3,4-methylenedioxy aniline preparation method

Abstract

A 3,4-methylenedioxy aniline preparation method applied to the field of chemosynthesis comprises the following steps: (1) adding dilute nitric acid into a reaction vessel for heating; (2) dropwise adding 1,2-methylenedioxy benzene into the reaction vessel slowly, carrying out intense stirring during the dropwise adding, and carrying out heat preservation after the dropwise adding is finished; (3) carrying out cooling and filtration to obtain a wet product of 3,4-methylenedioxy nitrobenzene, carrying out washing with purified water till the pH value of the wet product reaches 7, and carrying out vacuum drying to obtain 3,4-methylenedioxy nitrobenzene; (4) putting 3,4-methylenedioxy nitrobenzene, a nickel catalyst and one or more reaction solvents into a high-pressure reaction kettle for heating, injecting hydrogen, filtering out the nickel catalyst after the reaction is finished, carrying out high vacuum distillation after a low-boiling-point substance is removed through reduced pressure distillation, and collecting fractions to obtain 3,4-methylenedioxy aniline. The 3,4-methylenedioxy aniline preparation method has the advantages that nitrification reduction and hydrogenation reduction processes are adopted; less waste water, waste gas and solid waste are treated; the selectivity is high; the product treatment is easy; the product yield and the product quality are high; nitric acid, the hydrogenation catalyst and the hydrogenation organic solvents can be recovered for direct application.

Description

technical field [0001] The invention relates to a method for preparing 3,4-methylenedioxyaniline by using 1,2-methylenedioxybenzene as a raw material in the field of chemical synthesis. Background technique [0002] 3,4-Methylenedioxyaniline, also known as piperonylamine, has the molecular formula C 7 h 7 NO 2 , piperonylamine is a very important dye and pharmaceutical intermediate, it can be used as a raw material to develop a variety of high value-added downstream products, such as synthetic antioxidants and pharmaceutical intermediates sesamol, the preparation of antibacterial drugs oxolinic acid and Cinoxacin, a synthetic drug for treating liver diseases and anti-tumor drugs, piperonamine is widely used, and has a large market demand at home and abroad. [0003] At present, there are two main preparation process routes for the preparation of piperonylamine, one is to use 1,2-methylenedioxybenzene as raw material to prepare by halogenation and diazotization, and the ot...

AI Technical Summary

Problems solved by technology

However, it is difficult to separate the finished product and the unreacted intermediate of the halogenated diazotization process, and it is impossible to realize industrialization. At present, most of the industrialization adopts nitration and reduction processes, and the alkali sulfide method in the reduction process has a low yield. Under these conditions, amino compounds are easily oxidized and are rarely used; the metal reduction environment is seriously polluted, and it is very difficult to treat waste water and residue.

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