Synthesis of new serotonergic 2-substituted 4,6-diaryl pyridazin-3-ones

A series of 4,6-diaryl pyridazin-3-ones substituted in the 2-position by [4-(4-aryl piperazin-1-yl]-but-2-ynyl moieties was synthesized and evaluated for antidepressant activity. The structures of these new pyridazine derivatives were confirmed by IR, 1H-NMR spectra and by elementary analysis. At 150 mg/kg i.p., they induced little or no reduction of the duration of immobility of mice in the forced swimming test. Head twitches produced by L-5-hydroxytryptophan in mice pretreated with pargyline were significantly potentiated by most of the tested compounds. In addition, pyridazine derivatives did not antagonize reserpine-induced palpebral ptosis or enhance the toxic effects of yohimbine and were almost devoid of anticholinergic properties in mice.