Crystal structure and mol-ecular docking study of (E)-2-{[(E)-2-hy-droxy-5-methyl-benzyl-idene]hydrazinyl-idene}-1,2-di-phenyl-ethan-1-one.

The title compound, C22H18N2O2, is a Schiff base that exists in the phenol-imine tautomeric form and adopts an E configuration with respect to the C=N bond. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, pairs of C-H⋯O hydrogen bonds link the mol-ecules to form inversion dimers. Weak π-π stacking inter-actions along the a-axis direction provide additional stabilization of the crystal structure. The mol-ecule is non-planar, the aromatic ring of the benzaldehyde residue being nearly perpendicular to the phenyl and 4-methyl-phenol rings with dihedral angles of 88.78 (13) and 82.26 (14)°, respectively. A mol-ecular docking study between the title mol-ecule and the COVID-19 main protease (PDB ID: 6LU7) was performed, showing that it is a potential agent because of its affinity and ability to adhere to the active sites of the protein.

Synthesis, spectroscopy, crystal structure, TGA/DTA study, DFT and molecular docking investigations of (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one.

In this study, we present the synthesis of novel pyridazin-3(2H)-one derivative namely (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one (MBSP). The chemical structure of MBSP was characterized using spectroscopic techniques such as FT-IR, 1H NMR, 13C NMR, UV-Vis, ESI-MS, and finally, the structure was confirmed by single X-ray diffraction studies. The DFT calculation was performed to compare the gas-phase geometry of the title compound to the solid-phase structure of the title compound. Furthermore, a comparative study between theoretical UV-Vis, IR, 1H- and 13C NMR spectra of the studied compound and experimental ones have been carried out. The thermal behavior and stability of the compound were analyzed by using TGA and DTA techniques which revealed that the compound is thermostable up to its melting point. Finally, the in silico docking and ADME studies are performed to investigate whether MBSP is a potential therapeutic for COVID-19.

Crystal structure, Hirshfeld surface analysis, DFT and mol-ecular docking investigation of 2-(2-oxo-1,3-oxazolidin-3-yl)ethyl 2-[2-(2-oxo-1,3-oxazolidin-3-yl)eth-oxy]quinoline-4-carboxyl-ate.

In the mol-ecular structure of the title compound, C20H21N3O7, the quinoline ring system is slightly bent, with a dihedral angle between the phenyl and the pyridine rings of 3.47 (7)°. In the crystal, corrugated layers of mol-ecules extending along the ab plane are generated by C-H⋯O hydrogen bonds. The inter-molecular inter-actions were qu-anti-fied by Hirshfeld surface analysis and two-dimensional fingerprint plots. The most significant contributions to the crystal packing are from H⋯H (42.3%), H⋯O/O⋯H (34.5%) and H⋯C/ C⋯H (17.6%) contacts. Mol-ecular orbital calculations providing electron-density plots of the HOMO and LUMO as well as mol-ecular electrostatic potentials (MEP) were computed, both with the DFT/B3LYP/6-311 G++(d,p) basis set. A mol-ecular docking study between the title mol-ecule and the COVID-19 main protease (PDB ID: 6LU7) was performed, showing that it is a good agent because of its affinity and ability to adhere to the active sites of the protein.

5-((1H-imidazol-1-yl)methyl)quinolin-8-ol as potential antiviral SARS-CoV-2 candidate: Synthesis, crystal structure, Hirshfeld surface analysis, DFT and molecular docking studies.

A potential new drug to treat SARS-CoV-2 infections and chloroquine analogue, 5-((1H-imidazol-1-yl)methyl)quinolin-8-ol (DD1) has been here synthesized and characterized by FT-IR, 1H-NMR, 13C-NMR, ultraviolet-visible, ESI-MS and single-crystal X-ray diffraction. DD1 was optimized in gas phase, aqueous and DMSO solutions using hybrid B3LYP/6-311++G(d,p) method. Comparisons between experimental and theoretical infrared spectra, 1H and 13C NMR chemical shifts and electronic spectrum in DMSO solution evidence good concordances. Higher solvation energy was observed in aqueous solution than in DMSO, showing in aqueous solution a higher value than antiviral brincidofovir and chloroquine. on Bond orders, atomic charges and topological studies suggest that imidazole ring play a very important role in the properties of DD1. NBO and AIM analyses support the intra-molecular O15-H16•••N17 bonds of DD1 in the three media. Low gap value supports the higher reactivity of DD1 than chloroquine justified by the higher electrophilicity and low nucleophilicity. Complete vibrational assignments of DD1 in gas phase and aqueous solution are reported together with the scaled force constants. In addition, better intermolecular interactions were observed by Hirshfeld surface analysis. Finally, the molecular docking mechanism between DD1 ligand and COVID-19/6WCF and COVID-19/6Y84 receptors were studied to explore the binding modes of these compounds at the active sites. Molecular docking results have shown that the DD1 molecule can be considered as a potential agent against COVID-19/6Y84-6WCF receptors.