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Process for preparing disubstituted urea

A technology for disubstituted urea and urea, which is applied in the preparation of urea derivatives, the preparation of organic compounds, chemical instruments and methods, etc., can solve the problems of polluting the environment waste gas-hydrogen chloride and hydrogen halide pollute the environment, and the equipment is corroded. The effect of decolorization treatment, simple post-treatment process and mild reaction conditions

Inactive Publication Date: 2007-05-23
LANZHOU INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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AI Technical Summary

Problems solved by technology

The traditional synthesis method of disubstituted urea adopts the phosgene method, although the method is simple and feasible, but the method needs to use highly toxic raw material phosgene, and produces a large amount of waste gas-hydrogen chloride which corrodes equipment and pollutes the environment during production; This production method is currently being phased out
However, in the synthetic method of utilizing urea reported in the past to synthesize diphenylurea ("Fine Organic Chemical Intermediates Handbook" 3-556), a large amount of hydrochloric acid will be used, which will corrode the equipment; Nandakumar et al. reported using copper as catalyst to catalyze haloalkane Coupling with urea to prepare disubstituted urea (Nandakumar M.V., Tetra.Lett., 45 (2004) 1989), but the yield of disubstituted urea is only 65%, and hydrogen halide is released during the reaction to pollute the environment

Method used

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  • Process for preparing disubstituted urea
  • Process for preparing disubstituted urea

Examples

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Effect test

Embodiment 1

[0022] Mix urea and aniline compounds in a ratio of 1:1, add them into a container containing N,N-dimethylformamide as a solvent, raise the temperature to 150°C while stirring, and keep the reaction time 120 minutes, then the reaction system was cooled to room temperature. After adding water to the reaction system, the white solid obtained by suction filtration is the corresponding urea. The filtrate passes through the separation, and the reaction substrate can be put back into use. Diphenylurea was dried and weighed, and the yield was 20%.

Embodiment 2

[0024] Same as Example 1, the ratio of urea to aniline is 1:4, and the yield of diphenylurea is 40%.

Embodiment 3

[0026] With example 2, temperature is 160 ℃, and the yield of diphenylurea is 56%.

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Abstract

The invention relates to a synthesis method for urea. The method includes carrying out a reaction of urea with a variety of substituted amines under the mild reaction conditions to prepare disubstituted urea. Corresponding isocyanates can be obtained through direct pyrolysis of urea. Meanwhile, ammonia and amine formed in the reaction process can be reused. The invention has non-use of the catalyst, and product separation process is simple, therefore suitable for large-scale industrialized production.

Description

technical field [0001] The invention belongs to a method for synthesizing urea, and relates to the synthesis of isocyanate. Specifically, it relates to a synthetic method of disubstituted urea and isocyanate under mild conditions. Background technique [0002] Isocyanate is an important organic reaction intermediate, which has a very wide range of uses in industry, agriculture, medicine and health, etc. Important raw materials for agents and other materials. But so far, the main method adopted in the industry is still to use amine and phosgene to produce the corresponding isocyanate (such as formula one). Phosgene is a highly toxic compound, and the waste generated during the production process will corrode equipment, and once phosgene leaks, it will cause personal injury and environmental pollution. [0003] [0004] formula one [0005] With the increasing environmental pollution around the world, countries around the world are constan...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C273/18C07C275/06C07C275/26C07C275/28
Inventor 夏春谷肖林飞陈静
Owner LANZHOU INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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