scholarly journals Synthesis and Regularities of the Structure–Activity Relationship in a Series of N-Pyridyl-4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamides

2019 ◽  
Vol 87 (2) ◽  
pp. 12
Author(s):  
Igor V. Ukrainets ◽  
Anna A. Burian ◽  
Ganna M. Hamza ◽  
Natali I. Voloshchuk ◽  
Oxana V. Malchenko ◽  
...  
Keyword(s):  
Molecular Conformation ◽  
Sulfo Group ◽  
Spatial Arrangement ◽  
Mutual Arrangement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ring Nitrogen ◽  
Anti Inflammatory ◽  
Pharmacological Screening ◽  
High Level

According to our quantum and chemical calculations 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acid imidazolide is theoretically almost as reactive as its 2-carbonyl analog, and it forms the corresponding N-pyridyl-4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamides with many aminopyridines. However, in practice, the sulfo group introduces significant changes at times and prevents the acylation of sterically hindered amines. One of these products was 2-amino-6-methylpyridine. Thus, it has been concluded that aminopyridines interact with imidazolide in aromatic form where the target for the initial electrophilic attack is the ring nitrogen. To confirm the structure of all substances synthesized, 1H-NMR spectroscopy and X-ray diffraction analysis were used. From X-ray diffraction data it follows that in the crystalline phase the carbonyl and sulfo group may occupy different positions with respect to the plane of the benzothiazine bicycle: this position may be unilateral, typical for 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamides, versatile, and not yet encountered in compounds of this type. A comparison of these data with the results of the pharmacological screening conducted on the standard model of carrageenan inflammation showed that the N-pyridylamides of the first group demonstrated a direct dependence of their analgesic and anti-inflammatory activity on the mutual arrangement of the planes of the benzothiazine and pyridine fragments. The new molecular conformation of the benzothiazine nucleus provides a sufficiently high level of analgesic (but not anti-inflammatory) properties in all N-pyridylamides of the second group with an extremely weak dependence on the spatial arrangement of the pyridine cycle. All substances presented this article proved themselves in varying degrees as analgesics and antiphlogistics. Moreover, two of them—N-(5-methylpyridin-2-yl)- and N-(pyridin-3-yl)-4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamides—exceeded the most effective drug of oxicam type Lornoxicam by these indicators.

Synthesis, crystal structure and molecular conformation of (±)-1-oxoferruginol and (±)-shonanol

2004 ◽  
Vol 219 (10) ◽  
Author(s):  
Swastik Mondal ◽  
Monika Mukherjee ◽  
Arnab Roy ◽  
Debabrata Mukherjee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Diffraction Data ◽  
Molecular Conformation ◽  
Membered Ring ◽  
Methyl Groups ◽  
Single Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures

Abstract(±)-1-oxoferruginol and (±)-shonanol, two potential intermediates in the synthesis of tricyclic diterpenoid ferruginol, have been prepared and crystal structures of the compounds have been investigated using single-crystal X-ray diffraction data. The methyl groups of the isopropyl moiety in (±)-shonanol are disordered over two positions with occupation factors 0.65(1) and 0.35(1), respectively. Although the chemical structures of two compounds are very similar, a C—C single bond in the terminal six-membered ring of (±)-1-oxoferruginol is replaced by a C=C bond in (±)-shonanol, the quantitative isostructurality index calculations indicate that the structures are not isostructural. Intermolecular O—H…O hydrogen bonds between pairs of molecules in the compounds related by center of inversion lead to characteristic dimers forming R

scholarly journals Shape Tuning of Magnetite Nanoparticles Obtained by Hydrothermal Synthesis: Effect of Temperature

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Nayely Torres-Gómez ◽  
Osvaldo Nava ◽  
Liliana Argueta-Figueroa ◽  
René García-Contreras ◽  
Armando Baeza-Barrera ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Nanoparticle Synthesis ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pure Phase ◽  
High Level ◽  
Shape Tuning ◽  
Magnetite Phase

