Method for reducing generation of nitrophenol in preparation process of nitroanisole

Abstract

A special feeding mode is adopted in the invention to reduce generation of nitrophenol, and is characterized in that a sodium methoxide solution prepared from methanol and sodium hydroxide is added to an autoclave in t he production process of nitroanisole from m-oil (o-nitrochlorobenzene, p-nitrochlorobenzene and m-nitrochlorobenzene) in the autoclave, so generation of nitrophenol is reduced, thereby the reaction time is greatly shortened, the raw material conversion rate is improved, the reaction selectivity and the yield of the above product are improved, the cost is reduced, and three wastes are reduced.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a method for reducing the generation of nitrophenol during the reaction of mixed nitrochlorobenzenes in an autoclave to generate nitroanisole. Background technique [0002] Nitroanisole (o-nitroanisole, p-nitroanisole) is an important intermediate for the synthesis of dyes, spices and medicines. ) is an important raw material. [0003] The traditional production process of o-aminoanisole or p-aminoanisole is made from o-nitrochlorobenzene or p-nitrochlorobenzene through etherification, hydrogenation, separation, rectification and other processes. . This traditional preparation process has the disadvantage of high raw material cost. [0004] Changzhou Jiasen Chemical Co., Ltd. discloses a process for producing o-nitroanisole, p-nitroanisole and m-nitrochlorobenzene with chlorobenzene (Chinese patent CN200610085488.8). As a raw material, chlorobenzene undergo...

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Problems solved by technology

[0007] In order to solve the existing problem of producing nitrophenol in the process of utilizing meta-position oil to synthesize nitroanisole in an autoclave, the present invention adopts a special feeding method to reduce the generation of nitrophenol, that is, in the autoclave In the process of nitration of chlorinated benzene to produce p- and o-nitrochlorinated benzene, the rectification still liquid is the meta-position oil (o-nitrochlorinated benzene, p-nitrochlorinated benzene and m-nitrochlorinated benzene) to produce amino In the process of anisole, during the etherification reaction, the solvent methanol and sodium hydroxide are prepared into sodium methoxide solution and then added to the autoclave, thereby reducing the generation of nitrophenol, which not only greatly shortens the reaction time, but also improves the conversion of raw materials It also improves the selectivity of the reaction and the yield of the product, reduces the cost, and reduces the three wastes, because according to the characteristics of nitrophenol, it exists in the form of sodium phenate under alkaline conditions, and most of them are soluble in water. This increases the difficulty of wastewater treatment

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