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.
