Method for preparing p-chlorobenzaldehyde through continuous oxidization of p-chlorotoluene

Abstract

The invention relates to a method for preparing p-chlorobenzaldehyde through continuous oxidization of p-chlorotoluene and belongs to the technical field of organic synthesis processes. The method is a process technology for preparing p-chlorobenzaldehyde by continuously oxidizing p-chlorotoluene in a tubular reactor with a p-chlorotoluene compound as a raw material, one or more metal ion complexes of cobalt, molybdenum and bromine as a catalyst, hydrogen peroxide as an oxidizing agent and acetic acid as a solvent. The method has mild conditions and takes short time, the utilization rate of the raw material is high, effective control in the reaction process can be realized, safe, stable and continuous operation is realized, and the production efficiency is high.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis technology, and relates to a method for preparing p-chlorobenzaldehyde by continuous oxidation of p-chlorotoluene under liquid phase reaction conditions, more specifically using p-chlorotoluene as a substrate, hydrogen peroxide as an oxidant, cobalt, One or several metal ion complexes of molybdenum and bromine are used as catalysts, monocarboxylic acid is used as solvent, and p-chlorobenzaldehyde products are continuously prepared in tubular reactors with different microstructures. Background technique [0002] 4-Chlorobenzaldehyde is an important chemical intermediate, which has very important application value in medicine, pesticides, dyes, etc. Amino acid and other drugs. In addition, p-chlorobenzaldehyde is also used in the synthesis of acid blue 7BF, acid brilliant blue 6B and other fuels and intermediates in the synthesis of photosensitive materials. [0003] The industrial produ...

AI Technical Summary

Problems solved by technology

The advantage of this method is low cost and simple process; the disadvantage is that the reaction time is long, the catalyst cannot be reused, and the conversion rate is low.

In summary, existing technologies have many shortcomings such as high cost, high energy consumption, complicated process, and low selectivity to p-chlorobenzaldehyde.

[0007] The above method optimizes and improves the preparation of p-chlorobenzaldehyde from different angles by the oxidation of p-chlorotoluene, but there are still some problems to be solved: firstly still mainly adopt the batch production of batch still in the large-scale production; secondly in the above-mentioned method There are still disadvantages such as poor mass and heat transfer effect and low oxidant utilization rate in the above process, which is also the main reason for the large amount of oxidant used in the above process, increased side reactions, and low selectivity and low yield of the target product; in addition, in the above-mentioned In the batch production method, the decomposition rate of hydrogen peroxide is relatively fast, which is likely to cause safety accidents, which is also the reason why hydrogen peroxide oxidation has no large-scale application.

Images