Search

In the title molecule, C25H29N5O, the dihydroquinoxaline unit is not quite planar (r.m.s. deviation = 0.030 Å) as there is a dihedral angle of 2.69 (3)° between the mean planes of the constituent rings and the molecule adopts a hairpin conformation. In the crystal, the polar portions of the molecules are associated through C—H...O and C—H...N hydrogen bonds and C—H...π(ring) and C=O...π(ring) interactions, forming thick layers parallel to the bc plane and with the n-octyl groups on the outside surfaces.

In the title compound, C31H24N4O2, the dihydroquinoxaline units are both essentially planar with the dihedral angle between their mean planes being 64.82 (4)°. The attached phenyl rings differ significantly in their rotational orientations with respect to the dihydroquinoxaline planes. In the crystal, one set of C—H...O hydrogen bonds form chains along the b-axis direction, which are connected in pairs by a second set of C—H...O hydrogen bonds. Two sets of π-stacking interactions and C—H...π(ring) interactions join the double chains into the final three-dimensional structure.

In the title compound, C17H12N2O, the quinoxaline moiety shows deviations of 0.0288 (7) to −0.0370 (7) Å from the mean plane (r.m.s. deviation of fitted atoms = 0.0223 Å). In the crystal, corrugated layers two molecules thick are formed by C—H...N hydrogen bonds and π-stacking interactions.

The quinoxaline moiety in the title molecule, C13H13ClN2O3, is almost planar (r.m.s. deviation of the fitted atoms = 0.033 Å). In the crystal, C—H...O hydrogen bonds plus slipped π-stacking and C—H...π(ring) interactions generate chains of molecules extending along the b-axis direction. The chains are connected by additional C—H...O hydrogen bonds. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (37.6%), H...O/O...H (22.7%) and H...Cl/Cl...H (13.1%) interactions.

In the title compound, C31H24N4O2, the quinoxaline units are distinctly non-planar and twisted end-to-end. In the crystal, C—H...O and C—H...N hydrogen bonds link the molecules into chains extending along the a-axis direction. The chains are linked through π-stacking interactions between inversion-related quinoxaline moieties.

Ten new isatin derivatives (2–11) were synthesized by alkylation reactions under phase transfer catalysis (PTC) conditions. Structural characterization of all compounds was performed using 1H and 13C NMR spectroscopy. The molecular and crystal structures of three compounds (4, 7, and 8) were confirmed through single-crystal X-ray diffraction analysis. Spectral data were also calculated using density function theory (DFT) at the B3LYP/6–311++G(d, p) level and compared to the experimental results, to understand the non-binding intermolecular interactions in the solid phase crystal packing. The closest contacts between atoms of the three molecules studied were identified by 2D and 3D Hirshfeld surface analyses. The structures of 4, 7 and 8 are optimized and their HOMO and LUMO energies, as well as their orbital pictures were evaluated. The experimental results correlated well with the calculated results. Finally, molecular docking studies of 4, 7 and 8 were performed to investigate their binding patterns with inhibitory targets from the Protein Data Bank (PDB: 3G7B and PDB: 3T0T using the AutoDock Vina program. The antibacterial activities of 2–11 against Gram-positive and Gram-negative microbial strains, such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were evaluated, and the findings indicated that 4 and 8 exhibited the highest efficacy, as reflected in their minimal inhibitory concentration (MIC) values.

Overall, drug design is a dynamic and evolving field, with researchers constantly working to improve their understanding of molecular interactions, develop new computational methods, and explore innovative techniques for creating effective and safe medications. The process can involve steps such as the identification of targets, the discovery of lead compounds, lead optimization, preliminary testing, human trials, regulatory approval and finally post-marketing surveillance, all aimed at bringing a new drug from concept to market. In this article, the synthesis of the novel triazolequinoxalin (TZQ) 1-((1-hexyl-1H-1,2,3-triazol-5-yl)methyl)-3-phenylquinoxalin-2(1H)-one (4) is reported. The structure has been identified with a variety of spectroscopic methods (1H, 13C NMR, and LC-MS) and finally, the structure has been determined by X-ray diffraction (XRD) studies. The TZQ molecule has crystallized in the monoclinic space C2/c group with unit cell dimensions a = 41.201(2) Å, b = 10.6339(6) Å, c = 9.4997(4) Å, β = 93.904(4). The crystal structure is stabilized by intermolecular interactions (N–H ⋯ O and N–H … Cg) occurring within the molecule. The presence of these intermolecular interactions is evaluated through analysis of Hirshfeld surfaces (HS) and two-dimensional (2D) chemical fingerprints map. Additionally, energy frameworks were employed to identify the prevailing interaction energy influencing the molecular arrangement. Density Functional Theory (DFT) calculations were computed to establish concurrence between theoretical and experimental results. Furthermore, the HOMO-LUMO energy levels were determined using the B3LYP/6-31+G(d, p) level of theory. Finally, molecular docking was used to predict the anti-cancer activity of the compound (4) against PFKFB3 kinase and presented noticeable hydrophilic and hydrophobic interactions at the active site region.

