Search

The synthesis of β-(C3)-functionalized pyrroles is a challenging task and requires a multistep protocol. An operationally simple direct catalytic synthesis of β-substituted pyrroles has been developed. This one-pot multicomponent method combined aqueous succinaldehyde as 1,4-dicarbonyl, primary amines, and isatins to access hydroxyl-oxindole β-tethered pyrroles. Direct synthesis of the β-substituted free NH-pyrrole is the central intensity of this work. DFT-calculations and preliminary mechanism investigation support the possible reaction pathway.

A combined theoretical and experimental investigation on a pharmaceutically important binary complex 3,3'-[(3-benzimidazolyl)methylene] bis (4-hydroxy-2 H -1-benzopyran-2-one): 5-methyl-1,3-thiazol-2(3 H )-imine is presented in this manuscript. The compound crystallizes in the monoclinic crystal system with space group Cc with unit cell parameters: a = 19.8151(8) A, b = 15.2804(6) A, c = 8.3950(4) A, β = 94.0990(10)°, V = 2535.36(19) A 3 , Z = 4, T = 296(2) K, μ(MoKα) = 0.184 mm -1 , Dcalc = 1.490 g/cm 3 , 35833 reflections measured (5.332° ≤ 2Θ ≤ 56.678°), 6168 unique ( R int = 0.0467, R sigma = 0.0388) which were used in all calculations. The final R 1 was 0.0435 (I > 2σ(I)) and wR 2 was 0.1073 (all data). The crystal structure has been determined by the conventional X-ray diffraction method, solved by direct methods and refined by the full matrix least squares procedure. Intramolecular hydrogen bonding of the type C–H⋅⋅⋅O and O–H⋅⋅⋅O is present and the crystal structure stabilizes via N–H…O, C–H…N and O–H…N intermolecular interactions. The optimized structural parameters have been compared and the parameters like ionization potential, electron affinity, global hardness, electron chemical potential, electronegativity, and global electrophilicity based on HOMO and LUMO energy values were calculated at B3LYP/6-311G(d,p) level of theory for a better understanding of the structural properties of the binary complex.

The benzimidazole moiety found in a large number of biologically important drugs has not been completely realized as yet in respect of its strength and directionality of its molecular interactions. To understand the role played by the intermolecular interactions in the benzimidazole derivatives, lattice energy of a series of five important molecules has been computed and results accrued thereof have been discussed. Analysis of molecular packing based on the intermolecular interaction energies suggests existence of different molecular pairs that play an important role in the stabilization of the crystal structures. Interaction energy analysis of such motifs reveals that intermolecular interactions of the type N-H…N and C-H…N happen to be the major contributors to the stabilization of molecular packing in the unit cell. N-H…π and C-H…π type edge-to-face stacking interactions also contribute significantly to the stabilization of crystal packing. The pairs of N-H…N intermolecular hydrogen bonds link the molecules into centrosymmetric dimers making a contribution of -14 to -18.52 kcal/mol towards stabilization, whereas C-H…N bonds link the molecules into dimers in the energy range of -2 to -5 kcal/mol. Additionally, the role of π…π interactions has also been investigated in molecular stabilization.

A sequential multicomponent synthesis of highly substituted pyrrole-3-carboxaldehydes has been developed under metal-free conditions. This one-pot protocol involves proline-catalyzed direct chemoselective Mannich reaction-cyclization between 1,4-ketoaldehyde and in situ generated Ar/HetAr-imines followed by aerobic oxidative-aromatization at room temperature. A series of fully substituted pyrrole-3-carboxaldehydes and other diverse fused heterocycles have been synthesized. These compounds were tested for in vitro antibacterial and antifungal activities, and the selected ones display significant activity against the tested bacterial strains with a MIC value of 16 μg mL−1, which is close to that of the standard drug chloramphenicol. The bioactivity outcome was further analyzed using docking studies.

We explored the antibacterial potential (alone and combination) against multidrug resistant (MDR) Pseudomonas aeruginosa isolates KG-P2 using synthesized thieno[3,2-c]pyran-2-ones in combination with different antibiotics. Out of 14 compounds, two compounds (3g and 3l) abridged the MIC of tetracycline (TET) by 16 folds. Compounds was killing the KG-P2 cells, in time dependent manner, lengthened post-antibiotic effect (PAE) of TET and found decreased the mutant prevention concentration (MPC) of TET. In ethidium bromide efflux experiment, two compounds repressed the drug transporter (efflux pumps) which is further supported by molecular docking of these compounds with efflux complex MexAB-OprM. In another study, these compounds inhibited the synthesis of biofilm.

