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Preparations of 4‐Substituted 3‐Carboxypyrazoles
Author(s) -
Janin Yves L.
Publication year - 2013
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.1654
Subject(s) - chemistry , diazomethane , potassium permanganate , bromine , hydrazine (antidepressant) , cycloaddition , potassium hydroxide , pyrazole , acrylate , organic chemistry , hydrochloride , combinatorial chemistry , medicinal chemistry , chromatography , polymer , monomer , catalysis
The scopes of three synthetic methods reported for the preparation of an array of 3‐pyrazolecarboxylates featuring substituents on position 4 were investigated. The first one is based on the potassium permanganate oxidation of methylpyrazoles. The second starts with the condensation between DMF dimethylacetal and ethyl pyruvate and is followed by the addition of hydrazine hydrochloride. The last one makes use of the cycloaddition of diazomethane on acrylate esters followed by a bromine‐based oxidative rearrangement into 4‐substituted 3‐pyrazole esters.