2-Pyridinecarboxylic acid, 3,4,5,6-tetrachloro- , its cas register number is 10469-09-7. It also can be called 3,4,5,6-Tetrachloropicolinic acid ; Tetrachloropicolinic acid ; 3,4,5,6-Tetrachloropyridine-2-carboxylic acid .