One-Pot Synthesis of Linearly Fused N-Heterocyles from Their Angular Analogues and Studies of Their Redox and Electrochromic Properties

In an unusual chemical transformation, the angular heterocyclic compound [1]ClO4, upon reaction with a primary aromatic amine, is transformed to a linear heterocyclic compound 3 via the angular intermediate [2]ClO4 in one pot. Characterization of the compounds was primarily achieved by 1H and 13C NMR and mass spectral data. Analyses of single-crystal X-ray structures of the representative compounds confirmed their identities. These compounds exhibit notable spectral and redox properties. Their redox behavior is followed by spectral characterization of the electro-generated radicals. Electrochromic properties of the reference compounds are also explored.