In this work, we present a simple and efficient method for pure phase magnetite (Fe3O4) nanoparticle synthesis. The phase structure, particle shape, and size of the samples were characterized by Raman spectroscopy (Rm), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDS), and transmission electron microscopy (TEM). The morphology tuning was controlled by the temperature of the reaction; the nanoparticles were synthesized via the hydrothermal method at 120°C, 140°C, and 160°C, respectively. The Rm and XRD spectra showed that all the nanoparticles were Fe3O4 in a pure magnetite phase. The obtained nanoparticles exhibited a high level of crystallinity with uniform morphology at each temperature, as can be observed through TEM and SEM. These magnetic nanoparticles exhibited good saturation magnetization and the resulting shapes were quasi-spheres, octahedrons, and cubes. The samples showed striking magnetic properties, which were examined by a vibrating sample magnetometer (VSM). It has been possible to obtain a good morphological control of nanostructured magnetite in a simple, economical, and scalable method by adjusting the temperature, without the modification of any other synthesis parameter.

scholarly journals Biobased Poly(ethylene furanoate) Polyester/TiO2 Supported Nanocomposites as Effective Photocatalysts for Anti-inflammatory/Analgesic Drugs

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 564 ◽  
Author(s):  
Anastasia Koltsakidou ◽  
Zoi Terzopoulou ◽  
George Kyzas ◽  
Dimitrios Bikiaris ◽  
Dimitra Lambropoulou
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Transformation Products ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Analgesic Drug ◽  
Ion Release ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Anti Inflammatory ◽  
Poly Ethylene

In the present study, polymer supported nanocomposites, consisting of bio-based poly(ethylene furanoate) polyester and TiO2 nanoparticles, were prepared and evaluated as effective photocatalysts for anti-inflammatory/analgesic drug removal. Nanocomposites were prepared by the solvent evaporation method containing 5, 10, 15, and 20 wt% TiO2 and characterized using Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Thin films of them have been prepared by the melt press and optimization of the photocatalytic procedure was conducted for the most efficient synthesized photocatalyst. Finally, mineralization was evaluated by means of Total organic carbon (TOC) reduction and ion release, while the transformation products (TPs) generated during the photocatalytic procedure were identified by high-resolution mass spectrometry.

Molecular conformation of chymotrypsinogen and chymotrypsin by low-angle x-ray diffraction

Biochemistry ◽  
1968 ◽  
Vol 7 (9) ◽  
pp. 3126-3131 ◽  
Author(s):  
W. R. Krigbaum ◽  
R. W. Godwin
Keyword(s):  
Molecular Conformation ◽  
X Ray Diffraction ◽  
X Ray

Effect of Li, Fe, and B Addition on the Crystallization Behavior of Sodium Aluminosilicate Glasses as Analogues for Hanford High Level Waste Glasses

MRS Advances ◽  
2016 ◽  
Vol 2 (10) ◽  
pp. 549-555 ◽  
Author(s):  
José Marcial ◽  
Mostafa Ahmadzadeh ◽  
John S. McCloy
Keyword(s):  
Function Analysis ◽  
High Level Waste ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Sodium ◽  
Chemical Ordering ◽  
Sodium Aluminosilicate ◽  
Aluminosilicate Glasses ◽  
Heat Treated ◽  
High Level

ABSTRACTCrystallization of aluminosilicates during the conversion of Hanford high-level waste (HLW) to glass is a function of the composition of the glass-forming melt. In high-sodium, high-aluminum waste streams, the crystallization of nepheline (NaAlSiO4) removes chemically durable glass-formers from the melt, leaving behind a residual melt that is enriched in less durable components, such as sodium and boron. We seek to further understand the effect of lithium, boron, and iron addition on the crystallization of model silicate glasses as analogues for the complex waste glass. Boron and iron behave as glass intermediates which allow for crystallization when present in low additions but frustrate crystallization in high additions. In this work, we seek to compare the average structures of quenched and heat treated glasses through Raman spectroscopy, X-ray diffraction, vibrating sample magnetometry, and X-ray pair distribution function analysis. The endmembers of this study are feldspathoid-like (LiAlSiO4, NaAlSiO4, NaBSiO4, and NaFeSiO4), pyroxene-like (LiAlSi2O6, NaAlSi2O6, NaBSi2O6, and NaFeSi2O6), and feldspar-like (LiAlSi3O8, NaAlSi3O8, NaBSi3O8, and NaFeSi3O8). Such a comparison will provide further insight on the complex relationship between the average chemical ordering and topology of glass on crystallization.

