Synthesis and antidepressant activity of 5-(benzo[b]furan-2-ylmethyl)-6-methylpyridazin-3(2H)-one derivatives

A new series of pyridazin-3-one derivatives were designed, synthesized and evaluated for their preclinical antidepressant effect on Swiss mice. Among the series, compounds 6c, 6d and 6f exhibited significant activity profile in forced swimming test. Compounds 6c and 6d were most efficacious, which at dose of 50 mg kg-1 reduced the time of immobility by 42.85 and 38.09 %, respectively, as compared to the standard drug fluoxetine which reduced the immobility time by 45.23 % at the dose of 32 mg kg-1. All the test and standard compounds were administered orally 60 min before the test. Interestingly, all active compounds did not cause any significant alteration of locomotor activity in mice as compared to control, indicating that the hybrids did not produce any motor impairment effects. The results indicate that pyridazin-3(2H)-one derivatives may have potential therapeutic value for the management of mental depression.