Preparation and Reactions of 2-Nitropyridine-1-oxides

Specificity of 15N NMR chemical shifts to the nature of substituents and tautomerism in substituted pyridine N-oxides

“…The modified synthesis of 2-acetylaminopyridine N-oxides (2, 4) and 4-, 5-, and 6-methyl-(2-acetylaminopyridine-Noxides) (7,8,9) [8][9][10]13] has been presented previously [14]. By modification of methods by Brown and Adam et al [9,10], a remarkable shortening in reaction time (9 to 2 h) was achieved by substituting acetic acid by acetic anhydride in the reaction.…”

“…By modification of methods by Brown and Adam et al [9,10], a remarkable shortening in reaction time (9 to 2 h) was achieved by substituting acetic acid by acetic anhydride in the reaction.…”

“…These compounds were obtained by hydrolysis of the corresponding acetylaminopyridine N-oxides [13]. By Herz's hydrolysis method [13] with 50 % H 2 SO 4 instead of 10 % NaOH decreases, the reaction time varied from 5 to 1 h [9,10].…”

“…Otherwise, oxidation would have transformed aminopyridines into nitropyridines [7][8][9][10][11][12][13][14][15]. In hydrolysis, acetylamino derivatives of pyridine N-oxide gave the corresponding amino compounds [7].…”

“…In hydrolysis, acetylamino derivatives of pyridine N-oxide gave the corresponding amino compounds [7]. 2-Amino-and 2-acetylaminopyridine N-oxides as well as their 3-, 4-, 5-, and 6-methyl derivatives are reported in literature [8,9], but their synthesis were greatly improved [14] compared to the earlier reported methods [8][9][10][11][12][13].…”