A method for preparing 3-chloro-4-methylaniline

Abstract

The invention discloses a method for preparing 3-chloro-4-methylaniline. The method comprises the following steps: 0.48-0.54 weight parts of chlorine is pumped into paranitrotoluene for chlorination in a chlorine kettle under the condition of stirring temperature and stirred for 10 minutes, then materials in the chlorine kettle are washed in a washing kettle; the washed materials are transferred into a refining kettle to refine, then the refined materials are transferred into a reduction tower with a catalyst, and 0.038-0.044 weight parts of hydrogen is pumped into the reduction tower for reduction; and the reduced materials are transferred into the the refining kettle to repurify to obtain the final product. The method for preparing 3-chloro-4-methylaniline provided by the invention saves the usage of raw materials effectively and reduces energy consumption rationally.

Description

technical field

[0001] The invention relates to a preparation method of a pigment intermediate, in particular to a preparation method of 3-chloro-4-methylaniline. Background technique

[0002] The current production of 3-chloro-4-methylaniline is generally obtained by chlorination and reduction of p-nitrotoluene. The preparation method is simple. The general preparation method is: 1. Chlorination: add nitrotoluene to the reaction pot, heat To 75°C, put in anhydrous ferric chloride and iodine, stir for 10-20min, then start chlorine flow at 60°C, keep the chlorination temperature at 55-70°C, until the melting point of chloride > 58.5°C does not increase within 20min . Catch the air, raise the temperature to 80-90°C, and keep it for 1.5-2h to get 2-chloro-4-nitrotoluene with a yield of 98%. 2. Reduction: Add the prepared sodium sulfide solution into the reaction pot, add the above-mentioned 2-chloro-4-nitrotoluene at 70-80°C, reflux for 4 hours, the temperature is 110±5°C,...

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