Clopyralid → 3,6-dichloro-N-(3-methyl-1,2,4-thiadiazol-5-yl)pyridine-2-carboxamide

Participants

Reaction Steps

12 g of 5-amino-3-methyl-1,2,4-thiadiazole, 21.1 g of N-hydroxybenzotriazole hydrate and 29.8 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added to a chloroform (500 ml) solution of 21 g of 3,6-dichloro-2-pyridinecarboxylic acid, and stirred at room temperature for 1 hour and then stirred overnight at 50° C. The reaction liquid was diluted with chloroform, then washed with aqueous 0.2 N hydrochloric acid solution, water and saturated saline water. After this was dried with anhydrous magnesium sulfate, the solvent was evaporated away under reduced pressure, and ethyl acetate was added to the resulting residue for crystallization to obtain 22.7 g of the entitled compound as a white solid.

Provenance & Evidence