In this study, 15 new 3 (2H)-pyridazinone derivatives carrying N-(4- substitutedphenylmethylidene) acetohydrazide moiety on lactam nitrogen were synthesized and their chemical structures were confirmed by 1H-NMR, mass, and elemental analysis. Analgesic and anti-inflammatory activities of the synthesized compounds were evaluated in mice. Among the synthesized compounds, compound 11e exhibited the best analgesic ...