Synthesis and properties of ferrocenylalkyl derivatives of indazole

Ferrocenylmethylation and α-ferrocenylethylation of indazole were carried out for the first time. Both reactions afforded two isomers, which were characterized by physical and physicochemical methods, among them by X-ray diffraction analysis. 1-(α-Ferrocenylethyl)indazole is thermally more stable than the 2-substituted isomer. Both isomers serve as ferrocenylalkylating agents with respect to s-triazole.