We finally investigated the further reactivity of azoiodazinium salts to elaborate their potential as synthetic building blocks (Scheme 1). Treatment of 5aa with Ac2O yielded a non-selective ring-opening at both C-I-bonds to give the iodinated N-aryl benzimidazoles 6a and 6b in a mixture with 54% and 26% yield. A ring opening/closing cascade reaction with elemental sulfur resulted in the formation of the imidazo[4,5,1-kl]phenothiazine (7a) in 47% yield. The corresponding phenoselenazine 7b and the phenotellurazine 7c were isolated in lower yields of 16% and 8%, likely due to undesired oxidations of the selenium tellurium atoms. Substitutions with nitrogen nucleophiles were performed, giving the aniline substituted N-phenylphenazine 8 in 26% yield and the N-tosyl derivate 9 in 18% yield. Anion exchange reactions to iodide and bromide were performed for the salts 10a and 10b in excellent yields. Copper-catalyzed iodination gave the diiodinated product 11 in quantitative yield. Finally, an N-methylation of 5aa was performed, to yield the dicationic salt 5av in 56% yield without decomposition of the iodonium center. In this reaction, no complete conversion was observed, and the product formation could not be increased by adding more equivalents of MeOTf. Inspired by the latter result, we were eager to investigate other post-oxidation functionalizations on the benzimidazole ring while keeping the highly reactive hypervalent iodine center intact. Treatment of the ortho-pyrazole substituted salt 5bb