Pesticide Intermediates 2,3 - Dihalides -5 - (trifluoromethyl) Pyridine Synthesis

2,3-Dihalo-5-trifluoromethyl pyridine is an intermediate used to produce pesticide such as Chlorfluazuzon and Haloxyfop-r-methyl etc. There are many rout and method to synthesize 2,3-Dihalo-5-trifluoromethyl pyridine. Considering the resource of domestic material and the feasibility of industrializing, this paper choice 2-chloro-5-methyl pyridine (or 2-chloro-5-chloromethyl pyridine) as the start material to synthesize 2-fluoro-3-chloro-5-trifluoromethyl pyridine by chlorination, ring chlorination and fluorination.2-chloro-5-trichloromethyl pyridine is prepared by chlorinationof 2-chloro-5-methyl pyridine (or 2-chloro-5-chloromethyl pyridine) using light catalysed or joint catalysed method in liquid phase. The optimum reaction condition is acquired after many...