The majority of the title molecule, C28H34ClN3O9S, is disordered over two closely spaced sets of sites; the site occupancy of the major component = 0.542 (3). The conformation of each component is approximately U-shaped with the chlorobenzene ring forming the base and the indolinyl and sulfamoyl groups the sides; an intramolecular C—H...Cl hydrogen bond possibly contributes to the stabilization of the conformation. In the crystal, a corrugated layer structure parallel to the ab plane is formed by C—H...O and C—H...Cl hydrogen bonds together with C—H...π(ring) interactions.

This study investigated the crystallographic and electronic properties of 1,5-benzodiazepine compounds, namely: cis-(3S,4S)-3-hydroxy-7,8-dimethyl-4-phenyl-1,3,4,5-tetrahydro-1,5-benzodiazepin-2-one 3b, trans-(3R,4R)-1-ethyl-3-hydroxy-7,8-dimethyl-4-phenyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one 4, and trans-(3S,4S) 1-ethyl-3-ethoxy-7,8-dimethyl-4-phenyl-1,3,4,5-tetrahydro-1,5-benzodiazepin-2-one 5. Hirshfeld surface analysis was also applied to discern the intermolecular interactions, highlighting the significance of hydrogen bonding, van der Waals forces, and the influence of specific substituents. Furthermore, the MESP maps created using the density functional theory revealed the electrostatic nature of these molecules. The absence of dark blue regions on the MESP maps and variations due to different functional groups and substitutions were noteworthy findings. Collectively, this research offers crucial insights into the behaviour, interactions, and potential applications of new compounds. Finally, the anticancer effects of compounds 3b, 4, and 5 were evaluated against three cancer cell lines and one normal cell line, and the results showed that 3b and 4 had potent antiproliferative effects against all three cancer cell lines.

The asymmetric unit of the title compound, C14H13NO4, contains three independent molecules, which differ slightly in conformation. Each contains an intramolecular N—H...O hydrogen bond. In the crystal, O—H...O hydrogen bonds form chains of molecules, which are linked into corrugated sheets parallel to (\overline{1}03) plane by C—H...O hydrogen bonds together with π interactions between the carbonyl groups and the 2-hydroxyphenyl rings. The layers are linked by further C—H...O hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (49.0%), H...O/O...H (28.3%) and H...C/C...H (10.9%) interactions. van der Waals interactions are the dominant interactions in the crystal packing. Moreover, density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behavior was elucidated to determine the energy gap of 4.53 eV.

The quinoxaline moiety in the title molecule, C18H17N3O2, is not quite planar and the p-tolyl group is rotationally disordered over two nearly equally populated sets of sites. In the crystal, N—H...O and C—H...O hydrogen bonds form chains extending along the b-axis direction. Due to the disorder of the p-tolyl rings, short C...C distances are observed between adjacent chains.

The quinoxaline unit in the title molecule, C18H16N4O5, is slightly puckered [dihedral angle between the rings = 2.07 (12)°] while the whole molecule adopts an L-shaped conformation. Intramolecular hydrogen bonding determines the orientation of the substituted phenyl ring and the amide nitrogen atom is almost planar. The packing in the crystal is governed by C—H...O hydrogen bonds and slipped π-stacking interactions.

In the title compound, C12H10ClNO3, the dihydroquinoline moiety is not planar with a dihedral angle between the two ring planes of 1.61 (6)°. An intramolecular C—H...O hydrogen bond helps to establish the rotational orientation of the carboxyl group. In the crystal, sheets of molecules parallel to (10\overline{1}) are generated by C—H...O and C—H...Cl hydrogen bonds, and are stacked through slipped π-stacking interactions between inversion-related dihydroquinoline units. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (34.2%), H...O/O...H (19.9%), H...Cl/Cl...H (12.8%), H...C/C...H (10.3%) and C...C (9.7%) interactions. Computational chemistry indicates that in the crystal, the C—H...Cl hydrogen-bond energy is −37.4 kJ mol−1, while the C—H...O hydrogen-bond energies are −45.4 and −29.2 kJ mol−1. An evaluation of the electrostatic, dispersion and total energy frameworks revealed that the stabilization is dominated via the dispersion energy contribution. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state, and the HOMO—LUMO behaviour was elucidated to determine the energy gap.

