Abstract Reactions of 1, 3, 5-tri-tert-butylbenzene with 2, 4, 6, 8-tetraiodo-2, 4, 6, 8- tetraazabicyclo [3.3. 0] octane-3, 7-dione in acetic and trifluoroacetic acids involve substitution of one or two tert-butyl groups in the aromatic ring with formation of mono-, di-, and triiodo-substituted derivatives. No iodo derivatives are formed in acetonitrile.