Spectra and photolysis of the 1‐oxides of the pyridinecarboxylic acids and pyridinecarboxamides

Abstract

Abstract The ultraviolet absorption spectra of aqueous and alcoholic solutions of the pyridinemono‐carboxylic acids and amides, of the vicinal pyridinedicarboxylic acids, and of the 1‐oxides of these compounds, were measured and qualitatively interpreted. The photolysis of the 1‐oxides in aqueous solution resulted principally in their deoxygenation. Photolysis of picolinamide 1‐oxide also gave a rearrangement product, 1‐formyl‐2‐pyrrolecarboxamide. The photolyses of the 2‐ and 4‐monosubstituted 1‐oxides were somewhat faster than those of the 3‐substituted 1‐oxides. The experimental results are discussed in terms of possible hydrogen‐bonding effects.