JPH05255292A - Production of epoxide - Google Patents

Abstract

PURPOSE:To provide a method of producing epoxide capable of epoxidizing an olefin by oxygen having little danger of explosion even under a very mild condition and in high yield. CONSTITUTION:In producing an epoxide by oxidizing an olefin compound with oxygen, specifically an ammonium salt of heteropoly-acid is used as a catalyst in the presence of aldehyde compound.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an epoxide, and more particularly to a method for producing an epoxide by oxidizing an olefin compound with oxygen.

[0002]

BACKGROUND OF THE INVENTION Epoxy compounds (epoxides) are highly reactive compounds and are useful as raw materials for the synthesis of medicines, agricultural chemicals, and fragrances. Epoxides are compounds that have an oxirane ring formed by the addition of oxygen to the unsaturated double bond of an olefin compound. Most of them are conventionally oxidizable olefin compounds with hydrogen peroxide or organic peroxides. Was manufactured by.

However, the method of producing an epoxide using hydrogen peroxide has a drawback that the produced epoxide is ring-opened by water and the yield is lowered. Such a drawback is remarkable especially when the unsaturated alcohol is epoxidized. For example, in JP-A-52-65210, when the unsaturated alcohol is epoxidized with hydrogen peroxide, the product It is described that most of them are ring-opened triols. Moreover, in the method for producing an epoxide using hydrogen peroxide, an explosion may occur when the used hydrogen peroxide is concentrated, and the handling thereof requires great care, and the process is complicated. There was also a drawback that

Also, Journal of Organic Chemistry (J. Org. Chem.), Vol. 53, No. 15, 3587.
Pp. 3593 (1988), a method for producing an epoxy compound by oxidizing an olefin compound with hydrogen peroxide using a pyridinium salt of a heteropoly acid as a catalyst is described. The effect as a catalyst was not recognized at all.

The method for producing an epoxide using an organic peroxide does not have the disadvantage that the produced epoxide is ring-opened by water to lower the yield as in the case of using hydrogen peroxide. JP-A-283279 describes that by reacting an unsaturated alcohol with tert-butyl peroxide in the presence of vanadium pentoxide, the desired epoxide can be obtained in a yield of 50 to 70% under mild conditions. However, organic peroxides have a high risk of explosion and are not suitable for industrial handling in large quantities.

For this reason, it has been required to epoxidize the olefin with oxygen, which has a low risk of explosion, but when the conventionally used metal oxide type catalyst is used, the reaction almost proceeds. Therefore, it has been strongly desired to find a new catalyst suitable for this method.

[0007]

In view of the above situation, the present inventor has conducted various studies on a method of oxidizing an olefin compound with oxygen to obtain an epoxide, and as a result, in the presence of an aldehyde compound, a specific heteropoly compound as a catalyst has been obtained. The inventors have found that the use of an ammonium salt of an acid remarkably promotes the oxidation reaction of an olefin compound with oxygen, and that an epoxide can be obtained in a short time under mild conditions, and has reached the present invention.

That is, the present invention is a method for producing an epoxide by oxidizing an olefin compound with oxygen, wherein the reaction is carried out in the presence of an aldehyde compound using an ammonium salt of heteropolyacid as a catalyst. The present invention provides a method for producing an epoxide.

Hereinafter, the method for producing the epoxide of the present invention having the above gist will be described in detail.

Examples of the olefin compound epoxidized by the method for producing an epoxide of the present invention include 1-
Butene, isobutylene, 1-hexene, 2-methyl-1
Linear or branched aliphatic olefin such as hexene, 1-octene, 2-octene, 4-nonene, 1-decene, 1-dodecene, 1-octadecene, cyclohexene, 3-vinylcyclohexene, cyclooctadiene,
Alicyclic olefins such as norbornene and tetrahydroindene, allyl alcohol, 2-hexen-1-ol,
3-methyl-3-buten-1-ol, geraniol,
Unsaturated alcohols such as nerol are mentioned, and in particular, the method for producing an epoxide of the present invention is suitable for epoxidizing a liquid or solid olefin compound at room temperature, and when hydrogen peroxide is used, It is suitable for epoxidizing unsaturated alcohols that are difficult to epoxidize.

In the method for producing an epoxide of the present invention, oxygen is used as an oxidant for oxidizing an olefin compound to produce an epoxide. The use of oxygen gas as the oxygen source accelerates the reaction. Although preferable, a gas containing oxygen such as air may be used instead of the oxygen gas.

The amount of oxygen used is required to be equimolar or more with respect to the double bond to be epoxidized in the olefin compound, and it is usually preferable to use excess oxygen.

