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Two series of new 3,5-disubstituted-pyrazole-1-carbothioamides (4a-f and 5a-e) were designed and synthesized through condensation reaction between chalcones and thiosemicarbazides under alkaline condition via cyclocondensation reaction. The structures have been elucidated by Fourier-transform infrared (FTIR), High-resolution mass spectrometry (HRMS), one- and two-dimensional nuclear magnetic resonance (NMR) analyses. These compounds were assayed for in vitro anti-tuberculosis activity against Mycobacterium tuberculosis H37Ra using the Tetrazolium microplate assay (TEMA) method. As a result, six compounds (i.e., 4a, 4d, 4f, 5a, 5c, and 5d) showed a weak activity with minimum inhibition concentration (MIC) between 650–530 μM, and other compounds showed no inhibition against MTB. In addition, all tested compounds also did not show any cidal effects for minimum bactericidal concentration (MBC), even at the highest test concentration.

West Nile virus (WNV) is among the other four flavivirus genus, rapidly spreading worldwide. The number of cases increases globally as there are no clinically available approved drugs and vaccines against this disease. Based on our previous finding related to a flavivirus, a series of spiropyrrolidine derivatives were regioselectively synthesized via [3+2]-cycloaddition reaction of three components between isatins, sarcosine, and (E)-3,5-bis (arylidene)-4-piperidones. The yield of synthesized compounds was in a range between 81–95%. The structures of all the synthesized compounds were characterized using FT-IR, 1D- and 2D-NMR, and HRMS. Molecular docking studies of spiropyrrolidines on NS2B-NS3 protease were done to understand and explore the ligand-receptor interactions and hypothesize the drug's refinements. The inhibition of NS2B-NS3 protease has been considered a promising strategy because this enzyme is responsible for the viral replication process. Among them, compound 5c shows an excellent binding affinity with ‒7.71 kcal/mol free binding energy and an inhibition constant of 1.73 μM. It also showed the binding orientation into the active site of WNV NS2B-NS3 protease on Asn84, Tyr1161, Gly1151, and Gly1153.

A stereoselective chiral Lewis acid promoted reaction of siloxydiene (±)-13 and dienophile complex 18, gave a 4:1 mixture of urdamycinone B (1) and its C-3 epimer (24) in several steps in 12% overall yield. Separation of these products was achieved by high performance liquid chromatography (HPLC). Keywords: Urdamycinone B, Total synthesis, Stereoselectivity, Angucyclinone antibiotics

Abstract Coumarins are the phytochemicals, which belong to the family of benzopyrone, that display interesting pharmacological properties. Several natural, synthetic and semisynthetic coumarin derivatives have been discovered in decades for their applicability as lead structures as drugs. Coumarin based conjugates have been described as potential AChE, BuChE, MAO and β-amyloid inhibitors. Therefore, the objective of this review is to focus on the construction of these pharmacologically important coumarin analogues with anti-Alzheimer’s activities, highlight their docking studies and structure–activity relationships based on their substitution pattern with respect to the selected positions on the chromen ring by emphasising on the research reports conducted in between year 1968 to 2017.

Dibutyl phthalate (DBP) produced by Streptomyces sp. H11809 exerted inhibitory activity against human GSK-3β (Hs GSK-3β) and Plasmodiumfalciparum 3D7 (Pf 3D7) malaria parasites. The current study aimed to determine DBP’s plausible mode of action against Hs GSK-3β and Pf 3D7. Molecular docking analysis indicated that DBP has a higher binding affinity to the substrate-binding site (pocket 2; −6.9 kcal/mol) than the ATP-binding site (pocket 1; −6.1 kcal/mol) of Hs GSK-3β. It was suggested that the esters of DBP play a pivotal role in the inhibition of Hs GSK-3β through the formation of hydrogen bonds with Arg96/Glu97 amino acid residues in pocket 2. Subsequently, an in vitro Hs GSK-3β enzymatic assay revealed that DBP inhibits the activity of Hs GSK-3β via mixed inhibition inhibitory mechanisms, with a moderate IC50 of 2.0 µM. Furthermore, the decrease in Km value with an increasing DBP concentration suggested that DBP favors binding on free Hs GSK-3β over its substrate-bound state. However, the antimalarial mode of action of DBP remains unknown since the generation of a Pf 3D7 DBP-resistant clone was not successful. Thus, the molecular target of DBP might be indispensable for Pf survival. We also identified nocardamine as another active compound from Streptomyces sp. H11809 chloroform extract. It showed potent antimalarial activity with an IC50 of 1.5 μM, which is ~10-fold more potent than DBP, but with no effect on Hs GSK-3β. The addition of ≥12.5 µM ferric ions into the Pf culture reduced nocardamine antimalarial activity by 90% under in vitro settings. Hence, the iron-chelating ability of nocardamine was shown to starve the parasites from their iron source, eventually inhibiting their growth.

