scholarly journals Reducing-End Functionalization of 2,5-Anhydro-d-mannofuranose-Linked Chitooligosaccharides by Dioxyamine: Synthesis and Characterization

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1143 ◽  
Author(s):  
Maxence Coudurier ◽  
Jimmy Faivre ◽  
Agnès Crépet ◽  
Catherine Ladavière ◽  
Thierry Delair ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
13C Nmr ◽  
Nitrous Acid ◽  
Chemical Structure ◽  
Chemical Method ◽  
Reductive Amination ◽  
High Mass ◽  
Synthesis And Characterization ◽  
1H And 13C Nmr ◽  
Chitosan Oligosaccharides

The nitrous acid depolymerization of chitosan enables the synthesis of singular chitosan oligosaccharides (COS) since their reducing-end unit is composed of 2,5-anhydro-d-mannofuranose (amf). In the present study, we describe a chemical method for the reducing-end conjugation of COS-amf by the commercially available dioxyamine O,O′-1,3-propanediylbishydroxylamine in high mass yields. The chemical structure of resulting dioxyamine-linked COS-amf synthesized by both oximation and reductive amination ways were fully characterized by 1H- and 13C-NMR spectroscopies and MALDI-TOF mass spectrometry. The coupling of chemically attractive linkers such as dioxyamines at the reducing end of COS-amf forms a relevant strategy for the development of advanced functional COS-based conjugates.

scholarly journals (2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Molbank ◽  
10.3390/m1140 ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. M1140
Author(s):  
Jack Bennett ◽  
Paul Murphy
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
13C Nmr ◽  
Conjugate Addition ◽  
13C Nmr Spectroscopy ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Esi Mass Spectrometry ◽  
The One

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.

SYNTHESIS AND CHARACTERIZATION OF HETEROCYCLIC CHALCONES CONTAINING HALOGENATED THIOPHENES

2015 ◽  
Vol 77 (3) ◽  
Author(s):  
Helmi Mohammed Al-Maqtari ◽  
Joazaizulfazli Jamalis ◽  
Hasnah Mohd Sirat
Keyword(s):  
Sodium Hydroxide ◽  
Spectral Data ◽  
13C Nmr ◽  
Basic Medium ◽  
Synthesis And Characterization ◽  
Schmidt Reaction ◽  
Synthetic Compounds ◽  
1H And 13C Nmr ◽  
Heterocyclic Aldehydes

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.

scholarly journals Rearrangement of spiroderivatives of 1,3-benzo(naphtho)dioxin-4(1)-ones as a new method of synthesis of xanthene bromo derivatives

2021 ◽  
pp. 73-77
Author(s):  
A.V. Kovtun ◽  
◽  
S.A. Varenichenko ◽  
E.V. Zaliznaya ◽  
A.V. Mazepa ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
13C Nmr ◽  
Bromine Atom ◽  
Sodium Perchlorate ◽  
Building Blocks ◽  
Dimethylamino Group ◽  
1H And 13C Nmr ◽  
Molecular Building Blocks ◽  
Derivatives Of ◽  
Fold Excess

We have proposed a method for the synthesis of previously unknown bromo xanthenes using the reagent PBr3/DMF as a rearrangement initiator. Bromo derivatives of xanthenes in the form of organic perchlorates were prepared by reacting the corresponding benzo(naphtho)dioxin-4(1)-ones with a three-fold excess of Vilsmeier-Haack PBr3/DMF reagent at 1100C for 2 hours, followed by the addition of sodium perchlorate. The conditions for the synthesis of formyl derivatives of xanthenes under conditions of acid hydrolysis were selected. The structure of the compounds was confirmed by 1H and 13C NMR spectral data and mass spectrometry. Preliminary studies showed that it is possible to selectively replace the dimethylamino group and the bromine atom with various nucleophiles in bromo derivatives of xanthenes, which opens up wide possibilities for the synthesis of low-molecular building blocks and dyes.

scholarly journals Synthesis and Characterization of 1-phenyl-3-methyl-4-stearoylpyrazol-5-one and Its Lanthanum(III) and Tungsten(VI) Complexes

2020 ◽  
pp. 140-151
Author(s):  
A. I. C. Ehirim ◽  
C. K. Enenebeaku ◽  
C. Asimole ◽  
M. O. C. Ogwuegbu ◽  
E. N. O. Ejike
Keyword(s):  
Elemental Analysis ◽  
13C Nmr ◽  
Synthesis And Characterization ◽  
Conductivity Measurements ◽  
Melting Points ◽  
1H And 13C Nmr ◽  
Solubility Profile ◽  
Uv Visible ◽  
Metal Ligand

