Synthesis, cardiac electrophysiology, and beta-blocking activity of novel arylpiperazines with potential as class II/III antiarrhythmic agents

J Med Chem. 1992 Feb 21;35(4):743-50. doi: 10.1021/jm00082a016.


A series of novel arylpiperazines have been prepared in an attempt to incorporate both class II (beta-receptor blocking) and class III antiarrhythmic properties in a single molecule. The key step in the preparation of the new compounds involves a regioselective heterocyclic ring formation. All but four compounds significantly prolonged action potential duration in canine cardiac Purkinje fibers (class III activity). All but one of the compounds demonstrated beta-receptor affinity in a competitive binding assay and three had beta 1-receptor selectivity. Compared to sotalol, a reference class II/III agent, arylpiperazine 7a (4-[(methylsulfonyl)amino]-N-[(4- phenylpiperazin-2-yl)methyl]benzamide) demonstrated beta 1-selectivity and was 1 order of magnitude more potent in the in vitro class III and the beta 1-receptor screens. Compound 7a was evaluated further and found to be effective in preventing programmed electrical stimulation-induced arrhythmias in conscious dogs (class III activity) and against epinephrine-induced arrhythmias in halothane anesthetized dogs (class II activity).

Publication types

  • Comparative Study

MeSH terms

  • Action Potentials / drug effects
  • Adrenergic beta-Antagonists / chemical synthesis*
  • Adrenergic beta-Antagonists / pharmacology
  • Adrenergic beta-Antagonists / therapeutic use
  • Animals
  • Anti-Arrhythmia Agents / chemical synthesis*
  • Anti-Arrhythmia Agents / pharmacology
  • Anti-Arrhythmia Agents / therapeutic use
  • Arrhythmias, Cardiac / drug therapy
  • Arrhythmias, Cardiac / etiology
  • Benzamides / chemical synthesis*
  • Benzamides / pharmacology
  • Benzamides / therapeutic use
  • Binding, Competitive
  • Dogs
  • Electric Stimulation
  • Electrophysiology
  • Epinephrine
  • Heart / drug effects
  • Heart / physiology*
  • Molecular Structure
  • Piperazines / chemical synthesis*
  • Piperazines / pharmacology
  • Piperazines / therapeutic use
  • Purkinje Fibers / drug effects
  • Purkinje Fibers / physiology
  • Receptors, Adrenergic, beta / metabolism
  • Sotalol / pharmacology
  • Sotalol / therapeutic use
  • Structure-Activity Relationship


  • Adrenergic beta-Antagonists
  • Anti-Arrhythmia Agents
  • Benzamides
  • Piperazines
  • Receptors, Adrenergic, beta
  • 4-((methylsulfonyl)amino)-N-((4-phenylpiperazin-2-yl)methyl)benzamide
  • Sotalol
  • Epinephrine