ABSTRACT Mechanochemical synthetic route involving a simple, solvent‐free grinding technique proved effective for synthesizing four chromone‐based derivatives from chromone‐2‐carboxaldehyde and aromatic amines, affording isolated yields of 80%–81%. The products were characterized using FT‐IR, UV–Vis spectroscopy, NMR, elemental analysis, and mass spectrometry. The UV–Vis spectra showed absorption maxima at 370–393 nm, while the FT‐IR spectra exhibited characteristic C═N stretching frequencies between 1640 and 1693 cm −1 , confirming imine bond formation. The novelty of this work lies in the application of a purely mechanochemical route to access biologically relevant chromone–Schiff bases, combining green synthesis with comprehensive experimental and computational evaluation. Structural optimization and electronic analysis were supported by density functional theory (DFT) calculations. The synthesized compounds were evaluated for their antimicrobial screening against two Gram‐positive ( Staphylococcus aureus and Bacillus subtilis ) and two Gram‐negative bacteria ( Escherichia coli and Proteus vulgaris ), and also two fungal agents ( Aspergillus niger and Candida albicans ). Compounds 2‐((benzodthiazol‐2‐ylimino)methyl)‐4H‐chromen‐4‐one (I) and 2‐(((1H‐benzodimidazol‐2‐yl)imino)methyl)‐4H‐chromen‐4‐one (II) exhibited notable antibacterial activity with minimum inhibitory concentration (MIC) values of 31.25–62.5 µg/cm 3 , whereas compounds 2‐(((4‐acetylphenyl)imino)methyl)‐4H‐chromen‐4‐one (III) and 2‐((phenylimino)methyl)‐4H‐chromen‐4‐one (IV) showed significant antifungal activity with MIC values of 31.25–125 µg/cm 3 . These results highlight the effectiveness of mechanochemistry as an environmentally benign and efficient strategy for generating biologically active chromone–Schiff base derivatives. Overall, this study demonstrates the advantages of mechanochemistry—namely operational simplicity, reduced environmental impact, and high efficiency—as a powerful and green platform for the synthesis of biologically active chromone‐based imine derivatives.
Rashmi et al. (Wed,) studied this question.