Synthesis of Substituted Triazole-Pyrazole Hybrids using Triazenopyrazoles Precursors

A synthesis route to access triazole-pyrazole hybrids via pyrazolotriazenes was
developed. Contrary to existing methods, this route allows the facile N-functionalization
of the pyrazole before the attachment of the triazole unit via a copper-catalyzed azide-
alkyne cycloaddition. The developed methodology was used to synthesize a library of
over fifty novel multi-substituted pyrazole-triazole hybrids. We could also demonstrate
a one-pot strategy that renders the isolation of potentially hazardous azides obsolete.
In addition, the compatibility of the method with solid-phase synthesis was shown
exemplarily.