43222-89-5Relevant academic research and scientific papers
Mechanistic Studies on the Michael Addition of Amines and Hydrazines to Nitrostyrenes: Nitroalkane Elimination via a Retro-aza-Henry-Type Process
Kallitsakis, Michael G.,Tancini, Peter D.,Dixit, Mudit,Mpourmpakis, Giannis,Lykakis, Ioannis N.
, p. 1176 - 1184 (2018/02/09)
In this article we report on the mechanistic studies of the Michael addition of amines and hydrazines to nitrostyrenes. Under the present conditions, the corresponding N-alkyl/aryl substituted benzyl imines and N-methyl/phenyl substituted benzyl hydrazones were observed via a retro-aza-Henry-type process. By combining organic synthesis and characterization experiments with computational chemistry calculations, we reveal that this reaction proceeds via a protic solvent-mediated mechanism. Experiments in deuterated methanol CD3OD reveal the synthesis and isolation of the corresponding deuterated intermediated Michael adduct, results that support the proposed slovent-mediated pathway. From the synthetic point of view, the reaction occurs under mild, noncatalytic conditions and can be used as a useful platform to yield the biologically important N-methyl pyrazoles in a one-pot manner, simple starting with the corresponding nitrostyrenes and the methylhydrazine.
Preparation method for pyrazole
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Paragraph 0011; 0012; 0013; 0014; 0015; 0016; 0063; 0064, (2017/08/26)
The invention relates to a preparation method for pyrazole, belonging to the field of organic chemistry. The preparation method disclosed in the invention realizes preparation of pyrazole through a cyclization reaction of N-alkylated phenylsulfonylhydrazone with terminal alkyne. The reaction has good function group tolerance and high yield and is applicable to a wide range of substrates.
Regioselective synthesis of 1,3,5-Trisubstituted Pyrazoles from N-Alkylated Tosylhydrazones and terminal Alkynes
Kong, Yuanfang,Tang, Meng,Wang, Yun
, p. 576 - 579 (2014/04/03)
An efficient synthesis of 1,3,5-trisubstituted pyrazoles from Nalkylated tosylhydrazones and terminal alkynes was developed. The protocol was applied to a wide range of substrates and demonstrated excellent tolerance to a variety of substituents, includin
