Mendeleev Communications · 1993 · 22 citations · 2 references
Natural SciencesChemistryMedicinal ChemistryDrug DiscoveryOrganic ChemistryHeterocyclic ChemistryOrganic SynthesisRetrosynthetic AnalysisPyrazole ChemistryPyrazole SynthesisPyridine Chemistry
A general approach to N-amination of pyrazoles, allowing the synthesis of previously inaccessible N-aminopyrazoles with electron-acceptor substituents in the ring, has been proposed, consisting of treatment of the pyrazoles with hydroxylamine-O-sulfonic acid in aqueous media at controlled pH depending on pKa of the pyrazole.
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