SELECTIVE ELECTROCHEMICAL REDUCTION OF HALOGENATED 4-AMINOPICOLINIC ACIDS Russian patent published in 2005 - IPC

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing some 4-aminopicolinic acids by electrochemical reduction. Invention relates to a method for selective reduction of halogen substitutes at position 5 of halogenated 4-aminopicolinic acids in the presence of halogen substitutes at positions 3 and 6. Invention represents a method for preparing 4-amino-3-halogenpicolinic acid of the formula (I): wherein X represents Cl or Br atom; Y represents H, Cl or Br atom. Method involves passing direct or alternating current from anode to cathode through 4-amino-3,5-dihalogenpicolinic acid solution of the formula (II): wherein and Y are given above and wherein both X represent either Cl atom or Br atom at cathode potential from -0.4 to -1.7 V relatively to the comparison electrode Ag/AgCl (3.0 M Cl^-) and extraction of product under condition that when X represents Cl atom then Y doesn't mean Br atom. Invention provides possibility for selective reduction of halogenated amino-containing group pyridines.

EFFECT: improved method for preparing.

8 cl, 3 ex