Ethanol → 2-(4-bromophenyl)-5-cyclopropyl-6-nitro-2H-indazole-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of compound (vi) (3.3 g, 8.6 mmol) in ethanol (35 mL) was added aqueous NaOH (3.44 g, 86 mmol) and the reaction mixture was heated to 90° C. and maintained for 15 h when TLC and LCMS showed the absence of SM and formation of product. Concentration of the solvent gave a crude residue which was dissolved in water and filtered. The filtrate was acidified with dilute HCl at which time the product precipitated and was filtered to give the crude product which was purified by acid-base treatment to give 2-(4-bromophenyl)-5-cyclopropyl-6-nitro-2H-indazole-3-carboxylic acid (vii) (2.2 g, 63%).

Provenance & Evidence