Preparation method of sulfonamide

Abstract

The invention discloses a preparation method of sulfonamide, which comprises the step of: under an atmosphere of inert gas, heating sulfinic acid or sulfinate and a nitro compound for 3 to 30 hours at the reaction temperature from 20 DEG C to 200 DEG C by using transition metal or translation metal compound as a catalyst, so as to generate sulfonamide. The preparation method disclosed by the invention has the following technical effects of an improved reaction system and stable properties, low cost and high availability of nitro compound; in this method, the nitro compound is directly used as starting material, thus avoiding the step of selectively reducing nitro into an amino compound; sulfinate is more stable and easier to store than other sulfonating agents; and simultaneously, the reaction system is simple and easy for industrial production. The method disclosed by the invention is safer and more economical and effective than the existing methods, and is also safer in used catalyst; and normally, the method disclosed by the invention can realize the conversion of nitrobenzene raw material into sulfonamide at a conversation rate of 90%, typically above 95%.

Description

technical field [0001] The present invention relates to a method for preparing sulfonamides. Background technique [0002] N-(Substituted phenyl)sulfonamide compounds are important constituents of functional materials, drugs, etc. [ . There are many methods for synthesizing these compounds, which can be roughly classified into two categories: one is the reaction of halogenated aromatic hydrocarbons (or pseudohalogenated aromatic hydrocarbons) and sulfonamides. [ ; One is the reaction of aniline and sulfonated reagent [ . For example, the sulfonamides reported as herbicides in the patent US4,818,275 are by reacting the corresponding arylamine with methanesulfonyl chloride and excess triethylamine in dichloromethane, and then treating the resulting sulfonic acid with sodium hydroxide Amide derivatives. However, when the reaction is carried out on a large scale, the excess triethylamine must be recovered, recycled or disposed of as part of the process, and such recovery / re...

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Problems solved by technology

But also there are some deficiencies in some systems: (1) need to add monophosphine or diphosphine ligand in the reaction to improve yield; (2) need to add a large amount of hygroscopic cesium carbonate as alkali in some systems, or Add other additives; (3) Some sulfonated reagents have high activity, are sensitive to water, and are not easy to store, such as arylsulfonyl chloride

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