109809-19-0Relevant academic research and scientific papers
Construction of Multifunctionalized Azopyrazoles by Silver- Catalyzed Cascade Reaction of Diazo Compounds
Pandit, Rameshwar Prasad,Lee, Yong Rok
, p. 2657 - 2664 (2015)
A variety of multisubstituted azopyrazoles were synthesized in good yield from an efficient one-pot silver trifluoromethanesulfonate (AgOTf)-catalyzed cascade reaction of α-diazo-β-keto esters with two arylhydrazines or two arylhydrazine hydrochlorides. This cascade reaction included pyrazolone formation, NH insertion, and oxidation. For the synthesis of more diverse azopyrazoles bearing two different aromatic rings, the silver(I)-catalyzed cascade reaction of 4-diazopyrazol-3-one with arylhydrazine hydrochlorides was also developed. The advantages of these methodologies are easy handling, mild reaction conditions, and an effective and non-toxic catalyst usage.
Azopyrazole compounds and novel synthetic method thereof by silver catalysis
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Paragraph 0090-0093; 0098; 0099; 0123, (2018/04/21)
The present invention relates to an azopyrazole compound and a novel synthesis method thereof by silver catalysis. More specifically, a one-pot synthesis method using silver (Ag) catalysis of andalpha;-diazo-andbeta;-keto ester and arylhydrazine has an advantage of efficiently synthesizing various types of azopyrazole having multiple functions, and the azopyrazole synthesized by the above-described synthesis method can be widely used for the synthesis of natural materials andmedicines, or for dyestuff industry.COPYRIGHT KIPO 2018
Iodine-mediated construction of polyfunctionalized arylazopyrazoles from β-ketoesters or 2-arylpyrazol-3-ones and arylhydrazines
Pandit, Rameshwar Prasad,Kim, Sung Hong,Lee, Yong Rok
, p. 6996 - 7000 (2016/07/30)
This paper describes step-economic iodine-mediated construction of functionalized arylazopyrazoles in the presence of catalytic AgNO3 starting from simple β-ketoesters and two equivalents of arylhydrazines. This cascade reaction includes in situ α-iodination of β-ketoesters, pyrazol-3-one formation, substitution with a nitrogen nucleophile, and oxidation/aromatization.
