysts of (A) an acid selected from tungstic acid, tungstophosphoric acid, molybdic acid and molybdophosphoric acid and (B) quaternary amine salt are separately charged into a reaction system and the above-mentioned unsaturated carboxylic acid are oxidized by hydrogen peroxide to produce a corresponding saturated mono- and dicarboxylic acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an oxidation process for producing corresponding saturated monocarboxylic acids and saturated dicarboxylic acids from unsaturated carboxylic acids.

[0002]

2. Description of the Related Art Saturated carboxylic acids are widely used as raw materials for polyester plasticizers, nylons, polyester raw materials, lubricating oils and the like. Various methods for producing a saturated carboxylic acid are known, particularly olefinic hydrocarbons that are easily and inexpensively obtained are potassium permanganate, potassium dichromate, metal compounds such as ruthenium tetroxide and ozone and the like. A general method is oxidative cleavage with an oxidizing agent.

However, these methods have the problems that metals such as chromium and ruthenium and ozone are toxic, that the cost of the oxidizer is high, and that recovery or treatment after the reaction requires a great deal of labor. , Not suitable for manufacturing on an industrial scale. Therefore, hydrogen peroxide has attracted attention as a new oxidant in order to improve such a defect. For example, in (1) JP-A-60-34929, oleic acid is used as a catalyst using a complex compound of phosphotungstic acid and a quaternary amine. (2) Japanese Patent Application Laid-Open No. 63-93746 discloses a method for producing azelaic acid and pelargonic acid from oleic acid using a heteropolyacid as a catalyst.

[0004]

However, in (1), a reaction step for synthesizing a catalyst is required,
Furthermore, a very complicated extraction operation is indispensable for obtaining the target saturated carboxylic acid after completion of the reaction, and since the yield is not so high, it is industrially advantageous in terms of time and economy. It's hard to say. In (2), when low-concentration hydrogen peroxide is used,
Since the reaction rate decreases, a very long time is required for the reaction, which is not industrially desirable. On the other hand, when a high concentration of hydrogen peroxide is used, the reaction time can be shortened, but on the other hand, there are drawbacks such as an increase in cost, difficulty in handling, and danger, etc., which are not satisfactory in industrial practice. Therefore, regardless of the concentration of hydrogen peroxide, if a saturated mono- and dicarboxylic acid can be produced with a high yield by a simple production process, it will be industrially extremely advantageous, and a new oxidation method is desired.

[0005]

However, as a result of intensive studies to solve the above problems, the present inventor found that a specific unsaturated carboxylic acid selected from oleic acid, erucic acid, linoleic acid, linolenic acid or ricinoleic acid. When oxidizing (A) with hydrogen peroxide, (A) an acid selected from tungstic acid, phosphotungstic acid, molybdic acid, and phosphomolybdic acid, and (B) a quaternary amine salt are used as catalysts, and (A) and ( The present invention has been completed by finding that the above-mentioned purpose is met and the yield of the obtained target product is improved when (a) is separately charged into the system.

That is, in the present invention, in the method of oxidizing a specific unsaturated carboxylic acid with hydrogen peroxide, the catalysts (a) and (a) of the catalyst are not reacted in advance (rather, the object is to react in advance to form a complex). The feature is that a high yield of saturated carboxylic acid can be obtained by an easy production process even with a low concentration of hydrogen peroxide simply by separately charging the reaction system. The present invention will be specifically described below.

The oxidation method according to the present invention is generally carried out as follows. That is, an unsaturated carboxylic acid as a raw material, a catalyst, hydrogen peroxide, and a solvent are charged into the reaction system, and the reaction is performed with heating and stirring. There is no particular limitation on the method of charging the chemicals described above, and any method such as divided charging, continuous charging, and batch charging is possible and does not affect the yield of the product,
Batch charging is particularly preferable because the charging operation is the simplest. However, regarding the catalyst, as mentioned above, (a) and (a)
It is not possible to prepare a mixture or prepare it in the form of a reaction product beforehand. That is, the method of charging various chemicals used in the reaction is arbitrary as long as it avoids contact between (a) and (a) before charging.

The unsaturated carboxylic acid in the present invention is an acid selected from oleic acid, erucic acid, linoleic acid, linolenic acid or ricinoleic acid, and the effects of the present invention cannot be expected with unsaturated carboxylic acids other than the above. The catalyst used in the present invention is (a) an acid selected from tungstic acid, phosphotungstic acid, molybdic acid and phosphomolybdic acid, and (a) cetylpyridinium chloride, trioctylmethylammonium chloride, tetrabutylammonium bromide, benzyltriethylammonium chloride. And the like. The amount of the catalyst used is 0.1 to 15 mol% with respect to the unsaturated carboxylic acid of which (a) is a raw material, and preferably 0.1.
5 to 8 mol% is suitable, and (a) is not particularly limited, but it is advantageous to use the same amount as the proton of (a) from the viewpoint of activity as a catalyst and economical aspect.

