Triethylamine → 1-(methylsulfonyl)-5-nitro-1H-indazole

Participants

Reaction Steps

Methanesulfonyl chloride (887 μl, 7.20 mmol) was added to a suspension of 5-nitroindazole (979 mg, 6.00 mmol) and triethylamine (2.0 ml, 14.3 mmol) in dichloromethane (20 ml) at 0° C., and the resulting mixture was stirred at room temperature for 3 hours. Methanesulfonyl chloride (222 μl, 1.80 mmol) was further added thereto, followed by stirring for another 1 hour. The reaction mixture was poured into a saturated aqueous sodium hydrogencarbonate solution to terminate the reaction, followed by extraction with chloroform. The extract solution was washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate, and then distilled under reduced pressure to remove the solvent. The residue was purified by washing with methanol to obtain 1-(methylsulfonyl)-5-nitro-1H-indazole (1.16 g, 80%).

Provenance & Evidence