Synthesis of highly functionalized 4-amino-2-(trifluoromethyl)-1H-pyrroles

Synthesis ◽  
2021 ◽  
Author(s):  
Nilo Zanatta ◽  
Lucimara L Zachow ◽  
Mateus Mittersteiner ◽  
Estefania da Costa Aquino ◽  
Helio G Bonacorso ◽  
...  
Keyword(s):  
Single Crystal ◽  
2D Nmr ◽  
Aliphatic Amines ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reaction Condition ◽  
Primary Aliphatic Amines

In this work, the reactivity of 5-bromo-1,1,1-trifluoro-4-methoxypent-3-en-2-one toward primary aliphatic amines was studied. The reaction was found to be extremely selective to synthesize a series of 1-alkyl-4-aminoalkyl-2-trifluoromethyl-1H-pyrroles (13 examples, at yields up to 90%) and a series of highly functionalized β-enaminones (6 examples, at yields up to 78%), with only the amount of amine and the reaction condition needing to be controlled. The structure of the products was unambiguously determined by single crystal X-ray diffraction and 2D NMR experiments.

scholarly journals Two Dibenzoquinones from the Fungus Acremonium cavaraeanum

2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201
Author(s):  
Qiao Xu ◽  
Miao-Miao Zhang ◽  
Shu-Zhen Yana ◽  
Lu-Fen Cao ◽  
Qiang Lia ◽  
...  
Keyword(s):  
Single Crystal ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Time

Two symmetrical dibenzoquinone derivatives were isolated from solid cultures of the fungus Acremonium cavaraeanum. Compound 1 was new and identified as 2,7-dihydroxy-3,6,9-trimethyl-9 H-xanthene-1,4,5,8-tetraone. Compound 2 was 3,3’,6,6’-tetrahydroxy-4,4’-dimethyl-1,1’-bi- p-benzoquinone, i.e. oosporein, which was reported from A. cavaraeanum for the first time. The structure of the dibenzoquinone (1) was unambiguously elucidated using a combination of MS, IR, 1D- and 2D-NMR, and the dibenzoquinone (2) was further determined by single-crystal X-ray diffraction.

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.

scholarly journals Single Crystal X-ray Diffraction, Spectroscopic and Mass Spectrometric Studies of Furanocoumarin Peucedanin

2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900
Author(s):  
Magdalena Bartnik ◽  
Marta Arczewska ◽  
Anna A. Hoser ◽  
Tomasz Mroczek ◽  
Daniel M. Kamiński ◽  
...  
Keyword(s):  
Single Crystal ◽  
Crystal Lattice ◽  
2D Nmr ◽  
Unit Cell ◽  
Spectroscopic Techniques ◽  
Fragmentation Pattern ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Column ◽  
Biological Tests

The structure of peucedanin, isolated from Peucedanum tauricum Bieb. (Apiaceae), has been established using single crystal X-ray diffraction. This furanocoumarin isolated from the light petroleum extract of P. tauricum fruits was characterized by high resolution EI-MS, sATR-FTIR and 2D NMR spectroscopic techniques. The EI-MS showed the typical fragmentation pattern of methoxyfuranocoumarins. Extensive 1D (1H and 13C) as well as 2D NMR data enabled complete assignment of the carbon atoms in the peucedanin molecule. The FTIR data confirms intermolecular hydrogen bonding between peucedanin molecules in polar solvents. Peucedanin crystallises in the R-3 space group from the trigonal system with one molecule in the asymmetric part of the unit cell. The crystal lattice of peucedanin consists of the molecules arranged in separate columns. They are related by two fold screw axes and centres of symmetry. Interestingly, peucedanin columns form two channels per unit cell with a diameter of 7.5Å going through the crystal lattice in the Z-direction. These channels are filled with disordered water molecules, which are surrounded by hydrophobic methyl groups and are located exactly at the centres of the channels. The peucedanin molecules are stacked in a single column with the opposite orientation of the neighbouring molecules. These results could be interesting in further application of this molecule, for example in biological tests of its activity.