In this paper, a highly chemical stable 4,4′,4″-((1,3,5-triazine-2,4,6-triyl)tris(oxy))trianiline (TTA) was successfully synthesized with 4,4′-(4,4′-Isopropylidene-diphenoxy)bis(phthalic anhydride) (BPADA) using direct nucleophilic addition in Dimethylformamide (DMF). The resulting Hyperbranched Polyimide (HPI) was characterized by means of conventional methods such as Fourier transform infra-red (FT-IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy, gel permeation chromatography (GPC), solubility tests, Field Emission Scanning Electron Microscopy (FESEM), Electron Diffraction X-ray analysis (EDX), Vickers hardness test, thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and thermal conductivity. High molecular weight was obtained by extending the reaction time for 2 h. The TTA/BPADA HPI demonstrated a high chemical stability and could be readily used in the precursor state. The thermal curing led to an increase of the imidization degree and greatly improved the thermal stability (Tg above 200 °C, maximum mass loss >500 °C and char yield >55%), due to an increasing chain packing density). Therefore, it is believed that this incorporated HPI structure containing s-triazine moieties in a polyimide system shows potential as a new high performance and highly functional material. Keywords: Hyperbranched polyimide (HPI), S-triazine ring, Degree of imidization, Thermally stable, Highly chemical stable

Abstract A series of novel 4-thiazolidinone inhibitors SKYa–SKYg, containing coumarin as a core structure were synthesized via facile and efficient method. The structures of the synthesized compounds were established by extensive spectroscopic studies (FT IR, 1D NMR, 2D NMR, LC–MS) and elemental analysis. All the synthesized hybrids were further evaluated for their potential as anti-tubercular agents against Mycobacterium tuberculosis H37Rv ATCC 25618, and anti-bacterial agents against Escherichia coli, Enterobacter aerogenes, Salmonella typhi, Streptococcus pneumoniae and Staphylococcus aureus. Interestingly, the hybrids displayed potent bioactivity. However, compounds SKYc, SKYd, and SKYe appeared to be more effective against the tested bacterial strains, among which compound SKYb showed the highest inhibition against all the bacterial strains ranging from 41 to 165 μg/mL, as compared to the standards, streptomycin, kanamycin and vancomycin. Moreover, derivative SKYa was found to be the strongest against M. tuberculosis (83 μg/mL). Additionally, the anti-dengue potential of the coumarin hybrids as two-component NS2B/NS3 DENV flavivirus serine protease inhibitors was calculated using computational molecular docking approach, with reference to the standards 4-hydroxypanduratin, panduratin and ethyl 3-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy)propanoate with DS of − 3.379, − 3.189 and − 3.381, respectively. The docking results revealed that the synthesized hybrids exhibited potent anti-dengue activity among which compounds SKYf, SKYd, SKYc and SKYe were found to be the best ones with docking scores of − 4.014, − 3.964, − 3.905 and − 3.889. In summary, we discovered 4-thiazolidinone coumarin derivatives as a new scaffold that may eventually yield useful compounds in the treatment of bacterial and viral infections.

Abstract Background Costus speciosus, Cymbopogon citratus, and Tabernaemontana coronaria are herbal plants traditionally used as remedies for symptoms of tuberculosis (TB) including cough. The aims of the present study were to evaluate the in vitro anti-TB activity of different solvent partitions of these plants, to identify the phytochemical compounds, and to assess the effects of the most active partitions on the growth kinetics and cellular integrity of the tubercle organism. Methods The in vitro anti-TB activity of different solvent partitions of the plant materials was determined against M. tuberculosis H37Rv using a tetrazolium colorimetric microdilution assay. The phytochemical compounds in the most active partition of each plant were identified using gas chromatography-mass spectrometry (GC-MS) analysis. The effects of these partitions on the growth kinetics of the mycobacteria were evaluated over 7-day treatment period in a batch culture system. Their effects on the mycobacterial cellular integrity were observed under a scanning electron microscope (SEM). Results The respective n-hexane partition of C. speciosus, C. citratus, and T. coronaria exhibited the highest anti-TB activity with minimum inhibitory concentrations (MICs) of 100–200 μg/mL and minimum bactericidal concentration (MBC) of 200 μg/mL. GC-MS phytochemical analysis of these active partitions revealed that majority of the identified compounds belonged to lipophilic fatty acid groups. The active partitions of C. speciosus and T. coronaria exhibited high cidal activity in relation to time, killing more than 99% of the cell population. SEM observations showed that these active plant partitions caused multiple structural changes indicating massive cellular damages. Conclusions The n-hexane partition of the plant materials exhibited promising in vitro anti-TB activity against M. tuberculosis H37Rv. Their anti-TB activity was supported by their destructive effects on the integrity of the mycobacterial cellular structure.

