Due to the importance of both indazole forms, several synthetic routes have been developed for the preparation of 1H-and 2H-indazoles (Figure ) . The most commonly used synthetic strategies for 1H-indazoles include acylation, nitrosation, and cyclization of o-toluidine and intramolecular amination of 1-aryl-2-(2nitrobenzylidene)hydrazines . For example, the Cu-catalyzed sequential condensation of 2-bromobenzaldehyde, a primary amine and azide and the palladium-catalyzed cyclization of N-aryl-N-(o-bromobenzyl)hydrazines are used to form 2H-indazoles . These traditional chemical and electrochemical methods to prepare indazoles suber from drawbacks such as the need for hazardous hydrazine derivatives, the use of noble metal catalysts or redox cells, and often harsh reaction conditions. 1. Rüchardt et al. 2. Esmaeili-Marandi et al. 3. Kumar et al. 4. Song et al. 5. Frontana-Uribe et al. 1. 2.