A new improved process for producing pyridinaldehydes and hydrazone derivatives thereof, for example, pyridinaldehyde-phenylhydrazones, is described. This comprises reacting an aminomethylpyridine with an aldehyde or a ketone to give a compound of the formula ##STR1## isomerizing the compound (III), in the presence of suitable catalysts, to a compound of the formula ##STR2## and converting the compound (V), in the presence of an acid and optionally in the presence of a hydrazine, into a pyridinaldehyde or a pyridinaldehyde-hydrazone. It is possible to produce by the process according to the invention pyridinaldehydes and pyridinaldehyde-hydrazones in a simple manner, under mild ecologically favorable conditions and in good to very good yields.
本发明涉及一种生产
吡啶醛及其酰
肼衍
生物(例如,
吡啶醛-苯基
肼)的新改进工艺。该工艺包括将
氨甲基吡啶与醛或酮反应,得到式(III)的化合物,其中R1和R2分别为氢、烷基或芳基;在适当的催化剂存在下使化合物(III)异构化为式(V)的化合物,其中R3为氢、烷基或芳基;在酸存在下,可选地在
肼存在下,将化合物(V)转化为
吡啶醛或
吡啶醛-酰
肼。本发明的工艺可以在温和、环保的条件下,简单地制备出
吡啶醛和
吡啶醛-酰
肼,并且收率良好。