Dengue is a severe mosquito-borne viral infection causing half a million deaths annually. Dengue virus NS2B/NS3 protease is a validated target for anti-dengue drug design. A series of hitherto unreported 3,5-bis(arylidene)-4-piperidones analogues 4a4j were synthesized and screened in silico against DENV2 NS2B/NS3 protease to elucidate their binding mechanism and orientation around the active sites. Results were validated through an in vitro DENV2 NS2B/NS3 protease assay using a fluorogenic Boc-Gly-Arg-Arg-AMC substrate. Nitro derivatives of 3,5-bis(arylidene)-4-piperidones (4e and 4j) emerged as promising lead molecules for novel protease inhibitors with an IC50 of 15.22 and 16.23 µmol/L, respectively, compared to the standard, panduratin A, having IC50 of 57.28 µmol/L.

A total of fourteen pyrazoline derivatives were synthesized through cyclo-condensation reactions by chalcone derivatives with different types of semicarbazide. These compounds were characterized by IR, 1D-NMR (1H, 13C and Distortionless Enhancement by Polarization Transfer - DEPT-135) and 2D-NMR (COSY, HSQC and HMBC) as well as mass spectroscopy analysis (HRMS). The synthesized compounds were tested for their antituberculosis activity against Mycobacterium tuberculosis H37Ra in vitro. Based on this activity, compound 4a showed the most potent inhibitory activity, with a minimum inhibitory concentration (MIC) value of 17 μM. In addition, six other synthesized compounds, 5a and 5c–5g, exhibited moderate activity, with MIC ranges between 60 μM to 140 μM. Compound 4a showed good bactericidal activity with a minimum bactericidal concentration (MBC) value of 34 μM against Mycobacterium tuberculosis H37Ra. Molecular docking studies for compound 4a on alpha-sterol demethylase was done to understand and explore ligand–receptor interactions, and to hypothesize potential refinements for the compound.

A number of novel spiro-pyrrolidines/pyrrolizines derivatives were synthesized through [3+2]-cycloaddition of azomethine ylides with 3,5-bis[(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones 2a–n. Azomethine ylides were generated in situ from the reaction of 1H-indole-2,3-dione (isatin, 3) with N-methylglycine (sarcosine), phenylglycine, or proline. All compounds (50 μM) were evaluated for their antiproliferative activity against human breast carcinoma (MDA-MB-231), leukemia lymphoblastic (CCRF-CEM), and ovarian carcinoma (SK-OV-3) cells. N-α-Phenyl substituted spiro-pyrrolidine derivatives (5a–n) showed higher antiproliferative activity in MDA-MB-231 than other cancer cell lines. Among spiro-pyrrolizines 6a–n, a number of derivatives including 6a–c and 6i–m showed a comparable activity with doxorubicin in all three cell lines. Among all compounds in three classes, 6a, 6b, and 6m, were found to be the most potent derivatives showing 64%, 87%, and 74% antiproliferative activity in MDA-MB-231, SK-OV-3, and CCRF-CEM cells, respectively. Compound 6b showed an IC50 value of 3.6 mM in CCRF-CEM cells. These data suggest the potential antiproliferative activity of spiro-pyrrolidines/pyrrolizines.

A series of 2-methoxypyridine-3-carbonitrile (5a−i)-bearing aryl substituents were successfully synthesized in good yields by the condensation of chalcones (4a−i) with malononitrile in basic medium. The condensation process, in most cases, offers a route to a variety of methoxypyridine derivatives (6a−g) as side products in poor yields. All new compounds were fully characterized using different spectroscopic methods. Mass ESI-HMRS measurements were also performed. Furthermore, these compounds were screened for their in vitro cytotoxicity activities against three cancer cell lines; namely, those of the liver (line HepG2), prostate (line DU145) and breast (line MBA-MB-231). The cytotoxicity assessment revealed that compounds 5d, 5g, 5h and 5i exhibit promising antiproliferative effects (IC50 1−5 µM) against those three cancer cell lines.

