Method for synthesizing symmetrical urea compound

Abstract

The invention relates to a method for synthesizing a symmetrical urea compound. According to the technical scheme, the method comprises the following steps of: based on aromatic amines or fatty amines as raw materials, selenium as a catalyst, a nitro-compound or oxygen as an oxidant, and organic base as a promoter or without adding any promoter, continuously introducing carbon monoxide, and reacting at the temperature of 50 to 120 DEG C under normal pressure for 5 to 7 hours; and cooling to room temperature, stirring by replacing carbon monoxide with air, filtering, washing and performing ethanol recrystallization to obtain a target product. According to the method, the symmetrical urea compound is prepared under normal pressure without a solvent through a carbonyl reaction. The product has the selectivity of 100 percent and the separation yield of more than 20 percent. The method is easy, convenient and safe in operation and readily available in raw materials and has high environment friendliness, the catalyst and the mother solution can be recycled, and the products are easily separated.

Description

technical field [0001] The invention relates to the synthesis of symmetric urea compounds, in particular to a method for synthesizing symmetric urea by taking amine compounds as raw materials and utilizing carbon monoxide to catalyze selenium under normal pressure and reaction without solvent. Background technique [0002] Urea compounds are a class of compounds with a wide range of uses, so they play a very important role in both industrial applications and life science research. Since the molecular structure of urea contains differently substituted peptide bonds (—CONH—), most of them have biological activity, and can be used as antioxidants in gasoline, corrosion inhibitors, etc., and can be used as herbicides, insecticides, etc. in pesticides. Plant growth regulators and fungicides are important pharmaceutical intermediates in medicine. The traditional method for synthesizing ureas is to utilize the phosgene method to carbonylate amines [Bigi, F.; Maggi, R.; Sartori, G....

AI Technical Summary

Problems solved by technology

In recent years, it has been reported to use transition metals to catalyze carbon monoxide carbonylation of amine compounds, most of which are Mn, Au, Rh, Ru, etc., and the price is relatively expensive

Researcher Lu Shiwei and Dr. Wang Xiaofang from Dalian Institute of Chemical Physics proposed that selenium catalyzes the carbonylation of aniline to urea in the presence of nitrobenzene at atmospheric pressure, but the solvent used is DMF. The existence of the solvent makes the post-treatment more complicated and unfriendly to the environment.

The method of synthesizing symmetrical urea in carbon monoxide with aromatic amine as raw material under pure solvent-free normal pressure condition has not been reported

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