Method for synthesizing symmetric urea compounds from nitrocompounds

Abstract

The invention relates to a method for synthesizing symmetric urea compounds from nitrocompounds. The technical scheme is as follows: in the presence of carbon monoxide and water, by using nitrocompounds as the raw material, selenium as a catalyst and an organic alkali or inorganic alkali as a cocatalyst (or no cocatalyst is added), reaction is performed under the conditions of atmospheric pressure and no solvent to synthesize the symmetric urea compounds by one step, wherein the mol ratio of water to nitrocompounds is 1:1-1:2.5; the selenium accounts for 0.05-1 mol% of the nitrocompounds; the mol ratio of organic alkali or inorganic alkali to nitrocompounds is 1:10-1:4; the reaction time is 1-8 hours; and the reaction temperature is 35-95 DEG C. The invention is simple and safe to operate, and can synthesize the symmetric urea compounds from the nitrocompounds under the conditions of atmospheric pressure and no solvent by one step, and has the advantages of one-pot reaction, accessible raw material, no pollution, high selectivity and high yield; and after the reaction finishes, the catalyst can be separated and recycled.

Description

technical field [0001] The present invention relates to the synthesis of symmetrical urea compounds, in particular to the synthesis of nitro compounds as raw materials, under the presence of carbon monoxide and water, selenium as a catalyst, and organic or inorganic bases as cocatalysts under normal pressure and solvent-free conditions A method for symmetry of urea compounds. Background technique [0002] Urea compounds are a class of compounds with a wide range of uses and play a very important role in life science research and industrial applications. Due to the different substituted peptide bonds (—CONH—) in their structures, most of them are biologically active. They can not only be used as fiber dyes, but also as antioxidants in gasoline, corrosion inhibitors, etc., and in pesticides, medicines, etc. The application in the world is also quite extensive, many of which can be used as pesticides, pharmaceutical intermediates, herbicides, insecticides, plant growth regulat...

AI Technical Summary

Problems solved by technology

The traditional method of synthesizing urea compounds is to use phosgene as a carbonyl source to react with the same or different amines to form symmetrical or asymmetrical ureas [Bigi, F; Maggi, R; Sartori, G. Selected synthesis of ureas through phosgene substitutes. Green Chem.,2000,2,140-148], but its biggest disadvantage is that phosgene is highly toxic and generates corrosive chlorides

In recent years, it has been found that carbon monoxide is used as a reducing agent and carbonyl source, and transition metals Pd, Ru, Rh, W, Mn, Au, etc. are used as catalysts to catalyze the reductive carbonylation of aromatic nitro compounds and the oxidative carbonylation of amines to synthesize ureas. compounds, but these metals are expensive and the reaction conditions are harsh

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