Quaternary 1-aminobenzimidazolium salts in reactions with ?-dicarbonyl compounds. Formation of pyridazino[1,6-a]benzimidazolium cations and 1-arylpyrazoles
Quaternary 1-aminobenzimidazolium salts in reactions with ?-dicarbonyl compounds. Formation of pyridazino[1,6-a]benzimidazolium cations and 1-arylpyrazoles