Method for synthesizing p-dichlorobenzene

Abstract

The invention provides a method for preparing benzene dichloride. It comprises following steps: ventilizing chlorine gas into dichloronitrobenzene with catalyst existance at 150- 260 Deg. C for reaction for 1- 10 hours and getting coarsebenzene dichloride, treating coarse product and getting benzene dichloride. Said catalyst is oxide or azocompound, the amount of said catalyst is 0.1- 15 of that of p-nitrochlorobenzene. The inveiton is characterized by temperate reaction condition, simple operation, simple device, high product purity of 99.5%, and avoid of difficult separation of dichlorobenzene and trichlorobenzene and even tetrachlorobenzene.

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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