Acetic Acid → 1,3-dimethyl-1H-indazole-4,5-dicarboxylic acid

Participants

Reaction Steps

A mixture of ethyl 4-cyano-1,3-dimethyl-1H-indazole-5-carboxylate (7.03 g, 28.7 mmol), concentrated hydrobromic acid (35 mL) and acetic acid (35 mL) is stirred for 2 hours at reflux temperature, cooled, diluted with water (200 mL) and stirred for 2 hours. Filtration of the reaction mixture affords the title product as a pale blue solid (6.57 g, 97.8%), mp 228.5°-232.5° C.

Provenance & Evidence