Method for synthesizing 2,4-difluorobenzaldehyde by using micro-channel reactor

Abstract

The invention discloses a method for synthesizing 2,4-dichlorophenol by using a micro-channel reactor. The method mainly comprises the following steps: with 2,4-dinitrobenzaldehyde and potassium fluoride as raw materials, carrying out a reaction in micro-channel reactor for 50-55 s at a temperature of 200-210 DEG C, and finally rectifying and purifying a product to obtain a refined 2,4-difluorobenzaldehyde product with a purity of more than or equal to 99%. According to the preparation method disclosed by the invention, micro-channel continuous synthesis of 2,4-difluorobenzaldehyde is realized, production cost is reduced by 10-15% compared with the production cost of a traditional intermittent tank method, yield can be increased by 1-2%, and production efficiency and yield are increased by30-35%. According to the method, the micro-channel continuous flow reactor is adopted, the micro-channel continuous flow reaction technology has the characteristics of continuous reaction process, good reaction liquid mixing effect, mild reaction conditions, short reaction time, good product consistency and the like, is particularly suitable for synthesis and preparation of 2,4-difluorobenzaldehyde, and provides a powerful technical support for large-batch low-cost continuous synthesis and production of 2,4-difluorobenzaldehyde.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing 2,4-difluorobenzaldehyde with a microchannel reactor. Background technique [0002] 2,4-Difluorobenzaldehyde, referred to as DFBA, is a widely used organic synthesis intermediate, which can be used in the synthesis of medicine, pesticide, dye and fluorine-containing functional materials. And it is an intermediate for the preparation of a new generation of triazole antifungal drug fluconazole. However, so far, the demand for 2,4-difluorobenzaldehyde in my country is all imported, and the price is expensive, which greatly affects and limits the development of all aspects. [0003] Present 2,4-difluorobenzaldehyde reported synthetic technique method has following several kinds: [0004] (1) Synthetic route using 2,4-dinitrotoluene as raw material [0005] Chen Hongbiao and others used readily available 2,4-dinitrotoluene as a raw material to ob...

AI Technical Summary

Problems solved by technology

[0011] Although the raw materials and catalysts of this process route are all easy to get, there are many reaction steps, and the concentration of the alkaline solution has a very large impact on the overall reaction yield. Therefore, this method still has certain difficulties in realizing industrial production. of

[0012] In the production process of the above method, there are many reaction steps, a large amount of catalyst is used, it is difficult to recycle, and the reaction temperature is high, it is difficult to ensure the quality of the product, and the reaction conditions are too harsh to be implemented industrially.

At present, the traditional method of synthesizing 2,4-difluorobenzaldehyde is the conventional kettle method, which has high production cost, low yield, high impurity content in the product, and belongs to intermittent production, with low production efficiency and cannot meet market demand.

Although researchers at home and abroad have carried out extensive research on its synthesis methods and processes, there is no report on the continuous synthesis of 2,4-difluorobenzaldehyde by microchannel continuous flow reaction technology

Images