A conformational polymorphic transition in the high-temperature ∊-form of chlorpropamide on cooling: a new ∊′-form

2009 ◽  
Vol 65 (6) ◽  
pp. 770-781 ◽  
Author(s):  
Tatiana N. Drebushchak ◽  
Yury A. Chesalov ◽  
Elena V. Boldyreva
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Structural Changes ◽  
Molecular Conformation ◽  
Polymorphic Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Temperature Range ◽  
Two Phases

Structural changes in the high-temperature ∊-polymorph of chlorpropamide, 4-chloro-N-(propylaminocarbonyl)benzenesulfonamide, C10H13ClN2O3S, on cooling down to 100 K and on reverse heating were followed by single-crystal X-ray diffraction. At temperatures below 200 K the phase transition into a new polymorph (termed the ∊′-form) has been observed for the first time. The polymorphic transition preserves the space group Pna21, is reversible and is accompanied by discontinuous changes in the cell volume and parameters, resulting from changes in molecular conformation. As shown by IR spectroscopy and X-ray powder diffraction, the phase transition in a powder sample is inhomogeneous throughout the bulk, and the two phases co-exist in a wide temperature range. The cell parameters and the molecular conformation in the new polymorph are close to those in the previously known α-polymorph, but the packing of the z-shaped molecular ribbons linked by hydrogen bonds inherits that of the ∊-form and is different from the packing in the α-polymorph. A structural study of the α-polymorph in the same temperature range has revealed no phase transitions.

Übergangsmetallkomplexe mit Nitroxidradikalen: Palladium-, Platin-, Pentamethylcyclopentadienyl-rhodium- und -iridium-Komplexe sowie α-Aminocarboxylatkomplexe mit Donor-haltigen Derivaten des 2,5-Dihydroimidazol-l-oxyls / Transition Metal Complexes of Nitroxide Radicals, Palladium, Platinum, Pentamethylcyclopentadienyl Rhodium and Iridium Complexes, and α-Aminocarboxylate Complexes with Derivatives of 2,5-Dihydroimidazole-l-oxyls

1998 ◽  
Vol 53 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Frank Hintermaier ◽  
Sylvia Helding ◽  
Leonid B. Volodarsky ◽  
Karlheinz Sünkel ◽  
Kurt Polbom ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Molecular Structures ◽  
Iridium Complexes ◽  
X Ray Diffraction ◽  
Chelate Complexes ◽  
X Ray ◽  
Ring Nitrogen ◽  
Derivatives Of ◽  
Ring Nitrogen Atom ◽  
Palladium Platinum

2,5-Dihydroimidazoline-l-oxyl radicals I, II with imino substituents coordinate to Pd(II) and Pt(II) complexes with formation of the N,N chelate complexes 1-6. With oxygen containing substituents either monodentate N-coordination to give 8 or N ,O chelate formation to give 9 takes place, depending on the position of the oxygen atom relative to the ring nitrogen atom. With radicals III that also have the second ring nitrogen atom oxidized and the Rh(III) or Ir(III) complexes [Cp*MCl2]2 the O , O chelates 11 -13 could be obtained, while with Na2PdCl4 the heterocycle was destroyed with formation of a N,N chelate complex 10 of an α-nitrosooxime ligand. The orthopalladated 2,2,5,5 tetramethyl-4-phenyl-2,5-dihydroimidazoline-l-oxyl complex 7a reacts with several a-amino acidates under splitting of the dichloro bridge with formation of the C,N/N,O-bis-chelate complexes 7b-f. The molecular structures of 2 and 10 were determined by X-ray diffraction.

