Organic Syntheses, CV 5, 658
Submitted by H. Saltzman and J. G. Sharefkin
1.
Checked by Melvin S. Newman and Narinder Gill.
1. Procedure
Caution! This compound explodes if heated to 210°.
Finely ground
iodosobenzene diacetate2 (32.2 g., 0.10 mole) is placed in a
250-ml. beaker, and
150 ml. of 3N sodium hydroxide is added over a 5-minute period with vigorous stirring. The lumps of solid that form are triturated with a
stirring rod or
spatula for 15 minutes, and the reaction mixture stands for an additional 45 minutes to complete the reaction. One hundred milliliters of water is added, the mixture is stirred vigorously, and the crude, solid
iodosobenzene is collected on a
Büchner funnel. The wet solid is returned to the beaker and triturated in 200 ml. of water. The solid is again collected on the Büchner funnel, washed there with 200 ml. of water, and dried by maintaining suction. Final purification is effected by triturating the dried solid in
75 ml. of chloroform in a beaker. The
iodosobenzene is separated by filtration (Note
1) and air-dried; weight
18.7–20.5 g. (
85–93%); m.p.
210°
(Caution! Explodes!). Iodometric titration
3 shows the product to be more than 99% pure (Note
2).
2. Notes
1. The filtrate yields unreacted diacetate on evaporation.
2. The purity of the
iodosobenzene depends on the purity of the diacetate used.
3. Discussion
4. Merits of the Preparation
The procedure seems to be a general way of preparing iodosoarenes with electron-donating substituents, for the submitters have used it to obtain good yields of
o-, m- and p-iodosotoluene,
2- and 4-iodoso-m-xylene,
2-iodoso-p-xylene,
o-iodosophenetole, and
4-iodosobiphenyl.
Iodosoarenes are useful in the preparation of iodonium salts, Ar
2I
+X
−.
6
This preparation is referenced from:
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