Hydrochloric Acid → 3,5,6-Trichloropicolinic acid

Participants

Reaction Steps

A mixture was prepared by admixing 3 grams (0.01 mole) of 3,5,6-trichloro-4-hydrazinopicolinic acid with 15 milliliters of 20 percent sodium hydroxide and 20 milliliters of water. To this mixture at 30°C was added 25 milliliters (0.018 mole) of a 5.25 percent sodium hypochlorite solution. Immediate gas evolution was noted which ceased after about 3 minutes. Five minutes after the addition of the sodium hypochlorite solution, the reaction mixture was acidified to a pH of about 2 with concentrated hydrochloric acid. The mixture was extracted with methylene chloride. The methylene chloride was removed from the extract by evaporation leaving 2.5 grams of the crude 3,5,6-trichloropicolinic acid which was purified by sublimation at 130°C and 1 millimeter of mercury. There was thus obtained 2.0 grams of the purified product (88 percent of theoretical) which melted at 147°-151°C.

Provenance & Evidence