scholarly journals Synthesis of new bile acid-fused tetrazoles using the Schmidt reaction

2021 ◽  
Vol 17 ◽  
pp. 2611-2620
Author(s):  
Dušan Đ Škorić ◽  
Olivera R Klisurić ◽  
Dimitar S Jakimov ◽  
Marija N Sakač ◽  
János J Csanádi
Keyword(s):  
Bile Acid ◽  
Deoxycholic Acid ◽  
Hydrazoic Acid ◽  
Tumor Cell Lines ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Schmidt Reaction ◽  
X Ray ◽  
New Compounds ◽  
Tetrazole Derivatives

A practical and high-yielding Schmidt reaction for the synthesis of fused tetrazoles from bile acid precursors was developed. Mild reaction conditions using TMSN3 instead of hydrazoic acid as an azide source produced good yields of the desired tetrazoles. These conditions could be applied to other steroidal precursors. Additionally, an improved methodology for the synthesis of different ketone and enone precursors from cholic acid, deoxycholic acid, and chenodeoxycholic acid was established. Newly obtained tetrazole derivatives were characterized by NMR and X-ray diffraction spectroscopy. In a number of cases, preliminary antiproliferative tests of new compounds showed strong and selective activity towards certain tumor cell lines.

Surfactant involved in Copper Sulfide Nanocrystallites Synthesis

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Claudia Maria Simonescu ◽  
Valentin Serban Teodorescu ◽  
Camelia Capatina
Keyword(s):  
Copper Sulfide ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Shape Of Nanoparticles ◽  
Tem Transmission Electron Microscopy ◽  
Shape And Size

This paper presents the obtaining of copper sulfide CuS (covelite) from Cu(CH3COO)2.H2O and thioacetamide (TAA) system. The reaction was conducted in presence or absence of sodium-bis(2-ethylhexyl) sulfosuccinate (Na-AOT). The effects of various reaction parameters on the size and on the shape of nanoparticles have been examined. CuS obtained was characterized by X ray diffraction, IR spectroscopy, TEM � transmission electron microscopy and SAED selected area electron diffraction. The influence of surfactant to the shape and size of CuS (covellite) nanocrystals was established. The size of the nanocrystals varied from 10-60 nm depending on the reaction conditions such as quantity of surfactant.

scholarly journals UV-Accelerated Photocatalytic Degradation of Pesticide over Magnetite and Cobalt Ferrite Decorated Graphene Oxide Composite

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
Asma Tabasum ◽  
Mousa Alghuthaymi ◽  
Umair Yaqub Qazi ◽  
Imran Shahid ◽  
Qamar Abbas ◽  
...  
Keyword(s):  
Spectroscopic Techniques ◽  
Combined Effects ◽  
X Ray Diffraction ◽  
Contributing Factors ◽  
Reaction Conditions ◽  
X Ray ◽  
Oxidant Concentration ◽  
Optimized Conditions ◽  
High Degradation Rate ◽  
Considerable Loss

Pesticides are one of the main organic pollutants as they are highly toxic and extensively used worldwide. The reclamation of wastewater containing pesticides is of utmost importance. For this purpose, GO-doped metal ferrites (GO-Fe3O4 and GO-CoFe2O4) were prepared and characterized using scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopic techniques. Photocatalytic potentials of catalysts were investigated against acetamiprid’s degradation. A detailed review of the parametric study revealed that efficiency of overall Fenton’s process relies on the combined effects of contributing factors, i.e., pH, initial oxidant concentration, catalyst dose, contact time, and acetamiprid load. ~97 and ~90% degradation of the acetamiprid was achieved by GO-CoFe2O4 and GO-Fe3O4, respectively during the first hour under UV radiations at optimized reaction conditions. At optimized conditions (i.e., pH:3, [H2O2]: 14.5 mM (for Fe3O4, GO-Fe3O4, and GO-CoFe2O4) and 21.75 mM (for CoFe2O4), catalysts: 100 mgL−1, time: 60min) the catalysts exhibited excellent performance, with high degradation rate, magnetic power, easy recovery at the end, and efficient reusability (up to 5 cycles without any considerable loss in catalytic activity). A high magnetic character offers its easy separation from aqueous systems using an external magnet. Moreover, the combined effects of experimental variables were assessed simultaneously and justified using response surface methodology (RSM).

