Pyridinium N-heteroarylaminides: synthesis of N-heteroarylpolyamines

The synthesis of a set of new N-heteroarylpolyamines is reported. A multiple and regioselective alkylation on the exo nitrogen of pyridinium N-(heteroaryl)aminides with several polybromo compounds, followed by a clean N–N bond reduction of the corresponding pyridinium salts, provides an easy and general method to obtain the title compounds.