A retro-Claisen reaction of 1-(4-oxo-4H-pyrido [1,2-a]pyrimidin-3-yl)butane-1,3-dione, 3, in the presence of potassium hydroxide and 4-dimethylamino-pyridine has been carried out, leading to 4-(dimethylamino)pyridin-1-ium 2-methyl-4-oxo-pyrido [1,2-a]pyrimidine-3-carboxylate 5. A plausible mechanism explaining the formation of the title compound has been proposed. A single-crystal X-ray diffraction analysis confirms the crystal structure of the isolated organic salt (5). In the crystal, the title compound adopts a layered structure where there are stacks of cations and anions formed by slipped π-stacking interactions. These stacks are linked by regions consisting of water molecules that are hydrogen-bonded together. DFT and Hirshfeld surface analysis supported the experimental results of the molecular geometry and the intercontacts between different units in the crystal. The druglikeness, ADMET properties, and predicted targets were investigated, and the observed results suggest that 5 may act as a carbonic anhydrase I inhibitor. The assumption is confirmed by docking 5 into the active binding site of carbonic anhydrase, which shows it to have good binding affinities and to form stable complexes with the active residues of carbonic anhydrase I.

The title compound {systematic name: (S,E)-3-[4-(furan-2-yl)-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-2-ylidene]-6-methyl-2H-pyran-2,4(3H)-dione}, C19H16N2O4, is constructed from a benzodiazepine ring system linked to furan and pendant dihydropyran rings, where the benzene and furan rings are oriented at a dihedral angle of 48.7 (2)°. The pyran ring is modestly non-planar [largest deviation of 0.029 (4) Å from the least-squares plane] while the tetrahydrodiazepine ring adopts a boat conformation. The rotational orientation of the pendant dihydropyran ring is partially determined by an intramolecular N—HDiazp...ODhydp (Diazp = diazepine and Dhydp = dihydropyran) hydrogen bond. In the crystal, layers of molecules parallel to the bc plane are formed by N—HDiazp...ODhydp hydrogen bonds and slipped π–π stacking interactions. The layers are connected by additional slipped π–π stacking interactions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (46.8%), H...O/O...H (23.5%) and H...C/C...H (15.8%) interactions, indicating that van der Waals interactions are the dominant forces in the crystal packing. Computational chemistry indicates that in the crystal the N—H...O hydrogen-bond energy is 57.5 kJ mol−1.

The title molecule, C20H15NO3, adopts a Z-shaped conformation with the carboxyl group nearly coplanar with the dihydroquinoline unit. In the crystal, corrugated layers are formed by C—H...O hydrogen bonds and are stacked by C—H...π(ring) interactions. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (43.3%), H...C/C...H (26.6%) and H...O/O...H (16.3%) interactions. The optimized structure calculated using density functional theory at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO–LUMO energy gap is 4.0319 eV.

The title molecule, C13H16N4O, adopts an angular conformation. In the crystal a layer structure is generated by N—H...O and N—H...N hydrogen bonds together with C—H...π(ring) interactions. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (53.8%), H...C/C...H (21.7%), H...N/N...H (13.6%), and H...O/O...H (10.8%) interactions. The optimized structure calculated using density functional theory (DFT) at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO–LUMO energy gap is 5.0452 eV.

In the title molecule, C18H16N2O3, the dihydroquinoxaline moiety, with the exception of the N atom is essentially planar with the inner part of the methylpropanoate group (CH2—CH2—O) nearly perpendicular to it. In the crystal, inversion dimers formed by C—H...O hydrogen bonds are connected into oblique stacks by π-stacking and C—H...π(ring) interactions.

The quinoxaline portion of the title molecule, C21H19N5O3, is not quite planar as indicated by a dihedral angle of 3.38 (7)° between the constituent rings. The molecule is `U-shaped', which is consolidated by an intramolecular antiparallel carbonyl electrostatic interaction with C··O distances of 2.8905 (16) and 3.0221 (15) Å, in the crystal forms corrugated layers through C—H...O and C—H...N hydrogen bonds and C—H...π(ring) and π-stacking interactions.

The title molecule, C17H26N2O, adopts an L-shaped conformation, with the straight n-decyl chain positioned nearly perpendicular to the dihydrobenzimidazole moiety. The dihydrobenzimidazole portion is not quite planar as there is a dihedral angle of 1.20 (6)° between the constituent planes. In the crystal, N—H...O hydrogen bonds form inversion dimers, which are connected into the three-dimensional structure by C—H...O hydrogen bonds and C—H...π(ring) interactions. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H...H (75.9%), H...C/C...H (12.5%) and H...O/O...H (7.0%) interactions. Based on computational chemistry using the CE–B3LYP/6–31 G(d,p) energy model, C—H...O hydrogen bond energies are −74.9 (for N—H...O) and −42.7 (for C—H...O) kJ mol−1.

