Phenylimidazolidin-2-one Derivatives as Selective 5-HT<sub>3</sub> Receptor Antagonists and Refinement of the Pharmacophore Model for 5-HT<sub>3</sub> Receptor Binding
metoclopramide, a D2 receptorantagonist with weak 5-HT3receptorantagonist properties, and zetidoline, a D2 receptorantagonist. Starting from this premise, a series of phenylimidazolidin-2-one derivatives bearing a basic azabicycloalkyl or an imidazolylalkyl moiety were synthesized and evaluated for 5-HT3receptor radioligand binding affinity ([3H]-GR 43,694). In vitro 5-HT3receptorantagonist activity was