Preparation method of 3, 4-dichloronitrobenzene by solid acid catalyst

Abstract

The invention discloses a preparation method of 3, 4-dichloronitrobenzene by a solid acid catalyst, comprising the following steps of: taking p-toluenesulfonic acid as a catalyst; after fully mixing with o-dichlorobenzene solution in a kettle, dropping nitric acid with 98% of concentration, and performing nitration reaction at a certain temperature; after reaction, maintaining the temperature, and standing; performing solid and liquid separation to obtain crude 3, 4-dichloronitrobenzene; and after using NaOH to neutralize the crude product, using water to wash and separate so as to obtain pure 3, 4-dichloronitrobenzene. The product obtained by the method has 98% of yield and more than 99.8% of content.

Description

technical field [0001] The invention relates to an application method of a solid acid catalyst, in particular to a solid acid catalyst applied to the preparation of 3,4-dichloronitrobenzene. Background technique [0002] 3,4-Dichloronitrobenzene is an important intermediate of organic chemical products such as fluorochloroaniline, fluorochloronitrobenzene, and 3,4-dichloroaniline. [0003] There are currently two main production methods. One is nitration by o-dichlorobenzene, and the nitration temperature can be controlled at about 0°C, or it can be carried out at a temperature slightly higher than room temperature; the other production method is chlorination of p-nitrochlorobenzene. However, the traditional reaction system uses a stirred tank to stir for a long time, the reaction is incomplete, the yield is low, and the purity of the finished product is not high. Contents of the invention [0004] The main task of the present invention is to provide an external circulat...

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Problems solved by technology

However, the traditional reaction system uses a stirred tank to stir the reaction for a long time, the reaction is incomplete, the yield is low, and the purity of the finished product is not high