Reactions of some 8-(3-pyridyl)-6-thioxanthines with methyl iodide
Abstract
8-(3-Pyridyl)-6-thioxanthine (I) reacts with methyl iodide in dimethylformamide to produce the corresponding thioether (II). In the presence of an excess of methyl iodide the reaction further proceeds to quaternise the pyridine nitrogen atom, and to methylate N-3 and N-1 in the purine nucleus. Simultaneously, S-demethylation occurs, so that the end products are the N-methyl-thioxanthines (VI) and (IX).