Iodobenzene

Chembox new
Name = Iodobenzene
ImageFileL1 = Iodobenzene.gif
ImageSizeL1 = 100px
ImageNameL1 = Iodobenzene
ImageFileR1 = Iodobenzene-3D-vdW.png ImageSizeR1 = 120px
ImageName1 = Space-filling model of iodobenzene
IUPACName = Iodobenzene
Section1 = Chembox Identifiers
CASNo = 591-50-4
SMILES = Ic1ccccc1
Section2 = Chembox Properties
Formula = C₆H₅I
MolarMass = 204.01 g/mol
Density = 1.831 g/cm³
MeltingPt = -29 °C
BoilingPt = 188 °C

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. Since the C-I bond is weaker than C-Br or C-Cl, it is more reactive than bromobenzene or chlorobenzene. Iodobenzene can react with magnesium to form a Grignard reagent, phenylmagnesium iodide. Phenylmagnesium iodide, like the bromide analog, is a synthetic equivalent for the phenyl anion synthon.It can also serve as a substrate for the Sonogashira coupling, Heck reaction, and other metal-catalyzed couplings.

Preparation

Iodobenzene is commercially available, but it may be prepared in the laboratory from aniline. 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. [OrgSynth
author = H. J. Lucas, E. R. Kennedy
title = Iodobenzene
year= 1939
collvol = 2
collvolpages = 351
prep = cv2p0351]

Alternatively, it may be produced by refluxing iodine and nitric acid with benzene. [OrgSynth
author = F. B. Dains and R. Q. Brewster
title = Iodobenzene
year= 1941
collvol = 1
collvolpages = 323
prep = cv1p323]

References

ee 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.