Two novel carboxamide hydrazone hybrids are synthesized and characterized. Structural, spectroscopic, and computational analyses reveal dominant hydrogen bonding, π–π stacking, and reactive sites. Compound 2b exhibits potent antibacterial activity against Staphylococcus aureus, highlighting its potential as a cost-effective therapeutic agent. Insights aid future drug design efforts.

The current study reports a convenient synthetic approach to carboxamide hydrazone hybrids 2a, b. Their chemical structures are investigated using infrared, nuclear magnetic resonance, and mass spectroscopies. In addition, the 3D structure of 2a is explored using single-crystal X-ray analysis, while the important intermolecular contacts are described based on the Hirshfeld analysis. Fukui function, highest occupied molecular orbital-lowest unoccupied molecular orbital, molecular electrostatic potential, and Mulliken charge analysis reveal distinct electrophilic and nucleophilic regions of hydrazone 2a, and support its stability and moderate chemical reactivity. Their antimicrobial potency is also evaluated against six microbial strains. Compound 2b shows significant antibacterial activity against Staphylococcus aureus compared to Gentamicin.