A facile synthesis of 3,5-halo and aryl 1H-pyridin-2-ones from pyridinium N-(pyridin-2-yl)aminide

The synthesis of halogenated and arylated 1H-pyridin-2-ones starting from pyridinium N-(pyridin-2-yl)aminides is described. The synthetic pathway involves the reaction of pyridinium N-(5-bromopyridin-2-yl)aminide, N-(3-bromo-5-chloropyridin-2-yl)aminide or N-(3,5-dibromopyridin-2-yl)aminide with different boronic acids to afford monosubstituted and disubstituted aminides in good yields. An additional bromination in the 3-position of N-(5-arylpyridin-2-yl)aminides was performed. Finally, reduction of the N–N bond followed by the reaction of the corresponding 2-aminopyridines with sodium nitrite/sulfuric acid in water yields 3,5-disubstituted 1H-pyridin-2-ones in good yields.