Examples of the aldehyde compound used in the method for producing an epoxide of the present invention include acetaldehyde, propionaldehyde, butyraldehyde,
Examples thereof include aliphatic or aromatic aldehyde compounds such as isobutyraldehyde, hexyl aldehyde, benzaldehyde, and tolualdehyde, and aliphatic aldehyde is particularly preferable.

The amount of the aldehyde compound used is not particularly limited, but is usually 0.01 to 10 mol, particularly preferably 0.1 to 5 mol, per 1 mol of the olefin compound to be epoxidized. is there.

The heteropolyacid that constitutes the ammonium salt of the heteropolyacid used as a catalyst in the method for producing an epoxide of the present invention has one metal atom or an atom corresponding thereto as a central atom and a polyacid group of another metal. Is a polyacid formed by coordinating an inorganic acid, which is particularly preferably a central atom of silicon or phosphorus and a heteroatom of molybdenum, tungsten, vanadium or a mixture thereof. ..
Further, these ammonium salts of heteropoly acids usually contain water of crystallization, but they can be used in the method for producing an epoxide of the present invention regardless of the presence or absence of water of crystallization and the content thereof.

Therefore, specific examples of the catalyst used in the method for producing an epoxide of the present invention include, for example,
The following compounds of [Chemical formula 1] to [Chemical formula 5] (catalyst No. 1 to catalyst No. 5) can be mentioned.

[0017]

[Chemical 1] Catalyst No. 1 (NH ₄ ) ₅ H ₄ PV ₆ Mo ₆ O ₄₀

[0018]

[Chemical 2] Catalyst No. 2 (NH ₄ ) ₃ PMo ₁₂ O ₄₀

[0019]

[Chemical Formula 3] Catalyst No. 3 (NH ₄ ) ₃ PW ₁₂ O ₄₀

[0020]

[Chemical 4] Catalyst No. 4 (NH ₄ ) ₅ H ₄ PV ₆ W ₆ O ₄₀

[0021]

[Chemical 5] Catalyst No. 5 (NH ₄ ) ₆ HPV ₄ W ₈ O ₄₀

The above-mentioned catalyst can be produced by a well-known method for synthesizing a salt of a heteropoly acid, for example, phosphoric acid or sodium hydrogenphosphate and sodium molybdate.
Sodium metavanadate, sodium tungstate or a mixture thereof is reacted in an aqueous solution, then
It can be easily produced by treating with excess ammonium chloride.

Next, the method for producing the above-mentioned catalyst used in the method for producing the epoxide of the present invention will be specifically described with reference to synthesis examples.

Synthesis Example 1 (Synthesis of Catalyst No. 1) Sodium metavanadate (NaVO 3) dissolved in 38 ml of water
₃ ) To 60 mmol (7.32 g), 34 mmol (8.22 g) of sodium molybdate (Na ₂ MoO ₄ ) dissolved in 12 ml of hot water was added, to which 60 mmol of phosphoric acid diluted with 12 ml of water was added. (5.9 g) was added dropwise, and 1 at 95 ° C.
Heated for hours. After cooling to 0 ° C., an excess of ammonium chloride was added and a brown precipitate formed. After centrifuging, the product was thoroughly washed with distilled water and dried in vacuum to obtain a brown crystalline target product.

Synthesis Example 2 (Synthesis of Catalyst No. ₄ ) A brown crystalline target product was obtained in the same manner as in Synthesis Example 1 except that sodium tungstate (Na ₂ WO ₄ ) was used instead of sodium molybdate. It was

Synthesis Example 3 (Synthesis of Catalyst No. 5) To 40 mmol (4.88 g) of sodium metavanadate dissolved in 25 ml of water was added 67 mmol (22.00 g) of sodium tungstate dissolved in 25 ml of hot water. In addition, 67 mmol (6.6 g) of phosphoric acid diluted with 10 ml of water was added dropwise thereto, and the mixture was heated at 95 ° C. for 1 hour. 0
After cooling to ° C, an excess of ammonium chloride was added and a brown precipitate formed. After separation by filtration, the crystals were recrystallized from sulfuric acid having a concentration of 0.25 mol and dried in vacuum to obtain a brown crystalline target product.

The amount of the above-mentioned catalyst used in the method for producing an epoxide of the present invention is not particularly limited,
Usually, it is preferably 0.0001 to 0.1 mol, and particularly preferably 0.001 to 0.05 mol, relative to 1 mol of the olefin compound to be epoxidized.

