2,2'-Bipyridine → 2-Pyridinecarboxylic acid, 4,5,6-trichloro-

Participants

Reaction Steps

A 25 mL scintillation vial was charged with NiCl2.6H2O (84.0 mg, 0.353 mmol) and 2,2′-bipyridine (104.1 mg, 0.667 mmol). The vial was sealed and purged with nitrogen for 20 min. The inert reactor was charged with DMF (4.5 mL) and water (0.5 mL). The resulting mixture was allowed to stir for 24 h, and then solid 3,4,5,6-tetrachloropicolinic acid (0.834 g, 3.2 mmol) and zinc powder (1.6679 g, 25.5 mmol) were added through the top of the reactor. The reaction mixture was allowed to stir at ambient temperature for 3 h and was diluted to 20 mL with water. The resulting heterogeneous mixture was filtered to remove the solids, and the resulting clear, aqueous filtrate was made acidic (pH˜1) using concentrated HCl. Upon standing, a fine white solid formed and was collected via vacuum filtration to give the title compound (0.25 g, 35.1%) that was 66% pure as analyzed by calibrated HPLC. The residual material was 32% unreacted starting material and several unknown low level impurities, wherein low level is less than 3.5%.

Provenance & Evidence