[EN] PROCESS FOR THE PREPARATION OF 4,5,6-TRICHLOROPICOLINIC ACID<br/>[FR] PROCÉDÉ DE PRÉPARATION D'ACIDE 4,5,6-TRICHLOROPICOLINIQUE
申请人:DOW AGROSCIENCES LLC
公开号:WO2016022623A1
公开(公告)日:2016-02-11
4,5,6-Trichloropicolinic acid is prepared by selectively dechlonnating 3,4,5,6- tetrachloropicolinic acid with zinc and a catalyst prepared from a nickel compound and a bidentate ligand in a polar solvent. A process for the preparation of 4,5,6-trichloro-picolinic acid by the regioselective reductive dechlorination of 3,4,5,6-tetrachloropicolinic acid is provided. More particularly, the process is described for the preparation of 4,5,6-trichloropicolinic acid (Formula I) which comprises selectively dechlonnating 3,4,5,6-tetrachloropicolinic acid (Formula II) with zinc and a catalyst prepared from a nickel compound and a bidentate ligand in a polar solvent.
4,5,6-三氯吡啶甲酸是通过在极性溶剂中使用镍化合物和二齿配体制备的催化剂,选择性地脱氯3,4,5,6-四氯吡啶甲酸来制备的。提供了一种通过区域选择性还原脱氯3,4,5,6-四氯吡啶甲酸的方法来制备4,5,6-三氯吡啶甲酸的过程。更具体地说,该过程是用锌和在极性溶剂中制备的镍化合物和二齿配体催化剂,选择性地脱氯3,4,5,6-四氯吡啶甲酸(式II),以制备4,5,6-三氯吡啶甲酸(式I)。