English

Noun

1. The indole derivative 1H-indole-2,3-dione that is used in the synthesis of dyes

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.

Schiff bases of Isatin are investigated for their pharmaceutical properties .

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

Preparation

Isatin is commercially available. It may be prepared from cyclicizing the condensation product of chloral hydrate, aniline and hydroxylamine in sulfuric acid:

Isatins can be made from the corresponding indole in good yield by a mix of InCl3 and IBX in a acetonitrile-water solution at 80 °C.

References

Further reading