Characterization of Silk Produced in 12th Century Japan with the Aid of 13C NMR

Author(s):  
Riichirô Chûjô
Keyword(s):  
13C Nmr ◽  
2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Zena G. Alrecabi ◽  
Zainab Amer ◽  
Naeemah Al-Lami

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.


2017 ◽  
Vol 68 (10) ◽  
pp. 2436-2439
Author(s):  
Stefania Felicia Barbuceanu ◽  
Laura Ileana Socea ◽  
Constantin Draghici ◽  
Elena Mihaela Pahontu ◽  
Theodora Venera Apostol ◽  
...  

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.


2012 ◽  
Vol 518-523 ◽  
pp. 3989-3992 ◽  
Author(s):  
Yang Zhang ◽  
Xiao Hua Tu ◽  
Cheng Ping Miao ◽  
Jian Yi Wu

A novel CIL of N-butyl-N-methyl imidazolium-D-(-)-tartrate has been designed and synthesized by neutralization reaction. Its structure was characterized by 1H-NMR and 13C-NMR spectra, the optical rotation was characterized by polarimeter with the value of-15.0º, and the purity was characterized by ion chromatography with the value of 98.4%.


2015 ◽  
Vol 77 (3) ◽  
Author(s):  
Helmi Mohammed Al-Maqtari ◽  
Joazaizulfazli Jamalis ◽  
Hasnah Mohd Sirat

Heterocyclic chalcones containing halogenated thiophenes were synthesized. The first step was to synthesize 3-acetyl-2,5-dichlorothiophene and 2-acetyl-5-chlorothiophene as heterocyclic ketones by using Friedel-Crafts acylation. The ketones were then used to synthesize thiophene chalcones through Claisen-Schmidt reaction with the respective heterocyclic aldehydes such as 5-bromothiophene-2-carbaldehyde, 3-methyl-2-thiophene carboxaldehyde and 2-thiophene carboxaldehyde with 3-acetyl-2,5-dichlorothiophene or 2-acetyl-5-chlorothiophene in presence of basic medium, sodium hydroxide to form the corresponding chalcones. Structures of the synthetic compounds were confirmed by IR, MS, 1H and 13C NMR spectral data.


2019 ◽  
Vol 84 (4) ◽  
pp. 343-353
Author(s):  
Lina Rekovic ◽  
Lidija Kosychova ◽  
Irina Bratkovskaja ◽  
Regina Vidziunaite

Three new 1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one oximes were synthesized and characterized by the methods of 1H- and 13C-NMR, IR and elemental analysis. Along with previously described compounds bearing one additional methyl group on the 5th nitrogen atom, the new compounds were characterized in bulk by UV?Vis and fluorescence spectroscopy in various solvents. The influence of the nature of the organic solvent on the spectra of the title compounds was investigated and is discussed.


2020 ◽  
Vol 54 (9-10) ◽  
pp. 835-844
Author(s):  
GABRIEL LARS ◽  
ANTJE TIED ◽  
THOMAS HEINZE

The present study describes the heterogeneous carboxymethylation of xylan,α-1,3-glucan, glucomannan, pullulan, curdlan, galactoglucomannan, and agarose with sodium monochloracetate (SMCA) using iso-propanol as slurry medium in the presence of caustic soda. Using heteropolysaccharides for the carboxymethylation, higher DS values are obtained compared to the DS of homopolysaccharides. The influence of the amount caustic soda in the reaction medium is studied. The characterization of the products obtained is performed by means of 13C-NMR spectroscopy. Carboxymethylation transforms the investigated polysaccharides into water-soluble products.


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