In the title molecule, C13H13N3O, the isoxazole ring is inclined to the benzimidazole ring at a dihedral angle of 69.28 (14)°. In the crystal, N—H...N hydrogen bonds between neighboring benzimidazole rings form chains along the a-axis direction. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (48.8%), H...C/C...H (20.9%) and H...N/N...H (19.3%) interactions. The optimized structure calculated using density functional theory at the B3LYP/6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gap is 4.9266 eV.

In this work, we describe the synthesis of new macrocycles derived from 3-phenyl-1,2,4-triazole-5-thione 1 in a heterogeneous medium using liquid–solid phase transfer catalysis (PTC) conditions. The structures of the two compounds (3 and 4) isolated were elucidated based on spectral data (1H-NMR, 13C-NMR) and confirmed in the case of 3-phenyl-1,2,4-triazolo [3,4-h]-13,4--thiaza-11-crown-4 (3) by a single-crystal X-ray diffraction analysis. Furthermore, the experimental spectral and the X-ray geometrical parameters were compared with their corresponding predicted ones obtained at the B3LYP/6-311++G(d,p) level of theory. The intercontacts between crystal units were investigated through Hirshfeld surface analysis. The drug-like macrocycles were predicted using ADMET and drug-likeness properties, which showed that 3 may act as an inhibitor of DNA-dependent protein kinase (DNA-PK). This assumption was confirmed by the well-binding fitting of 3 into the binding site of DNA-PK and the formation of a stable 3-DNA-PK complex with a binding energy of −7 kcal-mol−1. Finally, the anticancer activity of 3 was assessed by an MTT assay against A549 cells, which showed that 3 has moderate anticancer activity compared to that of the doxorubicin reference drug.

The asymmetric unit of the title compound, C17H14N2O, contains two independent molecules each consisting of perimidine and phenol units. The tricyclic perimidine units contain naphthalene ring systems and non-planar C4N2 rings adopting envelope conformations with the C atoms of the NCN groups hinged by 44.11 (7) and 48.50 (6)° with respect to the best planes of the other five atoms. Intramolecular O—H...N hydrogen bonds may help to consolidate the molecular conformations. The two independent molecules are linked through an N—H...O hydrogen bond. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (52.9%) and H...C/C...H (39.5%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

The title compound, C22H25NOS, consists of methylbenzylidene and benzothiazine units linked to a hexyl moiety, where the thiazine ring adopts a screw-boat conformation. In the crystal, inversion dimers are formed by weak C—HMthn...OBnzthz hydrogen bonds and are linked into chains extending along the a-axis direction by weak C—HBnz...OBnzthz (Bnz = benzene, Bnzthz = benzothiazine and Mthn = methine) hydrogen bonds. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (59.2%) and H...C/C...H (27.9%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the C—HBnz...OBnzthz and C—HMthn...OBnzthz hydrogen-bond energies are 75.3 and 56.5 kJ mol−1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO—LUMO behaviour was elucidated to determine the energy gap. Moreover, the antibacterial activity of the title compound was evaluated against gram-positive and gram-negative bacteria.

The asymmetric unit of the title compound, C22H31NO3, comprises of one molecule. The molecule is not planar, with the carboxylate ester group inclined by 33.47 (4)° to the heterocyclic ring. Individual molecules are linked by aromaticC—H...Ocarbonyl hydrogen bonds into chains running parallel to [001]. Slipped π–π stacking interactions between quinoline moieties link these chains into layers extending parallel to (100). Hirshfeld surface analysis, two-dimensional fingerprint plots and molecular electrostatic potential surfaces were used to quantify the intermolecular interactions present in the crystal, indicating that the most important contributions for the crystal packing are from H...H (72%), O...H/H...O (14.5%) and C...H/H...C (5.6%) interactions.

The title compound, C19H16ClNO3S, consists of chlorophenyl methylidene and dihydrobenzothiazine units linked to an acetate moiety, where the thiazine ring adopts a screw-boat conformation. In the crystal, two sets of weak C—HPh...ODbt (Ph = phenyl and Dbt = dihydrobenzothiazine) hydrogen bonds form layers of molecules parallel to the bc plane. The layers stack along the a-axis direction with intercalation of the ester chains. The crystal studied was a two component twin with a refined BASF of 0.34961 (5). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H...H (37.5%), H...C/C...H (24.6%) and H...O/O...H (16.7%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, C—HPh...ODbt hydrogen bond energies are 38.3 and 30.3 kJ mol−1. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. Moreover, the antibacterial activity of the title compound has been evaluated against gram-positive and gram-negative bacteria.

