Method for synthesizing p-dichlorobenzene

Abstract

A preparation method of p-dichlorobenzene: in the presence of a catalyst, p-nitrochlorobenzene is passed through chlorine gas at a temperature of 150-260°C for 1-10 hours to react to obtain crude p-dichlorobenzene, crude p-dichlorobenzene p-dichlorobenzene is obtained through post-treatment, and the catalyst is a peroxide or an azo compound, and the amount of the catalyst used is 0.1-1% of the mass of p-nitrochlorobenzene. The technology of the present invention adopts catalytic chlorination, the reaction conditions are milder, the process operation is simple, the equipment is simple and easy, and the product purity reaches 99.5%; it avoids the benzene monochloride, ortho- and meta-position dichlorinated benzene in the synthesis of reaction products in the prior art , trichlorobenzene and even tetrachlorobenzene separation difficulties.

Description

(1) Technical field [0001] The invention relates to a new method for synthesizing p-dichlorobenzene. (2) Background technology [0002] P-dichlorobenzene is mainly used as anti-moth agent, anti-fungal agent and deodorant, and can also be used in engineering plastic polyphenylene sulfide, synthetic pesticide, medicine, dyestuff and synthetic fiber. It is a fine chemical product with a wide range of uses. Before the 1980s, p-dichlorobenzene was recycled as a by-product of the production of chlorinated benzene in my country. The output was small, the separation was difficult, the product quality was poor, and the scale was small. In 1988, after my country introduced refining equipment and technology, domestic production of p-dichlorobenzene embarked on a track of rapid development. And through development and research, the process of producing dichlorobenzene by directional catalytic chlorination of benzene was successfully developed. However, the reaction mixture contains mo...

AI Technical Summary

Problems solved by technology

Before the 1980s, p-dichlorobenzene was recycled as a by-product of the production of chlorinated benzene in my country. The output was small, the separation was difficult, the product quality was poor, and the scale was small.

However, the reaction mixture contains monochlorinated benzene, o- and para-dichlorinated benzene, trichlorobenzene and even tetrachlorobenzene, which also caused difficulties in separation.

[0003] Therefore, in the literature research, we found that the high-temperature denitrochlorination technology of nitrochlorobenzene can solve the above problems, and there is no literature report on the preparation of p-dichlorobenzene products by high-temperature denitrochlorination of p-nitrochlorobenzene

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