A method for preparing 2,5-dihalo- and 2,5,6-trihalopyridines corresponding to the formula ##SPC1## Wherein each X independently represents chloro, fluoro or bromo and R represents hydrogen, chloro, fluoro or bromo which comprises reacting a halohydrazinopyridine of one of the formulas ##SPC2## With an excess of an aqueous alkali metal hydroxide in the presence of a reaction medium from the group consisting of loweralkanols of 1 to 4 carbon atoms and loweralkylglycols of 2 to 4 carbon atoms.
一种制备与下列
化学式对应的2,5-二卤和2,5,6-三卤
吡啶的方法:其中每个X分别代表
氯、
氟或
溴,R代表氢、
氯、
氟或
溴,包括在以下反应介质中,将其中一种
化学式的卤酰
肼吡啶与过量的
水合碱
金属氢氧化物反应:反应介质选自1至4个碳原子的低碳醇和2至4个碳原子的低碳基
乙二醇。