In the method for producing an epoxide of the present invention, it is not necessary to use a solvent, but a solvent inert to the reaction is used for the purpose of dissolving the olefin compound or lowering the viscosity of the reaction system. Can also be used. Examples of the solvent include aromatic hydrocarbons such as benzene, toluene and xylene, hexane, heptane, octane, cyclohexane and cycloaliphatic saturated aliphatic hydrocarbons such as cyclooctane, dichloromethane, chloroform, carbon tetrachloride and dichloroethane. Halogenated hydrocarbons such as, dioxane, tetrahydrofuran, ethers such as diethyl ether and dibutyl ether, aliphatic ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and ethyl propionate, nitriles such as acetonitrile and the like. Be done.

In the method for producing an epoxide of the present invention, since the reaction proceeds rapidly even under mild conditions at room temperature and atmospheric pressure, it is not necessary to carry out the reaction under heating or pressurization, but the reaction rate is improved. For this purpose, the reaction can be carried out under heating and / or under pressure.

The reaction time in the method for producing an epoxide of the present invention varies depending on the kind of olefin compound to be epoxidized, but the reaction can be completed generally in several hours to several tens of hours.

[0031]

EXAMPLES Hereinafter, the method for producing the epoxide of the present invention will be described in more detail with reference to examples. However, the invention is in no way limited by these examples.

Example 1 In a reaction vessel, 3-methyl-3-buten-1-ol 10 was added.
Mmol, isobutyraldehyde 20 mmol, catalyst N
o. 1 [the above exemplified compound, (NH ₄ ) ₅ H ₄ PV ₆ Mo ₆ O ₄₀ ] 0.0
5 mmol and 8 ml of dichloroethane were taken, the inside of the container was replaced with oxygen, and the mixture was stirred at room temperature under an oxygen gas atmosphere for 24 hours. As a result of gas chromatography analysis of the reaction solution, 94% of 3-methyl-3-buten-1-ol as a raw material was obtained.
Was consumed, and the target 3,4-epoxy-3-methylbutan-1-ol was produced in a yield of 92%.

Example 2 The catalyst was replaced with catalyst No. 2 [The above exemplified compound, (NH ₄ ) ₃ PMo
₁₂ O ₄₀ ], but the same operation as in Example 1 was carried out. As a result, the desired 3,4-epoxy-3-methylbutane-1 was obtained.
The yield of ol was 65%.

Comparative Example 1 The same operation as in Example 1 was carried out except that (NH ₄ ) ₂ WO ₄ was used as the catalyst, but the yield of the desired 3,4-epoxy-3-methylbutan-1-ol was obtained. Was only 10%.

Example 3 3-methyl-3-buten-1-ol is trans-2-
As a result of performing the same operation as in Example 1 except that hexen-1-ol was used, the target 2,3-epoxyhexane-
The yield of 1-ol was 67%.

Comparative Example 2 The same operation as in Example 3 was carried out except that the catalyst was changed to H ₄ PMo ₉ V ₃ O ₄₀ or (NH ₄ ) ₂ MoO ₄ , but the desired 2,3-epoxyhexane- 1-ol was not obtained at all.

Examples 4 to 13 and Comparative Examples 3 to 6 The same operation as in Example 1 was carried out except that the kind of olefin compound, the kind of catalyst and the reaction time were changed. The results are shown in [Table 1] below.

[0038]

[Table 1]

From the above examples, according to the method for producing an epoxide of the present invention, an olefin compound can be epoxidized with oxygen and under extremely mild conditions without using an organic peroxide or hydrogen peroxide. It is clear that epoxidation with hydrogen peroxide makes it possible to epoxidize unsaturated alcohols, which were difficult to be epoxidized, in high yield.

On the other hand, when the heteropoly acid or its pyridinium salt or the ammonium salt of isopoly acid is used as the catalyst, the reaction hardly proceeds, and it is clear that the effect of the catalyst of the present invention is extremely specific. ..

[0041]

The method for producing an epoxide of the present invention comprises epoxidizing an olefin compound with oxygen in the presence of an aldehyde compound using an ammonium salt of a heteropoly acid as a catalyst. According to the present invention, it is extremely mild. The epoxide can be produced under various conditions and in high yield.

Claims (3)

[Claims] 1. A method for producing an epoxide by oxidizing an olefin compound with oxygen, which comprises reacting an ammonium salt of a heteropolyacid as a catalyst in the presence of an aldehyde compound. Production method. 2. The method for producing an epoxide according to claim 1, wherein the olefin compound is an unsaturated alcohol. 3. The ammonium salt of a heteropolyacid is phosphorus as the central atom and molybdenum, vanadium, tungsten and mixtures thereof as the heteroatoms.
A method for producing the epoxide described.