Benzenesulfonyl chloride → 5-Chloro-1-(phenylsulfonyl)indole

Participants

Reaction Steps

To a stirred solution of 5-chloroindole (20 g, 131.93 mmol, 1 eq.) in dry DMF (250 mL) at 0° C., was added NaH (5.38 g, 134.57 mmol, 1.02 eq.). After stirring at room temperature for 1 h, benzenesulfonyl chloride (23.77 g, 134.57 mmol, 1.02 eq.) was added slowly. The reaction mixture was stirred for additional 1 h, then poured into 1 L of 5% aq. NaHCO3 and extracted with EtOAc (×3). The organic layers were combined, washed with H2O (×3), brine (×3), dried over (Na2SO4), filtered, and the filtrate was concentrated. The material was purified by flash chromatography to yield 30 g of 1-phenylsulfonyl-5-chloroindole as colorless crystals.

Provenance & Evidence