Water → N-[3-(3-bromophenyl)-1H-indazol-5-yl]-2-methylsulfonylbenzenesulfonamide

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Reaction Conditions

Reaction Steps

N-[3-(3-Bromophenyl)-1H-indazol-5-yl]-2-methylsulfonylbenzenesulfonamide can be obtained in the follow way: 1.6 g of (3-bromophenyl)boronic acid, 8.7 ml of a saturated aqueous sodium hydrogencarbonate solution and 0.11 g of tetrakis(triphenylphosphine)palladium[0] are added successively to a suspension, maintained under an atmosphere of argon, of 2.3 g of tert-butyl 3-iodo-5-(2-methylsulfonylbenzenesulfonylamino)indazole-1-carboxylate in 90 ml of dimethylformamide. The reaction mixture is refluxed for 5 hours. After cooling to a temperature in the region of 20° C., the reaction mixture is hydrolyzed with 200 ml of water and extracted with 200 ml and then 100 ml of ethyl acetate. The pooled organic extracts are dried over magnesium sulfate, filtered and then concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C. The brown oil thus obtained is purified by chromatography on a silica column (particle size 63-200 μm), eluting with a dichloromethane/methanol (99/1 by volume) mixture. The fractions containing the expected product are pooled and concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C. 1.4 g of N-[3-(3-bromophenyl)-1H-indazol-5-yl]-2-methylsulfonylbenzenesulfonamide are obtained in the form of a yellow lac. This product is repurified by chromatography on a silica column (particle size 63-200 μm), with pure dichloromethane as eluent. The fractions containing the expected product are pooled and concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 40° C. 0.73 g of N-[3-(3-bromophenyl)-1H-indazol-5-yl]-2-methylsulfonylbenzenesulfonamide are obtained in the form of a white foam melting at 104° C.

Provenance & Evidence