The amount of hydrogen peroxide required for the present invention is 3 to 20 times, preferably 4 to 18 times the molar amount of the unsaturated carboxylic acid. The concentration of hydrogen peroxide in the reaction mixture can be selected from a wide range, but from the viewpoint of the reaction rate, it is advantageous that it is 2 to 35% by weight, preferably 4 to 18% by weight. Hydrogen peroxide is usually supplied in the form of an aqueous solution. Water is particularly preferable as the reaction solvent, but an organic solvent,
For example, halogenated hydrocarbons such as chloroform, dichloroethane and methylene chloride, alcohols having 1 to 5 carbon atoms, tetrahydrofuran, dioxane, acetonitrile and the like may be used alone or in admixture of two or more. The amount of the solvent used is not particularly limited, but it is suitable to use 0.5 to 20 times the weight of the unsaturated carboxylic acid in terms of the reaction rate.

The reaction temperature in the present invention is 10 to 120.
C., preferably the reflux temperature of the solvent used is employed. The reaction time depends on the concentration of unsaturated carboxylic acid, catalyst and hydrogen peroxide,
Although it may vary depending on the reaction temperature and the like, it is usually about 10 to 24 hours. After the completion of the reaction, the saturated mono- and dicarboxylic acids produced can be used as a mixture as they are, depending on the application, but they are usually isolated from the reaction mixture by any method. For example, after removing the catalyst by hot filtration, extraction is carried out with a solvent such as chloroform, dichloroethane, tert-butyl alcohol and the like, and the mixture is concentrated according to a known method to obtain a mixture of saturated mono- and dicarboxylic acids. Then, it is easily isolated by any method such as distillation and recrystallization.
The obtained crystals can be further purified by a usual means such as chromatography if necessary. The saturated mono- and dicarboxylic acids thus obtained are widely used as raw materials for polyester plasticizers, nylons, polyester raw materials, lubricating oils and the like.

[0011]

[Working] The present invention uses hydrogen peroxide that is easy to handle from a specific unsaturated carboxylic acid selected from oleic acid, erucic acid, linoleic acid, linolenic acid, and ricinoleic acid, and has a very easy manufacturing process. Since a saturated mono- and dicarboxylic acid in a yield can be obtained, it is industrially extremely advantageous.

[0012]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to practical examples. Example 1 9.0 g of oleic acid was added to a glass 3-necked flask equipped with a stirrer.
(0.032 mol), phosphotungstic acid 2.30 g, cetylpyridinium chloride 0.86 g, 35% hydrogen peroxide solution 14.0 g (0.144 mol), and water 20 ml were charged and reacted with heating while vigorously stirring. .. After reacting for 12 hours, the catalyst was removed by hot filtration, followed by chloroform 30
extracted with ml. This was concentrated and distilled to obtain 10.2 g of a mixture of saturated monocarboxylic acid and dicarboxylic acid. This mixture is subjected to distillation to obtain 4.30 g of a distillate of 100 ° C / 2 mmHg.
(27.2 mmol) was obtained. This was pelargonic acid, and the yield was 84.3% based on oleic acid. The distillation residue was added to 50 ml of hot water to remove insoluble oil, the aqueous solution was cooled, and the precipitated crystals were collected by filtration to obtain 5.54 g (29.4 mmol) of azelaic acid. This was a yield of 91.8% based on oleic acid.

Examples 2 to 4 Experiments were carried out according to Example 1 except that the catalysts shown in Table 1 were used. The results are summarized in Table 1.

[Table 1]

Example 5 11.2 g of erucic acid as a raw material instead of oleic acid
The reaction was carried out in the same manner as in the Example except that (0.032 mol) was used. The result was that pelargonic acid 4.07 g (25.7 mmol) (yield 80.3%) brassic acid 7.01 g (28.7).
Mmol) (yield 89.6%).

Example 6 2.97 g of linoleic acid as a raw material instead of oleic acid
(0.011 mol), phosphotungstic acid 1.44 g, cetylpyridinium chloride 0.54 g, 35% hydrogen peroxide solution 10.69 g (0.11 mol), and water 20 ml were charged, and the reaction was heated for 24 hours with vigorous stirring. Then, saturated mono- and dicarboxylic acids were obtained according to Example 1 below. As a result, caproic acid 0.80 g (6.9 mmol) (yield 62.3%) malonic acid 0.55 g (5.3 mmol) (yield 48.3%),
1.58 g (8.4 mmol) of azelaic acid (yield 76.
4%) was obtained.

Example 7 3.06 g of linolenic acid as a raw material instead of oleic acid
(0.011 mol), phosphotungstic acid 2.4 g, cetylpyridinium chloride 0.9 g, 35% hydrogen peroxide solution 14.
6 g (0.15 mol) and 20 ml of water were charged, and the mixture was heated and reacted with vigorous stirring for 24 hours to obtain saturated mono- and dicarboxylic acids according to Example 1 below. As a result, propionic acid 0.5 g (6.6 mmol) (yield 59.6%), malonic acid 1.14 g (11 mmol) (yield 50.0%), azelaic acid 1.41 g (7.5 mmol). ) (Yield 68.5
%)was gotten.

