- Electrochemical-Induced C(sp3)?H Dehydrogenative Trimerization of Pyrazolones to Tripyrazolones
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The electrochemical-induced three-component C(sp3)?H dehydrogenative trimerization of pyrazolones to tripyrazolones with hydrogen evolution has been accomplished under the metal- and external-oxidant-free conditions. This protocol provides an efficient and eco-friendly method for the synthesis of tripyrazolones, which avoids the use of metals and stoichiometric chemical oxidants. A wide range of functional groups was tolerated to give selectively the desired products in high yields. Importantly, such an electrochemical-oxidation-induced dehydrogenative trimerization reaction could be easily scaled up with excellent efficiency.
- Ma, Jing,Sun, Xue,Tian, Laijin,Wei, Wei,Wen, Jiangwei,Yan, Kelu,Yang, Jianjing
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supporting information
p. 5491 - 5496
(2021/11/01)
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- Preparation method of edaravone impurity standard product
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The invention discloses a preparation method of edaravone impurity standard product; the preparation takes edaravone as raw material, and performs catalytic oxidation and purification, so as to obtain 4, 4-bi(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-radical)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-ketone pure product; the pure product content is marked by regular analysis method. The impurity preparation method provided by the invention is easy to obtain raw material, simple and fast in technique, and short in preparation cycle; the marked product content is more than 99.0%. The edaravone provided by the invention can be used as the impurity standard product, and applied to qualitative and quantitative study and detection of edaravone raw materials and the impurities of its preparations.
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Paragraph 0016; 0042-0063
(2017/06/02)
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- Investigations on the Reaction of Pyrazolone Azomethine Dyes with 2-Pyrazolin-5-one-Derivatives
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The reaction between pyrazolone azomethine dyes 1 and different 2-pyrazolin-5-ones 2 was investigated.Among the reaction products compounds 5 > was isolated, which hitherto was unknown as a product of this reaction.A new reaction pathway is proposed.
- Kucybala, Z.,Gaca, J.
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p. 435 - 439
(2007/10/02)
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