Experimental spectral characterization, Hirshfeld surface analysis, DFT/TD-DFT calculations and docking studies of (2Z,5Z)-5-(4-nitrobenzylidene)-3-N(2-methoxyphenyl)-2-N'(2-methoxyphenylimino) thiazolidin-4-one.

We reported an experimental and theoretical spectroscopic studies of (2Z,5Z)-5-(4-nitrobenzylidene)-3-N (2-methoxyphenyl)-2-N' (2-methoxyphenylimino) thiazolidin-4-one (C24H19N3O5S) molecule, using FT-IR, NMR spectroscopy, and density functional theory (DFT) via time-dependent schema (TD-DFT) respectively. The molecular inter-contacts were explored using Hirshfeld surfaces (HS) analysis method. Vibrational frequencies, gauge-independent atomic orbital (GIAO)1H and13C NMR chemical shift values and frontier molecular orbitals (FMOs) have been calculated from the optimized structure of the molecule by DFT/B3LYP functional with 6-31G(d, p) basis set. Our theoretical results show a good agreement with the experimental data. The calculated UV-visible spectrum employing TD-DFT shows electronic transitions at 388 nm and 495 nm. To get insight on the charge interaction happening inside the molecule, HOMO and LUMO were scrutinized and their calculated energy gap was found to be 2.96 eV. The molecular docking was analyzed via interplay study ofacetyl cholinesterase, and Butyrylcholinesterase using molecular docking methodology.

Mol-ecular and crystal structure, Hirshfeld analysis and DFT investigation of 5-(furan-2-yl-methyl-idene)thia-zolo[3,4-a]benzimidazole-2-thione.

The thia-zolo[3,4-a]benzimidazole fused-ring system in the title compound, C14H8N2OS2, is nearly planar, the r.m.s. deviation being 0.0073 Å. The thia-zolo-benzimidazole-2-thione system is almost in the same plane as the furan-2-yl-methyl-ene moiety, with a dihedral angle of 5.6 (2)° between the two least-squares planes. In the crystal, adjacent mol-ecules are connected by weak inter-molecular inter-actions (C-H⋯N and slipped π-π stacking) into a three-dimensional network. The nature of the inter-molecular inter-actions was also qu-anti-fied by Hirshfeld surface analysis. DFT analysis indicates a good agreement of the experimentally determined and the theoretically calculated mol-ecular structures.

Synthesis, X-Ray Structure Determination and Related Physical Properties of Thiazolidinone Derivative by DFT Quantum Chemical Method.

In this paper we report the synthesis and characterization of the (Z)-3-N-(ethyl)-2-N'-((3-methoxyphenyl)imino)thiazolidine- 4-one by means of FT-IR, 1H and 13C NMR and by single crystal X-ray diffraction. The experimental determination of the crystal structure of the compound has been achieved using X-ray diffraction data. The important characteristic of the structure is the existence of a dihedral angle formed by the benzene and thiazolidinone rings being equal to 86.0° indicating an absence of α-α stacking as well as that the structure is non planar. In the crystal, the molecules are linked by C-H···O and C-H···N hydrogen bonds, these bonds being responsible for the three-dimensional molecular structure packing. In order to compare the experimental results with those of the theoretical calculation, quantum chemical DFT calculations were carried out using B3LYP/6-311G(d,p) basis set. In this context, the molecular electrostatic potential around the molecule and HOMO-LUMO energy levels were also computed. The dipole moment orientations were determined in order to understand the nature of inter- and intramolecular charge transfer. Finally, the stability of the title compound was confirmed throughout the calculation of the chemical reactivity descriptors.

Crystal and mol-ecular structure of (2Z,5Z)-3-(2-meth-oxy-phen-yl)-2-[(2-meth-oxy-phen-yl)imino]-5-(4-nitro-benzyl-idene)thia-zolidin-4-one.

In the title compound, C24H19N3O5S, the thia-zole ring (r.m.s. deviation = 0.012 Å) displays a planar geometry and is surrounded by three fragments, two meth-oxy-phenyl and one nitro-phenyl. The thia-zole ring is almost in the same plane as the nitro-phenyl ring, making a dihedral angle of 20.92 (6)°. The two meth-oxy-phenyl groups are perpendicular to the thia-zole ring [dihedral angles of 79.29 (6) and 71.31 (7)° and make a dihedral angle of 68.59 (7)°. The mol-ecule exists in an Z,Z conformation with respect to the C=N imine bond. In the crystal, a series of C-H⋯N, C-H⋯O and C-H⋯S hydrogen bonds, augmented by several π-π(ring) inter-actions, produce a three-dimensional architecture of mol-ecules stacked along the b-axis direction. The experimentally derived structure is compered with that calculated theoretically using DFT(B3YLP) methods.

Crystal structure and Hirshfeld surface analysis of ethyl 2-{[4-ethyl-5-(quinolin-8-yloxymeth-yl)-4H-1,2,4-triazol-3-yl]sulfan-yl}acetate.

In the title compound, C18H20N4O3S, the 1,2,4-triazole ring is twisted with respect to the mean plane of quinoline moiety at 65.24 (4)°. In the crystal, mol-ecules are linked by weak C-H⋯O and C-H⋯N hydrogen bonds, forming the three-dimensional supra-molecular packing. π-π stacking between the quinoline ring systems of neighbouring mol-ecules is also observed, the centroid-to-centroid distance being 3.6169 (6) Å. Hirshfeld surface (HS) analyses were performed.

