Preparation process for 4,4'-bis(chloromethyl)-1,1'-biphenyl

Abstract

The invention relates to a preparation process for 4,4'-bis(chloromethyl)-1,1'-biphenyl, and belongs to the technical field of chemical synthesis. The 4,4'-bis(chloromethyl)-1,1'-biphenyl is prepared by synthesizing raw materials paraformaldehyde and biphenyl under the catalytic action of zinc chloride, acetic acid and cyclohexane. According to the process, hydrogen chloride is continuously provided for synthesis reaction by virtue of reaction of sulfuryl chloride and concentrated hydrochloric acid to ensure smooth chloromethylation reaction, so that the yield and the product quality of the 4,4'-bis(chloromethyl)-1,1'-biphenyl are improved, the amount of sewage required to be treated is small, and the treatment cost is low. According to the preparation process for the 4,4'-bis(chloromethyl)-1,1'-biphenyl, the phenomenon that an excessive amount of water is introduced into a reaction system to further reduce the catalytic effect of the zinc chloride is avoided, and moreover, production of a highly carcinogenic intermediate product is avoided; the preparation process is environment-friendly and applied to industrial expanded production, and the production cost is reduced.

Description

technical field [0001] The invention relates to a preparation process of biphenyl benzyl dichloride, which belongs to the technical field of chemical synthesis. Background technique [0002] Biphenyl dichlorobenzyl, also known as 4,4'-dichloromethyl biphenyl, molecular formula C 14 C 12 Cl 2 , the relative molecular weight is 251, the melting point is 136°C, the boiling point is 235°C, and the structural formula is: [0003] [0004] Biphenyl dichlorobenzyl is an important intermediate in the synthesis of stilbene-type fluorescent whitening agent (CBS-X) and plastic whitening agent CBS-127, and is also a pharmaceutical intermediate 4,4'-dimethylolbiphenyl Raw material, the purity of biphenyl benzyl dichloride directly affects the quality of the synthesized product. [0005] The synthesis technique of biphenyl benzyl dichloride is generally adopted at home and abroad to take biphenyl and paraformaldehyde as raw materials, and under the effect of catalyst zinc chloride,...

AI Technical Summary

Problems solved by technology

There are a lot of shortcomings in the synthetic technique of biphenyl dichlorobenzyl at present: as catalyst zinc chloride and sulfuric acid consumption are very large, there is certain potential safety hazard in later stage zinc chloride and sulfuric acid recovery treatment, and the degree of industrialization popularization and application is low; Dichloromethyl ether is a strong carcinogen, volatile and pollutes the environment, causing harm to the human body after inhalation; the yield of biphenyl dichlorobenzyl is low, etc.

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