申请人:THE DOW CHEMICAL COMPANY
公开号:EP0254053A1
公开(公告)日:1988-01-27
Polychloropyridines containing chlorine substituents in the 2, 3, and 6 positions and, optionally, in the 4 and 5 positions, are prepared from polychloro-2,3-lutidines containing at least one chlorine substituent in each methyl group and, optionally, a chlorine substituent in the 6 position by liquid phase chlorination. Lewis acid metal halide catalysts are, optionally, employed. 2,3,5,6-Tetrachloropyridine is, accordingly, prepared by chlorination at 200 to 260°C in the presence of ferric chloride catalyst of a mixture of polychloro-2,3-lutidines obtained by the vapor phase chlorination of 2,3-lutidine.
在 2、3 和 6 位上含有氯取代基,以及在 4 和 5 位上含有氯取代基的聚氯吡啶,是由在每个甲基上至少含有一个氯取代基,以及在 6 位上含有一个氯取代基的聚氯-2,3-丁烷通过液相氯化法制备的。可选择使用路易斯酸金属卤化物催化剂。因此,2,3,5,6-四氯吡啶的制备方法是在 2,3-丁烷气相氯化反应中得到的多氯-2,3-丁烷混合物,在氯化铁催化剂存在下于 200 至 260℃进行氯化反应。