Pyrazolo[3,4-b]pyridines. The preparation of 1-protected-1H-pyrazolo[3,4-b]pyridines and attempts to remove the 1-substituent. Some reactions of 1-benzyl-1H-pyrazolo[3,4-b]pyridine and its 7-oxide was written by Dorgan, Roderick J. J.;Parrick, John;Hardy, Christopher R.. And the article was included in Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) in 1980.Recommanded Product: 1-Ethyl-1H-pyrazol-5-amine This article mentions the following:
The title compounds (I; R = CH2Ph, 1-C10H7, Et) (II–IV resp.) and (V; R = CH2Ph, 1-C10H7) were prepared by the Skraup reaction of an appropriate aminopyrazole VI (R as before) with (HOCH2)2CHOH. II and III were deprotected with refluxing pyridine/HCl. N-Oxidation of II gave the 7-oxide (VII) which gave the 6-oxo derivative VIII and the 5-acetyl derivative with Ac2O. Nitration of II or VII gave only I (R = CH2C6H4NO2–p) whereas chlorination or bromination gave 3-halo derivatives Irradiation of VIII (C6H6, 4 h) gave VII (48%). 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. 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.Recommanded Product: 1-Ethyl-1H-pyrazol-5-amine
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics