Synthesis method of 2, 2, 2', 4'-tetrachloroacetophenone

Abstract

The invention provides a synthesis method of 2, 2, 2', 4'-tetrachloroacetophenone, which effectively enhances the utilization ratio of the catalyst and promotes the reaction degree to be more thoroughby utilizing the temperature change and adding the catalyst in different time periods according to the proportion. Meanwhile, anhydrous aluminum trichloride is adopted as the catalyst, and the anhydrous aluminum trichloride is deposited on the high-stability carrier, so that the activity of the anhydrous aluminum trichloride is improved, the yield is increased, and the influence on the reaction degree due to the fact that the reaction rate is slowed down due to concentrated deposition of the catalyst in the reaction process is avoided; and besides, in the reaction process, the modified molecular sieve catalyst is used for carrying out directional isomerization treatment on the by-product, the treated modified molecular sieve catalyst has high stability and high selectivity, the p-dichlorobenzene by-product and the o-dichlorobenzene by-product in the reaction process are converted into the reaction raw material m-dichlorobenzene, the utilization rate of the raw material is increased, and the generation of the by-product is reduced.

Description

technical field [0001] The invention belongs to the field of organic chemical synthesis, in particular to a method for synthesizing 2,2,2',4'-tetrachloroacetophenone. Background technique [0002] 2,2,2',4'-tetrachloroacetophenone is an important fine chemical intermediate, widely used in medicine, pesticide and other fields; such as: 2,2,2',4'-tetrachloro Acetophenone can be used to synthesize carcarb, chlorpyramid, etc. At present, most of the synthesis of 2,2,2',4'-tetrachloroacetophenone is based on m-dichlorobenzene and dichloroacetyl chloride, and the acetylation reaction is carried out under the catalysis of Lewis acid aluminum chloride to obtain 2 , 2,2',4'-Tetrachloroacetophenone. Although some enterprises have made great improvements in equipment and the use of rectification towers, which can achieve a certain increase in selectivity and yield, but the effect is still mediocre, and the amount of catalyst used remains high, which not only wastes resources, but als...

AI Technical Summary

Problems solved by technology

Although some enterprises have made great improvements in equipment and the use of rectification towers, which can achieve a certain increase in selectivity and yield, but the effect is still mediocre, and the amount of catalyst used remains high, which not only wastes resources, but also The cost control of industrial production has brought enormous pressure. In addition, there are reports in the synthesis process that the molecular sieve catalyst is used to direct the isomerization of by-products to improve the yield and purity. However, due to the limited porosity of the molecular sieve catalyst and the Experiments have found that the thermal reaction stability of this type of molecular sieve is average, resulting in unsatisfactory conversion results.

[0003] Therefore, in order to solve 2,2,2',4'-tetrachloroacetophenone synthesis process catalyst consumption is many, the product yield is general and the problems such as poor purity, the present invention proposes a kind of 2,2,2',4 The synthetic method of '-tetrachloroacetophenone to overcome the deficiencies in the prior art