Process for the preparation of 4-Amino-3-chloro-5-fluoro-6-(substituted)picolinates

摘要

4-Amino-3-chloro-5-fluoro-6-(substituted)picolinates are conveniently prepared from 3,4,5,6-tetrachloropicolinonitrile by a series of steps involving fluorine exchange, amination, reaction with hydrazine, halogenation, hydrolysis and esterification, and transition metal assisted coupling.