Dimethylformamide → ethyl 4,6-dichloro-3-formyl-1H-indole-2-carboxylate

Participants

Reaction Steps

Combine 2-carboethoxy-4,6-dichloroindole (20.0 g, 0.077 mol), and dimethylformamide (9.0 mL, 0.117 mol) in dichloroethane (100 mL). Add phosphoryl chloride (18.0 g, 0.117 mmol). Heat to reflux. After 3.5 hours, cool the reaction mixture to ambient temperature to obtain a solid. Collect the solid by filtration, rinse with water. Combine the solid with aqueous 1 M sodium acetate solution and stir. After 1 hour, filter, rinse with water, and dry to give 3-formyl-2-carboethoxy-4,6-dichloroindole.

Provenance & Evidence