Hydrochloric Acid → 3-Chloro-1-(4-isopropoxyphenyl)-5-(5-trifluoromethylpyrid-2-yl)-1H-indole-2-carboxylic acid

Participants

Reaction Steps

To a solution of 3-chloro-1-(4-isopropoxyphenyl)-5-(5-trifluoromethylpyrid-2-yl)-1H-indole-2-carboxylic acid ethyl ester (see step (a) above; 500 mg, 1.0 mmol) in dioxane (5 mL) was added NaOH (aq. 2N, 2.5 mL) and the reaction was refluxed for 4 h. After cooling to room temperature, the reaction was diluted with water and acidified by the addition of HCl (aq. 1N) to about pH 6. The precipitate was filtered, washed with water and dried. Recrystallisation (from EtOAc/petroleum ether) afforded the title compound (289 mg, 62%).

Provenance & Evidence