Rearrangement and cyclo-α-elimination of N-substituted amidines using (diacetoxyiodo)benzene

The products of reaction of N-substituted amidines with (diacetoxyiodo)benzene are determined by the nature of the amidine substituents and the reaction temperature: rearrangement of N2-phenylfuran-2-carboximidamide provides a convenient route to N-(2-furyl)acetamide, whereas N-phenyl C-alkyl formimidamides cyclise to give benzimidazoles in good yield.