Acetylisatin → 2-Hydroxyquinoline-4-carboxylic acid

Participants

Reaction Steps

To a solution containing 30 g of sodium hydroxide in 1.5 liter of water was added 58 g of the above-mentioned N-acetylisatin and the mixture was refluxed for 1 hour. Then the reaction mixture was cooled a certain extent, then activated carbon was added and further refluxed for 30 minutes. The activated carbon was removed from the reaction mixture by filtration while the mixture being hot, and the mother liquor was cooled, then 6N-hydrochloric acid was added to the mother liquor to adjust the pH thereof to pH 3-4. The crystals precipitated were colledted by filtration, washed with water, dried to obtain 45 g of 4-carboxycarbostyril.

Provenance & Evidence