Medicinal chemistry of indole analogs constitutes important therapeutic agents with anti-oxidant, anti-HIV and anti-cancer activities. Indole nucleus is frequently found in synthetic and natural products, pharmaceuticals, functional materials, agrochemicals, etc. The title compound, N -(2-(2-(4-chlorophenoxy)acetamido)phenyl)-1 H -indole-2-carboxamide (5), has been synthesized in good yield by stirring the compound N -(2-aminophenyl)-2-(4-chlorophenoxy)acetamide (3) with 1 H -indole-2-carboxylic acid (4), in dry dichloromethane followed by the addition of 2,6-lutidine, and o -(benzotriazol-1-yl)- N , N , N ', N '-tetramethyl uraniumtetrafluoroborate in cooled condition. Compound 5 was synthesized and characterized by the conventional spectroscopic techniques ( 1 H NMR, 13 C NMR and LC-MS) and the three-dimensional structure was elucidated by using single crystal X-ray diffraction methods. It crystallizes in the monoclinic crystal system with space group P 2 1 /c. The structure was solved by direct methods and refined by full matrix least square procedure to a final R value of 0.043 for 2490 observed reflections. Three intra-molecular interactions of the type N-H···N and C-H···N were observed. The packing of molecules in the unit cell is governed by N-H···O and C-H···O intermolecular H-boned interactions which leads to the formation of infinite staking chain along [001] direction. In addition, two weak C-H···π interactions also contribute to molecular packing.

A pot-economic method for the enantio- and diastereoselective synthesis of a [2.2.2] azabicyclic isoquinuclidine system is developed. This protocol involves the proline-catalyzed direct Mannich rea...

A simple and straightforward method for the synthesis of 4-iodo and 5-iodopyrrole-3-carboxaldehydes is developed from a common set of starting materials by tuning the reaction conditions. This sequential multicomponent protocol involves I2-mediated regioselective C4-iodination and aromatization of intermediate dihydropyrrole, generated through proline-catalyzed direct Mannich reaction-cyclization sequence between succinaldehyde and imines, to access 4-iodopyrroles. While aerobic oxidative aromatization of dihydropyrrole to pyrrole followed by NIS-mediated regioselective iodination furnished 5-iodopyrroles in a two-pot fashion. A series of site-selective C4/C5-iodopyrroles have been synthesized in good to high yields (up to 78%) and DFT calculations of these compounds were also performed.

A widely used oxidizing agent in organic chemistry with an assumed structure of “[Ag(py)2]MnO4” and its perchlorate and perrhenate analogues are studied. Their synthesis in pure form is challenging...

The X-ray structure of 2-(3,4-dimethoxyphenyl)-4,5-diphenyl-1H-imidazole, has been determined. It crystallizes in orthorhombic space group Pna21, with a = 9.5018(6) A, b = 21.636(2) A, c = 19.040(1) A and Z = 8. The structure has been solved by direct methods and refined by full matrix least squares procedures to a final R value of 0.0675 for 2733 observed reflections. The asymmetric unit contains two crystallographic independent molecules. C H…O and C H…N intermolecular interactions were observed and these interactions are of paramount importance in assembling the molecules leading to packing stability. To understand pharmacological importance of the title compound, molecular docking was performed against two anti-inflammatory drug targets; Myeloperoxidase (MPO) and Cyclooxygenase (COX-2). Docking studies show binding mode of the titled molecule to be similar to the known inhibitor in their respective active site of anti-inflammatory drug targets. Thus, the title molecule also has similar mode of drug action.

An efficient protocol for the catalytic asymmetric synthesis of new dibenzo[ b, f][1,4]-oxazepine-fused 1,2-dihydropyridines (DHPs) has been described under metal-free conditions. This reaction proceeds through proline-catalyzed direct Mannich/cyclization between seven-membered dibenzo[ b, f][1,4]-oxazepine-imines and aqueous glutaraldehyde, followed by IBX-mediated site-selective dehydrogenative oxidation in one-pot operation with high yields (up to 92%) and excellent enantioselectivity (up to99:1 er).

A combined experimental and theoretical study is performed on DMSO solvated 7′-amino-1′,3′-dimethyl- 2,2′,4′-trioxo-1′,2′,3′,4′,4a′,8a′-tetrahydrospiro[indoline-3,5′-pyrano[2,3-d]pyrimidine]-6′-carbonitrile. The compound is studied by NMR, IR spectroscopy, and single crystal X-ray analysis. The crystal structure of the molecule is stabilized by intermolecular N–H…N, N–H…O, and C–H…π interactions. In the crystal, the molecules form hydrogen-bonded chains running along the b axis of the unit cell. In the present work, we have applied density functional theory (DFT) to explore the nonlinear properties of the molecule. The harmonic vibrational frequencies are calculated and compared with experimental FT-IR frequencies. The observed and calculated frequencies are found to be in good agreement. The calculated values of the HOMO-LUMO energy gap shows that a charge transfer occurs within the molecule.

