40497-11-8Relevant articles and documents
Intermediates Formed in the Reactions of Organocuprates with α,β-Unsaturated Nitriles
Putau, Aliaksei,Brand, Harald,Koszinowski, Konrad
, p. 12868 - 12876 (2016)
Conjugate additions of organocuprates are of outstanding importance for organic synthesis. To improve our mechanistic understanding of these reactions, we have used electrospray ionization mass spectrometry for the identification of the ionic intermediates formed upon the treatment of LiCuR2?LiCN (R=Me, Bu, Ph) with a series of α,β-unsaturated nitriles. Acrylonitrile, the weakest Michael acceptor included, did not afford any detectable intermediates. Fumaronitrile (FN) yielded adducts of the type Lin?1CunR2n(FN)n?, n=1–3. When subjected to fragmentation in the gas phase, these adducts were not converted into the conjugate addition products, but re-dissociated into the reactants. In contrast, the reaction with 1,1-dicyanoethylene furnished the products of the conjugate addition without any observable intermediates. Tri- and tetracyanoethylene proved to be quite reactive as well. The presence of several cyano groups in these substrates opened up reaction pathways different from simple conjugate additions, however, and led to dimerization and substitution reactions. Moreover, the gas-phase fragmentation behavior of the species formed from these substrates indicated the occurrence of single-electron transfer processes. Additional quantum-chemical calculations provided insight into the structures and stabilities of the observed intermediates and their consecutive reactions.
Preparation method of ethyl 2,3-dicyanopropionate
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Paragraph 0019-0026, (2021/02/20)
The invention discloses a preparation method of ethyl 2,3-dicyanopropionate. The preparation method comprises the steps of adding a liquid sodium cyanide aqueous solution into a reaction tank, conducting concentrating and dehydrating, and then adding dichloromethane to separate water; conducting cooling after the reaction is qualified, adding ethyl cyanoacetate, paraformaldehyde and a catalyst, keeping the temperature for reaction until the reaction is finished, starting to add hydrochloric acid for acidification, and conducting standing for layering to obtain a dichloromethane organic layer;and washing the organic layer with water, removing dichloromethane to obtain a crude product, and performing vacuum distillation to obtain a finished product. According to the method, dichloromethaneis directly used as a reaction solvent, and a small amount of catalyst is added, so that the reaction period is short, the solvent is easy to recover, and the used liquid sodium cyanide is safer to store and use compared with solid sodium cyanide.
Production process of ethyl 2,3-dicyanopropionate
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Paragraph 0028-0083, (2020/09/30)
The invention provides a production process of ethyl 2,3-dicyanopropionate. The production process comprises the following steps: S1, premixing of raw materials: adding ethyl cyanoacetate, dimethyl sulfoxide and diethyl malonate into a reaction kettle, and carrying out mixing and stirring to form a premixture; S2, a synthetic reaction: adding sodium cyanide and paraformaldehyde into the reaction kettle, and carrying out a constant-temperature reaction for 15-20 h under stirring and mixing conditions to form a reaction mixed solution; S3, addition of acid; step S4, extraction; S5, reduced-pressure distillation and recovery; and S6, rectification: removing a small amount of front fraction impurities to obtain a red oily target product, namely ethyl 2,3-dicyanopropionate. The raw materials ofthe process are composed of, in parts by weight, 100 parts of ethyl cyanoacetate, 100-150 parts of dimethyl sulfoxide, 60-100 parts of sodium cyanide, 50-80 parts of paraformaldehyde, and 20-30 partsof diethyl malonate. The production process of ethyl 2,3-dicyanopropionate in the invention provides has the advantages of high safety, high product yield and few byproducts.