A Publication
of Reliable Methods
for the Preparation
of Organic Compounds
Annual Volume
Org. Synth. 1942, 22, 52
DOI: 10.15227/orgsyn.022.0052
[Iodonium compounds, diphenyl—iodide]
Submitted by H. J. Lucas and E. R. Kennedy.
Checked by John R. Johnson and M. W. Formo.
1. Procedure
A mixture of 22 g. (0.1 mole) of iodosobenzene (p. 483), 24 g. (0.1 mole) of iodoxybenzene (p. 485), and 200 ml. of 1 N sodium hydroxide (Note 1) is gently stirred for 24 hours. The resulting brown slurry is thoroughly stirred with 1 l. of cold water, and, after the mixture settles, the supernatant solution of diphenyliodonium iodate is decanted through a filter. The solid residue is extracted twice with 500-ml. portions of water, and the extracts are separated, by decantation through a filter, from the small amount of tarry residue. An aqueous solution of 20 g. (0.12 mole) of potassium iodide is added to the combined filtrates. After the bulky white precipitate of diphenyliodonium iodide has stood for an hour or two, with occasional shaking, it is filtered with suction, washed with water, and dried on porous tile at room temperature. The product weighs 29–30 g. (70–72%) and melts at 172–175° with vigorous decomposition.
2. Notes
1. Since the reaction is catalyzed by hydroxide ions, the amount of base may be varied within wide limits. It is advantageous to grind the solid reactants with 50 ml. of water before the alkali is added.
3. Discussion
Diphenyliodonium iodide is obtained when sulfur dioxide or aqueous potassium iodide is added to a solution containing diphenyliodonium iodate.1,2 Such solutions have been prepared by the action of moist silver oxide, or of aqueous sodium or potassium hydroxide, on an equimolar mixture of iodosobenzene and iodoxybenzene;1,2 by shaking iodosobenzene with moist silver oxide;3 by shaking iodoxybenzene with sodium hydroxide;2 and by steam distillation of a mixture of iodosobenzene and iodoxybenzene.2 Diphenyliodonium iodide has been prepared by heating iodoxybenzene with aqueous potassium iodide and barium hydroxide.4

References and Notes
  1. Hartmann and Meyer, Ber., 27, 504, 506 (1894).
  2. Hartmann and Meyer, Ber., 27, 1598 (1894).
  3. Hartmann and Meyer, Ber., 27, 503 (1894).
  4. Willgerodt, Ber., 29, 2009 (1896).

Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

sodium or potassium hydroxide

sodium hydroxide (1310-73-2)

silver oxide (20667-12-3)

sulfur dioxide (7446-09-5)

potassium iodide (7681-11-0)

barium hydroxide (17194-00-2)


Iodosobenzene (536-80-1)

Iodoxybenzene (696-33-3)

diphenyliodonium iodate