Preparation method of malononitrile and malononitrile prepared by preparation method

Abstract

The invention relates to the technical field of chemical synthesis methods, particularly to a malononitrile preparation method and malononitrile prepared thereof. The malononitrile preparation method comprises the following steps: mixing cyanoacetamide, a catalyst and a solvent, heating, refluxing, and introducing phosgene to synthesize malononitrile, wherein the mass ratio of the cyanoacetamide to the catalyst to the solvent is (2.5-3.5):(0.005-0.02):(7.5-10.5), the solvent is any one of dichloromethane, dichloroethane or methylbenzene, and the catalyst is any one or more of diethylamine, N,N-dimethylformamide or pyridine. According to the invention, cyanoacetamide is adopted to synthesize malononitrile in one step under the action of phosgene, wherein the required raw materials are cheap and easy to obtain, the synthetic reaction steps are few, harsh conditions are avoided, the operation is simple, stable and good in controllability, and the yield of the prepared malononitrile can reach 93% or above and is far higher than that of malononitrile obtained through other process schemes; and the preparation method is low in three-waste treatment cost, and has objective economic benefit.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis methods, in particular to a method for preparing malononitrile and the prepared malononitrile. Background technique [0002] Malononitrile is an important raw material for organic synthesis. There are two cyano functional groups in the malononitrile molecule, and the cyano group is a strong polar group with strong electron-withdrawing properties. Due to the action of the two cyano groups, the electron cloud of the malononitrile molecule transfers to the nitrogen atom on the cyano group, so that the two hydrogen atoms on the methylene group in the malononitrile molecule are also quite active. Since both cyano and methylene groups can react, malononitrile is a chemically very active compound that can undergo a series of reactions such as addition, condensation, substitution, cyclization, and polymerization to synthesize a series of important chemical products. The following is the struc...

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Problems solved by technology

However, these methods must use high temperature and high pressure, which requires large equipment investment and high requirements, especially the gas phase reaction, which produces highly toxic cyanide gas, chlorine gas, hydrogen cyanide, etc., and the environmental protection problem is difficult to solve

[0006] Therefore, to develop a new synthesis process of malononitrile to overcome the problems of high cost, large amount of solid waste and difficult treatment of phosphorus-containing wastewater in the prior art is an urgent problem in this area.

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