VERFAHREN ZUR HERSTELLUNG VON 6-METHYLNIKOTINSAEUREESTER

A process for the production of 6-methylnicotinic acid ester by oxidation of 2-methyl-5-ethylpyridine at an elevated temperature. Specifically, 2-methyl-5-ethylpyridine is mixed while cooling with at least a molar quantity of sulfuric acid. The mixture is heated to a temperature of 140 DEG to 225 DEG C. At least 3 moles of nitric acid per mole of educt is added to the heated mixture in such a way that water and/or diluted nitric acid are continuously distilled off. The distillation after addition of the nitric acid which is needed for the oxidation is continued until all of the water and all of the nitric acid are removed. Subsequently the reaction mixture is mixed with an alcohol and the alcoholic reaction mixture is heated until the acids contained in the reaction mixture are esterified. The 6-methylnicotinic acid ester is isolated from the ester mixture.