Three isoflavanoids, isovestitol (1), medicarpin (2), and sativan (3), along with another known compound, betulinic acid (4), were isolated from the root of Sesbania grandiflora. The structures of the isolated compounds were characterised by means of spectroscopic techniques (UV, IR, MS, 1H- and 13C-NMR, DEPT, COSY, HMQC, HMBC, and MS analysis). All the tested compounds 1–4 exhibited antituberculosis activity against Mycobacterium tuberculosis H37Rv, with MIC values of 50 µg/mL for compounds 1–3, and 100 µg/mL for compound 4, whereas, the methanol extract exhibited antituberculosis activity of 625 µg/mL. This is the first report on the occurrence of isoflavonoids in this plant and their antituberculosis activity.

A series of novel 1-(2′-α-O-D-glucopyranosyl ethyl) 2-arylbenzimidazoles has been prepared via one-pot glycosylation of ethyl-1-(2'-hydroxyethyl)-2-arylbenzimidazole-5-carboxylate derivatives. Synthesis of the 2-arylbenzimidazole aglycones from 4-fluoro-3-nitrobenzoic acid was accomplished in four high-yielding steps. The reduction and cyclocondensation steps for the aglycone synthesis proceeded efficiently under microwave irradiation to afford the appropriate benzimidazoles in excellent yields within 2–3 min. Glycosylation of the hydroxyethyl aglycones with the perbenzylated 1-hydroxy- glucopyranose, pretreated with the Appel-Lee reagent, followed by catalytic hydrogenolysis delivered the desired 1-(2′-α-O-D-glucopyranosyl ethyl) 2-aryl-benzimidazoles in a simple and straightforward manner.

The reaction of Benzyl o-vanillin 1 and o-phenylene diamine 2 in dichloromethane produced new benzimidazole, 3. The complete assignments of 3 were made using 1D and 2D NMR including COSY, HMQC and HMBC NMR in CDCl3 and acetone-d6. The coupling constants J are reported in Hertz, and the differences in the peak splittings using both solvents are discussed. Keywords: 1H NMR; 13C NMR; 2D NMR; Benzimidazole

The reaction of o-vanillin A with benzyl bromide B2 in acetone as the solvent and K2CO3 as a base in the presence of tetra-n-butylammonium iodide (TBAI) as catalyst formed benzyl o-vanillin, C. The complete assignments of C using PROTON, APT, DEPT-135, COSY, NOESY, HMQC and HMBC NMR in both CDCl3 and acetone-d6 are discussed, and the coupling constants J are reported in Hertz (Hz). Keywords: 1H NMR; 13C NMR; 2D NMR; Benzyl o-Vanillin

The antioxidant activity of fresh and dried plant extracts of Paederia foetida and Syzygium aqueum were studied using β-carotene bleaching and the 2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical cation assay. The percentage of antioxidant activity for all extract samples using both assays was between 58 and 80%. The fresh samples of both plants had higher antioxidant activity than the dried samples. The results of the β-carotene bleaching assay were correlated (R2 = 0.9849) with those of the ABTS assay.

Benzyl-o-vanillin and benzimidazole nucleus serve as important pharmacophore in drug discovery. The benzyl vanillin (2-(benzyloxy)-3-methoxybenzaldehyde) compound shows anti-proliferative activity in HL60 leukemia cancer cells and can effect cell cycle progression at G2/M phase. Its apoptosis activity was due to disruption of mitochondrial functioning. In this study, we have studied a series of compounds consisting of benzyl vanillin and benzimidazole structures. We hypothesize that by fusing these two structures we can produce compounds that have better anticancer activity with improved specificity particularly towards the leukemia cell line. Here we explored the anticancer activity of three compounds namely 2-(2-benzyloxy-3-methoxyphenyl)-1H-benzimidazole, 2MP, N-1-(2-benzyloxy-3-methoxybenzyl)-2-(2-benzyloxy-3-methoxyphenyl)-1H-benzimidazole, 2XP, and (R) and (S)-1-(2-benzyloxy-3-methoxyphenyl)-2, 2, 2-trichloroethyl benzenesulfonate, 3BS and compared their activity to 2-benzyloxy-3-methoxybenzaldehyde, (Bn1), the parent compound. 2XP and 3BS induces cell death of U937 leukemic cell line through DNA fragmentation that lead to the intrinsic caspase 9 activation. DNA binding study primarily by the equilibrium binding titration assay followed by the Viscosity study reveal the DNA binding through groove region with intrinsic binding constant 7.39 µM/bp and 6.86 µM/bp for 3BS and 2XP respectively. 2XP and 3BS showed strong DNA binding activity by the UV titration method with the computational drug modeling showed that both 2XP and 3BS failed to form any electrostatic linkages except via hydrophobic interaction through the minor groove region of the nucleic acid. The benzylvanillin alone (Bn1) has weak anticancer activity even after it was combined with the benzimidazole (2MP), but after addition of another benzylvanillin structure (2XP), stronger activity was observed. Also, the combination of benzylvanillin with benzenesulfonate (3BS) significantly improved the anticancer activity of Bn1. The present study provides a new insight of benzyl vanillin derivatives as potential anti-leukemic agent.

