1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3) belongs to pyrazole derivatives. The strategies for the synthesis of pyrazoles generally can be applied for the construction of indazoles. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.Electric Literature of C5H9N3
A convenient synthesis of fluorinated pyrazolo[3,4-b]pyridine and pyrazolo[3,4-d]pyrimidine nucleosides was written by Iaroshenko, Viktor O.;Sevenard, Dmitri V.;Kotljarov, Anton;Volochnyuk, Dmitriy M.;Tolmachev, Andrei O.;Sosnovskikh, Vyacheslav Ya.. And the article was included in Synthesis in 2009.Electric Literature of C5H9N3 This article mentions the following:
Starting from 5-amino-1-(2,3-O-isopropylidene-灏?D-ribofuranosyl)-1H-pyrazole, F-containing 1,3-CCC-, 1,3-CNC-dielectrophiles, and 2,4,6-tris(trifluoromethyl)-1,3,5-triazine, a set of fluorinated pyrazolo[3,4-b]pyridine and pyrazolo[3,4-d]pyrimidine nucleosides was obtained. Synthetic access to stable 4-(polyfluoroalkyl)-4,7-dihydro-1H-pyrazolo[3,4-b]pyridin-4-ols was elaborated, which can be considered to be mimetics of the putative transition state involved in adenosine deaminase activity. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3Electric Literature of C5H9N3).
1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3) belongs to pyrazole derivatives. The strategies for the synthesis of pyrazoles generally can be applied for the construction of indazoles. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.Electric Literature of C5H9N3
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics