Iodobenzene
| |||
| Names | |||
|---|---|---|---|
| IUPAC name
Iodobenzene
| |||
| Identifiers | |||
3D model (JSmol)
|
|||
| ECHA InfoCard | 100.008.837 | ||
CompTox Dashboard (EPA)
|
|||
| |||
| Properties | |||
| C6H5I | |||
| Molar mass | 204.01 g/mol | ||
| Density | 1.831 g/cm3 | ||
| Melting point | −29 °C | ||
| Boiling point | 188 °C | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |||
Iodobenzene is an organic compound consisting of a benzene ring substitituted with one iodine atom. It is useful as a synthetic intermediate in organic chemistry.
Preparation
Iodobenzene is commercially available, but it may be prepared in the laboratory from aniline via the Sandmeyer reaction. In the first step, the amine functional group is diazotized with hydrochloric acid and sodium nitrite. Potassium iodide is added to the resultant diazonium chloride, causing nitrogen gas to evolve. Any excess nitrite is hydrolyzed with a strong base; the mixture is acidified and the desired product is separated by steam distillation.[1]
Alternatively, it may be produced by refluxing iodine and nitric acid with benzene.[2]
Reactions
Since the C–I bond is weaker than C–Br or C–Cl, iodobenzene is more reactive than bromobenzene or chlorobenzene. Iodobenzene can react with magnesium to form the Grignard reagent, phenylmagnesium iodide. Phenylmagnesium iodide, like the bromide analog, is a synthetic equivalent for the phenyl anion synthon. Iodobenzene reacts with chlorine to give the complex, iodobenzene dichloride,[3] which is used as an oxidant.
Iodobenzene can also serve as a substrate for the Sonogashira coupling, Heck reaction, and other metal-catalyzed couplings.
References
- ^ H. J. Lucas, E. R. Kennedy (1939). "Iodobenzene". Organic Syntheses; Collected Volumes, vol. 2, p. 351.
- ^ F. B. Dains and R. Q. Brewster (1941). "Iodobenzene". Organic Syntheses; Collected Volumes, vol. 1, p. 323.
- ^ H. J. Lucas and E. R. Kennedy. "Iodobenzene dichloride". Organic Syntheses; Collected Volumes, vol. 3, p. 482.
See also
- Gattermann-Wieland, "Laboratory Methods of Organic Chemistry," p. 283. Translated from the twenty-fourth German edition by W. McCartney, The Macmillan Company, New York, 1937.