N-Alkoxyimidazolylidines (NOHCs): Nucleophilic carbenes based on oxidized imidazolium core

2022 ◽  
Author(s):  
Vladyslav Bakhonsky ◽  
Jonathan Becker ◽  
Grzegorz Mlostoń ◽  
Peter Richard Schreiner
Keyword(s):  
13C Nmr ◽  
Nucleophilic Carbenes

We report the first preparation of a N-alkoxyimidazolylidene (NOHC), a nucleophilic carbene based on an oxidized imidazolium core. The carbene carbon shows the highest upfield 13C NMR shift compared to...

Study of collagen using liquid and solid 13C NMR

1992 ◽  
Vol 89 ◽  
pp. 227-236 ◽  
Author(s):  
M Bonnet ◽  
L Foucat ◽  
J Dupuis ◽  
JP Renou
Keyword(s):  
13C Nmr

Solid state 13C NMR in conducting polymers

1985 ◽  
Vol 46 (9) ◽  
pp. 1595-1601 ◽  
Author(s):  
F. Devreux ◽  
G. Bidan ◽  
A.A. Syed ◽  
C. Tsintavis
Keyword(s):  
Solid State ◽  
Conducting Polymers ◽  
13C Nmr ◽  
Solid State 13C Nmr

Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 49-53 ◽  
Author(s):  
CHRISTINE CHIRAT ◽  
LUCIE BOIRON ◽  
DOMINIQUE LACHENAL
Keyword(s):  
Carbon Content ◽  
Acid Hydrolysis ◽  
13C Nmr ◽  
Kraft Lignin ◽  
Kappa Number ◽  
Hydroxyl Groups ◽  
Kraft Pulps ◽  
Quaternary Carbon ◽  
Oxygen Delignification

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

Synthesis and Characterization of Some New Esters Containing Heterocyclic and Derived From Azo Dyes

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Zena G. Alrecabi ◽  
Zainab Amer ◽  
Naeemah Al-Lami
Keyword(s):  
Schiff Base ◽  
13C Nmr ◽  
Azo Dyes ◽  
Spectral Methods ◽  
Anthranilic Acid ◽  
Heterocyclic Compounds ◽  
Synthesis And Characterization ◽  
Cooh Group ◽  
Molecular Weights

This study including prepared new colored esters containing heterocyclic with high molecular weights. In the first part of work we synthesized azo dyes [1,2] from the reaction p-toluidine with β-naphthol and o-nitro phenol, thin we synthesized Schiff bases [3,4] by the reaction anthranilic acid with benzaldehyde and dimethyl benzaldehyde. The reaction azo dyes (contain OH group) with Schiff base (contain COOH group) these led to produce the new colored esters [A1-A4]. The second part of work was modification the (C=N-) group in esters to heterocyclic compounds by reacting with phenyl iso cyanide to produce new β-lactam [B1-B4] and with anthranilic acid to get new hydroquinazoline [C1-C4]. All these compounds were characterized by physical properties and spectral methods FTIR, 1H-NMR and 13C-NMR.

Synthesis and Biological Evaluation of Various New Substituted 1,3,4-oxadiazole-2-thiols

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Gabriela Laura Almajan ◽  
Stefania Felicia Barbuceanu ◽  
Ioana Saramet ◽  
Mihaela Dinu ◽  
Cristian Vasile Doicin ◽  
...  
Keyword(s):  
Biological Activity ◽  
Plant Growth ◽  
1H Nmr ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Biological Evaluation ◽  
Ethyl Chloroacetate ◽  
Low Concentrations ◽  
Synthesis And Biological Evaluation

5-[4-(4X-phenylsulfonyl)phenyl]-1,3,4-oxadiazole-2-thiols, X=H, Cl, Br, reacted with ethyl chloroacetate to give S-alkylated compounds. Aminomethylation of the thione form of oxadiazoles yielded N(3)-derivatives. All the products have been characterized by elemental analysis, IR, 1H-NMR and 13C-NMR. The plant-growth regulating effects of the title compounds were examined. From the biological activity results, we found that most compounds showed weak stimulatory activities at low concentrations.

Synthesis and Spectral Characterization of New S-Alkylated 1,2,4-Triazoles as Potential Biological Agents

2017 ◽  
Vol 68 (10) ◽  
pp. 2436-2439
Author(s):  
Stefania Felicia Barbuceanu ◽  
Laura Ileana Socea ◽  
Constantin Draghici ◽  
Elena Mihaela Pahontu ◽  
Theodora Venera Apostol ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Spectral Data ◽  
1H Nmr ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Ethyl Bromide ◽  
Spectral Characterization ◽  
Basic Medium ◽  
Phenacyl Bromide

In the work we presented the behavior of 5-(4-(4-X-phenylsulfonyl)phenyl)-4-(n-propyl)-2H-1,2,4-triazole-3(4H)-thiones (X= Cl or Br) with some alkylation agents. Thus, new S-alkylated 1,2,4-triazole derivatives were synthesized by reaction of the corresponding 1,2,4-triazole-3-thione derivatives with different �-halogenated compounds (ethyl bromide, ethyl chloroacetate or phenacyl bromide), in basic medium. The structures of synthesized compounds were elucidated by spectral data (1H-NMR, 13C-NMR, mass spectrometry) and elemental analysis.

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