459133-66-5

5188-07-8

201227-23-8

To a solution of 5-bromo-3-iodo-1H-indazole (3.7 g, 11.49 mmol) in dimethylsulfoxide (DMSO, 20 mL) was sequentially added an aqueous solution of 20% sodium methanethiol (MeSNa) (2.4 mL, 34.47 mmol) and cuprous iodide (CuI, 218 mg, 1.15 mmol). The resulting mixture was degassed and the reaction was heated at 120 °C for 3 h under nitrogen (N2) atmosphere. Upon completion of the reaction, it was cooled to room temperature and the reaction was quenched by the addition of water (50 mL), followed by extraction with ethyl acetate (50 mL x 3). The organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by fast column chromatography to afford the target product 5-bromo-3-(methylmercapto)-1H-indazole (2.5 g) as a yellow solid.