Example 8 Ricinoleic acid 6.96 as a raw material instead of oleic acid
g (0.023 mol), phosphotungstic acid 2.6 g, cetylpyridinium chloride 0.97 g, 35% hydrogen peroxide solution 18.5 g (0.19 mol), and water 20 ml were charged and heated for 24 hours with vigorous stirring. After reaction, saturated mono- and dicarboxylic acids were obtained according to Example 1 below. The result was 1.67 g (9.6 mmol) of 3-hydroxynonanoic acid (yield 41.
8%), 2.71 g (14.4 mmol) of azelaic acid
(Yield 62.7%) was obtained.

Example 9 Instead of 20 ml of water as a solvent in Example 1, ter was used.
The reaction was carried out according to the same procedure except that 10 ml of t-butyl alcohol and 10 ml of water were used. As a result, azelaic acid (5.12 g, 27.2 mmol) (yield: 85.0%) and pelargonic acid (3.95 g, 25.0 mmol) (yield: 78.
It was 0%).

Example 10 Instead of 20 ml of water as the solvent in Example 1, ter was used.
The reaction was carried out according to the same procedure except that 20 ml of t-butyl alcohol was used. The result is 4.95 g of azelaic acid (2
6.3 mmol) (yield 82.2%), pelargonic acid 3.
The amount was 90 g (24.6 mmol) (yield 76.9%).

Control Example 1 1.87 g of cetylpyridinium chloride was dissolved in 70 ml of water. When a solution prepared by dissolving 5.0 g of tungstophosphoric acid in 10 ml of water was added dropwise to the solution at 40 to 50 ° C, a white precipitate was formed almost at the same time as the addition. The solution was stirred for 5 hours, cooled to room temperature, and the precipitate formed by centrifugation was separated.
The obtained results were thoroughly washed with distilled water until the pH of the washing liquid became neutral, and then dried under reduced pressure to obtain 5.36 g of tricetylpyridinium tungstophosphate. 2.46 g (0.6 mmol) of tricetylpyridium tungstophosphate obtained above, 60 ml of tert-butyl alcohol, and 14.0 g of 35% hydrogen peroxide solution were added to a 3-neck glass flask equipped with a stirrer. (144 mol) and after stirring for a while, 9.0 g (0.032 mol) of oleic acid was added dropwise, and the mixture was reacted for 24 hours under heating under reflux. Crystals were obtained in the same manner as in Example 1 below. The result is 4.52 g of azelaic acid (2
4.0 mmol) (yield 75.0%), pelargonic acid 3.
It was 36 g (21.2 mmol) (yield 66.3%).

[0021]

[Effects] The present invention oxidizes a specific unsaturated carboxylic acid selected from oleic acid, erucic acid, linoleic acid, linolenic acid, and ricinoleic acid with hydrogen peroxide solution to obtain high yield in a very easy manufacturing process. A proportion of saturated mono- and dicarboxylic acids is obtained.

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[Procedure amendment]

[Submission date] June 9, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

Control Example 1 1.87 g of cetylpyridinium chloride was dissolved in 70 ml of water. When a solution prepared by dissolving 5.0 g of tungstophosphoric acid in 10 ml of water was added dropwise to the solution at 40 to 50 ° C, a white precipitate was formed almost at the same time as the addition. The solution was stirred for 5 hours, cooled to room temperature, and the precipitate formed by centrifugation was separated.
After PH of resulting crystals washings was washed well with distilled water until neutral and is dried under reduced pressure, tungstophosphoric acid tri cetylpyridinium was obtained 5.36 g. 2.46 g (0.6 mmol) of tricetylpyridium tungstophosphate obtained above, 60 ml of tert-butyl alcohol, and 14.0 g of 35% hydrogen peroxide solution were added to a 3-neck glass flask equipped with a stirrer. (144 mol) and after stirring for a while, 9.0 g (0.032 mol) of oleic acid was added dropwise, and the mixture was reacted for 24 hours under heating under reflux. Crystals were obtained in the same manner as in Example 1 below. The result is 4.52 g of azelaic acid (2
4.0 mmol) (yield 75.0%), pelargonic acid 3.
It was 36 g (21.2 mmol) (yield 66.3%).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C07C 55/02 6742-4H // C07B 61/00 300

Claims (1)

Claim: What is claimed is: 1. An unsaturated carboxylic acid selected from oleic acid, erucic acid, linoleic acid, linolenic acid, and ricinoleic acid is selected from (a) tungstic acid, phosphotungstic acid, molybdic acid, and phosphomolybdic acid. Selected acid and (a) 4
When the corresponding saturated monocarboxylic acid and saturated dicarboxylic acid are produced by oxidation with hydrogen peroxide in the presence of a catalyst of a primary amine salt, (a) and (a) are separately charged into the system. Method for oxidizing unsaturated carboxylic acid