Results.–BTPPICl2 is an efficient, mild, and versatile reagent for the iodination of phenols. The best reagent/substrate ratio was found to lie between 1.05 and up to 4.05 depending on the number of iodination positions. For example, the ratio for the iodination of phenol to 2, 4, 6-triiodophenol was 3.05, and 2, 6-dimethylphenol to 4-iodo-2, 6-dimethylphenol was 1.05. Using too low reagent/substrate ratios for substrates with several positions for the ...