Isatin

Isatin

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Names
IUPAC name 1H-indole-2,3-dione
Identifiers
CAS Number	91-56-5 Y
ChEBI	CHEBI:27539 Y
ChEMBL	ChEMBL326294 Y
ChemSpider	6787 Y
DrugBank	DB02095 Y
Jmol 3D model	Interactive image
KEGG	C11129 Y
PubChem	7054
InChI InChI=1S/C8H5NO2/c10-7-5-3-1-2-4-6(5)9-8(7)11/h1-4H,(H,9,10,11) Y Key: JXDYKVIHCLTXOP-UHFFFAOYSA-N Y InChI=1/C8H5NO2/c10-7-5-3-1-2-4-6(5)9-8(7)11/h1-4H,(H,9,10,11)
SMILES O=C2c1ccccc1NC2=O
Properties
Chemical formula	C8H5NO2
Molar mass	147.1308 g/mol
Appearance	Orange-red solid
Melting point	200 °C (392 °F; 473 K)
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Isatin or 1H-indole-2,3-dione is an indole derivative. The compound was first obtained by Erdmann 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, such as Isatis tinctoria, Calanthe discolor and in Couroupita guianensis.

Schiff bases of isatin are investigated for their pharmaceutical properties.

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

Synthesis

The classical methods for the synthesis of isatins are Sandmeyer’s method, the Stolle procedure, and Gassman procedure, all using aniline as substrate.

Drugs

Isatin is a precursor used in the syntheses of pirquinozol, talnetant, tacrine, dibucaine, and ciclazindol, respectively.

A variety of tryptamine derivatives, including many substituted with alkyl or aryl groups in the α-position, have been prepared from isatin intermediates.

Tryptamine Derivative Synthesis:

7-Trifluoromethyl-isatin is used as a precursor in the synthesis of mefloquine.

6-Chloro-isatin is for the drug Ziprasidone, respectively.

N-dichlorophenyl-isatin is for diclofenac. N-phenyl-isatin is for Linopirdine.

Reactions

Isatoic anhydride synthesis:

Oxidation of isatin using either hydrogen peroxide or chromic anhydride yields isatoic anhydride (used for tranilast). In the oxidation of isatin to isatoic anhydride, the oxidizing agent selected should be able to introduce an oxygen atom between the two adjacent carbonyl groups without substantial decomposition of the ring system. A mixture of aqueous hydrogen peroxide in acetic or formic acid in the presence of catalytic amount of sulfuric acid is also used for the oxidation of isatin to isatoic anhydride. Another economic and environment-friendly procedure for the oxidation of isatins is through the use of the urea–hydrogen peroxide complex (percarbamide, H2NCONH2 · H2O2).

See also

• Pfitzinger reaction

Reviews

• S. Pietra, Farmaco, Ed. Sci., 12, 946 (1957).
• S. Pietra, Farmaco, Ed. Sci., 13, 75 (1958).
• S. Pietra, G. Tacconi, Farmaco, Ed. Sci., 16, 483 (1961).