Dibenzo[b,e][1,4]diazepin-1-ones and their Ring-Opened Derivatives: Revisited Synthesis, 2D NMR and Crystal Structure

Synlett ◽  
2017 ◽  
Vol 28 (17) ◽  
pp. 2247-2252 ◽  
Author(s):  
Norah Bennamane ◽  
Oualid Talhi ◽  
Artur Silva ◽  
Brahim Cherfaoui ◽  
Houria Lakhdari ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Single Crystal ◽  
Ring Opening ◽  
Oxalyl Chloride ◽  
2D Nmr ◽  
Positional Isomers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Free

The synthesis of 2,3,4,5,10,11-hexahydro-1H-dibenzo[b,e][1,4]diazepin-1-ones was revisited and a catalyst-free method was established, by exploring the reactivity of 3-[(2-aminoaryl)amino]dimedones towards carbonylated electrophiles. 2D NMR and single-crystal X-ray diffraction studies were used to characterize the structures unequivocally and to review the mechanism leading to the formation of supposed positional isomers. The action of 3-[(2-aminoaryl)amino]dimedones on chromene-3-carboxylic acid, fumaryl, and oxalyl chloride has led to dibenzo[b,e][1,4]diazepin-1-one ring opening to produce novel Z-configured enaminone and linear diamides.

Purification, characterization, crystal structure and NO production inhibitory activity of three new sesquiterpenoids from homalomena occulta

2018 ◽  
Vol 74 (11) ◽  
pp. 1440-1446
Author(s):  
Qi Zhang ◽  
Li Ma ◽  
Zhaoxia Qu ◽  
Guige Hou ◽  
Yanan Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
2D Nmr ◽  
Inhibitory Effect ◽  
Raw 264.7 Cells ◽  
No Production ◽  
Raw 264.7 ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spectroscopic Analyses

Two new isodaucane-type sesquiterpenoids, namely (1R,4S,5S,6R,7S,10R)-isodauc-6,7,10-triol, C15H28O3, (1), and (1R,4S,5S,6S,7S,10R)-isodauc-6,7,10-triol, (2), and a new eudesmane-type sesquiterpenoid, 1β,4β,5α-trihydroxyeudesmane, (3), were obtained from the rhizomes of homalomena occulta with the aid of column chromatography. Their structures were elucidated based on extensive spectroscopic analyses, including 1D NMR, 2D NMR and HRESIMS. The structure of (1) was confirmed by single-crystal X-ray diffraction and the absolute configuration was assigned with respect to that of the precursor. The single-crystal structure reveals that adjacent molecules of (1) embrace through two groups of intermolecular O—H...O hydrogen bonds to generate a two-dimensional sheet with a 63-net topology. The three compounds were evaluated for their activity against lipopolysaccharide-induced production of nitrogen oxide (NO) in RAW 264.7 cells, and (1) showed an inhibitory effect on NO production, with IC50 values of 5.7±0.22 µM.

A New Supramolecular Synthon Using N-Methylaniline. The Crystal Structure of the 1 : 1 Adduct of N-Methylaniline with 5-Nitrofuran-2-carboxylic Acid

1998 ◽  
Vol 51 (9) ◽  
pp. 867 ◽  
Author(s):  
Daniel E. Lynch ◽  
Lisa C. Thomas ◽  
Graham Smith ◽  
Karl A. Byriel ◽  
Colin H. L. Kennard
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Proton Transfer ◽  
Single Crystal ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Supramolecular Synthon ◽  
X Ray ◽  
C 23 ◽  
A Cell

The crystal structure of the 1 : 1 adduct of N-methylaniline with 5-nitrofuran-2-carboxylic acid has been determined by single-crystal X-ray diffraction. Crystals are monoclinic, space group P21/c with Z 4 in a cell of dimensions a 8·467(5), b 6·106(2), c 23·95(1) Å, β 94·48(3)°. The molecules associate in a tetrameric, proton-transfer formation which has potential as a new supramolecular synthon.

The crystal and molecular structure of (±)-('E')-N-Acetylpiperidine-2-carboxylic acid

1980 ◽  
Vol 33 (1) ◽  
pp. 215 ◽  
Author(s):  
ID Rae ◽  
CL Raston ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Carboxylic Acid ◽  
Single Crystal ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal structure of N-acetylpiperidine-2-carboxylic acid has been determined by single-crystal X-ray diffraction methods at 295(1) K and refined by least squares to a residual of 0.039 for 846 'observed' reflections. Crystals are orthorhombic, with space group Pbca, a 13.684(6), b 11.602(4), c 11.171(4)Ǻ, Z 8. The ring is a chair structure in which, contrary to an earlier proposal based on 1H n.m.r. studies, there is almost perfect staggering about the C(2)-C(3) bond.

scholarly journals Efficient and regioselective synthesis of dihydroxy-substituted 2-aminocyclooctane-1-carboxylic acid and its bicyclic derivatives

2022 ◽  
Vol 18 ◽  
pp. 77-85
Author(s):  
İlknur Polat ◽  
Selçuk Eşsiz ◽  
Uğur Bozkaya ◽  
Emine Salamci
Keyword(s):  
Carboxylic Acid ◽  
Ring Opening ◽  
Density Functional ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
2D Nmr Spectroscopy ◽  
Functional Theory ◽  
X Ray ◽  
Amine Oxidation ◽  
Acid Methyl

