A palladium-catalyzedoxidative carbonylation of arylhydrazines and alkynes with balloon pressure CO/O2 to afford trisubstituted pyrazoles in a one-pot manner has been developed. The formation of trisubstituted pyrazoles involves a sequential C–N bond cleavage, carbonylation, Sonogashira coupling, Michael addition, and intramolecular condensation cyclization tandem process. An unprecedented oxidative
已经开发了用球罐压力CO / O 2进行钯催化的芳基肼和炔烃的氧化羰基化反应,以一锅法得到三取代的吡唑。三取代吡唑的形成涉及连续的C–N键断裂,羰基化,Sonogashira偶联,迈克尔加成和分子内缩合环化串联过程。芳基肼的空前的氧化Sonogashira-羰基化反应在如此简便的吡唑方法中起着关键作用。
Radical Addition of Hydrazones by α-Bromo Ketones To Prepare 1,3,5-Trisubstituted Pyrazoles via Visible Light Catalysis
novel efficient tandem reaction of hydrazones and α-bromo ketones is reported for the preparation of 1,3,5-trisubstituted pyrazoles by visible light catalysis. In this system, the monosubstituted hydrazones show wonderful reaction activity with alkyl radicals, generated from α-bromo ketones. A radical addition followed by intramolecular cyclization affords the important pyrazole skeleton in good to
Synthesis and Anti-inflammatory Activity of Fluorinated Phenyl Styryl Ketones and N-Phenyl-5-Substituted Aryl-3-p-(fluorophenyl) Pyrazolins and Pyrazoles
作者:L.V.G. Nargund、V. Hariprasad、G.R.N. Reddy
DOI:10.1002/jps.2600810910
日期:1992.9
ranged from 7 to 59% for substituted p-(fluorophenyl) styrylketones and from 12 to 21% for pyrazoles. No correlation was found between the anti-inflammatory activity of p-(fluorophenyl) styrylketones or substituted pyrazoles and their effectiveness at inhibiting bovine serum albumin denaturation. The low toxicity of p-(fluorophenyl) styrylketones was reflected by the dose that was lethal in 50% of
Previous studies demonstrated that some pyrazole derivatives could be considered as potential
anticancer agents. A series of 1,3,5-triaryl-1H-pyrazole derivatives were prepared by the reaction
of phenylhydrazin and different chalcones. The previous classic synthesis method was developed for a simpler procedure.
The cytotoxicity of these compounds was determined against three cancer cell lines (HT-29), (MCF-7), (AGS) as
well as fibroblastic cell line (NIH-3T3) using MTT assay. These biological studies proved that 5f and 5l were the most potent
compounds in this series. Furthermore, 5f showed a partial selectivity in cytotoxicity effect between the cancerous
and normal cell lines.
Electrochemically enabled oxidative aromatization of pyrazolines
作者:Silja Hofmann、Martin Linden、Julian Neuner、Felix N. Weber、Siegfried R. Waldvogel
DOI:10.1039/d3ob00671a
日期:——
Pyrazoles are a very important structural motif widely found in pharmaceuticals and agrochemicals. An electrochemically enabled approach for the sustainable synthesis of pyrazoles via oxidativearomatization of pyrazolines is presented. Inexpensive sodium chloride is employed in a dual role as a redox mediator and supporting electrolyte in a biphasic system (aqueous/organic). The method is applicable