General procedure for the synthesis of methyl 6-chloro-1H-indazole-3-carboxylate from the compound (CAS: 717134-46-8): to a stirred solution of methyl (2-acetamido-4-chlorophenyl)acetate (32.0 g, 133 mmol) in acetic acid (200 mL), tert-butyl nitrite (20.5 mL, 172.3) was slowly added dropwise at 90 °C. mmol), and the dropwise addition time was controlled at 1 hour. Upon completion of the reaction, the reaction mixture was poured into water (1.4 L) and the solid product was recovered by filtration. The resulting yellow precipitate was dissolved in ethyl acetate (EtOAc) and subsequently washed with saturated sodium chloride (NaCl) solution. The organic phase was dried with anhydrous magnesium sulfate (MgSO), filtered and concentrated to obtain a solid. Finally, the solid was ground with hexane and filtered to afford the target product methyl 6-chloro-1H-indazole-3-carboxylate (21.63 g, 77% yield).