Two types of Ln2Cu2 hydroxo-trimethylacetate complexes with 0D and 1D motifs: synthetic features, structural differences, and slow magnetic relaxation

2021 ◽  
Author(s):  
Anna Bovkunova ◽  
Evgeniya S. Bazhina ◽  
Igor Evstifeev ◽  
Yulia V. Nelyubina ◽  
Maxim Shmelev ◽  
...  
Keyword(s):  
Magnetic Relaxation ◽  
X Ray Diffraction ◽  
Metal Core ◽  
X Ray ◽  
Trimethylacetate Complexes ◽  
Structural Differences ◽  
Slow Magnetic Relaxation ◽  
New Compounds

Two series of heterometallic LnIII−CuII compounds containing a butterfly-like tetranuclear metal core were synthesized and characterized by X-ray diffraction and magnetometry. The structures of the new compounds were shown to...

Replacing sulfonate by carboxylate: application of pyridyliminocarboxylato copper(II) complexes in rac-lactide polymerization and Chan–Evans–Lam coupling

2019 ◽  
Vol 97 (3) ◽  
pp. 178-190 ◽  
Author(s):  
Valérie Hardouin Duparc ◽  
Clémentine Dimeck ◽  
Frank Schaper
Keyword(s):  
Molecular Sieves ◽  
Weight Control ◽  
Phenylboronic Acid ◽  
Side Reactions ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
One Pot ◽  
X Ray ◽  
Induction Periods ◽  
Lactide Polymerization

Copper(II) complexes carrying pyridylmethyleneaminobenzoate or –propanoate ligands, LCuX, were prepared in one-pot reactions from pyridinecarboxaldehyde, aminobenzoic acid or β-alanine, and CuX2 (X = Cl, NO3, OAc, or OTf). All complexes were characterized by single-crystal X-ray diffraction studies and formed either dimers, tetramers, or coordination polymers. Attempted preparation of the respective alkoxide complexes, LCu(OR), was unsuccessful, but use of LCuX/NaOMe mixtures in rac-lactide polymerization indicated under some conditions coordination–insertion polymerization via a copper alkoxide as the mechanism. The complexes performed poorly in rac-lactide polymerization, showing low activities (12 h to completion at 140 °C), low to moderate heterotacticity (Pr = 0.6–0.8), and poor polymer molecular weight control (intramolecular transesterification). They were competent catalysts for Chan–Evans–Lam couplings with phenylboronic acid, without any indication of side reactions such as deboration or aryl homocoupling. The complexes were active in undried methanol, without addition of base, ligand, or molecular sieves. Aniline, n-octylamine, and cyclohexylamine were coupled quantitatively under identical reaction conditions. There is only little influence of the anion on activities (less than a factor of 2) but a strong influence on induction periods. The complexes were not active in CEL coupling with alcohols, phenols, or alkylboronic acids.

Synthese und Kristallstrukturen einiger Tetramethylstibonium-Hydrogendicarboxylate / Synthesis and Crystal Structures of Some Tetramethylstibonium Hydrogendicarboxylates

1982 ◽  
Vol 37 (11) ◽  
pp. 1393-1401 ◽  
Author(s):  
Beatrix Milewski-Mahrla ◽  
Hubert Schmidbaur
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Spectroscopic Data ◽  
Molar Ratio ◽  
Ionic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Donor Acceptor ◽  
New Compounds

