Synthesis of Some New 7-(arylidene/heteroylidene imino)-2-(3,4-dimethoxy-phenyl)-5-oxo- 1,5-dihydro-[1,2,4]triazolo[1,5-α]pyridine-6-carbonitrile Derivatives as Potent Antibacterial and Anti-inflammatory Agents

A new series of 7-(arylidene/heteroylidene imino)-2-(3,4-dimethoxy-phenyl)-5-oxo-1,5-dihydro-[1,2,4] triazolo[1,5-α]pyridine-6-carbonitrile derivatives i.e., Schiff bases (4a-4j) was synthesized from reaction of 7-amino-2-(3,4-dimethoxy-phenyl)-5-oxo-1,5-dihydro-[1,2,4]triazolo[1,5-α]pyridine-6-carbonitrile (3) with substituted benzaldehydes or hetraldehydes in presence of glacial acetic acid. The antibacterial and anti-inflammatory properties of compounds 3, 4a-4j were investigated, and the results showed that some of the synthesized compounds had better activity than the standard reference drugs. The minimum inhibitory concentration of compounds 4b, 4c, 4f, 4g, and 4i was found to be 10 μg/mL, which was lower than that of ciprofloxacin. The compounds were also tested for anti-inflammatory properties in vitro, and compounds 4a and 4f were found to have superior anti-inflammatory action at 100 μg/mL compared to the standard reference drug ibuprofen.