In the title compound, C40H34N2O2, the central piperidine ring adopts a half-chair conformation and the fused pyrrolidine rings adopt twisted envelope (with the C atom bearing the methylphenyl ring as the flap atom) and envelope (with the C atom bound to the N atom, common to the pyridinone and pyrrolidine rings being the flap atom) conformations. The molecular structure features weak intramolecular N—H...O and C—H...O interactions. In the crystal, O—H...O hydrogen bonds generate a C(7) chain along the b-axis direction. C—H...O interactions also occur.

The microwave-assisted three-component reactions of 3,5-bis(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones, acenaphthenequinone and cyclic α-amino acids in an ionic liquid, 1-butyl-3-methylimidazolium bromide, occurred through a domino sequence affording structurally intriguing diazaheptacyclic cage-like compounds in excellent yields.

In the title compound, C29H34N2O2, the central piperidine ring adopts a half-chair conformation, whereas the terminal one adopts a chair conformation. The mean plane of the central piperidine ring [maximum deviation = 0.384 (2) Å] makes dihedral angles of 64.82 (13) and 17.55 (13)° with the benzene rings. In the crystal, molecules are linked into a tape along the b axis via C—H...O interactions, generating R22(20) and R21(6) graph-set motifs. C—H...π interactions are observed between the tapes.

In the title compound, C13H10N2O2S, the essentially planar 2H-chromene ring system [maximum deviation = 0.0297 (13) Å] and the thiazole ring [maximum deviation = 0.0062 (11) Å] form a dihedral angle of 3.47 (5)°. In the crystal, N—H...N and C—H...O hydrogen bonds link the molecules into two-dimensional networks parallel to the bc plane. C—H...π and π–π [centroid–centroid separation = 3.6796 (8) Å] interactions further stabilize the crystal structure.

In the title compound, C34H28N2O2S, the piperidine ring adopts a chair conformation. One of the pyrrolidine rings adopts an envelope conformation with the methylene C atom at the flap whereas the other pyrrolidine ring and the thiazolidine ring adopt half-chair conformations. The mean plane of the dihydroacenaphthylene ring system [maximum deviation = 0.067 (1) Å] makes dihedral angles of 28.31 (5) and 31.32 (6)° with the two terminal benzene rings. An intramolecular O—H...N hydrogen bond forms an S(5) ring motif. In the crystal, molecules are linked by C—H...O and C—H...S hydrogen bonds into layers lying parallel to the ac plane.

In the title compound, C34H26F2N2O2S, an intramolecular O—H...N hydrogen bond forms an S(5) ring motif. The piperidine ring adopts a chair conformation. The thiazolidine ring and one of the pyrrolidine rings adopt envolope conformations with methylene C atoms at the flap, whereas the other pyrrolidine ring adopts a half-chair conformation. The fluoro-substituted benzene rings form dihedral angles of 32.25 (10) and 38.27 (10)°, respectively, with the mean plane of the dihydroacenaphthylene ring system [maximum deviation = 0.043 (2) Å]. The dihedral angle between the fluoro-substituted benzene rings is 64.13 (14)°. In the crystal, molecules are linked by weak C—H...O, C—H...F and C—H...S hydrogen bonds into a three-dimensional network.

In the title compound, C14H11N3O3, the chromene ring is almost planar, with a maximum deviation of 0.065 (2) Å from the mean plane for one of the C atoms. In the crystal, inversion dimers linked by pairs of N—H...O hydrogen bonds generate R22(8) loops. The dimers are linked by C—H...N and C—H...O interactions into a three-dimensional network. An aromatic π–π stacking interaction, with a centroid–centroid distance of 3.562 (10) Å, is also observed.

The asymmetric unit of the title compound, C30H48ClN3O, contains two molecules, A and B. In both molecules, the three cyclohexane rings in the steroid fused ring systems adopt chair conformations, while the cyclopentane rings adopt envelope and twist conformations in molecules A and B, respectively. In molecule B, the cyano group is disordered over two orientations with refined site-occupancies of 0.593 (8) and 0.407 (8). An intramolecular C—H...N interaction forms an S(10) ring in both molecules. In the crystal, molecules are linked by N—H...O, C—H...O and C—H...N interactions, resulting is chains propagating along the a-axis direction.

