Benzenesulfonyl chloride → 4-Bromo-1-(phenylsulfonyl)-1H-indazole

Participants

Reaction Conditions

Reaction Steps

To a stirring suspension of NaH (0.78 g) in anhydrous THF (17.5 ml) at −5° C. was added 4-bromo-1H-indazole (3.5 g) in anhydrous THF (35 ml). Benzenesulfonyl chloride (2.5 ml) in anhydrous THF (17.5 ml) was added dropwise over 10 mins. The reaction was stirred for 1 h at 0° C. then quenched with water. The layers were separated and the aqueous was re-extracted with ethyl acetate. The combined organics were washed with brine, dried over magnesium sulfate, filtered and then evaporated to yield a solid residue that was triturated with methanol to give title compound, 5.18 g.

Provenance & Evidence