Continuous preparation method of high-selectivity alpha-ionone

Abstract

The invention provides a continuous preparation method of high-selectivity alpha-ionone, pseudoionone is taken as a raw material, alpha-ionone is prepared under the condition of a catalyst system, thecatalyst system comprises a catalyst 1, a catalyst 2 and an auxiliary agent, the catalyst 1 is concentrated sulfuric acid or methanesulfonic acid, and the catalyst 2 is liquid organic carboxylic acid. Pseudoionone, a solvent and a catalyst system are uniformly mixed in a static mixer, then enter a pipeline reactor and react in the pipeline reactor, then the reaction liquid is discharged from an outlet of the pipeline reactor and enters a quenching stirring kettle to be quenched, and the reaction is ended. The synthesis process provided by the invention has the advantages of high catalytic efficiency, short reaction time, high alpha ionone content, continuous application of the catalyst and less three wastes, realizes continuous reaction, greatly saves the reaction time, operation and device cost, meets the requirements of green chemistry, and is suitable for industrial large-scale production.

Description

technical field [0001] The invention belongs to the technical field of fragrance chemistry and fine chemicals, and in particular relates to a continuous preparation method of highly selective α-ionone. Background technique [0002] Ionone, chemical name: 4-(2,6,6-trimethyl-2-cycloocten-1-yl)-3-buten-2-one, is widely used in the perfume industry and pharmaceutical industry , it has two common isomers, namely α-ionone and β-ionone. Among them, α-ionone has a strong violet aroma and a little warm woody aroma. It is widely used in daily chemical toiletries and cosmetics, and is also used in a small amount in the food industry. And β-ionone is an important intermediate in the synthesis of vitamin A, mainly used in the pharmaceutical industry. [0003] Using pseudo-ionone as raw material and using acid as catalyst, this process was first proposed by Hibbert et al. in 1924. On this basis, after nearly a hundred years of research by generations of scientific and technological work...

AI Technical Summary

Problems solved by technology

After the organic acid is added in this scheme, there will be a part of the inorganic base catalyst to neutralize the condensation reaction. After the cyclization reaction, an alkali needs to be added to neutralize the organic acid. On the one hand, the price of the organic acid is high, and it cannot be applied mechanically, resulting in high production costs. The two acid-base neutralization reactions release a large amount of heat, which is not conducive to the control of the reaction temperature and produces a large amount of waste salt

[0007] At present, the industrial synthesis of α-ionone mainly uses about 85% phosphoric acid as a catalyst, but the proportion of α-ionone in the product does not exceed 78%, and it is impossible to directly obtain a higher content of α-ionone through the reaction. When used as a catalyst, the reaction speed is slow, and continuous reaction devices such as pipeline reactors cannot be used

[0008] Therefore, the existing method for preparing α-ionone also has the following technical problems: the reaction time of the existing process is long, the selectivity of α-ionone is low, the energy consumption is high, it is not suitable for continuous operation, the production cost is high, and the production cost is high. low efficiency

Images