Catalyst, preparation method thereof, and application of catalyst in preparation of beta-isophorone

Abstract

The invention provides an N-(2-hydroxyethyl)diethylenetriamine Schiff base catalyst, a preparation method thereof, and an application of the catalyst in the preparation of beta-isophorone. The preparation method of the catalyst comprises the following steps: 1) reacting diethylenetriamine with aromatic aldehyde to prepare a bis-Schiff base; and 2) reacting the bis-Schiff base compound with ethylene oxide to obtain the N-(2-hydroxyethyl)diethylenetriamine Schiff base. The invention also provides a method for preparing beta-isophorone from alpha-isophorone through an isomerization reaction underthe action of the Schiff base. The catalyst is simple to prepare and easy to industrialize. The prepared N-(2-hydroxyethyl)diethylenetriamine Schiff base has the advantages of high selectivity and high yield for the reaction of isomerizing alpha-isophorone to generate beta-isophorone, low generation possibility of byproducts, easiness in industrial production, and no corrosion to equipment.

Description

technical field [0001] The present invention relates to a kind of preparation process of isophorone, relate in particular to a kind of N-(2-hydroxyethyl)diethylenetriamine Schiff base catalyst, the preparation method of the catalyst and its use in the preparation of β-isophorone The application of the invention belongs to the technical field of preparation of isophorone and catalyst. Background technique [0002] β-isophorone (3,5,5-trimethylcyclohex-3-en-1-one, β-IP) is an important intermediate for the synthesis of vitamin E, carotenoids, astaxanthin and various spices body, and is the main raw material for the synthesis of tea aroma ketone (2,6,6-trimethyl-2-cyclohexene-1,4-dione, KIP). [0003] The conventional preparation method of β-isophorone is to use α-isophorone (3,5,5-trimethylcyclohex-2-en-1-one) as a raw material, through isomerization under the action of a catalyst The chemical reaction is obtained. α-isophorone and β-isophorone are a pair of isomers, and th...

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Problems solved by technology

[0004] In view of the complex operation of the above-mentioned isomerization reaction, a large amount of research has been carried out on the catalyst in the prior art, in order to expect to improve the reaction yield:

[0005] U.S. Patent No. 4010205A uses triethanolamine as a catalyst for reactive distillation, and the reaction solution is washed with tartaric acid and brine to obtain β-isophorone; the disadvantage of this technical solution is that the purity of the obtained β-isophorone is relatively low and the The processing process is complex;

[0006] U.S. patents US5907065A and US6005147A use Co 3 o 4 , CaO, Fe 3 o 4 The oxide is used as a catalyst, and the isomerization reaction is carried out by vacuum distillation, and the purity of the obtained β-isophorone can reach more than 97%, but there are many by-products in the reaction and the space-time yield is low;

[0007] Chinese patents CN1288882 and CN1292374 use alkaline hydroxide (KOH, NaOH, etc.) as a catalyst to produce β-isophorone through isomerization reaction, although this technical scheme can obtain β-isophorone with higher purity , but the strong alkaline catalyst will seriously corrode the equipment;

However, the Schiff base-modified esterified β-cyclodextrin has poor dispersibility and exists in flocculent form in the reaction system, which affects the catalytic efficiency of the reaction. In addition, the preparation of the catalyst by this method is cumbersome, which brings difficulties for large-scale industrial application.

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