Reinvestigation of the Reaction of Caro's Acid with 3-Aminopyrideine. An Improved Synthesis and Characterization of 3,3′-Azoxypyridine

Abstract

Pursuant to our interest in the effects of β-substituents upon the gas phase basicities of heteroaromatic compounds, we needed various mono-substituted pyridines, especially 3-nitropyridine. Reports concerning the synthesis of this compound include the direct electrophilic nitration of pyridine,¹ and the perhydrol oxidation of 3-aminopyridine.^2,3 The procedures for both methods were unattractive and the yields poor. Recently a convenient preparation of 3-nitropyridine via Caro's acid⁴ oxidation of 3-aminopyridine was reported.⁵ Although this report has been widely referenced, it did not provide experimental details, such as procedure, yields, or spectral characterization.