Utilization of 5-Chloro-2-(cyanoacetamido)pyridines in the Synthesis of Biologically Active Heterocyclic Hybrids

A simple synthesis for a series of chloropyridine derivatives incorporating heterocyclic hybrids has been accomplished. The key reaction involving employment of 5-chloro-2-(cyanoacetamido)pyridines 3 in the synthesis of chloropyridinyl-pyridone, chloropyridinyl-pyrazole, chloropyridinyl-thiazole and chloropyridinyl-thiophene hybrids. The newly synthesized heterocycles were evaluated for their antioxidant and antibacterial activities against Gram-positive and Gram-negative bacterial strains. 3-Amino-N-(3,5-dichloropyridin-2-yl)-1H-pyrazole-4-carboxamide (12 b) was found to be the most potent compound against Escherichia coli and Staphylococcus aureus exhibiting inhibition percent of 92.3% and 100%, respectively, when compared to the standard drug ampicillin. Moreover, compound 12b displayed the most significant antioxidant activity with percent inhibition 87.8% which is close to the antioxidant activity of ascorbic acid.