3,5-dichloro-2-hydrazinylpyridine is a useful reactant for the synthesis of (1S,3R)-N-{[1-(3-chloropyridin-2-yl)-5-(5-fluoro-6-methylpyridin-3-yl)-4-methyl-1H-pyrazol-3-yl]methyl}-3-fluorocyclopentanamine, a possible potent opioid receptor-like 1 antagonists.