An efficient sequential multi-component method for the synthesis of N-arylpyrrole-3-carbaldehydes has been developed. This reaction involved a proline-catalyzed direct Mannich reaction-cyclization sequence between succinaldehyde and in situ generated Ar/HetAr/indolyl-imines, followed by IBX-mediated oxidative aromatization in one-pot operation. The practical utility of this procedure is shown at gram-scale and the synthesis of diverse bioactive fused heterocyclic scaffolds such as pyrroloquinoline, pyrrolo-oxadiazole, dihydro pyrroloquinoline, and pyrrolo-phenanthridine.

2-(4-Chlorophenyl)-3-(phenylamino)-5-(thiophen-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one, C20H14N3OSCl was synthesized and its crystal structure was determined by single crystal X-ray diffraction. The crystals are triclinic, sp. gr. P1, Z = 2. All three rings are planar, and imidazole ring is almost perpendicular to the phenyl ring with the dihedral angle of 88.65(2)°. In the crystal, pairs of O–H···O hydrogen bonds link molecules into inversion dimers, featuring R22(10) graph set motif. Crystal structure is further stabilized by π···π interactions.

Today the fundamental aspect of the researchers is to explore maximum physical properties of the material for device fabrication. In the present article, single crystal X-ray diffraction has been carried out to verify the formation of the synthesized compound. In addition to that, powder X-ray diffraction has been performed to obtain diffraction pattern of l -Prolinium Picrate single crystal. The strain present inside the single crystal was measured using Hall-Williamson equation from PXRD measurements. The dark current and photon current was obtained from photoconductivity technique whose plot depicted that the sample was negative photoconducting material. Optical homogeneity of the single crystal was analyzed using birefringence technique. Its resistance towards Nd: YAG laser was scrutinized for l -Prolinium Picrate single crystal by applying 1 pulse per second. Different thermal parameters like thermal conductivity, thermal diffusivity, thermal effusivity and specific heat were computed using photo-pyroelectric technique. Solid state parameters were calculated from Clausius Mossotti relation by taking structural information of the title compound. Also, optical parameters like refractive index, reflectance etc were calculated through UV–Vis–NIR analysis.

A new method for the direct one-pot synthesis of substituted pyrrole-2,4-dialdehdyes is developed. This overall pseudo-[3+2] annulation reaction between glutaraldehyde and N-PMP-aldimines (PMP = p-OMeC6H4) proceed through proline-catalyzed direct Mannich reaction/ cyclization, followed by IBX-mediated oxidative rearrangement of in situ generated intermediate compound to pyrrole-2,4-dialdehydes with high yields (up to 80%).

A one-pot method has been described to synthesize benzopyran-annulated pyrano[2,3-c]pyrazoles, effectively by combining O-alkenyloxy/alkynyloxy-acetophenones with various pyrazolones in triethylammonium acetate (TEAA) under microwave irradiation. While combination of O-allyloxy- or O-prenyloxy-acetophenones with pyrazolones occurred efficiently, that of O-propargyloxy-acetophenones was found effective in the presence of ZnO catalyst, via a domino Knoevenagel-hetero-Diels-Alder (DKHDA) reaction. Aminobenzopyran frameworks were also synthesized, after nitro-containing products were reduced in tandem with iron(II) in an acidic medium. The in vitro antiproliferative activity of these compounds was measured and discussed against gram-positive, gram-negative and M. tuberculosis bacteria, fungi, and various representative human solid tumor cell lines, in addition to their ferric reducing antioxidant capability.

The title compound (6bR,14bR,15R,15aR)-ethyl 5-bromo-14b-phenyl-1,6b,8,9,14,14b,15,15a- octahydrochromeno [3′,4′:2,3] indolizino [8,7-b] indole-15-carboxylate belongs to an indole derivative. The compound crystallizes in the triclinic crystal system with the space group P1. The asymmetric unit cell consists of two molecules. In the crystal, hydrogen bond interactions of the type N–H⋅⋅⋅O, C–H⋅⋅⋅O and C–H⋅⋅⋅N are present. Further, the molecular structure is stabilized by C–H⋅⋅⋅π interactions. Intermolecular interactions were analyzed using Hirshfeld surface analysis.

