Verfahren zur kontinuierlichen Herstellung von 2,2,6,6-letramethylpiperidin

摘要

The reduction of triacetonamine with hydrazine also proceeds continuously by means of a reactive distillation if the hydrazone is first formed and this is continuously transported at the bottom of a distillation column into the distillation bottom, which consists of a high-boiling solvent and an alkali, and the resulting 2,2,6,6-tetramethylpiperidine is distilled off as an azeotrope. In this procedure, a hydrazine/triacetonamine ratio of 1.5 : 1 to 2.0 : 1 is sufficient, it being possible distinctly to increase the product yield (> 90%) compared with the conventional synthesis. Additionally, the amounts of alkali and solvents used can be distinctly reduced.