Although the β-adrenergic antagonist propranolol (1) binds at rodent 5-HT1B serotonin receptors, it displays low affinity (K i> 10 000 nM) for its species homologue 5-HT1Dβ (ie, h5- HT1B) receptors. The structure of propranolol was systematically modified in an attempt to enhance its affinity for the latter population of receptors. Removal of the alkyl hydroxyl group, shortening of the O-alkyl chain from three to two methylene groups, and variation of the ...
