Hydrochloric Acid → 3,5,6-Trichloro-4-hydrazinylpyridine-2-carboxylic acid

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Reaction Conditions

Reaction Steps

To a reaction flask was added 26.1 grams (0.1 mole) of tetrachloropicolinic acid, 200 milliliters of water, 3.6 grams of 95 percent hydrazine (0.11 mole) and 10.6 grams (0.1 mole) of sodium carbonate. The mixture was heated with stirring and maintained under reflux conditions for about 1 hour. The reaction mixture was cooled to 25° C and 25 milliliters of 5 normal hydrochloric acid was added. The solid which precipitated was recovered by filtration, and washed successively with water, ethanol, benzene and hexane and air dried. The 3,5,6-trichloro-4-hydrazinopicolinic acid product was recovered in a yield of 25.6 grams (93 percent of theoretical) having a melting point of 165°-170° C. After recrystallization from a 50:50 dimethylformamide-water mixture the product (as the mono-hydrate) was found by analysis to have carbon, hydrogen and nitrogen contents of 26.6, 2.1 and 15.3 percent, respectively, as compared with the theoretical contents of 26.2, 2.2 and 15.3 percent, respectively, calculated for the above named compound.

Provenance & Evidence