Abstract
1-Oxides of substituted pyridine derivatives easily form their N-methoxylated quaternary salts by reacting with dimethyl sulfate. Potassium cyanide was added to the solution of the resulting salts in water or water containing other solvents, by which the reaction took place immediately at temperatures between 15° and 30°. After stirring for 15-45 minutes the product was extracted with chloroform and separated by alumina chromatography or vacuum distillation. Thus, corresponding 2- and 4-cyanopyridine were obtained. However, N-alkoxylated quaternary salts of 4-dimethylaminopyridine and 2-ethoxycarbonylaminopyridine did not react with potassium cyanide. The methoxyl group of 1, 4- or 1, 2-dimethoxypyridinium methylsulfate was found to undergo substituted with cyano group and 2, 4- or 2, 6-dicyanopyridine was isolated in considerable amount.