The asymmetric unit of the title compound, C8H15N3S, contains two independent molecules. In both molecules, the seven-membered cycloheptane ring adopts a chair conformation. An intramolecular N—H...N hydrogen bond is observed in both molecules, forming S(5) graph-set motifs. In the crystal, the two independent molecules are connected through N—H...S hydrogen bonds, forming dimers which are in turn further connected by N—H...S hydrogen bonds into chains along [010].

(2E)-3-(anthrance-9-yl)-1-(3,4-dichlorophenyl)prop-2-en-1-one [C23H14OCl2] is synthesized and its crystal structure is determined by single X-ray diffraction. There exist two molecules in the asymmetric unit. The dihedral angle between the benzene and anthracene moiety of the molecule A and B is 86.51(12)° and 76.42(13)°, respectively. No classical hydrogen bonds are observed and only van der Waals forces stabilize the crystal packing.

In the title compound, C11H8Cl2N2O3, the plane of the pyrrolidine ring (r.m.s. deviation = 0.065 Å) makes a dihedral angle of 52.9 (2)° with the plane of the benzene ring. The least-squares plane of the central amide fragment makes dihedral angles of 49.3 (7) and 77.9 (7)° with those of the benzene and pyrrolidine rings, respectively. In the crystal, molecules are linked via N—H...O hydrogen bonds, forming chains along the b-axis direction. π–π interactions link these chains into a two-dimensional network parallel to (100).

Being crucial part of plant-based novel discovery of drug from natural resources, a study was done to explore the antibacterial potential of curcumin mimics in combination with antibiotics against multidrug resistant isolates of Pseudomonas aeruginosa. The best candidate Van D, a curcumin mimics reduced the MIC of tetracycline (TET) up to 16 folds against multidrug resistant clinical isolates. VanD further inhibited the efflux pumps as evident by ethidium bromide efflux and by in-silico docking studies. In another experiment, it was also found that Van D inhibits biofilm synthesis. This derivative kills the KG-P2, an isolate of P. aeruginosa in a time dependent manner, the post-antibiotic effect (PAE) of tetracycline was extended as well as mutant prevention concentration (MPC) of TET was also decreased. In Swiss albino mice, Van D reduced the proinflammatory cytokines concentration. In acute oral toxicity study, this derivative was well tolerated and found to be safe up to 1000 mg/kg dose. To the best of our knowledge, this is the first report on curcumin mimics as synergistic agent via inhibition of efflux pump.

A new indoline derivative, tert-butyl 2′-amino-3′-cyano-6′-methyl-2-oxospiro[indoline-3,4′-pyran]-5′-carboxylate is eco-friendly synthesized, and its spectral properties and X-ray crystal structure are studied. In the molecule, the oxindole and pyran moieties are perpendicular to each other. The crystal structure is stabilized by intermolecular N−H···O and intramolecular C−H···O hydrogen bonds. Centrosymmetric dimer units are formed by intermolecular N−H···O hydrogen bonds. In addition, one C−H···π interaction is also observed.

The organic carbonitrile namely methyl (6-amino-5-cyano-2-methyl-4-(2-nitrophenyl)-4H-pyran)- 3-carboxylate is synthesized via one-pot multi-component reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst and its crystal structure is determined by X-ray technique. The crystals are monoclinic, sp. gr. C2/c, a = 12.3069(8) A, b = 9.7023(7) A, c = 24.812(2) A, β = 94.862(6)°, Z = 8. The dihedral angle between pyran and phenyl rings is 87.8(1)°; the pyran ring is almost planar The dihedral angle between the mean planes of phenyl ring and nitro group is 44.4(2)°. The crystal structure is stabilized by N−H···N and N−H···O hydrogen bonds. In addition, C−H···π interactions are also observed in the crystal structure.

The domino aldol/hetero-Diels-Alder synthesis of some new tricyclic pyrano[3,4-c]chromene derivatives has been achieved successfully after assembling a variety of acyclic or cyclic monoketones with prenyl ether-tethered aldehydes in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene in glycerol at 120 °C. The hitherto unreported stereochemical outcome of this synthetic sequence was studied and established on the basis of single-crystal X-ray diffraction data and 2D NMR NOESY spectroscopy along with the isolation and characterization of the intermediate Aldol condensation product.

The new indole derivative, 5,5′′-Difluoro-1H,1′′H-[3,3′:3′,3′′-terindol]-2′(1′H)-one C24H15F2N3O, is synthesized in 87% yield, and its crystal structure is determined by X-ray structure analysis. The crystals are monoclinic, sp. gr. P21/n, a = 15.4563(7), b = 10.8340(6), c = 16.4718(6) A, β = 102.403(4)°, Z = 4. Bicyclic indole moieties form dihedral angle of 61.92(5)° with each other; the oxindole ring is twisted with respect to them at angles of 85.70(5)° and 75.62(5)°. The crystal structure is stabilized by N–H···O and C–H···O hydrogen bonds involving both the DMSO solvent molecules. In addition, one C–H···π interaction is observed.

