Two new series of 4-(1-alkyl-piperidin-4-yloxy)-benzonitriles and 4-(1-isopropyl-piperidin-4- yloxy)-benzylamines have been prepared. In vitro activity was determined at the recombinant human H3 receptor and several members of these new series were found to be potent H3 antagonists. The present compounds contain a 4-phenoxypiperidine core, which behaves as a conformationally restricted version of the 3-amino-1-propanol moiety ...