4-Toluenesulfonyl chloride → 6-Bromo-1-[(4-methylphenyl)sulfonyl]-1H-indazol-4-amine

Participants

Reaction Conditions

Reaction Steps

To a suspension of sodium hydride (5.66 g) in anhydrous DMF (75 ml) stirring at 0° C. was added a solution of 6-bromo-1H-indazol-4-amine (30 g), also in anhydrous DMF (125 ml), dropwise. The reaction mixture was stirred for 1 h at 0° C. then a solution of 4-methylbenzenesulfonyl chloride (27 g) in anhydrous DMF (100 ml) was added dropwise. The reaction was stirred for 2 h. A further portion of sodium hydride (0.57 g) was added followed by 4-methylbenzenesulfonyl chloride (2.70 g). The reaction mixture was left to stand overnight at room temperature, before pouring onto ice/water (1800 ml). A precipitate formed that was collected by filtration, tritrurated using diethyl ether:methanol (1:1, v/v), then re-collected by filtration and dried in vacuo at 40° C. over the weekend to give title compound, (26.5 g).

Provenance & Evidence