The title compound, 2-(thiophen-2-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)ethenyl] benzamide:N,N-dimethylformamide (1: 1), (C15H11N3O2S2 · C3H7NO), was synthesized, and its structure was established by spectral analysis and X-ray diffraction studies. The compound crystallizes in the monoclinic space group P21/n with a = 10.8714(7), b = 9.0497(5), c = 19.8347(13) A, β = 91.093(5)°, Z = 4. The crystal structure is stabilized by N–H···S, C–H···O and N–H···O hydrogen bonds. The π···π interactions are also observed between the rings.

In this paper, a supported ionic liquid catalyst (SILC) was synthesized by dissolving palladium acetate in [BMIM][OH] and immobilizing it on the surface of HAP. Further, it was characterized by SEM, TEM, TGA, FTIR, AAS and EDAX. This SILC was then used to synthesize various derivatives of chromenes under solvent-free conditions in excellent yields. The products obtained were characterized by 1H NMR, 13C NMR and mass analysis. One of the products, 2-amino-4-(3-nitrophenyl)-6,6,8,8-tetrahydro-7,7-dimethyl-5-oxo-4H-chromene-3-carbonitrile, was also characterized by single crystal X-ray crystallography.

Ultrasonic-assisted, catalyst-free reactions of ninhydrin with ethyl cyanoacetate and diethyl malonate led to the unprecedented formation of an indenopyran and a spiroindenofuran viz. diethyl 4-cyano-2-hydroxy-5-oxo-4,5-dihydroindeno[1,2-b]pyran-3,4-dicarboxylate 1 and diethyl 3a′,8b′-dihydroxy-1,3,4′-trioxo-1,3,3a′,4′-tetrahydrospiro[indene-2,2′-indeno[1,2-b]furan]-3′,3′(8b′H)-dicarboxylate 3, respectively. In addition to these unprecedented results, reactions of ninhydrin with dimedone, ethyl acetoacetate and ethyl nitroacetate yielded 4b,9b-dihydroxy-7,7-dimethyl-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione 5, ethyl 3a,8b-dihydroxy-2-methyl-4-oxo-4,8b-dihydro-3aH-indeno[1,2-b]furan-3-carboxylate 6 and 2-hydroxy-2-(nitromethyl)-1H-indene-1,3(2H)-dione 7, respectively. The structures of 1, 3, 5, 6 and 7 were determined by X-ray crystallography and attempts have been made to propose the mechanism of their formation.

Thiosalicylato complexes of Zn(II) and Hg(II), [Zn(SC6H4CO2)(TMEDA)]2 (1) and [TMEDA-H2][Hg(SC6H4CO2)2] (2) where (TMEDA = N,N,N',N'-tetramethylethylenediamine) have been synthesized and characterized by spectral and single crystal X-ray analyses. Thiosalicylate opted different binding modes; in 1 all three binding sites are used whereas in 2 bonding of the ligands are mainly through S atoms, however, Hg-O distances indicate the existence of significant Hg…O interactions. Bonding features have been explained on the basis of DFT calculations. Electronic absorption and emission spectral properties of both complexes have been studied. Electronic transitions have been calculated by TDDFT method and the results are consistent with the experimental spectra. We further have evaluated anti-bacterial, anti-biofilm and anti-tumour activities of 1 in addition to its cytotoxicity profile. It has been found to be highly effective against Escherichia coli, Klebsiella pneumoniae, Methicillin sensitive Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa clinical as well as reference strains. Interestingly, complex 1 has been found to be more potent than earlier reported Au(III) as well as Pt(II) thiosalicylate complexes. The effect of complex 1 on 72 h old biofilms of S. Aureus (MDR isolate 3) has been investigated by confocal laser scanning microscopy which revealed its bactericidal activities at the concentration as low as 0.125 µg/mL possibly by membrane alterations as evident by clear propidium iodide (PI) uptake. However, its antibiofilm activity is possibly due to interactions with biofilm matrix constituents.

