3-methylthiopyridine-2-carboxylic acid and its methylic ester have been investigated by recent electrochemical techniques such as direct (DC), alternating (AC) current, differential pulse polarography (DPP), controlled potential coulometry and cyclic voltammetry. The influence of polarographical parameters, pH and concentration on the electrochemical behaviour of these compounds permits to explore several of their chemical properties. On the other hand, the optimal conditions for the quantitative determination of traces have been established.

AbstractBei der Kondensation des Pyridins (I) mit dem Thiouracil (II) mit KOH in möglichst wenig Wasser entsteht die Titelverbindung (III) unter weitestgehender Vermeidung einer Bildung des isomeren S‐Substitutionsprodukts.

2-methylthiopyridine-5-carboxylic methylic ester and 2-methylthiopyridine-5-carboxylic acid have been studied by recent polarographic and voltammetric technics (3,4). These molecules are irreversibely reduced at the thioether site. When considering the direct current, alternative and the differential pulse polarograms compared to cyclic voltammograms, the behaviour of these compounds can be elucidated. The pH influence on each basic fonction proton exchange and the adsorption impact on this protonation are described. A complementary study as a fonction of concentration establish the optimal conditions to quantify these compounds by classical and differential pulse polarography.