Heterocyclic Betaines. XXIII. Access to Novel Dipolar Ethyleneimidazolium(pyridinium) 4-Nitrobenzimidazolate Inner Salts. Synthesis, Characterization and Reactivity Concerning a Type of .BETA.-Elimination Reaction.
Heterocyclic Betaines. XXIII. Access to Novel Dipolar Ethyleneimidazolium(pyridinium) 4-Nitrobenzimidazolate Inner Salts. Synthesis, Characterization and Reactivity Concerning a Type of .BETA.-Elimination Reaction.
The first synthesis of the hitherto unknown ethyleneimidazolium benzimidazolate inner salts is described. Their dipolar structure is well reflected on the basis of the 1H and 13C NMR parameters. Under neutral and mild conditions the title compounds underwent a type of β-elimination, affording their corresponding 2-vinyl-1H-benzimidazoles in high yields.