Isatin

Isatin
IUPAC name

1H-indole-2,3-dione
Identifiers
CAS number 91-56-5 Y
ChemSpider 6787 Y
DrugBank DB02095
KEGG C11129 Y
ChEBI CHEBI:27539 Y
ChEMBL CHEMBL326294 Y
Jmol-3D images Image 1
Properties
Molecular formula C8H5NO2
Molar mass 147.1308 g/mol
Appearance Orange-red solid
Melting point

200 °C, 473 K, 392 °F
Hazards
EU classification Harmful (Xn)
R-phrases R22 R36 R37 R38
 Y (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Isatin or 1H-indole-2,3-dione is an indole derivative. The compound was first obtained by Erdman[1] and Laurent[2] 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 .[3]

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 responsible for this reaction from benzene. This new heterocyclic compound was thiophene.[4]

Preparation

Isatin is commercially available. It may be prepared from cyclicizing the condensation product of chloral hydrate, aniline and hydroxylamine in sulfuric acid:.[5][6] This reaction is called the Sandmeyer isonitrosoacetanilide Isatin Synthesis and discovered by Traugott Sandmeyer in 1919.

Another classic reaction, the Sandmeyer diphenylurea isatin synthesis (Sandmeyer 1903), starts from diphenylthiourea, potassium cyanide, and lead carbonate [7]

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.[8]

References

  1. ^ Otto Linné Erdmann (1840). "Untersuchungen über den Indigo". Journal für Praktische Chemie 19 (1): 321–362. doi:10.1002/prac.18400190161. 
  2. ^ Auguste Laurent (1840). "Recherches sur l'indigo". Ann. Chim. Phys. 3 (3): 393–434. http://gallica.bnf.fr/ark:/12148/bpt6k347443/f370.table. 
  3. ^ Synthesis of 3,3´-[methylenebis(3,1-phenylenenitrilo)]bis[1,3-dihydro]-2H-indol-2-one as a novel bis-Schiff base A. A. Jarrahpour, D. Khalili Molbank 2005, M437 Online Article
  4. ^ Ward C. Sumpter (1944). "The Chemistry of Isatin". Chemical Reviews 34 (3): 393–434. doi:10.1021/cr60109a003. 
  5. ^ C. S. Marvel and G. S. Hiers (1941), "Isatin", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0327 ; Coll. Vol. 1: 327 
  6. ^ Sandmeyer, T.: Über Isonitrosoacetanilide und deren Kondensation zu Isatinen, in: Helv. Chim. Acta 1919, 2 (1), 234–242; doi:10.1002/hlca.19190020125.
  7. ^ Isatin synthesis @ drugfuture.com
  8. ^ Yadav, J. S.; Reddy, B.; Reddy, Ch.; Krishna, A. (2007). "Indium(III) Chloride/2-Iodoxybenzoic Acid: A Novel Reagent System for the Conversion of Indoles to Isatins". Synthesis 2007 (5): 693–696. doi:10.1055/s-2007-965930. 

Further reading