反应详情

To a solution of 7-bromo-2-methyl-2H-indazole (6: R=Me; 0.500 g, 2.37 mmol) in 5 mL of acetic acid was added sulfuryl chloride (0.29 mL, 3.6 mmol). The mixture was stirred for 5 h, then 30 mL of a 2 M aqueous NaOH solution were added. The mixture was extracted with three 30 mL portions of ethyl acetate, and the combined organic layers were dried over Na2SO4, filtered, and concentrated to a white solid. Column chromatography (0→15% EtOAc/hexanes) afforded slightly impure 7-bromo-3-chloro-2-methyl-2H-indazole (25: R=Me; 0.530 g; 90%) that was used without further purification.

1. extractionThe mixture was extracted with three 30 mL portions of ethyl acetate
2. dry with materialthe combined organic layers were dried over Na2SO4
3. filtrationfiltered
4. concentrationconcentrated to a white solid