Glutaraldehyde preparation method

Abstract

The invention discloses a glutaraldehyde preparation method. Glutaraldehyde is prepared by using acetylene, methanol and acraldehyde as raw materials to produce and prepare 2-methoxy-3.4 dihydropyranand hydrolyzing 2-methoxy-3.4 dihydropyran under negative pressure to prepare glutaraldehyde. The method includes following steps: a, synthesizing vinyl methyl ether; b, synthesizing pyran; c, hydrolyzing pyran to purify glutaraldehyde. Generally, the method has the advantages of high reaction conversion rate, long catalyst service life, mild reaction condition, simplicity and convenience in operation, supportiveness of continuous production, high product purity, little environment pollution and extremely high practical value.

Description

technical field [0001] The invention belongs to the field of synthetic methods of chemical products, and relates to a method for preparing glutaraldehyde by hydrolyzing 2-methoxy-3.4-dihydropyran under negative pressure. Background technique [0002] Glutaraldehyde is an important saturated linear fatty cluster dialdehyde, which is widely used in petroleum exploration, medical and health, biochemistry, leather tanning agent, protein crosslinking agent, biological enzyme, food, cosmetics and other fields. At present, the synthesis methods of glutaraldehyde mainly include pyridine method, pentanediol oxidation method, reduction method, pyran method, and cyclopentene oxidation method. Glutadioxime is decomposed by sodium nitrite and hydrochloric acid to obtain glutaraldehyde. This method has a long process route, large consumption, large pollution, and high cost. It is not suitable for production and use; pentanediol oxidation method, the oxidation depth of this reaction is not...

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Problems solved by technology

[0003] JP7226488, US2546018 announced the synthesis of glutaraldehyde with phosphoric acid or alkyl dibasic acid as a catalyst. The reaction conditions are mild and the yield is high, but the requirements for equipment anticorrosion are high. After the reaction, the catalyst remains in the system and the glutaraldehyde solution is easy to change color. And easily produce polycondensation deterioration; EP0717026, US7709686 and CN1233610 have reported the use of solid acid catalyst hydrolysis 2-methoxy-3.4-dihydropyran synthesis glutaraldehyde, solid acid comprises acidic resin, heteropoly acid etc., although this method overcomes It overcomes the disadvantage that the liquid acid corrosion equipment catalyst is difficult to separate, and the conversion rate of pyran is also high, but the resin is expensive and easily swells and deforms, which increases the production cost

US5679868, CN1709573 have released the method that uses zeolite as catalyst hydrolysis dihydropyran, although this method conversion rate is higher, but the hydrolysis time of this reaction is too long and cannot carry out continuous production; CN1371348A has reported a kind of glutaraldehyde continuous hydrolysis method, but the catalyst and reaction conditions are not described in detail, and the reaction speed is slow

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