The asymmetric unit of the title compound, C27H45ClO, consists of two crystallographically independent molecules. In both molecules, the three cyclohexane rings in the steroid fused-ring systems adopt chair conformations, while the cyclopentane ring adopts a half-chair conformation in one molecule and an envelope conformation in the other. In the crystal, the molecules are linked into a two-dimensional network by weak C—H...O hydrogen bonds. The crystal studied is a nonmerohedral twin with a refined ratio of twin components of 0.264 (3):0.736 (3).

The asymmetric unit of the title complex, {[Mn(C20H10Br2N3O5)(H2O)]·(CH3)2NCHO}n, consists of one MnIII ion, one (E)-5-bromo-N-[2-(5-bromo-2-oxidobenzylideneamino)-4-nitrophenyl]-2-oxidobenzamidate ligand (Schiff base), one water molecule and an N,N-dimethylformamide molecule. The coordination geometry around the MnIII ion is a distorted octahedron, being surrounded by two O and two N atoms from the Schiff base, which are positioned in the equatorial plane. The water molecule and the O atom of the carbonyl group from the adjacent MnIII complex are situated at the axial positions, leading to a polymeric chain along the c axis. In the crystal, the complex and N,N-dimethylformamide molecules are connected via O—H...O, C—H...O and C—H...Br hydrogen bonds, forming a three-dimensional network.

In the asymmetric unit of the title compound, C16H11FO5S, the 2H-chromene ring is essentially planar, with a maximum deviation of 0.040 (2) Å. The dihedral angle between the 2H-chromene ring and the 4-fluorophenyl ring is 2.17 (8)°. One of the sulfonamide O atoms is approximately coplanar with the benzene ring [C—C—S—O torsion angle = 166.00 (14)°], whereas the other O atom lies well below the plane [C—C—S—O = −61.35 (17)°]. In the crystal, molecules are connected by weak C—H...O hydrogen bonds, forming two-dimensional networks parallel to the ac plane.

In the title compound, C27H21NO, the piperidine ring adopts a chair conformation. The mean plane through the piperidine ring makes dihedral angles of 49.27 (5) and 63.07 (5)° with the naphthalene ring systems. In the crystal, molecules are linked into dimers via pairs of intermolecular C—H...O interactions, generating ten-membered R22(10) ring motifs. C—H...π interactions further stabilize the crystal structure.

In the title molecule, C19H20N2O4·H2O, the benzimidazole ring system is essentially planar [maximum deviation = 0.013 (11) Å] and is inclined to the 4-methoxyphenyl ring by 30.98 (5)°. In the crystal, O—H...O and O—H...N hydrogen bonds involving the water molecule link neighbouring molecules, forming a two-dimensional network lying parallel to the bc plane. There are also C—H...π and π–π interactions present. The latter involve inversion-related benzimidazole rings with centroid–centroid distances of 3.5552 (8) and 3.7466 (8) Å.

The asymmetric unit of the title compound, C32H51N3O3, consists of two crystallographically independent molecules, A and B; the 2-methylpentane group of molecule A and the propane group of molecule B are each disordered over two sets of sites, with refined site-occupancies of 0.825 (5):0.175 (5) and 0.630 (18):0.370 (18), respectively. In both molecules, the three cyclohexane rings in the steroid fused ring systems adopt chair conformations while the cyclopentane rings adopt envelope and twist conformations in molecules A and B, respectively. In the crystal, N—H...O and C—H...O hydrogen bonds link the two independent molecules together, generating R21(7) and R22(8) ring motifs.

In the title compound, C26H25FO5, the terminal cyclohexane rings of the xanthene ring system adopt half-boat conformations. The 4H-chromene ring make a dihedral angle of 87.94 (5)° with the xanthene ring system and its carbonyl O atom lies above the xanthene O atom. In the crystal, molecules are linked into ribbons propagating along the a-axis direction by C—H...O hydrogen bonds. Aromatic π–π stacking interactions [centroid–centroid distance = 3.7367 (12) Å] also occur.

The title compound, C11H15NO6S, features a distorted tetrahedral geometry for the S atom. One of the sulfonamide O atoms is approximately coplanar with the benzene ring [C—C—S—O torsion angle = −160.81 (7)°], whereas the other lies well below the plane [C—C—S—O = −29.66 (8)°]. In the crystal, O—H...O and C—H...O hydrogen bonds link the molecules into chains parallel to the b axis.

