After reaction of ICI and Ag2SO4 in sulfuric acid and separation of resulti
ng AgCl a stable solution is formed, containing very active forms of electr
ophilic iodine. This solution has a powerful iodination ability with respec
t to aromatic compounds. Deactivated arenes are iodinated easily and in mil
d conditions by action of this new reagent in generally good yields of the
iodoarenes.