The title hydrate, C13H10ClN3O·H2O, is the orthorhombic polymorph of the previously reported monoclinic compound [Fun et al. (2012). Acta Cryst. E68, o2303–o2304). In the title compound, the dihedral angle between the pyridine and benzene rings is 18.0 (2)°. In the crystal, the Schiff base molecules and water molecules are linked via O—H...O, N—H...O and O—H...N hydrogen bonds, forming a two-dimensional network parallel to (001). In addition, the Schiff base molecules are linked end-to-end by weak C—H...Cl hydrogen along the c-axis direction, forming an overall three-dimensional network. Weak C—H...π interactions are also observed.

The asymmetric unit of the title compound, C30H33N5O3, contains two independent molecules,AandB. In moleculeA, thetert-butyl 4-methylpiperazine-1-carboxylate group was refined as disordered over two sets of sites with an occupancy ratio of 0.821 (4):0.179 (4). The piperazine ring adopts a chair conformation in both molecules. The dihedral angles between the pyrimidine ring and methoxyphenyl ring are 20.27 (14) and 8.72 (11)° for moleculesAandB, respectively. The quinoline ring system makes dihedral angles of 30.68 (11) and 37.76 (10)° with the pyrimidine ring in moleculesAandB, respectively. In the crystal, C—H...O hydrogen bonds link the molecules into chains along [100].

In the title compound, C26H27N5O, the piperazine ring adopts a chair conformation. The pyrimidine ring makes a dihedral angle of 1.5 (1)° with the methoxyphenyl ring and 33.1 (1)° with the quinoline ring system. In the crystal, molecules are consolidated in the crystal packing by weak C—H...π interactions and π–π stacking interactions.

The title compound, 2-amino-7,7-dimethyl-5-oxo-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4Hchromene-3-carbonitrile was synthesized by multicomponent reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst. Its structure was determined by X-ray structure analysis. The crystals are monoclinic, sp. gr. C2/c, a = 22.010(6), b = 11.0364(10), c = 17.147(4) A, β = 130.37(4)°, Z = 8, R = 0.0433 for 2377 observed reflections.

The title compound, C13H14O2N3Cl, has been synthesized by the reaction of chloroacetyl chloride with 4-aminoantipyrine in basic media and characterized by FT-IR, CHN elemental analysis, UV-Vis, TGA, DTA, DSC and single crystal X-ray diffraction. crystals are monoclinic, sp. gr. P21/c, a = 6.9994(6), b = 12.4035(13), c = 15.836(2) A, β = 100.367(9)°, Z = 4. The crystal structure is stabilized by N–H···O and C–H···O interactions, the former interactions result in the formation of dimers corresponding to R 2 2 (10) graphset motif and the dimers are further connected by C–H···O hydrogen bonding forming chains. In addition, the thermal stability of the compound was determined by TGA, DTA, DSC analysis, and absorption at λmax = 298 nm was determined by UV-Vis spectrophotometer.

The new pyrazolone derivative, (Z)-3-methyl-4-((naphthalen-1-ylamino)methylidene)-1-phenyl-1H-pyrazol-5(4H)-one, C21H17N3O, is synthesized, and its crystal structure is determined by X-ray structure analysis. The crystals are orthorhombic, sp. gr. P212121, a = 6.5683(7), b = 12.7384(15), c = 20.198(3) A, Z = 4, R = 0.0564 for 983 observed reflections. In crystal, the molecule exists in amine-one tautomeric form. The crystal structure is stabilized by N–H···O and C–H···O hydrogen bonds. In addition, C–H···π and π-π-interactions are observed.

Two carbonitrile compounds, 2-amino-4-(3-nitrophenyl)-5-oxo-4,5-dihydropyrano[3,2-c] chromene-3-carbonitrile (I) and 2-amino-7,7-dimethyl-4-(4-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (II), were synthesized, and their crystal structures were determined by X-ray diffraction technique. The crystals are triclinic, a = 7.7970(12), 8.2171(7), b = 9.0390(10), 9.2238(7), c = 15.148(2), 14.5585(11) A, α = 81.439(10)°, 74.895(6)°, β = 75.194(12)°, 87.392(6)°, γ = 76.151(11)°, 78.552(7)°, for I and II, respectively, Z = 2, sp. gr. P\(\overline 1\). The pyran ring in both the compounds deviates significantly from planarity and adopts boat conformation. The crystal structure is stabilized by N–H···O and N–H···N hydrogen bonds.

2-Amino-7-methyl-5-oxo-4-phenyl-4,5-dihydropyrano[3,2-c]pyran-3-carbonitrile, C16H12N2O3 is synthesized via one-pot multi-component reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst. Its structure is determined by single-crystal X-ray diffraction technique The crystals are monoclinic, a = 10.7357(12), b = 8.7774(8), c = 15.0759(16) A, β = 103.575(11)°, Z = 4, sp. gr. P21/n, R = 0.0551 for 1696 observed reflections. The crystal structure is stabilized by N–H···N, C–H···O, and C–H···π interactions.