The first synthesis of 2-amino-3,4-dihydroxycyclooctane-1-carboxylic acid, methyl 6-hydroxy-9-oxo-8-oxabicyclo[5.2.1]decan-10-yl)carbamate, and 10-amino-6-hydroxy-8-oxabicyclo[5.2.1]decan-9-one starting from cis-9-azabicyclo[6.2.0]dec-6-en-10-one is described. cis-9-Azabicyclo[6.2.0]dec-6-en-10-one was transformed into the corresponding amino ester and its protected amine. Oxidation of the double bond in the N-Boc-protected methyl 2-aminocyclooct-3-ene-1-carboxylate then delivered the targeted amino acid and its derivatives. Density-functional theory (DFT) computations were used to explain the reaction mechanism for the ring opening of the epoxide and the formation of five-membered lactones. The stereochemistry of the synthesized compounds was determined by 1D and 2D NMR spectroscopy. The configuration of methyl 6-hydroxy-9-oxo-8-oxabicyclo[5.2.1]decan-10-yl)carbamate was confirmed by X-ray diffraction.

scholarly journals Synthesis and crystal structure of Cu(II) and Co(II) complexes with 1,3-dimethyl-pyrazole-5-carboxylic acid ligand

2015 ◽  
Vol 80 (7) ◽  
pp. 867-875 ◽  
Author(s):  
Zeljko Jacimovic ◽  
Milica Kosovic ◽  
Sladjana Novakovic ◽  
Gerald Giester ◽  
Ana Radovic
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Acid Ligand ◽  
Square Planar ◽  
Monodentate Coordination ◽  
Carboxylic Acid Ligand

In the reaction of 1,3-dimethyl-pyrazole-5-carboxylic acid (HL) with M(OAc)2?4H2O, (M = Cu, Co) two novel complexes have been prepared, square-planar [CuL2(H2O)2] and octahedral [CoL2(MeOH)4]. The crystal structures have been determined by single-crystal X-ray diffraction. In both complexes the deprotonated acid displays monodentate coordination to the metal ions. According to the results of CSD survey this is the first structural report on the metal complexes with N1-substituted pyrazole-5-carboxylic ligand.

Imine-coordinated 2-Aminoazole Complexes of Au(I): Complicating Reactions and Verification of Products by Crystal Structure Determination

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1073-1087 ◽  
Author(s):  
Leigh-Anne de Jongh ◽  
Liliana Dobrzańska ◽  
Christoph E. Strasser ◽  
Helgard G. Raubenheimer ◽  
Stephanie Cronje
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Structural Characterization ◽  
Structure Determination ◽  
Ring Opening ◽  
Crystal Structure Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Sites

Abstract When Au(I) is provided with endocyclic soft thioether or endocyclic hard amine, endocyclic borderline imine and exocyclic hard amine coordination sites, the softer borderline endocyclic imine coordination site is favored. This is demonstrated by the synthesis and structural characterization (IR, MS, 1H, 13C and 31P NMR experiments and single-crystal X-ray diffraction analysis) of 2-aminoazole (2-amino-4-methylthiazole, 2-aminobenzothiazole and 2- aminobenzimidazole) complexes of [AuPPh3]+ (1-3). An unusual ring opening is observed for the reaction of 2-aminothiazoline with [Au(NO3)PPh3] yielding μ2-(2-mercapto-ethyl-cyanamide- k,S)bis(triphenylphosphine)gold(I) nitrate (4). Reactions of 2-aminoazoles with Au(C6F5)THT (THT=tetrahydrothiophene) yield [Au(C6F5)2]- stabilized by various cations. The formation of Au(2-aminothiazoline)C6F5 is again the exception

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

scholarly journals Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 272
Author(s):  
Seungyeol Lee ◽  
Huifang Xu ◽  
Hongwu Xu ◽  
Joerg Neuefeind
Keyword(s):  
Crystal Structure ◽  
Distribution Function ◽  
Single Crystal ◽  
Pair Distribution Function ◽  
Atomic Displacement ◽  
Single Crystal Xrd ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutron Pair ◽  
Atomic Displacement Parameters

The crystal structure of moganite from the Mogán formation on Gran Canaria has been re-investigated using high-resolution synchrotron X-ray diffraction (XRD) and X-ray/neutron pair distribution function (PDF) analyses. Our study for the first time reports the anisotropic atomic displacement parameters (ADPs) of a natural moganite. Rietveld analysis of synchrotron XRD data determined the crystal structure of moganite with the space group I2/a. The refined unit-cell parameters are a = 8.7363(8), b = 4.8688(5), c = 10.7203(9) Å, and β = 90.212(4)°. The ADPs of Si and O in moganite were obtained from X-ray and neutron PDF analyses. The shapes and orientations of the anisotropic ellipsoids determined from X-ray and neutron measurements are similar. The anisotropic ellipsoids for O extend along planes perpendicular to the Si-Si axis of corner-sharing SiO4 tetrahedra, suggesting precession-like movement. Neutron PDF result confirms the occurrence of OH over some of the tetrahedral sites. We postulate that moganite nanomineral is stable with respect to quartz in hypersaline water. The ADPs of moganite show a similar trend as those of quartz determined by single-crystal XRD. In short, the combined methods can provide high-quality structural parameters of moganite nanomineral, including its ADPs and extra OH position at the surface. This approach can be used as an alternative means for solving the structures of crystals that are not large enough for single-crystal XRD measurements, such as fine-grained and nanocrystalline minerals formed in various geological environments.

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