Hydrochloric Acid → 4,6-Dichloro-1H-indole

Participants

Reaction Steps

Dissolve 4,6-dichloro-indole-2-carboxylic acid (1.0 g, 4.35 mmol) in quinoline (25 mL). Add copper powder (100 mg) and heat to 220° C. for 3 hours. Pour the resulting black solution into cold concentrated hydrochloric acid (300 mL) and extract into ethyl ether (500 mL). Filter, wash with 1M hydrochloric acid (2×200 mL), water (100 mL) and dry (MgSO4). Evaporate the solvent in vacuo to give a brown oil (0.76 g). Purify by silica gel chromatography (17% ethyl acetate/hexane) to give the title compound as an amber oil (0.66 g, 81%).

Provenance & Evidence