Methods of preparation and application of 2,3-difluoro-5-chloropyridin

Synthesis of 5-Chloro-2,3-difluoropyridine in Ionic Liquid;

Using (S)-2-chloro-propionic acid and 5-chloro-2,3-difluoropyridine and propargyl chloride as the starting material, chodinafop-propargyl was synthesized via Williamson, Ullmann and condensation reaction.

Several synthesis routes of 2,3-dichloropyridine were evaluated in this paper,and therefore an economic and reasonable one-pot synthesis of 2,3-dichloropyridine was explored through chlorination,diazotization and sandmeyer reaction starting with 3-aminopyridine yield and purity of the product was 66.