Synthesis and Characterization of 9-Hydroxyphenalenone Using 2D NMR Techniques

2008 ◽  
Vol 85 (3) ◽  
pp. 413 ◽  
Author(s):  
Benjamin Caes ◽  
Dell Jensen
Keyword(s):  
2D Nmr ◽  
Synthesis And Characterization ◽  
Nmr Techniques

Synthesis and Characterization of Hybrid Dimeric Steroid Spiroketals

Synthesis ◽  
2021 ◽  
Author(s):  
Martha C. Mayorquín-Torres ◽  
Mauricio Maldonado-Domínguez ◽  
MARCOS FLORES-ALAMOS ◽  
Martín A. Iglesias-Arteaga
Keyword(s):  
Dft Calculations ◽  
Structural Characterization ◽  
2D Nmr ◽  
Synthesis And Characterization ◽  
Sonogashira Coupling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthetic Procedure ◽  
Nmr Techniques

The synthesis of six dimeric spiroketals bearing an estradiol half fused to the 5-or 5-epimers of androstane, cholestane and spirostane nuclei is described. The synthetic procedure comprises the Sonogashira coupling of different steroid alkynes with 2-iodoestradiol 17-monoacetate, followed by Pd-catalyzed spiroketalization. The structural characterization of the obtained hybrid dimers was performed using a combination of 1D and 2D NMR techniques, and was assisted by DFT calculations. Single crystal X-ray diffraction of one of the obtained compounds confirmed the proposed structures.

scholarly journals Synthesis and Characterization of Low-Cost Cresol-Based Benzoxazine Resins as Potential Binders in Abrasive Composites

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2995
Author(s):  
Artur Jamrozik ◽  
Mateusz Barczewski ◽  
Grzegorz Framski ◽  
Daniel Baranowski ◽  
Paulina Jakubowska ◽  
...  
Keyword(s):  
Low Cost ◽  
2D Nmr ◽  
Additional Analysis ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Voc Emission ◽  
Chemical Structures ◽  
Oxazine Ring ◽  
Nmr Techniques

A series of cresol-based benzoxazines were synthesized for potential application as a polymer matrix in abrasive composites. The chemical structures of the obtained benzoxazine resins were investigated in detail using Fourier transform infrared spectroscopy (FTIR) and hydrogen-1 as well as carbon-13 nuclear magnetic resonance spectroscopy (1H NMR, 13C NMR) with an additional analysis using two-dimensional NMR techniques (2D NMR 1H-1H COSY, 1H-13C gHSQC and gHMBC). Structural analysis confirmed the presence of vibrations of -O-C-N- at ~950 cm−1 wavenumber, characteristic for an oxazine ring. The thermal properties of benzoxazine monomers were examined using differential scanning calorimetry (DSC) analysis. The polymerization enthalpy varied from 143.2 J/g to 287.8 J/g. Thermal stability of cresol-based benzoxazines was determined using thermogravimetry (TGA) analysis with additional analysis of the amount of volatile organic compounds (VOC) emitted from the synthesized benzoxazines during their crosslinking by static headspace coupled with gas chromatography technique (HS-GC). The amount of residual mass significantly differed between all synthesized polybenzoxazines in the range from 8.4% to 21.2%. The total VOC emission for benzoxazines decreased by 46–77% in reference to a conventional phenolic binder. The efficiency of abrasive composites with the benzoxazine matrix was evaluated based on abrasion tests. Performed analyses confirmed successful synthesis and proper chemical structure of cresol-based benzoxazines. All the experiments indicated that benzoxazines based on different cresol isomers significantly differ from each other. Good thermal performance and stability of the abrasive composites with the polybenzoxazine matrix and significantly lower VOC emission allow us to state that benzoxazines can be a promising and valuable alternative to the phenolics and a new path for the development of modern, eco-friendly abrasives.

scholarly journals Isolation and Characterization of Two New Antimicrobial Acids from Quercus incana (Bluejack Oak)

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Rizwana Sarwar ◽  
Umar Farooq ◽  
Sadia Naz ◽  
Nadia Riaz ◽  
Syed Majid Bukhari ◽  
...  
Keyword(s):  
Ethyl Acetate Fraction ◽  
Structural Formula ◽  
2D Nmr ◽  
Spectroscopic Technique ◽  
Pentanoic Acid ◽  
One Dimensional ◽  
Isolation And Characterization ◽  
Nmr Techniques ◽  
New Compounds

Two new compounds [1-2] were purified from ethyl acetate fraction of Quercus incana. The structure of these compounds is mainly established by using advanced spectroscopic technique such as UV, IR, one-dimensional (ID) and two-dimensional (2D) NMR techniques, and EI mass. The structural formula was deduced to be 4-hydroxydecanoic acid [1] and 4-hydroxy-3-(hydroxymethyl) pentanoic acid [2]. Both isolated compounds were tested for their antimicrobial potential and showed promising antifungal activity against Aspergillus niger and Aspergillus flavus.

