Cascade Wolff Rearrangement/Acylation: A Metal-Free and Eco-Friendly Approach for 4-Hydroxy-pyrazolo[3,4-b]pyridin-6-ones and N-Pyrazole Amides Synthesis from 5-Aminopyrazoles and 浼?Diazoketones was written by Zhang, Xiang-Jin;Zhang, Jie;Xu, Yu-Ning;Li, Yi-Ming;Chi, Man;Yan, Yu;Wu, Rui-Xue;Zhang, Hui-Ru;Zhu, Yan-Ping. And the article was included in Journal of Organic Chemistry in 2021.Recommanded Product: 1-Ethyl-1H-pyrazol-5-amine This article mentions the following:
A highly chemoselective cascade Wolff rearrangement/acylation reaction between 5-aminopyrazoles and diazo compounds has been developed. The protocol can facilitate the switchable synthesis of 4-hydroxy-pyrazolo[3,4-b]pyridin-6-ones I (R1 = Me, Et, Ph, etc.; R2 = Ph, t-Bu, 2-naphthyl, etc.; R3 = Ph, 4-MeOC6H4, 3-thienyl, etc.) and N-pyrazole amides II (R1 = Me, t-Bu, Ph; R2 = Ph, 4-FC6H4, 2-naphthyl, etc.; R3 = Me, c-hexyl, Ph, etc.; R4 = Me, Et) with the merits of a broad substrate scope, high functional group compatibility, and green and sustainable performance manner. All reactions proceeded efficiently without any catalyst and additives (acid and base) and resulted in the release of benign N2, wherein di-Et carbonate served as a green benign solvent. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3Recommanded Product: 1-Ethyl-1H-pyrazol-5-amine).
1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3) belongs to pyrazole derivatives. An alternative way to synthesize multisubstituted pyrazoles is the Csingle bondH arylation of simple pyrazoles. Pyrazole rings have been used as core components of several leading non-steroidal anti-inflammatory drugs (NSAIDs) and antihypertensive drugs. It has also been found to be useful as a bifunctional ligand for metal catalysis.Recommanded Product: 1-Ethyl-1H-pyrazol-5-amine
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics