A series of triazolopyridinone derivatives originating from the antidepressant trazodone was designed and pharmacologically evaluated. Most of the compounds with a multireceptor functional profile exhibited high potency at the D<sub>2</sub>, 5-HT<sub>1A</sub>, and 5-HT<sub>2A</sub> receptors. Compounds S1, S3, S9 and S12 were selected for further evaluation of druggable potential. Among these compounds, S1, as a D<sub>2</sub> receptor partial agonist, demonstrated very potent inhibition of quipazine-induced head-twitch response, which validated its 5-HT<sub>2A</sub> receptor antagonistic efficacy in vivo. S1 also demonstrated a dose-dependent effect on PCP-induced hyperactivity when administered orally. Thus, S1 endowed with a triazolopyridinone scaffold represents a valuable lead for the development of novel atypical antipsychotics.