Synthesis and characterization of various unsubstituted and mono-N-substituted tetraazamacrocycles

1995 ◽  
Vol 73 (5) ◽  
pp. 685-695 ◽  
Author(s):  
I. Meunier ◽  
A.K. Mishra ◽  
B. Hanquet ◽  
R. Guilard ◽  
P. Cocolios
Keyword(s):  
Mass Spectrometry ◽  
Template Synthesis ◽  
2D Nmr ◽  
Spectral Studies ◽  
Synthesis And Characterization ◽  
Difference Spectroscopy ◽  
Protective Group ◽  
Noe Difference Spectroscopy ◽  
C Nmr

Syntheses of tetraazamacrocycles have been carried out by using p-toluenesulfonyl chloride as protective group. The [14(ane) N4] and [15(ane) N4] were also obtained by the template synthesis. Mono-N-functionalization of tetraazamacrocycles was accomplished by reaction of a fivefold excess of the free macrocycles with 1 equivalent of a suitable alkylating or arylating reagent. The key point of the synthesis lies in the use of an excess of the macrocycle over the substituting reactants to reduce the formation of polysubstituted derivatives, and in the easy separation of the excess of unreacted macrocycle. All the products were characterized on the basis of spectral studies (1H and l3C NMR, including 2D NMR and NOE difference studies) and mass spectrometry. Keywords: tetraazamacrocycles, improved synthesis, protective group, N-tosylation, template synthesis, NOE difference spectroscopy.

scholarly journals Versatile1H−31P−31P COSY 2D NMR Techniques for the Characterization of Polyphosphorylated Small Molecules

2010 ◽  
Vol 75 (10) ◽  
pp. 3214-3223 ◽  
Author(s):  
Ananya Majumdar ◽  
Yan Sun ◽  
Meha Shah ◽  
Caren L. Freel Meyers
Keyword(s):  
Small Molecules ◽  
2D Nmr ◽  
Nmr Techniques

scholarly journals Synthesis and characterization of allyl- and vinyl-substituted 1,2-bis(tetrazolo)ethanes as polymeric precursors

2016 ◽  
Vol 71 (12) ◽  
pp. 1199-1209
Author(s):  
Vera A. Hartdegen ◽  
Maximilian S. Hofmayer ◽  
Konstantin Karaghiosoff ◽  
Thomas M. Klapötke
Keyword(s):  
Allyl Bromide ◽  
2D Nmr ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
Physical Stimuli ◽  
Thermal Stability Of

AbstractOn the basis of 1,2-bis(5-tetrazolo)ethane (BTE) the corresponding twofold vinyl and allyl N-substituted derivatives were synthesized using 1,2-dibromoethane and allyl bromide, respectively. The compounds were obtained as two different constitutional isomers. Both species were analyzed using NMR and IR spectroscopy, elemental analysis, as well as mass spectrometry. In the case of the diallyl bistetrazoles, the two isomers were characterized using 2D NMR spectroscopy. The synthesis of the divinyl compounds gave crystals of the 2,2′-N-substituted isomer, which were analyzed by single-crystal X-ray diffraction. The thermal stability of the compounds was determined using differential scanning calorimetry (DSC) and gave decomposition temperatures around 190°C and 230°C. For the investigation of the inherent energetic potential, sensitivities toward physical stimuli and detonation parameters were determined. The compounds turned out to be insensitive toward friction and impact and possess moderate energetic properties.

Characterization of non-cellulosic glucans in Eucalyptus globulus Labill. wood and kraft pulp

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 478-482 ◽  
Author(s):  
Sara A. Lisboa ◽  
Dmitry V. Evtuguin ◽  
Carlos Pascoal Neto
Keyword(s):  
Eucalyptus Globulus ◽  
Fiber Surface ◽  
2D Nmr ◽  
Structural Features ◽  
Kraft Pulping ◽  
Hot Water ◽  
Pulp Yield ◽  
Naoh Solution ◽  
Nmr Techniques

Abstract The amount of non-cellulosic glucans in Eucalyptus globulus wood (approx. 4.5%) was assessed by extraction of sawdust with a 0.5 M NaOH solution at 90–120°C and the structural features were elucidated in a glucan-enriched polysaccharide fraction isolated by hot water extraction (120°C, 2 h). Isolated soluble glucans were characterized by wet chemistry methods and a set of 1D and 2D NMR techniques. The major proportion of glucans consisted of amylose (20%) and amylopectin (80%), although a small proportion of β-(1→3)-glucan (<0.2% on wood weight) was also detected. Although glucans are easily removed in the initial phase of kraft pulping, notable amounts were found in unbleached pulp and it was supposed that in the final stage of kraft pulping a fraction of α-glucan is precipitated onto the fiber surface and contributes to the pulp yield.

Characterization of partially deuteriated transition metal polyhydrido complexes by heteronuclear 2D NMR techniques

1991 ◽  
Vol 29 (13) ◽  
pp. S38-S44 ◽  
Author(s):  
Daniel Nanz ◽  
Wolfgang Von Philipsborn ◽  
Urs E. Bucher ◽  
Luigi M. Venanzi
Keyword(s):  
Transition Metal ◽  
2D Nmr ◽  
Nmr Techniques

Synthesis and ‎characterization ‎of a new acid ‎molten salt and ‎the study of ‎its ‎thermal ‎behavior and ‎catalytic ‎activity ‎in Fischer ‎esterification ‎

2021 ◽  
Author(s):  
Lia Zaharani ◽  
Nader Ghaffari Khaligh ◽  
Mohd Rafie Johan ◽  
Hayedeh Gorjian
Keyword(s):  
Mass Spectrometry ◽  
Catalytic Activity ◽  
Thermal Behavior ◽  
Molten Salt ◽  
Structure Elucidation ◽  
Chemical Structure ◽  
2D Nmr ◽  
Synthesis And Characterization ◽  
Fischer Esterification

A new acid molten salt was ‎‎prepared and its structure ‎‎elucidation was conducted ‎‎by FTIR, ‎‎1D NMR, 2D NMR, ‎‎and mass spectrometry. ‎Further support to ‎elucidate the chemical ‎structure of...

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