The ‘inverse electron-demand’ Diels–Alder reaction in polymer synthesis. Part 5: Preparation and model reactions of some electron-rich bis-dienamines

The m- and p-phenylene-bridged bis-azolopyridinium salts have been synthesized and converted into the corresponding bis-dienamines by reaction with pyrrolidine. These dienamines react readily with dimethyl 1,2,4,5-tetrazine-dicarboxylate to yield the bis-azolylvinyl-pyridazines.