Adrenoceptor and tetrabenazine antagonism activities of some pyridinyltetrahydropyridines

A series of pyridinyltetrahydropyridine derivatives was synthesized and evaluated as adrenoceptor and tetrabenazine antagonists. 4-(3-Fluoro-2-pyridinyl)-1,2,5,6-tetrahydropyridine proved to be the most potent and selective alpha 2-adrenoceptor antagonist of the series as measured in vitro by displacement of [3H]clonidine and [3H]prazosin from membrane binding sites of calf cerebral cortex and by antagonism of the effects of clonidine and methoxamine in the rat isolated, field-stimulated vas deferens. In addition, this compound, and the corresponding desfluoro derivative, blocked tetrabenazine-induced ptosis in the mouse.