Reactions of pentamethylantimony (CH3)5Sb with carboxylic acids in the molar ratio 1:2 afford one equivalent of methane and essentially quantitative yields of crystalline tetramothylstibonium hydrogendicarboxylates. Six new compounds of this series have been synthesized using benzoic, o-phthalic, salicylic, 4-ethoxy-salicylic, oxalic, and malic acid, and characterized by analytical and spectroscopic data. An ionic structure with strong hydrogen bonds in the anionic components is proposed.The crystal structures of the hydrogen-dibenzoato (1), hydrogen-ortho-plithalato (2) and 4-ethoxy-hydrogen-salicylate (3) were determined by single crystal X-ray diffraction. The compounds can be described as having ionic lattices with some donor-acceptor inter­actions between the stibonium centers and the carboxylate oxygen atoms. The anions are characterized by strong hydrogen bonds O...H...O. Thus, the (CH3)4Sb-tetrahedron in 1 is distorted by two benzoate oxygon atoms (at 304(2) and 340(2) pin). The cation in 2 is largely undistorted and the anion has a hydrogenphthalate hydrogen bond of d(O...H...O) = 232 pm. The cation-anion contact in 3 is as short as d(Sb-O) = 289 pm rendering the Sb atom pentacoordinate.

scholarly journals Lanthanoid Complexes Supported by Retro-Claisen Condensation Products of β-Triketonates

2018 ◽  
Author(s):  
Laura Abad Galán ◽  
Alexandre N. Sobolev ◽  
Eli Zysman-Colman ◽  
Mark Ogden ◽  
Massimiliano Massi
Keyword(s):  
Chelating Ligands ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Claisen Condensation ◽  
X Ray ◽  
Condensation Products ◽  
Complexation Reactions ◽  
The Impact ◽  
Low Solubility

<i>β</i>-Triketonates have been recently used as chelating ligands for lanthanoid ions, presenting unique structures varying from polynuclear assemblies to polymers. In an effort to overcome low solubility of the complexes of tribenzoylmethane, four <i>β</i>-triketones with higher lipophilicity were synthesised. Complexation reactions were performed for each of these molecules using different alkaline bases in alcoholic media. X-ray diffraction studies suggested that the ligands were undergoing decomposition under the reaction conditions. This is proposed to be caused by <i>in situ</i>retro-Claisen condensation reactions, consistent with two examples that have been reported previously. The lability of the lanthanoid cations in the presence of a varying set of potential ligands gave rise to structures where one, two, or three of the molecules involved in the retro-Claisen condensationreaction were linked to the lanthanoid centres. These results, along with measurements of ligand decomposition in the presence of base alone, suggest that using solvents of lower polarity will mimimise the impact of the retro-Claisen condensation in these complexes. <br>

Evolution of Crystalline Phase and Morphology of the Products Formed during the Hydrothermal Synthesis of Y2O3 Powders

2011 ◽  
Vol 189-193 ◽  
pp. 1275-1279
Author(s):  
Ying Wang ◽  
Gao Yang Zhao ◽  
Li Yuan
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Treatment ◽  
Crystalline Phase ◽  
Hydrothermal Reaction ◽  
Yttrium Nitrate ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron

The crystalline phase and morphology of the products formed during the synthesis of yttrium oxide via the hydrothermal treatment yttrium nitrate were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Products with high OH/NO3ratios are formed with the increasing of hydrothermal treatment. The crystalline phases are evolved from Y2(OH)5.14(NO3)0.86•H2O toY4O(OH)9(NO3) and finally Y(OH)3. The hydrothermal reaction conditions play an important role in the synthesis of the microstructures. Results show the particle size and final morphology of samples could be controlled by reaction temperature, reaction time, and OH-concentration. Sheets, hexagonal and needle-like Y2O3powders are obtained with the hydrothermal treatment of yittrium nitrate at 180 oC to 200oC for 2-8 hours at pH 9-13.