The title compound, 2,4,6-triisopropyl-2',5'-dimethoxybiphenyl was synthesized from 1-choloro-2.5-dimethoxy benzene, 1,3,5-triisopropylbenzene boronic acid and potassium phosphate in the presence of lead acetate as a catalyst and toluene as a solvent. Its crystal structure is determined by X-ray structure analysis. The crystals are the orthorhombic, a = 12.3281(4), b = 17.4235(5), c = 19.6550(6) A, Z = 8, sp. gr. Pbca. R = 0.0603 for 2494 observed reflections.

The carbonitrile compound, 2-amino-5-oxo-4-propyl-4,5-dihydropyrano[3,2-c]chromene-3-carbonitrile was synthesized, in 83% yield, by one-pot multicomponent reaction of butyraldehyde, malononitrile and 4-hydroxycoumarin using 10 mol% urea as an organo-catalyst at room temperature, and its crystal structure was determined by X-ray diffraction technique. The crystals are triclinic, a = 7.7379(5), b = 8.7520(6), c = 11.6589(5) A, α = 96.668(4)°, β = 100.033(4)°, γ = 112.547(6)°, Z = 2, sp. gr. P. Both pyran rings in the molecule adopt a boat conformation. The crystal structure is stabilized by N-H···O and N-H···N hydrogen bonds.

A symmetric hydrogen-bonded liquid crystalline complex was synthesized from 4-n-butyloxy benzoic acid and 1,2-di-(4-pyridyl)-ethylene. The complex was analyzed by optical polarizing microscopy, differential scanning calorimetery, and thermal gravimetric analysis. The existence of hydrogen-bonding for the complex was confirmed by Fourier transform infrared spectroscopy and x-ray crystallography. The liquid crystalline complex crystallizes with a triclinic space group P1with the parameters a = 7.3331(4) A, b = 9.0701(4) A, c = 11.6957(5) A and α = 81.896(4)°, β = 79.239(4)°, and γ = 85.652(4)°.

O-Cinnamyloxy/geranyloxy/cyclohexenyloxy/cinnamoyloxy-acetophenones yielded pyrazol-heterocycles, all of which contained an angular methyl-attached pyranopyran unit with pyrazolones in the ionic liquid (IL), 1,8-diazabicyclo[5.4.0]undec-7-ene-8-ium acetate [DBU][Ac], via the domino/Knoevenagel-hetero-Diels–Alder (DKHDA) reaction. Besides, isoxazol yielded isoxazol-heterocycles possessing a framework to similar to O-allyloxy/prenyloxy-acetophenones, which did not involve chromatography to isolate the desired product. However, propargyl-substrates needed ZnO to promote the reaction. The heterosteroid-mimicking structure thus achieved may have different bioprofiles than the aldehyde-derived one. Moreover, the IL is recyclable and capable of promoting reaction effectively, which is indicative of an economical and greener way of achieving the interesting heterocycles. The stereochemistry of all the compounds was confirmed by 1H NMR, 13C NMR, 2D NMR NOESY and the single crystal X-ray diffraction data.

Syntheses of some new pyrrolo-fused pyrrolo[1,2-a] indole derivatives have been achieved by combining N-allyl-indole-2-carbaldehyde with a variety of N-alkyl-glycine esters as well as tetrahydroisoquinolines in an ionic liquid, triethylammonium acetate (TEAA), a recyclable reaction medium, via intramolecular [3+2] cycloaddition reaction. This new method is highly efficient, and the ionic liquid employed is recyclable. The stereochemistry of all the compounds was confirmed by 2D NMR NOESY and in some cases single crystal X-ray diffraction data. The in vitro screening of all new candidates against various bacterial strains and representative human solid tumor cell lines, A549 (lung), HeLa (cervix), SW1573 (lung), T-47D (breast) and WiDr (colon), revealed that many of them have good antibacterial, antifungal and antitubercular and antiproliferative activities.

An ionogel was synthesized through the confinement of 1,3,5-trimethyl pyrazolium chloride as an ionic liquid in a silica-gel matrix through a sol–gel process, and its catalytic activity was compared with a silica supported ionic liquid for the synthesis of benzothiazoles using 2-aminothiophenol and aldehydes/ketones. The reaction between 3-methoxyacetophenone and 2-aminothiophenol produced 2-(3-methoxyphenyl)benzothiazole, and its structure was determined using X-ray crystallography. The ionogel was characterized with SEM, TEM, FTIR and TGA.