The title compound, C18H16N2O2, consists of perimidine and methoxyphenol units, where the tricyclic perimidine unit contains a naphthalene ring system and a non-planar C4N2 ring adopting an envelope conformation with the NCN group hinged by 47.44 (7)° with respect to the best plane of the other five atoms. In the crystal, O—HPhnl...NPrmdn and N—HPrmdn...OPhnl (Phnl = phenol and Prmdn = perimidine) hydrogen bonds link the molecules into infinite chains along the b-axis direction. Weak C—H...π interactions may further stabilize the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (49.0%), H...C/C...H (35.8%) and H...O/O...H (12.0%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the O—HPhnl...NPrmdn and N—HPrmdn...OPhnl hydrogen-bond energies are 58.4 and 38.0 kJ mol−1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

A new triazolopyrimidine derivative, namely, 6-hydroxy-7-phenyl-6,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-one (HPTP) was synthesized. Its corrosion inhibition performance on mild steel in 1 M HCl solution was researched through weight loss, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) approaches. The experimental results show that the inhibition efficiency of HPTP increases with the increase of concentrations, whereas decreases as the temperature rises. PDP data reveal that the HPTP acts as a mixed type inhibitor. EIS results imply that the HPTP molecules form an antiseptic layer at the steel/solution interface. The adsorption of the inhibitor molecules on the steel surface follows Langmuir's adsorption isotherm. In addition, density functional theory (DFT) calculations were also employed to gain further insight into the adsorption behavior and inhibition mechanism.

The title compound, C15H14N2O2, consists of pyrrole and benzodiazepine units linked to a propargyl moiety, where the pyrrole and diazepine rings adopt half-chair and boat conformations, respectively. The absolute configuration was assigned on the the basis of l-proline, which was used in the synthesis of benzodiazepine. In the crystal, weak C—HBnz...ODiazp and C—HProprg...ODiazp (Bnz = benzene, Diazp = diazepine and Proprg = propargyl) hydrogen bonds link the molecules into two-dimensional networks parallel to the bc plane, enclosing R44(28) ring motifs, with the networks forming oblique stacks along the a-axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (49.8%), H...C/C...H (25.7%) and H...O/O...H (20.1%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, C—H...O hydrogen-bond energies are 38.8 (for C—HBnz...ODiazp) and 27.1 (for C—HProprg...ODiazp) kJ mol−1. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

In the title molecule, C12H13N3O2S, the benzothiazine moiety is slightly non-planar, with the imidazolidine portion twisted only a few degrees out of the mean plane of the former. In the crystal, a layer structure parallel to the bc plane is formed by a combination of O—HHydethy...NThz hydrogen bonds and weak C—HImdz...OImdz and C—HBnz...OImdz (Hydethy = hydroxyethyl, Thz = thiazole, Imdz = imidazolidine and Bnz = benzene) interactions, together with C—HImdz...π(ring) and head-to-tail slipped π-stacking [centroid-to-centroid distances = 3.6507 (7) and 3.6866 (7) Å] interactions between thiazole rings. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (47.0%), H...O/O...H (16.9%), H...C/C...H (8.0%) and H...S/S...H (7.6%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, C—H...N and C—H...O hydrogen-bond energies are 68.5 (for O—HHydethy...NThz), 60.1 (for C—HBnz...OImdz) and 41.8 kJ mol−1 (for C—HImdz...OImdz). Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state.

The title compound, C24H27Cl2NOS, contains 1,4-benzothiazine and 2,4-dichlorophenylmethylidene units in which the dihydrothiazine ring adopts a screw-boat conformation. In the crystal, intermolecular C—HBnz...OThz (Bnz = benzene and Thz = thiazine) hydrogen bonds form chains of molecules extending along the a-axis direction, which are connected to their inversion-related counterparts by C—HBnz...ClDchlphy (Dchlphy = 2,4-dichlorophenyl) hydrogen bonds and C—HDchlphy...π (ring) interactions. These double chains are further linked by C—HDchlphy...OThz hydrogen bonds, forming stepped layers approximately parallel to (012). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (44.7%), C...H/H...C (23.7%), Cl...H/H...Cl (18.9%), O...H/H...O (5.0%) and S...H/H...S (4.8%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, C—HDchlphy...OThz, C—HBnz...OThz and C—HBnz...ClDchlphy hydrogen-bond energies are 134.3, 71.2 and 34.4 kJ mol−1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. The two carbon atoms at the end of the nonyl chain are disordered in a 0.562 (4)/0.438 (4) ratio.

In the title molecule, C24H21N5O·H2O, the dihydrobenzodiazole moiety is not quite planar, while the whole molecule adopts a U-shaped conformation in which there is a close approach of the two benzyl groups. In the crystal, chains of alternating molecules and lattice water extending along [201] are formed by O—HUncoordW...ODhyr and O—HUncoordW...NTrz (UncoordW = uncoordinated water, Dhyr = dihydro and Trz = triazole) hydrogen bonds. The chains are connected into layers parallel to (010) by C—HTrz...OUncoordW hydrogen bonds with the dihydrobenzodiazole units in adjacent layers intercalating to form head-to-tail π-stacking [centroid-to-centroid distance = 3.5694 (11) Å] interactions between them, which generates the overall three-dimensional structure. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H...H (52.1%), H...C/C...H (23.8%) and O...H/H...O (11.2%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

In the title molecule, C13H16N4O3, the mean planes of the phenyl and triazole rings are nearly perpendicular to one another as a result of the intramolecular C—H...O and C—H...π(ring) interactions. In the crystal, layers parallel to (101) are generated by O—H...N, N—H...O and N—H...N hydrogen bonds. The layers are connected by inversion-related pairs of C—H...O hydrogen bonds. The experimental molecular structure is close to the gas-phase geometry-optimized structure calculated by DFT methods. Hirshfeld surface analysis indicates that the most important interaction involving hydrogen in the title compound is the H...H contact. The contribution of the H...O, H...N, and H...H contacts are 13.6, 16.1, and 54.6%, respectively.

In the title molecule, C11H10N2O, the dihydrobenzimidazol-2-one moiety is essentially planar, with the prop-2-yn-1-yl substituent rotated well out of this plane. In the crystal, C—HMthy...π(ring) interactions and C—HProp...ODhyr (Mthy = methyl, Prop = prop-2-yn-1-yl and Dhyr = dihydro) hydrogen bonds form corrugated layers parallel to (10\overline{1}), which are associated through additional C—HBnz...ODhyr (Bnz = benzene) hydrogen bonds and head-to-tail, slipped, π-stacking [centroid-to-centroid distance = 3.7712 (7) Å] interactions between dihydrobenzimidazol-2-one moieties. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H...H (44.1%), H...C/C...H (33.5%) and O...H/H...O (13.4%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry calculations indicate that in the crystal, C—H...O hydrogen-bond energies are 46.8 and 32.5 (for C—HProp...ODhyr) and 20.2 (for C—HBnz...ODhyr) kJ mol−1. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

In this work, we are interested in the synthesis of new N-glucosyl 1,4-benzothiazin-3-ones by grafting 5,6-anhydro-3-O-alkyl-1,2-O-isopropylidene-α-D-glucofuranoses onto (Z)-2-benzylidene-3,4-dihydro-2H-1,4-benzothiazin-3-one 1. Deprotection of compounds 3a-c was performed in the mixture CF3COOH-H2O (9/1: v/v) leading to the corresponding compounds 4a-c with good yields. The structures of the synthesized compounds have been characterized using 1H NMR and 13C NMR. Compounds 3a-c and 4a-c were subjected to the evaluation of antibacterial activity. Some compounds tested showed significant activity.

The title compound, C22H15Cl2NOS, contains 1,4-benzothiazine and 2,4-dichlorobenzylidene units, where the dihydrothiazine ring adopts a screw-boat conformation. In the crystal, intermolecular C—HBnz...OThz (Bnz = benzene and Thz = thiazine) hydrogen bonds form corrugated chains extending along the b-axis direction which are connected into layers parallel to the bc plane by intermolecular C—HMethy...SThz (Methy = methylene) hydrogen bonds, enclosing R44(22) ring motifs. Offset π-stacking interactions between 2,4-dichlorophenyl rings [centroid–centroid = 3.7701 (8) Å] and π-interactions which are associated by C—HBnz...π(ring) and C—HDchlphy...π(ring) (Dchlphy = 2,4-dichlorophenyl) interactions may be effective in the stabilization of the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (29.1%), H...C/C...H (27.5%), H...Cl/Cl...H (20.6%) and O...H/H...O (7.0%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the C—HBnz...OThz and C—HMethy...SThz hydrogen-bond energies are 55.0 and 27.1 kJ mol−1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/6-311G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

The bicyclic imidazo[1,2-a]pyridine core of the title compound, C19H19N3, is relatively planar with an r.m.s. deviation of 0.040 Å. The phenyl ring is inclined to the mean plane of the imidazo[1,2-a]pyridine unit by 18.2 (1)°. In the crystal, molecules are linked by N—H...H hydrogen bonds, forming chains along the c-axis direction. The chains are linked by C—H...π interactions, forming slabs parallel to the ac plane. The Hirshfeld surface analysis and fingerprint plots reveal that the crystal structure is dominated by H...H (54%) and C...H/H...C (35.6%) contacts. The crystal studied was refined as an inversion twin

A new quinoline-based compounds have been synthesized from 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (2) and involved in alkylation reactions using phase transfer catalysis conditions. The esterification and protection of the carboxylic acid function of (2) have been also studied. The structures of the prepared compounds have been determined by spectroscopic methods: IR, 1H NMR, 13C NMR and the structure of compound 4 was confirmed by single crystal X-ray diffraction. The antioxidant activity of these compounds was evaluated using DPPH, FRAP and β-carotene bleaching techniques. Their antimicrobial activity was evaluated against E. coli, S. aureus, B. subtilis, B. cereus and Salmonella typhi using a microplate protocol.

