Synthesis and computational investigation of N,N-dimethyl-4-[(Z)-(phenylimino)methyl]aniline derivatives: Biological and quantitative structural activity relationship studies

This study describes the synthesis, characterisation and biological activities of four Schiff base compounds, namely: N, N-dimethyl-4-(((4-nitrophenyl)imino)methyl)aniline (ABS1), 4-(((2-chlorophenyl)imino)methyl)-N,N-dimethylaniline (ABS2), 4‑bromo-2‑chloro-N-(4-dimethylamino)benzylidene) aniline (ABS3), and N,N-dimethyl-4-(((2-(trifluoromethyl)phenyl)imino)methyl)aniline (ABS4). These compounds were characterised by UV–Visible, FTIR, CHN-elemental analysis, PXRD, HRMS, and NMR (¹H, ¹³C, DEPT, ¹H¹H– COSY, NOESY, HSQC, and HBMC) spectroscopic techniques. Furthermore, compounds ABS2–4 were suitable for single crystal X-ray diffraction analysis, and support the structures proposed. The antibacterial, antifungal and antioxidant activities of the compounds were investigated using both micro dilution and DPPH radical scavenging assays, showing a broad range of activity from high to moderate. Computational chemistry (molecular electrostatic potential maps, conceptual density functional theory calculations and non-covalent-interactions analysis) correlates with the experimental electronic properties as well as structure-reactivity relationship for the drug-likeness properties of the compounds. Molecular docking studies identified potential binding modes of the compounds, and the results corroborate with those obtained from MIC and MFC studies. The lead compounds (ABS1 and ABS3) exhibit outstanding drug-like properties.