Crystal structure of N'-[2-(benzo[d]thia-zol-2-yl)acet-yl]benzohydrazide, an achiral compound crystallizing in space group P1 with Z = 1

Novel Fluorescent Benzothiazolyl-Coumarin Hybrids as Anti-SARS-COVID-2 Agents Supported by Molecular Docking Studies: Design, Synthesis, X-ray Crystal Structures, DFT, and TD-DFT/PCM Calculations

This study revealed the design and preparation of new 3-(benzo[d]thiazol-2-yl)-2H-chromen-2-one derivatives 9a-h. The structures of the synthesized products were elucidated by their spectroscopic data and X-ray crystallography for compounds 9a and 9d. The prepared new compounds were measured for their fluorescence, and a good result indicated that the emission efficiency was decreased by increasing the electron-withdrawing groups from the unsubstituted compound 9a to the highly substituted derivative 9h (2 Br heavy atoms). On the other hand, the B3LYP/6-311G** theoretical level of theory was used to optimize the quantum mechanical calculations of the geometrical characteristics and energy of the novel compounds 9a-h under study. The electronic transition was investigated using the TD-DFT/PCM B3LYP approach, which uses time-dependent density functional calculations. Moreover, the compounds exhibited nonlinear optical properties (NLO) and a small HOMO-LUMO energy gap, which makes them easy to polarize. Furthermore, the acquired infrared spectra were compared with the expected harmonic vibrations of the substances 9a-h. On the other hand, binding energy analyses of compounds 9a-h with human corona virus nucleocapsid protein Nl63 (PDB ID: 5epw) were predicted using molecular docking and virtual screening tools. The results showed a promising binding and how these potent compounds were inhibiting the COVID-19 virus. Compound 9h was the most active anti-COVID-19 agent among all the synthesized benzothiazolyl-coumarin derivatives, as it forms five bonds. The presence of the two bromine atoms in its structure was responsible for the potent activity.

Crystal structure of 3-(benzo[d]thia-zol-2-yl)-6-methyl-2H-chromen-2-one

The mol-ecule of the title compound, C₁₇H₁₁NO₂S, is almost planar, with an inter-planar angle of 3.01 (3)° between the benzo-thia-zole and chromene ring systems. A short intra-molecular S⋯O=C contact of 2.727 (2) Å is observed. The crystal packing involves a layer structure parallel to (211), containing dimeric inversion-symmetric units connected by a 'weak' C-H⋯O=C hydrogen bond.

Crystal structure of N-[3-(benzo[d]thia-zol-2-yl)-6-bromo-2H-chromen-2-yl-idene]-4-methyl-benzenamine

The title compound, C₂₃H₁₅BrN₂OS, was the unexpected product in an attempted synthesis of the isomeric 3-(benzo[d]thia-zol-2-yl)-6-bromo-1-p-tolyl-quinolin-2(1H)-one. The C_chromene=N-C angle is wide [125.28 (8)°]. The benzo-thia-zole and chromene ring systems are almost coplanar, with their planes parallel to (10); the toluene ring system is rotated by ca 40° out of the chromene plane. The mol-ecular packing involves layers with π-stacking, borderline 'weak' hydrogen bonds and possible C-H⋯π contacts.

4-Amino-5-(4-bromobenzoyl)-3-(benzo[d]thiazol-2-yl)-2-[(2′,3′,4′,6′-tetra-O-acetyl-β-D-galactopyranosyl)sulfanyl]thiophene

In the title compound, C32H29BrN2O10S3, the benzothiazole and thiophene ring systems subtend an interplanar angle of 7.43 (12)°. The NH2 group forms intramolecular hydrogen bonds to Nthiazole and Ocarbonyl. The Sgalactose—Cthiophene bond is short [1.759 (2) Å]. The molecules are connected to form ribbons parallel to the b axis by two `weak' hydrogen bonds and a short Namino...Sgalactose contact.

Crystal structure of 2-(2,5-dimethoxyphenyl)benzo[d]thiazole

The title compound was synthesized efficiently in the solid state by exploiting pepsin catalysis. The ring systems are nearly coplanar. A short intra­molecular S⋯O=C contact is observed.

The title compound, C₁₅H₁₃NO₂S, was synthesized efficiently in the solid state by exploiting pepsin catalysis. The ring systems are nearly coplanar [inter­planar angle of 5.38 (2)°] with an associated intra­molecular S⋯O=C short contact of 2.7082 (4) Å. The packing involves C—H⋯O, C—H⋯π and π–π contacts.

3-(Benzo[d]thiazol-2-yl)-2H-chromen-2-one

The inter­planar angle is 6.47 (6)°, with an associated intra­molecular S⋯O= C contact. The packing involves various secondary inter­actions.

In the title compound, C₁₆H₉NO₂S, the inter­planar angle is 6.47 (6)°. An intra­molecular S⋯O=C contact of 2.727 (2) Å is observed. The packing is determined by several types of weak inter­action (‘weak’ hydrogen bonds, S⋯S contacts and π–π stacking).

Crystal structure of 2-(benzo[d]thiazol-2-yl)-3,3-bis(ethylsulfanyl)acrylonitrile

In the title compound, C14H14N2S3, the double-bond system of the acrylonitrile moiety is significantly non-planar, with absolute cis torsion angles of 13.9 (2) and 15.1 (2)°. The ring system and the double bond system subtend an interplanar angle of 11.16 (4)°. The wide angle C—C(CN)=C of 129.40 (12)° may be associated with a balance between planarity and avoidance of a very short S...S contact.