In the title compound, C21H24N2O3, the mean planes of the benzene ring and the benzimidazole ring system form a dihedral angle of 69.94 (7)°. The ethyl group atoms of the ethanoate fragment are disordered over two sets of sites, with refined occupancies of 0.742 (6) and 0.258 (6). In the crystal, there are weak C—H...N hydrogen bonds which connect molecules into chains along the b axis. A weak intermolecular C—H...π interaction is also observed.

In the title compound, C17H14O6S, the 2H-chromene ring is essentially planar, with a maximum deviation of 0.016 (1) Å. The dihedral angle between the 2H-chromene and the benzene rings is 54.61 (5)°. The C atom of the methoxy group is close to coplanar with its attached ring [deviation = 0.082 (2) Å]. In the crystal, molecules are connected via C—H...O hydrogen bonds, forming sheets lying parallel to the bc plane. Weak C—H...π interactions are also observed.

In the title compound, C38H30N2O2, the acenaphthylene ring is close to being planar [maximum deviation = 0.1047 (11) Å]. The dihedral angles between the three benzene rings and the acenaphthylene system are 39.47 (3), 37.65 (3) and 44.47 (3)°. An intramolecular O—H...N interaction forms an S(5) hydrogen-bond ring motif. In the crystal, molecules are linked into [101] chains by a set of C—H...O interactions.

In the title compound, C36H32N2O4S, the piperidine ring adopts a chair conformation, while the five-membered pyrrolidine (with a C atom as the flap atom) and thiazolidine (with the S atom as the flap atom) rings adopt envelope conformations. The naphthalene ring system makes dihedral angles of 18.82 (5) and 40.92 (5)° with the two methoxy-substituted benzene rings. In the crystal, centrosymmetrically-related molecules are linked into dimers via pairs of C—H...O and C—H...N hydrogen bonds. An intramolecular O—H...N hydrogen bond is also observed. The crystal structure is further stabilized by C—H...π interactions.

In the title compound, C38H28F2N2O2, the piperidine ring adopts a chair conformation and the pyrrolidine ring adopts an envelope conformation with the spiro C atom as the flap atom. The naphthalene ring system makes dihedral angles of 39.89 (8), 35.33 (8) and 46.45 (8)° with the two fluoro-substituted benzene rings and the phenyl ring, respectively, while the dihedral angle between the two fluoro-substituted benzene rings is 75.21 (10)°. An intramolecular O—H...N hydrogen bond generates an S(5) ring. In the crystal, molecules are connected by C—H...O hydrogen bonds, forming supramolecular chains propagating along the c-axis direction. Weak C—H...π interactions further consolidate the structure.

In the title compound, C20H14BrN3O3S, the molecule adopts an E configuration about the central C=N double bond. The chromene ring system and the thiazole ring are approximately planar [maximum deviations = 0.029 (3) and 0.007 (3) Å, respectively]. The chromene ring system is inclined at angles of 7.37 (12) and 13.90 (13)° with respect to the thiazole and benzene rings, respectively, while the thiazole ring makes a dihedral angle of 12.58 (15)° with the benzene ring. In the crystal, molecules are connected by N—H...O hydrogen bonds, forming C(8) supramolecular chains along the c axis.

In the title compound, C15H8Cl2N2O2, the molecule adopts an E configuration about the central C=N double bond. The isoindoline ring is essentially planar, with a maximum deviation of 0.019 (2) Å. The dihedral angle between the isoindoline ring and the dichloro-substituted benzene ring is 6.54 (9)°. An intramolecular C—H...O hydrogen bond occurs. A short Cl...Cl contact of 3.4027 (9) Å is present in the crystal structure. The crystal packing is further stabilized by weak C—H...π interactions.

The asymmetric unit of the title compound, C21H26O4S, consists of two independent molecules. In both molecules, intramolecular O—H...O hydrogen bonds stabilize the molecular structure. In the crystal, each molecule and its symmetry-related molecule by twofold rotation form a dimer through a pair of intermolecular C—H...O hydrogen bonds. In one of the molecules, the thiophene group is disordered over two sets of sites with occupancies of 0.735 (3) and 0.265 (3).

The asymmetric unit of the title compound, C27H30N2O2, comprises two independent molecules. The dihedral angles between the phenyl rings in the two molecules are 55.59 (8) and 55.39 (8)°. The piperidine rings adopt chair conformations. The crystal structure is stabilized by weak intermolecular C—H...O and C—H...N hydrogen bonds. The crystal studied was a non-merohedral twin with a domian ratio of 0.75 (2):0.25 (2).