Influence of Molecular Conformation on the Solid State Packing of 1,2-Diglycerides Study of 1,2-Dipalmitin and Some Structural Analogs by Electron Diffraction, X-Ray Diffraction, and Infrared Spectroscopy

1978 ◽  
Vol 33 (1-2) ◽  
pp. 39-49 ◽  
Author(s):  
Douglas L. Dorset ◽  
Walter A. Pangborn ◽  
Anthony J. Hancock ◽  
Iris S. Lee
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Room Temperature ◽  
Molecular Conformation ◽  
Crystalline Solid ◽  
X Ray Diffraction ◽  
Chain Packing ◽  
X Ray ◽  
Monoclinic Form ◽  
Extended Chain

Abstract Diffraction studies on natural 1,2-dipalmitin and on analogs, including those based on the configurational isomers of cyclopentane-1,2,3-triol reveal that the 1,2-diglycerides crystallize from solvent with chain methylene packing identical to the monoclinic form of even-chain alkanes. The chains probably are folded back in “hairpin” fashion as found in phospholipid crystal structures. Acyl shifts are observed to occur in the crystalline solid state at room temperature to give the 1,3-diglyceride. Analogs based on the above-mentioned cyclitols show that isomers with adjacent chains trans to the ring (possibly extended chain packing) or with chains cis to the ring (“hair­ pin”) crystallize readily. Both possibly extended chain configurational isomers have the α-form as well as β′-forms and a β-polymorph. The hairpin isomers each give a β′-polymorph but only the all-cts isomer gives an α-form.

The influence of the type of halogen substituent and its position on the molecular conformation, intermolecular interactions and crystal packing for a series of 1-benzoyl-3-(halogenophenyl)thioureas

2021 ◽  
Vol 77 (1) ◽  
pp. 11-19
Author(s):  
Damian Rosiak ◽  
Andrzej Okuniewski ◽  
Jarosław Chojnacki
Keyword(s):  
Intermolecular Interactions ◽  
Phenyl Ring ◽  
Benzoyl Chloride ◽  
Molecular Conformation ◽  
Crystal Packing ◽  
Theoretical Calculations ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
C Nmr

By the reaction of benzoyl chloride, potassium isothiocyanate and the appropriate halogenoaniline, i.e. 2/3/4-(bromo/iodo)aniline, we have obtained five new 1-benzoyl-3-(halogenophenyl)thioureas, namely, 1-benzoyl-3-(2-bromophenyl)thiourea and 1-benzoyl-3-(3-bromophenyl)thiourea, C14H11BrN2OS, and 1-benzoyl-3-(2-iodophenyl)thiourea, 1-benzoyl-3-(3-iodophenyl)thiourea and 1-benzoyl-3-(4-iodophenyl)thiourea, C14H11IN2OS. Structural and conformational features of the compounds have been analyzed using X-ray diffraction and theoretical calculations. The novel compounds were characterized by solid-state IR and 1H/13C NMR spectroscopy. The conformations and intermolecular interactions, such as hydrogen bonds, π–π and S(6)...π stacking, and X...O (X = I or Br), I...S and I...π, have been examined and rationalized, together with four analogous compounds described previously in the literature. The set of nine compounds was chosen to examine how a change of the halogen atom and its position on the phenyl ring affects the molecular and crystal structures.

Cold Crucible Vitrification of U-bearing SRS SB4 HLW Surrogate

2010 ◽  
Vol 1265 ◽  
Author(s):  
Sergey Stefanovsky ◽  
Alexander Ptashkin ◽  
Oleg Knyazev ◽  
Olga Stefanovsky ◽  
James C Marra
Keyword(s):  
High Level Waste ◽  
Cold Crucible ◽  
Savannah River ◽  
X Ray Diffraction ◽  
Alumina Crucible ◽  
X Ray ◽  
Xrd Study ◽  
Processing Facility ◽  
High Level ◽  
River Site

AbstractSavannah River Site Defense Waste Processing Facility (DWPF) Sludge Batch 4 (SB4) high level waste (HLW) simulant at 55 wt % waste loading was produced in the demountable cold crucible and cooled to room temperature in the cold crucible. Appreciable losses of Cs, S and Cl took place during the melting. A second glass sample was subjected to canister centerline cooling (CCC) regime in an alumina crucible in a resistive furnace. X-ray diffraction (XRD) study showed that the glass blocks were composed of vitreous and spinel structure phases. No separate U-bearing phases were found.

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