Synthesis and antimycobacterial activities of some new N-acylhydrazone and thiosemicarbazide derivatives of 6-methyl-4,5-dihydropyridazin-3(2H)-one

In this study, twenty-five new 6-methyl-4,5-dihydropyridazin-3(2H)-one derivatives having N-acylhydrazone and thiosemicarbazide moieties were synthesized. The target compounds were tested for their antimycobacterial activity in vitro against Mycobacterium tuberculosis H37Rv using the agar dilution method. Among the synthesized compounds, N′-(2,4-dichlorobenzylidene)-2-(3-methyl-6-oxo-5,6-dihydropyridazin-1(4H)-yl)acetohydrazide 4g was found to be the most active compound with minimum inhibitory concentration of 0.78 μM and was more potent than ethambutol and ciprofloxacin.