Molecular design and synthesis of 1,4-disubstituted piperazines as α(1)-adrenergic receptor blockers.

A new series of 4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylic acid amide and 3,5,6,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4-one derivatives were designed, synthesized, their binding and functional properties as α1-adrenoreceptors blockers were evaluated. A new validated α1-adrenoreceptor blocker pharmacophore model (hypothesis) was generated using Discovery Studio 2.5. The compare-fit study for the designed molecules with the generated hypothesis was fulfilled and several compounds showed significant high fit values. Compounds IVa-c, VIIa-d, VIIIa-c, Xa-c, XIa-d have shown blocking activity ranging from 46.73% up to 94.74% compared to 99.17% for prazosin.