Indazole

Indazole, also called isoindazole, is a heterocyclic aromatic organic compound. This bicyclic compound consists of the fusion of benzene and pyrazole.

Indazole derivatives display a broad variety of biological activities.

Indazoles are rare in nature. The alkaloids nigellicine, nigeglanine, and nigellidine are indazoles. Nigellicine was isolated from the widely distributed plant Nigella sativa L. (black cumin). Nigeglanine was isolated from extracts of Nigella glandulifera.

The Davis–Beirut reaction can generate 2H-indazoles.