摘要:
A number of derivatives structurally related to cirazoline (1) were synthesized and studied with the purpose of modulating alpha(2)-adrenoreceptors selectivity versus both alpha(1)-adrenoreceptors and I-2 imidazoline binding sites. The most potent alpha(2)-agonist was 2-[1-(biphenyl-2-yloxy)ethyl]-4,5-dihydro-1H-imidazole (7), whose key pharmacophoric features closely matched those found in the alpha(2)-agonist 2-(3-exo-(3-phenylprop-1-yl)-2-exo-norborn,I)amino-2-oxazoline (15).(30) (S)-(-)-7 was the most potent of the two enantiomers, confirming the stereospecificity of the interaction with alpha(2)-adrenoreceptors. This eutomer was tested on two algesiometric paradigms and, because of the interaction with alpha(2)-adrenoreceptors, showed a potent and long-lasting antinociceptive activity, since it was abolished by the selective alpha(2)-antagonist RX821002.