Dimethylformamide → ethyl 5-chloro-3-(chlorosulfonyl)-1-(phenylsulfonyl)-1H-indole-2-carboxylate

Participants

Reaction Steps

To a solution of the 5-chloro-2-(ethoxycarbonyl)-1-(phenylsulfonyl)-1H-indole-3-sulfonic acid (9.52 g, 21.4 mmol) in 100 mL of dichloromethane at 0° C. was added oxalyl chloride (5.61 mL, 64.3 mmol). Dimethylformamide (0.2 mL) was added, and the reaction was allowed to warm to room temperature. After 24 hours, another portion of oxalyl chloride (3.0 mL) was added, and the reaction was stirred for an additional 16 hours. The mixture was concentrated in vacuo to provide a yellow foam. Proton NMR for the product was consistent with the titled compound. ESI+MS: 426.2 [M−Cl]+.

Provenance & Evidence