Isatin

Isatin or 1H-indole-2,3-dione is an indole derivative. The compound was first obtained by Erdman and Laurent in 1841 as a product from the oxidation of Indigo dye by nitric acid and chromic acids. The compound is found in many plants and Schiff bases of Isatin are investigated for their pharmaceutical properties.

It was observed that isatin forms a blue dye if it s mixed with sulfuric acid and crude benzene. The formation of the blue indophenin was long believed to be areaction with benzene. Victor Meyer was able to isolate the substance resposible for this reaction from benzene. This new heterocyclic compound was thiophene.