In the title molecule, C17H23NO2, the dihydroindole portion is planar (r.m.s. deviation = 0.0157 Å) and the nonyl substituent is in an `extended' conformation. In the crystal, the nonyl chains intercalate and the dihydroindoledione units are associated through C—H...O hydrogen bonds to form micellar blocks. Based on the Hirshfeld surface analysis, the most important intermolecular interaction is the H...H interaction.

In the title quinoline derivative, C24H19NO3, the two benzyl rings are inclined to the quinoline ring mean plane by 74.09 (8) and 89.43 (7)°, and to each other by 63.97 (10)°. The carboxylate group is twisted from the quinoline ring mean plane by 32.2 (2)°. There is a short intramolecular C—H...O contact forming an S(6) ring motif. In the crystal, molecules are linked by bifurcated C—H,H...O hydrogen bonds, forming layers parallel to the ac plane. The layers are linked by C—H...π interactions, forming a supramolecular three-dimensional structure.

The title compound, C18H12Cl2N2OS, consists of a dihydrobenzothiazine unit linked by a –CH group to a 2,4-dichlorophenyl substituent, and to a propanenitrile unit is folded along the S...N axis and adopts a flattened-boat conformation. The propanenitrile moiety is nearly perpendicular to the mean plane of the dihydrobenzothiazine unit. In the crystal, C—HBnz...NPrpnit and C—HPrpnit...OThz (Bnz = benzene, Prpnit = propanenitrile and Thz = thiazine) hydrogen bonds link the molecules into inversion dimers, enclosing R22(16) and R22(12) ring motifs, which are linked into stepped ribbons extending along [110]. The ribbons are linked in pairs by complementary C=O...Cl interactions. π–π contacts between the benzene and phenyl rings, [centroid–centroid distance = 3.974 (1) Å] may further stabilize the structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (23.4%), H...Cl/Cl...H (19.5%), H...C/C...H (13.5%), H...N/N...H (13.3%), C...C (10.4%) and H...O/O...H (5.1%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry calculations indicate that the two independent C—HBnz...NPrpnit and C—HPrpnit...OThz hydrogen bonds in the crystal impart about the same energy (ca 43 kJ mol−1). Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

In the title quinoline derivative, C14H14ClNO3, there is an intramolecular C—H...O hydrogen bond forming an S(6) graph-set motif. The molecule is essentially planar with the mean plane of the ethyl acetate group making a dihedral angle of 5.02 (3)° with the ethyl 6-chloro-2-ethoxyquinoline mean plane. In the crystal, offset π–π interactions with a centroid-to-centroid distance of 3.4731 (14) Å link inversion-related molecules into columns along the c-axis direction. Hirshfeld surface analysis indicates that H...H contacts make the largest contribution (50.8%) to the Hirshfeld surface.

The title compound, C20H16Cl2N2O3S, is built up from a dihydrobenzothiazine moiety linked by –CH– and –C2H4– units to 2,4-dichlorophenyl and 2-oxo-1,3-oxazolidine substituents, where the oxazole ring and the heterocyclic portion of the dihydrobenzothiazine unit adopt envelope and flattened-boat conformations, respectively. The 2-carbon link to the oxazole ring is nearly perpendicular to the mean plane of the dihydrobenzothiazine unit. In the crystal, the molecules form stacks extending along the normal to (104) with the aromatic rings from neighbouring stacks intercalating to form an overall layer structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (28.4%), H...Cl/Cl...H (19.3%), H...O/O...H (17.0%), H...C/C...H (14.5%) and C...C (8.2%) interactions. Weak hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO—LUMO behaviour was elucidated to determine the energy gap.

In the title molecule, C19H16N4O, the planar pyrazolopyrimidine moiety is inclined to the attached phenyl rings by 35.42 (4) and 54.51 (6)°. In the crystal, adjacent molecules are linked into chains parallel to [110] and [1\overline{1}0] by C—H...O and C—H...N hydrogen bonds. Additional C—H...π(ring) interactions lead to the formation of the final three-dimensional network structure. The Hirshfeld surface analysis of the title compound suggests that the most significant contributions to the crystal packing are from H...H (48.2%), C...H/H...C (23.9%) and N...H/H...N (17.4%) contacts.

