Synthesis, spectroscopic, DFT calculations, biological activities and molecular docking studies of new isoxazolone, pyrazolone, triazine, triazole and amide derivatives

•Synthesis of some heterocycles.•DFT calculations•Cytotoxicity and docking calculations. Ethyl-2-cyano-2-(2-(3-nitrophenyl)hydrazono)acetate was synthesized and used as a versatile reagent for the synthesis of different heterocyclic compounds such as isoxazolone, pyrazolone, triazine, triazole and amide derivatives via its reactions with different nucleophiles. Conventional, microwave and grinding techniques were used for synthesis of the newly isolated derivatives. Various physical parameters were calculated from the percentage yield and reaction time in order to compare between the three techniques. The reported compounds were characterized by elemental analyses and different spectroscopic tools such as IR, 1H NMR, 13C NMR and mass spectrometry. The optimized molecular geometries of some selected compounds were investigated using the density functional theory (DFT/B3LYP) method with the use of double zeta plus polarization basis set 6–31 G (d,p) for the C, H, N, O and S atoms. The quantum global reactivity descriptors were also calculated and discussed. The antibacterial and cytotoxicity screening of those compounds were performed to determine their therapeutic potential. Molecular docking of the compounds was also examined. The different biological studies as well as the molecular docking were correlated to each other, and supported that the compounds could bind to DNA, possibly, via intercalative mode and showed a various DNA binding potency. [Display omitted]