The method of synthesizing cyanophyll

Abstract

The invention discloses a method for synthesizing cyanophyll, comprising the following steps: placing raw materials benzyl alcohol and vinyl ether and a liquid acid catalyst in a tubular oscillating flow reactor for continuous addition reaction; Add sodium bicarbonate solution to the last 1 / 2 section of the reaction tube of the reactor to neutralize the product of the continuous addition reaction to weak alkalinity; send the reaction product to the stratifier to stand still and separate the water and oil , the product cyanin was purified from the oil layer. The method can not only suppress side reactions, improve reaction rate and selectivity, but also realize continuous production of cyanophyll, with stable product quality, high yield and compact structure.

Description

technical field [0001] The invention relates to the fields of fine chemical industry and fragrance synthesis, in particular to a method for synthesizing cyanophyll. Background technique [0002] Yeocyanin, that is, acetaldehyde ethyl benzyl acetal, has a soft green leaf aroma and a faint floral aroma. Because of its pleasant smell and stable chemical properties, it is often used to prepare various daily chemical essences such as soaps, detergents, perfumes, and cosmetics. . The use of chlorophyll is becoming more and more extensive, and the research on its synthesis has also attracted much attention. [0003] At present, the synthesis methods of cyanin mainly include the following: paraldehyde synthesis method, α-chloroethyl ether method, 2-benzyloxypropionic acid decarboxylation method, vinyl ether and alcohol addition method, and acetal Alcohol exchange method with benzyl alcohol. Among them, the product obtained by the paraldehyde synthesis method is a mixture of vario...

AI Technical Summary

Problems solved by technology

Among them, the product obtained by the paraldehyde synthesis method is a mixture of various acetals, which is difficult to post-process; the raw materials in the α-chloroethyl ether method have not been industrialized and need to be prepared by themselves, thereby affecting the yield and purity of the target product; 2-benzyl Oxypropionic acid decarboxylation requires unconventional catalysts, and the catalytic effect is difficult to control

Among them, the addition method and the alcohol exchange method are widely used. The product obtained by the alcohol exchange method also has ethanol in addition to cyanin, which is relatively troublesome for post-processing, and in the application research, it is found that the raw material acetal must be in excess to ensure a higher yield. rate, and the reaction involved in the alcohol exchange method is a reversible reaction, and its final conversion rate is limited by the thermodynamic balance; the addition method is currently mainly used in the industry. The operation method of batch reactors is very intense and exothermic. The reaction kettle is easy to cause the local temperature to be too high, resulting in the increase of by-products, but the addition method has high atom economy, mild reaction conditions, and safe process. As long as the reaction end point is well controlled, the quality and yield of the product are high and stable, so As long as its production process is improved, better results may be obtained

[0004] In view of the above-mentioned common problems in the cyanophyll synthesis process, several key points need to be resolved: firstly, the mixing of the raw materials should be uniform, so as to avoid excessive benzyl alcohol locally, and continue to react with the target product cyanophyll to form benzhydrin acetal, i.e. The control of the reaction end point also needs to be precise; secondly, the reaction is very intense, heat transfer is the key to obtain selectivity and yield, poor heat dissipation will also lead to the side reaction of dimerization of the raw material vinyl ether; thirdly, in order to avoid the occurrence of side reactions , the reaction needs to be carried out at a lower temperature, which requires a longer reaction time, and the use of the fully mixed flow method of the reactor is more unfavorable for the reaction