Ultrasound-assisted synthesis and spectral correlations of some bioactive E-imines

Some aryl E-imines were synthesized by nano-fly-ash H₃PO₄-catalyzed condensation of various aryl anilines and benzaldehydes under ultrasound irradiated greener solvent medium. In this condensation, the obtained yield was more than 75%. These E-imines were characterized by their physico-chemical data, microanalysis, and spectroscopic data. The characteristic spectral frequencies were employed for spectral quantitative structure–activity relationship study. The spectral QSAR study was performed with single and multi-regression analysis using Hammett σ, σ, σ_I, σ_R F R, and Swain–Lupton’s constants. From the outcome of the regression, the effect of substituents on the spectral frequencies was predicted. The molecular docking study of these imines was performed by the assessment of protein–ligand interaction study with a characteristic protein. The antimicrobial activities of these imines were studied using the Bauer–Kirby disk diffusion technique with various bacterial and fungal microbes. The in vitro antimalarial activity of these imines was measured using P. Falciparum Thai protein microbes.