Design, Synthesis, and Biological Evaluation of Aryl‐Pyrazin‐2‐yl‐ <scp> <i>N</i> , <i>N</i> </scp> ‐Dimethyl Piperidine Amine and Sulfonyl‐Pyridine‐3‐yl‐Pyrazinamine Derivatives, and Their Anticancer and Antibacterial Activity

ABSTRACT A novel series of biologically active aryl‐pyrazin‐2‐yl‐ N , N ‐dimethyl piperidine amines and sulfonyl‐pyridine‐3‐yl‐pyrazinamine derivatives ( 3/5a‐e ) was synthesized and confirmed through 1 H NMR, 13 C NMR, and mass spectrometry. All synthesized compounds were evaluated for their antibacterial activity against pathogenic microorganisms. Among them, compound 3b demonstrated the most potent antibacterial activity, particularly against Staphylococcus aureus and Escherichia coli . Furthermore, compound 3b was screened for anticancer activity against the A549 lung cancer cell line, showing promising cytotoxicity with an IC 50 value of 40 μg/mL. Structure–activity relationship (SAR) studies indicated that electron‐donating groups significantly enhanced antibacterial activity, while electron‐withdrawing groups led to a reduction in activity, and halogen substituents showed moderate antibacterial activity.