α1-Adrenoceptor antagonists. rational design, synthesis and biological evaluation of new trazodone-like compounds

A rational design approach has been applied to synthesize a novel class of compounds with affinity for α1 adrenergic receptors (AR). Molecular structures are characterized by a benzimidazolylpyridazinone or an imidazolylpyridazinone moiety, an original fragment in the field of the arylpiperazine compounds with α1-AR blocking properties. A 1.1 nM affinity toward α1-AR was found for compound 3, the most active of this series.