Synthesis and Anti-tubercular Activity of 6-(4-Chloro/Methyl-phenyl)-4- Arylidene-4,5-dihydropyridazin-3(2H)-one Derivatives Against Mycobacterium tuberculosis

Two series of 6-(4-Cl-Phenyl)-4-arylidene-4,5-dihydropyridazin-3(2H)-one (3a-e) and 6- (4-CH3-Phenyl)-4-arylidene-4,5-dihydropyridazin-3(2H)-one derivatives (3f-j) were synthesized and evaluated as antitubercular agents against Mycobacterium tuberculosis H37Rv strain by using Microplate Alamar Blue Assay (MABA) method. These compounds (3a-e & 3f-j) were synthesized from 6-(4-Cl-Phenyl)-4,5-dihydropyridazin-3(2H)-one (2a) and 6-(4-CH3-Phenyl)-4,5-dihydropyridazin- 3(2H)-one (2b) compounds by reacting with appropriate aldehydes respectively. All title compounds (3a-e & 3f-j) were characterized on the basis of IR, 1HNMR, mass spectral and elemental analysis data. All title compounds (3a-e & 3f-j) were used at 0.2µg/mL to 100µg/mL dose levels for antitubercular activity. Result showed that all the title compounds (3a-e & 3f-j) exhibited less antitubercular activity as compared to the reference drugs streptomycin (MIC value of 6.25µg/mL) and pyrizinamide (MIC value of 3.125µg/mL), except compound 3e, which was equally effective as streptomycin but less effective than pyrazinamide.