2-Fluoro-4-methylpyridin-3-amine is auseful reactant in the synthesis of phenylsulfonamidomethylbenzamides, oxopyridopyrrolopyrazinyacetamides, carbamoylalkylthiophenylmethylpicolinamides and benzylthiotriazolylpyridines, which exhibit SAR and kappa opioid receptor agonistic and antagonistic activity.