Synthesis of novel 2H-indazole analogues via the Davis-Beirut reaction and conjugation onto magnetic nanoparticles

Abstract

Methods for the construction of C3-amino substituted 2H-indazole motifs are scarce. While the Davis-Beirut reaction proved useful and versatile in the construction of alkoxy- and thia- C3-substituted 2H-indazoles under mild basic conditions, the same success was not enjoyed when confronted with nitrogen-based nucleophiles. Therefore, we set out to expand the scope of the Davis-Beirut reaction and investigated the ability of amine nucleophiles to prompt the heterocyclization. In addition, a model 2H-indazole analogue was successfully conjugated onto magnetic nanoparticles for the first time. The toxicity of the synthesized analogues was estimated using in silico T.E.S.T software. This report provides a reliable approach for the synthesis of indazole-loaded nanoparticles whose applications have not been investigated before.