Fluorescent non-imidazole histamine H3 receptor ligands with nanomolar affinities

ω-Piperidinoalkanamine derivatives with fluorescent moieties (2-cyanoisoindol-1-yl, 7-nitrobenzofurazan-4-yl) have been synthesized starting from piperidine in three steps. The compounds display moderate to good histamine hH3 receptor affinities with Ki values ranging from 178 to 11 nM. The new compounds may act as tools for identification and understanding of the binding site on the histamine H3 receptor.