Method for preparing 2, 4-dinitroaniline by using microreactor

Abstract

The invention relates to the technical field of preparation of 2, 4-dinitroaniline, in particular to a method for preparing 2, 4-dinitroaniline by using a microreactor. The method comprises the following steps: (1) preparing equipment, namely preparing a preheater, the microreactor and two chromatographic pumps; (2) connecting reaction equipment, respectively connecting two chromatographic pumps with the preheater and the micro-reactor, then connecting the preheater with the micro-reactor, and putting the preheater and the microreactor into a constant-temperature oil bath after the connectionis completed; (3) conveying a reaction material, namely conveying ammonia water to the preheater at a preset flow rate, conveying the molten 2, 4-dinitrochlorobenzene to the microreactor at a preset flow rate, and mixing and reacting with the ammonia water to obtain 2, 4-dinitroaniline; and (4) after the reaction of the material in the step (3) is completed, preparing the redundant ammonia gas into ammonia water again for reuse through an ammonia gas recovery device, and continuing to reuse the ammonia generated by the reaction of ammonium chloride generated by the reaction and potassium hydroxide. Tthe method has the characteristics of high production efficiency, low energy consumption, economy, environmental protection, safety and reliability.

Description

technical field [0001] The invention relates to the technical field of 2,4-dinitroaniline preparation, and the specific field is a method for preparing 2,4-dinitroaniline by using a microreactor. Background technique [0002] Using 2,4-dinitrochlorobenzene and ammonia water as the reaction raw materials, the reaction principle of preparing 2,4-dinitroaniline is that 2,4-dinitrochlorobenzene and ammonia water undergo a bimolecular nucleophilic substitution reaction. Ammonia molecules with unshared electron pairs attack the carbon connected to the chlorine atom on the aromatic ring to obtain a polar intermediate product, which reacts rapidly and transforms into the final product 2,4-dinitroaniline. [0003] At present, the existing and previously reported production of 2,4-dinitroaniline is intermittent single-pot production and continuous-pot production, with low production efficiency, long reaction time, relatively large pollution, and high-pressure exothermic reaction. Low...

AI Technical Summary

Problems solved by technology

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing 2,4-dinitroaniline using a microreactor, which has solved the problems of low production efficiency, large pollution, high cost and safety factor of the traditional Kebai reaction. low technical issues