Synthesis method of butanedione

Abstract

The invention discloses a synthesis method of butanedione. According to the synthesis method, a salicylaldehyde derivative reacts with compounds of diamine to generate a schiff base ligand, then coordination with a transition metal salt solution is conducted to prepare metal schiff base complexes, then an F-C acylation reaction is conducted, the metal schiff base complexes are immobilized in a polystyrene microsphere carrier containing an acyl group to be prepared into an immobilized catalyst, and finally acetoin serves as a raw material and is added to the immobilized catalyst, air is introduced for catalytic oxidation, and the butanedione is obtained. According to the synthesis method, the F-C acylation reaction is conducted, the metal schiff base complexes are immobilized in the polystyrene microsphere carrier containing the acyl group, the immobilization rate of the immobilized metal schiff base complexes is raised through chemical bonds, posttreatment of a product obtained through the immobilized catalyst is simple, and the yield of is high; besides, the adopted raw material is the acetoin, production cost is lowered for enterprises producing the acetoin, product diversity is increased, and enterprise competitiveness can be improved.

Description

technical field [0001] The invention relates to the field of synthesis of fine chemicals, in particular to a synthesis method of diacetyl. Background technique [0002] Butanedione (2,3-Butanedione), also known as diacetylphthalein, is a yellow-green liquid with a creamy and buttery aroma and a boiling point of 88.0-89.0°C. It is an important food flavor compound and exists in the natural form of angelica. , magnolia, lavender, cardamom, citronella and other essential oils, also detected in cream, milk, coffee, fruit, tomato, wine. It is mainly used as food spice additives, milk-flavored food flavors and feed flavors, and can also be used in margarine, cheese, chocolate, coffee, cocoa, cheese, sugar, vanilla beans, honey, cocoa, rum, Nuts, almonds, etc. on top. It can also be added in a small amount to fresh fruit flavors or new flavors for cosmetics. [0003] At present, the production route of diacetyl at home and abroad can be mainly divided into: (1) direct extraction...

AI Technical Summary

Problems solved by technology

[0003] At present, the production route of diacetyl at home and abroad can be mainly divided into: (1) direct extraction method: this method is to use the leaves and flowers of plants containing this spice in nature as raw materials, and obtain it by organic solvent extraction. The content is limited and cannot be extracted on a large scale, so industrial production is limited

(2) Biological fermentation method: This method refers to the use of specific microorganisms to use sugar as raw material to obtain a small amount of diacetyl in the microbial metabolites obtained through fermentation. Because the microorganisms required by this method are inconvenient to cultivate, and the metabolites The content of diacetyl is too small and less than 5%, so it is difficult to extract, the output is not very high at this stage, and there is still a lot of room for development

(3) Chemical oxidation method: It is prepared by chemical synthesis, mainly including catalytic oxidation of ozone oxidizers, transition metal salts and hydrogen peroxide, sodium nitrite, copper complex catalysts and oxygen in the air and other oxidants and catalysts. - butanone to obtain diacetyl, or catalyzed oximation reaction with methyl nitrite and Lewis acid salt-phosphoric acid-hydrochloric acid catalyst, and then prepare diacetyl through crystallization, hydrolysis, distillation, anhydrous calcium chloride dehydration and other treatment processes and other synthetic methods, some of these chemical oxidation methods are very cumbersome in operation and consume a lot of raw materials. In addition, the oxidants used are harmful to water and soil in the environment, and some of them have not very high yields and low selectivity. More by-products make separation difficult and economically uneconomical