Antimycobacterial Activity of Some New Pyridinylpyridazine Derivatives

SUMMARY. Some new pyridazine compounds were synthesized, characterized, and evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis by the microplate Alamar blue dye assay (MABA) method. Isonicotinohydrazide was condensed with appropriate heterocyclic aldehydes to form compounds N-(heteroaryl-2-yl-methylidene)-isonicotinohydrazides. Intramolecular cyclization of compound N-(heteroaryl-2-yl-methylidene)-isonicotinohydrazideto formed 4-(pyridine-4-yl)furo[2,3-d]pyr-idazine,4-(pyridine-4-yl)-1H-pyrrolo[2,3-d]pyridazineand4-(pyridin-4-yl) thieno [2,3-d]pyridazine, respec-tively. All the title compounds were characterized byusing IR, NMR, and mass spectral data. Docking study, optimized geometries, electrical and optical parameters were also studied in a solvent phase of synthesized pyridazine derivatives. Compound 4-(pyridin-4-yl) thieno[2,3-d]pyridazinewas found to have the most sig-nificant antimycobacterial activity (12.5 μg/mL) when compared to reference drugs streptomycin (6.25 μg/ mL) and pyrazinamide (3.125 μg/mL).