2-{[(2-(2,6-Dimethoxyphenoxy)ethyl]}-1,4-benzoxathiano:A New Antagonist With High Potency and Selectivity Toward alpha1-Adrenoreceptors.

These results emphasize the importance of the position 4 in both thebenzodioxan and benzoxathian nucleus for the interactionat a,-adrenoreceptors. Since sulfur cannot form a productivehydrogen bond, the position 4 of antagonists bearinga benzodioxan or a benzoxathian nucleus would interactwith the receptor, either increasing the electron densityof the phenyl ring by a way of an electron-releasing effector giving rise to a dipole-dipole interaction.In conclusion, compound 1 is a potent and selectivealpha1-adrenoreceptor antagonist that may represent a valuabletool in the characterization of a-adrenoreceptor subtypes.