The reaction of phenyliodoso acetate with substituted acetanilides appears
to be quite complex in the presence of perchloric
acid. Although there is no change in the reaction products (at least
initially), there is evidence for a change in mechanism on the addition of
acid. Experimental evidence suggests that the reaction involves an electrophilic
substitution-yielding an acetoxy derivative in the case of p-methyl and p-methoxy
compounds.