GP didn't like the title of that other thread, so he started a new one, hope no one minds.
First of all, GP would like to clairify the DMF/Acetone @ 4C. The reference is:
J. CHEM. SOC. Perkin Trans I, 1985 p2521
Now at first this seems like an odd reference as it's title has nothing to do with what we want, but upon further investigation we find that they needed an Iodo derivative of their multiple ringed compound, catechin. They did work with both OH and OMe substituted catechin, using NIS to Iodinate their intermediate. This procedure was applied to various phenols in GP's research group, with varied success. It would seem as though the more electron rich the ring, the easier iodination occurs. Attempts with methoxy derivatives were not attempted by GP, so he don't know for sure on those. It DOES work for phenols, some better than others.
Another procedure:
Tetrahedron Lett. Vol. 37, No. 23, pp. 4081-4084, 1996
This paper is titled:
"Mild and Regiospecific Nuclear Iodination of Methoxybenzenes and Naphthalenes with N-Iodosuccinimide in Acetonitrile"
They apply NIS in MeCN to a good number of Methoxy derivatives, all giving high yields (85+) of the iodinated products. GP has not seen success with phenols, but that's not what we are concerned with here now is it..dumb GP.
Next..Tetrahedron Lett., Vol 33, No 20, pp. 2883-2886, 1992
This one is a bit 'out there' but this statement caught GP's eye:
"Halogenated salicylic acid derivatives were prepared by direct halogenation of salicylic acids in DMF at ambient temp. using NBS or NIS"
They are sticking that Iodine on the ring, so it couldn't hurt investigation.
One more NIS ref:
J. Am. Chem. Soc. Vol 105, No. 9, 1983
This one is strange. They use NIS and NBS on coumarin, which is another big molecule. This one uses glacial acetic acid as the solvent.
And FINALLY, GP would like to restate:
Tetrahedron Lett. vol 40 (1999) 6051-6054
Now THIS one is probably the best, but it does not use NIS. GP posted this but never got much reply, anyhow, here it is (PAY ATTENTION!
)
Titled "A Practical Iodination of Aromatic Compounds using Tetrabutylammonium Peroxydisulfate and Iodine"
They apply the title peroxide as a source of tetrabutylammonium sulfate radical, which is one mamma of an oxidizer, to generate the I+ in situ which attacks the ring. They apply this to a whole slew of Methoxy compounds, some of them seem VERY suspicious to GP... And these people get GRANTS to do this shit.. GP loves it the most. This method seems to work with short chain substituents along with the Methoxys. (hint, hint) They claim high yields of 85+%. The title peroxide can be *EASILY* generated in only a days work from... Tetrabutyl ammonium persulfate and...?? damn.. don't have that paper here. The Ref for the peroxide is: Synlett, 1995, 207-208.
Can't remember the other reagent, but believe GP, it's NOT something that would be watched by any means, and the peroxide preparation is easy shmeezy (isn't all inorganic chemistry that way?)
GP hopes this helps.. around the lab GP is known as the "iodination guy"...he hopes to live up to this.
GP out..