Effects of Reaction Conditions on Deposition of Ferrites from Alkaline Metal Hydroxide Gels

1997 ◽  
Vol 495 ◽  
Author(s):  
Karl F. Schoch ◽  
Theodore R. Vasilow
Keyword(s):  
Flow Rate ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Metal Hydroxides ◽  
X Ray ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Mg Content

ABSTRACTFormation of ferrites from aqueous solution of metal salts is a well known process involving precipitation of metal hydroxides followed by oxidation of the resulting gel. The purpose of the present work was to determine the effects oxygen flow rate on the progress of the reaction and on the structure and properties of the resulting precipitate. The reaction was carried out at 70°C with pH of 10.5 and oxygen flow rate of 2,4, or 8 standard liters per hour. The progress of the reaction was monitored by following the oxidation-reduction potential of the solution, which changes dramatically after the Fe(II) is consumed. The reaction rate increased with increasing oxygen flow rate. The Mg content of the precipitate was lower than that of the reaction mixture, possibly because of the pH of the reaction mixture. X-ray diffraction and infrared spectroscopy confirmed formation of a ferrite under these conditions.

Synthesis of Novel 2-Alkoxy-5H-benzo[6,7]cyclohepta[1,2-b]pyridine-3-carbonitriles

2003 ◽  
Vol 58 (7) ◽  
pp. 698-703 ◽  
Author(s):  
Adel S. Girgis ◽  
I. S. Ahmed-Farag
Keyword(s):  
Single Crystal ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Independent Synthesis

Reaction of 6-arylmethylene-6,7,8,9-tetrahydro-5H-benzocyclo-hepten-5-ones (1) with malononitrile in the appropriate alcohol in the presence of sodium afforded the corresponding 2-alkoxy-4-aryl- 6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-b]pyridine-3-carbonitriles (2) and not their isomeric forms 2-alkoxy-4-aryl-6,7-dihydro-5H-benzo[3,4]-cyclohepta[1,2-c]pyridine-1-carbonitriles (3). The proposed structure was confirmed via independent synthesis of (2) through the reaction of 6,7,8,9- tetrahydro-5-benzocycloheptenone (4) with the appropriate ylidenemalononitriles 5 under the same reaction conditions. Single crystal X-ray diffraction proves the structures of 2a,b.

Crystal Structures and Stability of Two Bipyridyl Complexes of Metal Chloroacetates

2007 ◽  
Vol 62 (10) ◽  
pp. 1271-1276 ◽  
Author(s):  
Liang Chen ◽  
Xian-Wen Wanga ◽  
Jing-Zhong Chen ◽  
Jian-Hong Liu
Keyword(s):  
Binuclear Complexes ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Reaction Conditions ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Dimensional Network

The complexes Mn(Cl3CCOO)2(4,4′-bpy) (1) and [Cu2(ClCH2COO)(2,2′-bpy)2(OH)(H2O)]-(NO3)2(2) (bpy = bipyridine) were generated under mild reaction conditions and characterized by IR spectra, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and single crystal X-ray diffraction. Compound 1 exhibits a two-dimensional network with octahedrally coordinated Mn(II) atoms linked by 4,4′-bpy ligands and Cl3COO− ligands. Compound 2 features a supramolecular structure of binuclear complexes, with edge-sharing five-coordinated square-pyramidal units bridged by the ClCH2COO− ligand, an OH− group and a water molecule. Complex 1 crystallizes in the orthorhombic space group Pbcn with cell parameters: a = 16.5390(17), b = 11.6396(17), c = 9.9181(12) Å, V = 1909.3(4) Å3, Z = 4, wR2 = 0.1576. Complex 2 crystallizes in the triclinic space group P1̅ with cell parameters: a = 7.6190(15), b = 11.151(2), c = 16.640(3) Å , α = 73.13(3), β = 80.89(3), γ = 74.51(3)°, V = 1298.73(4) Å3, Z = 2, wR2 = 0.1265.

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