Ethyl 2-amino-4-(4-fluorophenyl)-6-phenylcyclohexa-1,3-diene-1-carboxylate was synthesized from ethyl 6-(4-bromophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate and ammonium acetate in glacial acetic acid. The synthesized compound was characterized by elemental analysis, FT-IR, thermogravimetric analysis (TGA), differential thermal analysis (DTA), UV-Visible, and single-crystal X-ray diffraction. The title compound, ethyl 2-amino-4-(4-fluorophenyl)-6-phenylcyclohexa-1,3-diene-1-carboxylate, C21H2OFNO2, crystallizes in the orthorhombic space group Pbca with the following unit-cell parameters: a = 17.417(2), b = 9.7287(9), c = 21.014(2) A, and Z = 8. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 0.0644 for 1616 observed reflections. An intramolecular N–H…O hydrogen bond generates an S(6) graph-set motif. In the crystal, molecules are linked by N...

In the title molecule, C24H25N3O2, the piperazine ring adopts a chair conformation. The methoxyphenyl-substituted ring makes a dihedral angle of 6.79 (5)° with the quinoline ring system. In the crystal, molecules are consolidated in the crystal packing by a combination of weak C—H...N and C—H...O interactions. π–π stacking interactions also occur.

We report herein the facile synthesis and structural characterization of a highly stable dinuclear Cu(I) complex, [(PPh3)2Cu(μ-tda)Cu(PPh3)2]·6H2O 1 (tda = thiodiacetate anion), in which the Cu–Cu distance is 7.197 A. This “pre-formed” complex serves as an extremely efficient and recyclable homogeneous catalyst (2 mol%, 30 min) for CuAAC in dichloromethane solvent. The synthesis of a variety of glycoconjugates under ambient conditions is successfully achieved using 1 as a catalyst. The products are obtained in high yields and very short reaction times while complying with the “click protocols”. A simpler procedure solely involving the mixing of substrates with 1 (i.e. base free and solvent free) gave the corresponding glycoconjugate in 10 min using 2 mol% of the catalyst.

The preparation of some novel 3-(arylideneamino)-3a,8a-dihydroxy-1,3,3a,8a-tetrahydroindeno[1,2-d]imidazole-2,8-diones 8(i-xiv) and 3-(arylideneamino)-3a,8a-dihydroxy-2-thioxo-1,3,3a,8a-tetrahydroindeno[1,2-d]imidazol-8(2H)-ones 9(i-xiv) have been reported via one-pot catalyst-free reaction of aldehydes, semicarbazide hydrochloride/thiosemicarbazide with ninhydrin. All the synthesized compounds have been screened for anti-microbial activity and some of them were observed to possess broad spectrum anti-bacterial potential as well as significant antagonistic potential against fungal pathogens.

N-Protected derivatives of 1-aminocyclohexaneacetic acid (β3,3-Ac6c), namely Valeroyl-β3,3-Ac6c-OH [2-(1-pentanamidocyclohexyl)acetic acid, C13H23NO3], (I), Fmoc-β3,3-Ac6c-OH [2-(1-{[(9H-fluoren-9-yloxy)carbonyl]amino}cyclohexyl)acetic acid, C23H25NO4], (II), and Pyr-β3,3-Ac6c-OH {2-[1-(pyrazine-2-amido)cyclohexyl]acetic acid, C13H17N3O3}, (III), were synthesized and their conformational properties were determined by X-ray diffraction analysis. The backbone torsion angles (ϕ, θ) for β3,3-Ac6c-OH are restricted togaucheconformations in all the derivatives, with a chair conformation of the cyclohexane ring. In the crystal structure of (I), the packing of molecules shows both carboxylic acidR22(8) O—H...O and centrosymmetricR22(14) N—H...O hydrogen-bonding interactions, giving rise to chains along thec-axis direction. In (II), centrosymmetric carboxylic acidR22(8) O—H...O dimers are extended through N—H...O hydrogen bonds and together with inter-ring π–π interactions between Fmoc groups [ring centroid distance = 3.786 (2) Å], generate a layered structure lying parallel to (010). In the case of compound (III), carboxylic acid O—H...Npyrazinehydrogen bonds give rise to zigzag ribbon structures extending along thec-axis direction.

The thiopyrazole gave many new polycyclic thiopyranopyrazole-heterocycles when it was assembled with a variety of O-alkenylated/alkynylated salicylaldehydes and naphthaldehydes in Bronsted acidic ionic liquid, [Hmim]HSO4, via domino/Knoevenagel–hetero-Diels–Alder (DKHDA) reaction. The reaction is highly stereoselective and the work-up procedure required no chromatography of products in many cases.