56119-91-6Relevant articles and documents
Preparation method for pyrazole
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Paragraph 0011; 0012; 0013; 0014; 0015; 0016; 0095; 0096, (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
supporting information, 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
The preparation of substituted pyrazoles from β,β-dibromo-enones by a tandem condensation/Suzuki-Miyaura cross-coupling process
Beltrán-Rodil, Sandra,Edwards, Michael G.,Pugh, David S.,Reid, Mark,Taylor, Richard J.K.
scheme or table, p. 602 - 606 (2010/09/18)
Two consecutive tandem processes are described for the regioselective, two-step synthesis of 1,3,5-trisubstituted pyrazoles from α- hydroxyketones. The first, a tandem MnO2-mediated oxidation/Ramirez olefination reaction, provides a facile route to β,β-dibromo-enones. These valuable 1,3-dicarbonyl synthons can then be converted into 1,3,5-trisubstituted pyrazoles via a second tandem hydrazine condensation/Suzuki-Miyaura cross-coupling reaction. Using these procedures, a range of aryl and alkyl α-hydroxyketones have been transformed regioselectively into 1,3,5-trisubstituted pyrazoles. Georg Thieme Verlag Stuttgart.