Patent ID: 7666293

Claim:
An improved process for the preparation of a 4-amino-3-halopicolinic acid of Formula I wherein X represents Cl or Br, Y represents H, F, Cl, Br or C 1 -C 4 alkyl, with the proviso that when X is Cl, Y is not Br, and R independently represents H or C 1 -C 4 alkyl, in which a direct or alternating electric current is passed from an anode to a silver cathode through a solution of a 4-amino-3,5-dihalopicolinic acid of Formula II wherein X, Y and R are as previously defined, and wherein both of X are either Cl or Br, at a cathode potential of about −0.4 to about −1.7 volts relative to an Ag/AgCl (3.0 M Cl − ) reference electrode, the improvement characterized by activating the cathode in the presence of the 4-amino-3,5-dihalopicolinic acid of Formula II, about 1 to about 4 wt % excess of alkali metal hydroxide and about 0.5 to about 4 weight percent of an alkali metal chloride, bromide or sulfate.