Preparation method of [beta]-ionone

Abstract

The invention provides a preparation method of [beta]-ionone. The method comprises the steps of feeding and isomerization reaction. The reaction conversion rate and selectivity are high, the raw material conversion rate is 98.1%-99.3%, the selectivity is 94.1%-99.3%, and the yield is 93.3%-98%; the purity of the [beta]-ionone product is high, and the [beta] body content is 98.61%-99.12%, the content of the [alpha] body is 0.36-0.51%, and the content of the [gamma] body is 0.07-0.19%; wherein the dihydro-[beta]-ionone is not detected, and the tetrahydro-ionone is not detected; and the catalystcan be suitable for isomerization reaction of raw materials with different contents of [alpha]-ionone, [gamma]-ionone and beta-ionone. Particularly, the method can be used for independently preparingthe front part of the [alpha]-ionone / [beta]-ionone pure product in the rectification process in industry. Raw materials are wide in source and low in price; and the activity of the catalyst is high, the feeding amount of the catalyst accounts for less than 5.0%, and the reaction time is 15 hours.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, in particular to a method prepared by isomerization reaction of α-ionone or a mixture of α-ionone and γ-ionone or a mixture of α-ionone, γ-ionone and β-ionone β-ionone method. Background technique [0002] β-ionone [4-(2,6,6-trimethyl-1-cyclohexenyl)-3-buten-2-one] is a kind of precious spice, which also has certain biological activity. Show strong anti-cancer effect, especially the obvious inhibitory effect on the occurrence of tumor. In addition, this product is widely used in industry and is a very important pharmaceutical intermediate and an important raw material for the synthesis of vitamins A, E, β-carotene, carotenoids, retinoic acid and phytol. [0003] At present, there are usually two processes for preparing β-ionone: cyclization method and isomerization method, and cyclization method is usually used in industry to produce β-ionone. The cyclization method uses pseudo-ionon...

AI Technical Summary

Problems solved by technology

This method can quickly remove the heat generated by the cyclization reaction, can greatly reduce the progress of side reactions, and the reaction process is easier to control, and the reaction is safer, but the microchannel reactor used in this method is due to the channel size. Smallness also brings the disadvantage of easy clogging

[0005] The main disadvantages of the current cyclization process are: ① a large amount of sulfuric acid wastewater is produced in the production process, and the waste water has high impurity content and high treatment costs; ② the process requires enhanced heat transfer and mass transfer, which is difficult to control and consumes high energy consumption

③The reaction inevitably produces α-ionone and γ-ionone isomers, which are difficult to separate and the product purity is not high

The advantage of this method is that the supported Pd catalyst is used instead of the traditional acidic catalyst, which is safe and environmentally friendly, the process is simple and the yield is high, but the disadvantage of this method is that ① the use of noble metal Pd as the main catalyst is expensive

②The isomerization reaction needs to be carried out under the condition of hydrogen, and the side reaction of hydrogenation of ionone will inevitably occur, and hydrogenation products such as dihydroionone, tetrahydroionone and ionol will be obtained, especially dihydroionone and tetrahydroionone. The boiling point of hydroionone is similar to that of β-ionone, so it is difficult to separate and affect the aroma quality of β-ionone

The advantage of this scheme is that the sulfuric acid solution can be used gradiently and recycled, and the utilization rate of sulfuric acid is high. The disadvantage is that the large amount of nitric oxide added in the isomerization reaction cannot be recycled, resulting in high cost.

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