The title compound, C18H12FNOS, is built up from a 4-fluorobenzylidene moiety and a dihydrobenzothiazine unit with a propynyl substituent, with the heterocyclic portion of the dihydrobenzothiazine unit adopting a shallow boat conformation with the propynyl substituent nearly perpendicular to it. The two benzene rings are oriented at a dihedral angle of 43.02 (6)°. In the crystal, C—HFlurphen...FFlurphen (Flurphen = fluorophenyl) hydrogen bonds link the molecules into inversion dimers, enclosing R22(8) ring motifs, with the dimers forming oblique stacks along the a-axis direction. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H...H (33.9%), H...C/C...H (26.7%), H...F/F...H (10.9%) and C...C (10.6%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

The title compound, C17H18N2O3, is constructed from a benzodiazepine ring system linked to a pendant dihydropyran ring, where the benzene and pendant dihydropyran rings are oriented at a dihedral angle of 15.14 (4)°. Intramolecular N—HDiazp...ODhydp and C—HDiazp...ODhydp (Diazp = diazepine and Dhydp = dihydropyran) hydrogen bonds link the seven-membered diazepine ring to the pendant dihydropyran ring, enclosing S(6) ring motifs. In the crystal, N—HDiazp...ODhydp hydrogen bonds link the molecules into infinite chains along [10\overline{1}]. These chains are further linked via C—HBnz...ODhydp, C—HDhydp...ODhydp and C—HMth...ODhydp (Bnz = benzene and Mth = methyl) hydrogen bonds, forming a three-dimensional network. The observed weak C—HDiazp ... π interaction may further stabilize the structure. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (51.1%), H...C/C...H (25.3%) and H...O/O...H (20.3%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing.

The asymmetric unit of the title compound, C20H20N4O·0.5H2O, contains two independent organic molecules (1 and 2) and a water molecule of crystallization. The two molecules differ primarily in the dihedral angles between the aromatic rings, which are 7.79 (7) and 29.89 (7)° in molecules 1 and 2, respectively. In each molecule there is intramolecular C—H...O hydrogen bond forming an S(6) ring motif. In molecule 1 there is an intramolecular N—H...π(pyrazole) interaction and an intramolecular C—H...π(pyrazole) interaction present. Molecule 1 is linked to molecule 2 by a C—H...π(benzene ring) interaction. An intramolecular N—H...N hydrogen bond and an intramolecular C—H...N hydrogen bond are also present in molecule 2. In the crystal, the three components are linked by Owater—H...N, N—H...Owater and N—H...N hydrogen bonds, forming chains along the [100] direction. The chains are linked by C—H...O and C—H...N hydrogen bonds, forming layers parallel to the ab plane. Finally, the layers are linked by C—H...π interactions, forming a three-dimensional structure.

In the title molecule, C21H25N3O, the 1-decyl substituents are in an extended conformation and intercalate in the crystal packing to form hydrophobic bands. The packing is further organized by π–π-stacking interactions between pyrrole and phenyl rings [centroid–centroid distance = 3.6178 (11) Å] and a C=O...π(pyrrole) interaction [3.447 (2) Å]. Hirshfeld surface analysis indicates that the H...N/N...H interactions make the highest contribution (17.4%) to the crystal packing.

In the title compound, C10H8Cl2N2O, the seven-membered diazepine ring adopts a boat-shaped conformation. The mean planes of the two rings of the benzodiazepine unit are inclined to each other by 22.05 (6)°. In the crystal, molecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(8) ring motif. The dimers are linked by C—H...π interactions, forming layers lying parallel to (10\overline{1}). The roles of the intermolecular interactions in the crystal packing were clarified using Hirshfeld surface analysis; the most important contributions are from Cl...H/H...Cl (30.5%) and H...H (22.5%) interactions.

The title compound, C20H17N3O3 [systematic name: 2-(6-methyl-2,4-dioxopyran-3-ylidene)-4-(pyridin-4-yl)-2,3,4,5-tetrahydro-1H-1,5-benzodiazepine], is built up from a benzodiazepine ring system linked to pyridyl and pendant dihydropyran rings, where the benzene and pyridyl rings are oriented at a dihedral angle of 43.36 (6)°. The pendant dihydropyran ring is rotationally disordered in a 90.899 (3):0.101 (3) ratio with the orientation of each component largely determined by intramolecular N—HDiazp...ODhydp (Diazp = diazepine and Dhydp = dihydropyran) hydrogen bonds. In the crystal, molecules are linked via pairs of weak intermolecular N—HDiazp...ODhydp hydrogen bonds, forming inversion-related dimers with R22(26) ring motifs. The dimers are further connected along the b-axis direction by π–π stacking interactions between the pendant dihydropyran and pyridyl rings with centroid–centroid distances of 3.833 (3) Å and a dihedral angle of 14.51 (2)°. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (50.1%), H...C/C...H (17.7%), H...O/O...H (16.8%), C...C (7.7%) and H...N/N...H (5.3%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing.