Benzenesulfonyl chloride → ethyl 5-chloro-1-(phenylsulfonyl)-1H-indole-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 60% dispersion of NaH in mineral oil (1.07 g, 26.9 mmol) was washed with hexane, and the resulting powder was suspended in 40 mL of DMF. After cooling the stirred mixture to 0° C., ethyl 5-chloro-1H-indole-2-carboxylate (5.00 g, 22.4 mmol) was added in portions. The solution was warmed to room temperature, during which gas was released. After 15 minutes, the mixture was cooled again to 0° C., and benzenesulfonyl chloride was added dropwise (3.14 mL, 24.6 mmol). After warming to room temperature, the reaction was stirred for 1.5 hours, then poured into a mixture of EtOAc and saturated aqueous NaHCO3 solution. The organic phase was washed with water and brine, dried with Na2SO4, filtered, and concentrated in vacuo. The resulting solid was stirred in 50 mL of a 10% EtOAc/hexane solution for 30 minutes, then filtered to provide the titled product as a white powder. Proton NMR for the product was consistent with the titled compound. ESI+MS: 364.1 [M+H]+.

Provenance & Evidence