The asymmetric unit of the title compound, C22H15Cl4NO2·0.5H2O, consists of a (3E,5E)-1-acryloyl-3,5-bis(2,4-dichlorobenzylidene)piperidin-4-one molecule and a half-molecule of water (the O atom of the water molecule lies on a twofold axis). The piperidin-4-one ring adopts an envelope conformation. The dihedral angle between the two terminal benzene rings is 8.84 (11)°. In the crystal, molecules are connected by C—H...O hydrogen bonds forming supramolecular chains along the c axis. Furthermore, adjacent chains are interconnected by the water molecules via O—H...O hydrogen bonds.

In the title compound, C20H15N3O3S, the thiazole ring is approximately planar, with a maximum deviation of 0.003 (1) Å, and makes dihedral angles of 7.44 (6) and 1.88 (6)° with the hydroxy-substituted phenyl ring and the pyran ring, respectively. The hydroxyl group is disordered over two sets of sites, with an occupancy ratio of 0.567 (3):0.433 (3). In the crystal, the major disorder component molecules are connected via bifurcated (three-centre) O—H...O and C—H...O hydrogen bonds, generating R12(6) motifs and resulting in supramolecular chains along the a axis. In the minor occupancy component, however, molecules are connected via C—H...O hydrogen bonds, forming supramolecular chains along the b axis. Furthermore, the crystal structure is stabilized by π–π interactions between the thiazole rings [centroid–centroid distance = 3.5476 (7) Å].

In the title compound, C22H17Cl2NO2, the asymmetric unit consists of two crystallographically independent molecules and each piperidinone ring adopts an envelope conformation. The dihedral angles between the two chlorobenzene rings are 24.81 (10) and 19.15 (8)° in the two molecules. In the crystal, molecules are connected via weak intermolecular C—H...O hydrogen bonds forming layers perpendicular to the a axis.

In the title compound, C25H16BrN3O2S·CHCl3, the thiazole ring is approximately planar [maximum deviation = 0.002 (3) Å] and makes dihedral angles of 10.75 (14) and 87.75 (15)/2.80 (14)° with the pyran ring system and the two terminal phenyl rings, respectively. The solvent molecule is disordered over two sets of sites, with refined occupancies of 0.639 (7) and 0.361 (7). In the crystal, molecules are connected via pairs of weak C—H...O interactions, forming centrosymmetric dimers. An intramolecular C—H...O hydrogen bond generates an S(6) ring motif.

The whole molecule of the title compound, C23H14O6S, is disordered over two sets of sites with refined occupancies of 0.8733 (12):0.1267 (12). The dihedral angle between the mean planes through the chromene ring systems is 56.31 (5) and 55.2 (3)° for the major and minor components, respectively. In both components, a pair of intramolecular O—H...O interactions generate rings of S(8) graph-set motif. In the crystal, the molecules are linked by intermolecular C—H...O interactions, forming chains along the b axis. The structure is further stabilized by π–π interactions with centroid–centroid distances of 3.594 (2) and 3.608 (5) Å.

In the title compound C19H11N3O2SClBr·C2H6OS, the molecule adopts an E configuration about the central C=N double bond. The chromene ring system and the thiazole ring are approximately planar, with maximum deviations of 0.027 (2) and 0.003 (1) Å, respectively. The central thiazole ring makes dihedral angles of 21.82 (9) and 5.88 (7)° with the chloro-substituted phenyl ring and the chromene ring, respectively. In the crystal, molecules are connected via N—H...O, N—H...S and C—H...O hydrogen bonds, forming supramolecular chains along the c axis. An intramolecular C—H...O hydrogen bond occurs. π–π interactions are observed between the thiazole and phenyl rings [centroid–centroid distance = 3.6293 (10) Å]. A short Br...Cl contact of 3.37 (6) Å also occurs.

In the title compound, C19H11N3O2SClBr, the chromene ring system and the thiazole ring are each approximately planar, with maximum deviations of 0.033 (3) Å and 0.006 (3) Å, respectively. The molecule adopts an E configuration about the central C=N double bond. The central thiazole ring makes dihedral angles of 9.06 (14)° and 12.07 (11)° with the chloro-substituted phenyl ring and the chromene ring, respectively. The molecular structure features a short C—H...O contact, which generates an S(6) ring motif. The crystal structure is stabilized by intermolecular N—H...O hydrogen bonds, which link the molecules into chains along the b axis. π–π stacking interactions [centroid-centroid distance = 3.4813 (15) Å] are also present.