阅读说明：本技术 2-乙基-2,3-环氧丁醛及其制造方法 (2-ethyl-2, 3-epoxy butyraldehyde and preparation method thereof ) 是由 川岛正敏 于 2019-03-20 设计创作，主要内容包括：本发明提供一种被认为是在有机合成化学中有用的合成砌块的2-乙基-2,3-环氧丁醛及其制造方法。在碱的存在下,使过氧化氢与2-乙基巴豆醛反应,而制成由式(1)所表示的2-乙基-2,3-环氧丁醛。在所述反应中,也可添加表面活性剂。<Image he="318" wi="285" file="DDA0002609431540000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The present invention provides 2-ethyl-2, 3-epoxybutanal which is considered to be a synthetic building block useful in organic synthetic chemistry and a method for producing the same. Reacting hydrogen peroxide with 2-ethylcrotonaldehyde in the presence of a base to produce 2-ethyl-2, 3-epoxybutyraldehyde represented by the formula (1). In the reaction, a surfactant may also be added.)

1. A2-ethyl-2, 3-epoxybutanal represented by the formula (1),

2. a method for producing 2-ethyl-2, 3-epoxybutylaldehyde according to claim 1, wherein hydrogen peroxide is reacted with 2-ethylcrotonaldehyde in the presence of a base.

3. The method for producing 2-ethyl-2, 3-epoxybutanal according to claim 2, wherein a surfactant is added.

Technical Field

The invention relates to 2-ethyl-2, 3-epoxy butyraldehyde and a preparation method thereof.

Background

Epoxidation of α, β -unsaturated aldehydes has been carried out since long ago, and for example, as epoxidation of acrolein or methacrolein, a method of causing hydrogen peroxide water to act under alkaline conditions has been known (non-patent document 1); as the epoxidation of crotonaldehyde, a method of reacting hydrogen peroxide supported on polyvinylpyrrolidone under an alkaline condition (non-patent document 2) or the like is known; as epoxidation of 2-hexanal, a method of reacting hydrogen peroxide in the presence of a solid base catalyst and a surfactant, and the like are known (non-patent documents 3, 4, 5, and 6); as the epoxidation of 2-ethyl-2-hexanal, a method of acting sodium hypochlorite is known (non-patent document 7) and the like, but an epoxide of tiglic aldehyde (tiglic aldehyde) is synthesized not by the epoxidation of tiglic aldehyde but by the oxidation of a hydroxyl group after the epoxidation of the corresponding allyl alcohol (non-patent document 8) and the like. However, the epoxide of 2-ethylcrotonaldehyde, 2-ethyl-2, 3-epoxybutyraldehyde, has not been synthesized so far.

Disclosure of Invention

Problems to be solved by the invention

Detailed Description

The present invention includes the following items [1] to [3 ].

[1] A2-ethyl-2, 3-epoxybutanal represented by formula (1).

[2] A process for producing 2-ethyl-2, 3-epoxybutylaldehyde, which comprises reacting 2-ethyl-2, 3-epoxybutylaldehyde as defined in item [1] with hydrogen peroxide in the presence of a base.

[3] The process for producing 2-ethyl-2, 3-epoxybutylaldehyde according to item [2], wherein a surfactant is added.

The concentration of the hydrogen peroxide solution to be applied to 2-ethylcrotonaldehyde is preferably 10 to 50 wt%, more preferably 25 to 35 wt%. The amount of hydrogen peroxide relative to 2-ethylcrotonaldehyde is preferably 1 to 3 equivalents, and more preferably 1 to 2 equivalents. The reaction temperature is usually 0 to 60 ℃, preferably 0 to 30 ℃, and more preferably 0 to 20 ℃.

The base is preferably sodium hydroxide, potassium hydroxide, or lithium hydroxide, and more preferably sodium hydroxide. Usually, the concentration is preferably 10 to 50% by weight, more preferably 20 to 50% by weight. The alkali metal hydroxide may be used in the form of an alcohol solution, or sodium alkoxide, potassium alkoxide, or lithium alkoxide may be used in the form of a powder or an alcohol solution. As the alcohol solution, or alcohol for alkoxide, there may be preferably mentioned: methanol, ethanol, propanol, isopropanol, tert-butanol, isobutanol, sec-butanol, tert-butanol, octanol, 2-ethylhexanol, and the like, and methanol or ethanol is more preferable.

The amount of the alkali metal hydroxide or alkali metal alkoxide used is usually 0.01 to 1 equivalent, preferably 0.1 to 0.5 equivalent, and more preferably 0.2 to 0.4 equivalent to 2-ethylcrotonaldehyde. If the alkali concentration decreases with the progress of the reaction, the reaction rate decreases, and therefore, an addition may be made as necessary.

Since this reaction is a two-layer reaction, the use of a surfactant is preferable because the reaction is accelerated. In order to avoid the risk of rapid heat generation or to increase the conversion rate, it is preferable to use a surfactant which functions as a transfer catalyst to smoothly start the reaction and to reliably terminate the reaction. As the surfactant to be added, it is preferable to use: anionic surfactants such as sodium fatty acid, monoalkyl sulfate, alkyl polyoxyethylene sulfate, alkylbenzene sulfonate, and monoalkyl phosphate, and cationic surfactants such as quaternary ammonium salts and pyridinium salts; and nonionic surfactants such as polyethers, and further preferably used are: monoalkyl sulfates, alkylbenzene sulfonates, alkylpyridinates. Specifically, there may be mentioned: sodium lauryl sulfate, sodium 4-dodecylbenzenesulfonate, dodecylpyridinium chloride, hexadecylpyridinium chloride, and the like.

The amount of the surfactant is usually 0.01 to 10 mol%, preferably 0.1 to 1 mol%, based on 2-ethylcrotonaldehyde, as the amount of the catalyst to obtain the effect.

The reaction solvent may be any organic solvent that does not react with hydrogen peroxide or a base, but is not particularly required. In addition, water can also be used as a solvent, but because 2-ethyl-2, 3-epoxy butyl aldehyde is water-soluble, when the need to anhydrous state separation of target material, preferably without using water.

The order of adding the reaction raw materials is not particularly limited, and any of the following methods can be used: (1) a method of adding a base to a mixture of 2-ethylcrotonaldehyde, a surfactant and hydrogen peroxide; (2) a method of dropwise adding 2-ethylcrotonaldehyde to a mixture of hydrogen peroxide, an alkali and a surfactant; (3) the method of dropping hydrogen peroxide into a mixture of 2-ethylcrotonaldehyde, a base and a surfactant, but the methods (2) and (3) are easy to control the reaction heat, and the method (3) can be particularly preferably used.

After the reaction, unreacted hydrogen peroxide remains on the water layer side and is thus removed by separation, but when it is to be more surely removed, various methods known as a method for removing hydrogen peroxide as follows can be used: washing with saturated salt solution; decomposing with reducing agent such as sodium sulfite, sodium bisulfite and sodium thiosulfate while maintaining neutrality with sodium bicarbonate; decomposition is performed by catalase, manganese dioxide, activated carbon, or the like.