109-77-3Relevant articles and documents
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Ardis et al.
, p. 1305 (1950)
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Cyanocarbon Acids: Direct Evidence That Their Ionization Is Not an Encounter-Controlled Process and Rationalization of the Unusual Solvent Isotope Effects
Hojatti, M.,Kresge, A. J.,Wang, W.-H.
, p. 4023 - 4028 (1987)
The rate of exchange of the acidic hydrogen of tert-butylmalononitrile was examined by using as a tracer, and the process was found not to be inhibited by hydronium ions in dilute aqueous hydrochloric acid solutions.This rules out the Swain-Grunwald mechanism for this reaction under these conditions.The bromination of malonitrile was investigated under conditions where reprotonation of the dicyanomethyl carbanion and its reaction with bromine occur at comparable rates, and the bromination reaction was found to have a specific rate twice that for reprotonation.Reprotonation therefore cannot be a diffusion-controlled process, and malonitrile is not a "normal" acid.The unusually large solvent kinetic isotope effects found for these cyanocarbon acid ionization reactions are explained by postulating that the transferring hydrogen and its positive charge are becoming associated with a solvent cluster rather than with a single water molecule.The thermodynamic acidity constant of malonitrile was determined to be 11.41 in aqueous solution at 25 deg C.
Preparation method of malononitrile and malononitrile prepared by preparation method
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Paragraph 0056-0103, (2021/05/01)
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.
Preparation method of malononitrile
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Paragraph 0044-0051, (2020/07/24)
The invention discloses a preparation method of an important organic synthesis raw material malononitrile, which comprises the following steps: performing a reaction on chloroacetonitrile and hydrogencyanide as raw materials in a tubular reactor, and separating the reaction product by condensation and negative pressure distillation to obtain the malononitrile. The method has the advantages of mild reaction conditions, simple separation and purification process, high product yield and purity, energy saving, environmental protection and low cost.
Synthesis method of malononitrile
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Paragraph 0038-0041, (2019/02/06)
The invention discloses a synthesis method of malononitrile. Metal hydride and dihalomethane are used as an initial reactant system; under the existence of metal iodate catalysts, a dipolar aprotic solvent is used as a reaction auxiliary agent to prepare a target product of malononitrile. The method has the advantages that through the addition of the reaction auxiliary agent for reaction promotion, the malononitrile hydrolysis or alcoholysis due to polar solvents of water, alcohol and the like can be avoided; high yield and high quality of malononitrile are ensured; the malononitrile with theyield higher than 91.0 percent and the purity higher than 99.3 percent can be obtained.