Crystal Structure, Hirshfeld Surface Analysis and Computational Studies of Thiazolidin-4-one derivative: (Z)-5-(4-Chlorobenzylidene)-3-(2-ethoxyphenyl)-2-thioxothiazolidin-4-one.

The title compound (Z)-5-(4-chlorobenzylidene)-3-(2-ethoxyphenyl)-2-thioxothiazolidin-4-one (CBBTZ) was characterized by X-ray single crystal diffraction, 1H NMR and 13C NMR spectra. Theoretical investigations were carried out using HF and DFT levels of theory at 6-31G(d,p) basis set. The X-ray structure is compared with that computed. The calculated geometrical parameters are in good agreement with those determined by X-ray diffraction. The dihedral angle between the two benzene rings is 16.89(5)° indicating that the structure is non planar. The molecule exhibits intraand intermolecular contacts of type C-H···O, C-H···S and C-H···Cl. The intercontacts in the crystal structure are explored using Hirshfeld surfaces analysis method.

Crystal structure of (2Z,5Z)-3-(4-meth-oxy-phen-yl)-2-[(4-meth-oxy-phenyl)-imino]-5-[(E)-3-(2-nitro-phen-yl)allyl-idene]-1,3-thia-zolidin-4-one.

In the title compound, C26H21N3O5S, the thia-zole ring is nearly planar with a maximum deviation of 0.017 (2) Å, and is twisted with respect to the three benzene rings, making dihedral angles of 25.52 (12), 85.77 (12) and 81.85 (13)°. In the crystal, weak C-H⋯O hydrogen bonds and C-H⋯π inter-actions link the mol-ecules into a three-dimensional supra-molecular architecture. Aromatic π-π stacking is also observed between the parallel nitro-benzene rings of neighbouring mol-ecules, the centroid-to-centroid distance being 3.5872 (15) Å.

Synthesis of novel highly functionalized 4-thiazolidinone derivatives from 4-phenyl-3-thiosemicarbazones.

We present herein the synthesis in good yields of two series of highly functionalized thiazolidinone derivatives from the reactions of various 4-phenyl-3-thio-semicarbazones with ethyl 2-bromoacetate and diethyl acetylenedicarboxylate, respectively.

Synthesis and structural determination of novel 5-arylidene-3-N(2-alkyloxyaryl)-2-thioxothiazolidin-4-ones.

As part of our project devoted to the synthesis of heterocycles including thiazole rings, some new 5-arylidene-2-thioxo-3-N-arylthiazolidin-4-ones were synthesized by Knoevenagel condensation. An interesting feature of these compounds is that their chirality is induced by that of their 3-N-(2-alkyloxyaryl)-2-thioxothiazolidin-4-one precursors, which in turn is due to the presence of a C2 axis of chirality. These new compounds were characterized by spectroscopic methods (IR, 1H-NMR, 13C-NMR). The structure of compound (Z)-(2g) was further determined by X-ray diffraction.

3-(2-aminophenyl)-4-methyl-1,3-thiazole-2(3H)-thione as an ecofriendly sulphur transfer agent to prepare alkanethiols in high yield and high purity.

A new process is described for preparing very pure linear alkanethiols and linear alpha,omega-alkanedithiols using a sequential alkylation of the title compound, followed by a ring closure to quantitatively give the corresponding 3-methyl[1,3]thiazolo[3,2-a]-[3,1]benzimidazol-9-ium salt and the alkanethiol derivative under mild conditions. The alkanethiol and the heteroaromatic salt are easily separated by a simple extraction process. The intermediate thiazolium quaternary salts resulting from the first reaction step can be isolated in quantitative yields, affording an odourless protected form of the thiols.

Atropisomerism in the 2-arylimino-N-(2-hydroxyphenyl)thiazoline series: influence of hydrogen bonding on the racemization process.

A series of original atropisomeric iminothiazolines 1 in which X = OH or (and) Y = OH were prepared from the corresponding methoxy precursors. The resolution of the atropisomeric enantiomers on chiral support is reported, and the barriers to enantiomerization are given. These barriers were determined either by off-line racemization studies or by treatment of the plateau-shape chromatogram during chromatography on chiral support. When X = OH, the barriers are quite low due to the development of a hydrogen bond between the proton of the OH group and the nitrogen of the imino group. For these compounds, plateau shape chromatograms were obtained during HPLC on chiral support. DFT calculations confirmed the occurrence of hydrogen bonding all along the rotation process and produced calculated barriers in close agreement with the experimental data. Compound 1i (OH, OH) in which both X and Y are hydroxy groups was particularly easy to prepare by demethylation with BBr3 of the dimethoxy precursor. Since the above-mentioned precursor is readily available from N,N'-bis(2-methoxyphenyl)thiourea and 1-chloropropan-2-one, 1i (OH, OH) is a good candidate for further functionalization. Atropisomerism in a 12-membered bridged bisether prepared from 1i (OH, OH) is reported as an illustrating example.

One-pot synthesis of 5-arylidene-2-imino-4-thiazolidinones under microwave irradiation.

A rapid and easy solvent free one-pot synthesis of 5-arylidene-2-imino-4-thiazolidinones by condensation of the thioureas with chloroacetic acid and an aldehyde under microwave-irradiation is described.