Triiodoisocyanuric acid: a new and convenient reagent for regioselective iodination of activated arenes

triiodoisocyanuric acid (tica) was prepared in 90% yield by heating trichloroisocyanuric acid with iodine in a sealed tube. the reaction of tica with activated arenes in acetonitrile led to an efficient and highly regioselective formation of the corresponding iodoarenes, in 73-93% isolated yield. aniline and phenol are monoiodinated regioselectively using meoh (53%) and ch2cl2 (88%) as solvents, respectively.