28899-75-4

7-chloro-1H-indole-2-carboxylic acid is an important pharmaceutical intermediate compound used in the preparation of protease inhibitors.

A mixture of 111.5 g of 7-chloroindole-2-carboxylate in 31.25 g of 96percent sodium hydroxide in 183 ml of methanol and 183 ml of water were heated under reflux for 1 hour, cooled to 45 ° C, and 10 percent hydrochloric acid was added dropwise to a pH of 3 to 4. The mixture was sufficiently cooled to obtain 89.7 g of product as an off-white 7-chloro-1H-indole-2-carboxylic acid.

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