Hydrochloric Acid → 6-chloro-5-(3,4-dimethoxyphenyl)-1H-indole-3-carboxylic acid

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Reaction Steps

A solution of methyl 6-chloro-5-(3,4-dimethoxyphenyl)-1H-indole-3-carboxylate (75 mg, 0.22 mmol), methanol (2.2 mL), and aqueous sodium hydroxide (1M, 0.75 mL, 0.75 mmol) was heated at 75° C. for 24 hours. The reaction was acidified with 1M HCl to pH=2 then diluted with ethyl acetate. The aqueous layer was back-extracted twice with ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo to provide a crude solid. The crude product was dissolved in methylene chloride and methanol and silica gel was added. The solvent was removed in vacuo and the crude material adsorbed onto silica was loaded onto a column of silica gel and eluted with ethyl acetate (with 0.2% formic acid)/heptanes (1:1 to 1:0) to provide the title compound (17 mg, 24%) as a tan solid.

Provenance & Evidence