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 α-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.Formula: C8H15N3 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-(tert-Butyl)-3-methyl-1H-pyrazol-5-amine (cas: 141459-53-2Formula: C8H15N3).
1-(tert-Butyl)-3-methyl-1H-pyrazol-5-amine (cas: 141459-53-2) belongs to pyrazole derivatives. Pyrazoles, a five-membered heterocycle containing two adjacent nitrogen atoms, are the core structures found in a number of molecules that possess a wide range of pharmaceutical and agricultural activities. Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Formula: C8H15N3
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics