Sodium Hydroxide → 5,6-Difluoro-1H-indole-2-carboxylic acid

Participants

Reaction Steps

A solution of 2.06 g of ethyl 5,6-difluoroindole-2-carboxylate in 90 ml of ethanol was treated with 45 ml of 2N sodium hydroxide solution and stirred at room temperature for 17 hours. The alcohol was evaporated and the residue was treated with 50 ml of 2N hydrochloric acid. The separated crystals were filtered off, washed with water and dried. 1.78 g (98.8%) of 5,6-difluoroindole-2-carboxylic acid were obtained as brown crystals with m.p. 279°-280°.

Provenance & Evidence