N-oxides and related compounds. Part 55. 1-Pyridinio-4-pyridone cations and 1-pyridiniopyridinium dications: preparation and reactions
Abstract
1-Aminopyridinium cations react with 4-pyrone and various derivatives to give 1-pyridinio-4-pyridones [(4) and (5)], which are converted by phosphoryl chloride into 4-chloropyridiniopyridinium salts [(6) and (7)]. These compounds are transformed into 1-arylpyridinium salts, pyridine disulphones, cyanopyridines, and aminopyridinio-pyridinium cations in reactions of potential synthetic utility.