Hydrochloric Acid → HCID 59606505, compound

Participants

Reaction Steps

3-Cyano-1-ethyl-2-[4-(propane-1-sulfonylamino)-phenyl]-1H-indole-6-carboxylic acid methyl ester (1.25 g, 3.04 mmol), prepared by the method described in example 1Y from methyl 2-(4-aminophenyl)-3-cyano-1-ethyl-1H-indole-6-carboxylate, is treated with 0.5N KOH (30 mL, 15.2 mmol) and heated at reflux for 2.5 h. After cooling to room temperature, the aqueous phase is acidified with 3N HCl to pH 2 and the resultant precipitate is filtered, washed with water (2×) and dried until constant weight to afford 1.15 g (96%) of 3-cyano-1-ethyl-2-[4-(propane-1-sulfonylamino)-phenyl]-1H-indole-6-carboxylic acid as a white solid.

Provenance & Evidence