Regioselective and Catalyst-Free Epoxidation of (E)-3-[3-(2-Hydroxyaryl)-3-oxoprop-1-en-1-yl]chromones

Synlett ◽  
2018 ◽  
Vol 29 (20) ◽  
pp. 2633-2637 ◽  
Author(s):  
Mohamed Hammadi ◽  
Oualid Talhi ◽  
Artur Silva ◽  
Rachid Ameraoui ◽  
Ridha Hassaine ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Double Bond ◽  
Single Crystal ◽  
Density Functional ◽  
2D Nmr ◽  
Theoretical Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uncatalyzed Reaction ◽  
High Yields

The uncatalyzed reaction of hydrogen peroxide with (E)-3-[3-(2-hydroxyaryl)-3-oxoprop-1-en-1-yl]chromones resulted in a regio­selective epoxidation of the chromone intracyclic C(2)=C(3) double bond to afford unique isomeric (E)-7a-[3-(2-hydroxyphenyl)-3-oxoprop-1-en-1-yl]-1aH-oxireno[2,3-b]chromen-7(7aH)-ones in high yields. 2D NMR and single-crystal X-ray diffraction were used to elucidate the structures of the chromanone epoxides. Density functional theoretical studies demonstrated a high electrophilicity of the starting chromones.

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.

scholarly journals Sessilifol A and B, Urease Inhibitory Pimarane-type Diterpenes from Hymenocrater sessilifolius

2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201
Author(s):  
Sadia Khan ◽  
Muhammad Shaiq Ali ◽  
Zeeshan Ahmed ◽  
Mehreen Lateef ◽  
Sammer Yousuf ◽  
...  
Keyword(s):  
Single Crystal ◽  
Vanillic Acid ◽  
Nmr Spectra ◽  
Soluble Fraction ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inhibitory Potential ◽  
Urease Inhibitory ◽  
C Nmr

New pimarane type diterpenes named sessilifol A (1) and B (2) have been isolated from the EtOH soluble fraction of Hymenocrater sessilifolius Benth., along with eight known constituents cirsimaritin (3), gardenin C (4), β-sitosterol (5), saringosterol (6), β-sitosterol glucoside (7), ursolic acid (8), sucrose (9) and vanillic acid (10). Their structures were elucidated on the basis of 1H- and 13C-NMR spectra and by 2D-NMR experiments. The structure of 1 was further confirmed by single crystal X-ray diffraction technique. The compound 2 showed potent inhibitory potential against the enzyme urease while 1, 3, 4 and 10 were moderately active.

scholarly journals Structural corroboration of two important building blocks of the anticancer drug eribulin mesylate through two-dimensional NMR and single-crystal X-ray diffraction studies

2016 ◽  
Vol 72 (1) ◽  
pp. 14-20
Author(s):  
Srinivas Venkata Pullela ◽  
Vinod Acharya ◽  
Nagarjuna Reddy ◽  
Jayvant Harlikar ◽  
Amar Kulkarni ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structural Integrity ◽  
Building Blocks ◽  
2D Nmr ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Eribulin Mesylate ◽  
X Ray ◽  
Stage Synthesis ◽  
The Absolute

Eribulin mesylate, one of the most synthetically challenging drugs to date, possesses 19 stereocentres in its structure and ascertaining the absolute stereochemistry at every stage of the 64-stage synthesis is crucial. In our quest to synthesize eribulin, we identified two critical building blocks of this molecule, namely 3,4:6,7-di-O-cyclohexylidene-D-glycero-α-L-talo-heptopyranose methanol monosolvate, C19H30O7·CH3OH, and (2R,3R,4R,5S)-5-allyl-2-[(S)-2,3-dihydroxypropyl]-4-[(phenylsulfonyl)methyl]tetrahydrofuran-3-ol, C17H24O6S, for which two-dimensional NMR (2D-NMR) data were not sufficient to prove the absolute configuration. To ensure structural integrity, single-crystal X-ray diffraction data were obtained to confirm the structures. This information provides useful insights into the structural framework of the large eribulin mesylate molecule.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

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

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