The ligand, 1-phenyl-3-methyl-4-stearoylpyrazol-5-one (HSPy), and its La(III) and W(VI) complexes were synthesized and characterized spectroscopically using elemental analysis, UV-visible, IR, 1H and 13C NMR. Physical properties such as colour, melting points, conductivity measurements and solubility profile were also investigated. La(III) and W(VI) reacted with the ligand in the metal-ligand mole ratios of 1:3 and 1:2 to form neutral complexes of diaquo-trischelate La(SPy)3.2H2O and dioxoaquo-bischelate, WO2(SPy)2.H2O respectively.

scholarly journals Alkaloids from Mongolian species of Peganum multisectum (Maxim) Bobrov

2016 ◽  
Vol 16 ◽  
pp. 48-53 ◽  
Author(s):  
S. Javzan ◽  
D. Selenge ◽  
N. Amartuvshin ◽  
D. Nedelcheva ◽  
V Christov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
13C Nmr ◽  
Gas Chromatography Mass Spectrometry ◽  
Nmr Analysis ◽  
1H And 13C Nmr ◽  
Aerial Parts ◽  
13C Nmr Analysis ◽  
Pure Compounds ◽  
First Time

Alkaloids of the aerial parts of P. multisectum (Maxim) Bobrov (Zygophyllaceae) growing in Mongolia have been studied by capillary Gas Chromatography-Mass Spectrometry (GC-MS) and Column Chromatography (CC). Four compounds comprising of 2-methylquinoline (1), 9-amino-2, 3,5,6,7,8-hexahydro-1H-cyclopenta [b] quinoline (2), vasicinone (3) and harmine (4) have been determined by GC-MS, while harmine (4), peganine (5), deoxypeganine (6), deoxyvasicinone (7) and harmane (8) were isolated as pure compounds by the CC. The structures of the five alkaloids 4, 5, 6, 7 and 8 were elucidated by the MS and 1H and 13C NMR analysis. The alkaloids 1, 2 and 8 were identified for the first time from this species.Mongolian Journal of Chemistry 16 (42), 2015, 48-53

scholarly journals Synthesis and Characterization of New Silver (I) N-Heterocyclic Ccarbene Ccomplex Dderived from Imidazol-2-ylidene salt

2018 ◽  
Vol 28 (2) ◽  
pp. 55
Author(s):  
Mohammedl Mujbe Hasson
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Room Temperature ◽  
13C Nmr Spectroscopy ◽  
Synthesis And Characterization ◽  
Imidazolium Salt ◽  
In Situ Method

A new N, N'-imidazolium salt 1-(2,6-diisopropylphenyl)-3- (4,6-dimorpholino -1,3,5-traizine-2-yl)-1H-imidazol-3-ium chloride) as a precursor of N - heterocyclic carbene ligand was prepared via the reaction of 1 - (2, 6 - diisopropyl phenyl - 1H - imidazole) with 1, 3, 5 - triazine derivative bearing morpholine substituent (2, 6 -dimorpholine - 6- chloro-1, 3, 5-triaziazine). Linear coordi-nated Ag (І) NHC complex was synthesised via deprotonation of the imidazolium salt and reac-tion with Ag2O in darkness at room temperature by in situ method. The complex was synthesised for using as transfer agent to prepare another transition metals complexes by transmetallation method in the future. The imidazolium salt and their silver complex have been characterized by 1 H and 13C NMR spectroscopy as well as mass spectrometry.

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...

scholarly journals Antifungal Activity against Botrytis cinerea of 2,6-Dimethoxy-4-(phenylimino)cyclohexa-2,5-dienone Derivatives

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 706 ◽  
Author(s):  
Paulo Castro ◽  
Leonora Mendoza ◽  
Claudio Vásquez ◽  
Paz Pereira ◽  
Freddy Navarro ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Wall ◽  
Antifungal Activity ◽  
Botrytis Cinerea ◽  
Aromatic Ring ◽  
13C Nmr ◽  
Trametes Versicolor ◽  
Fungal Cell Wall ◽  
Fungal Cell ◽  
1H And 13C Nmr

In this work the enzyme laccase from Trametes versicolor was used to synthetize 2,6-dimethoxy-4-(phenylimino)cyclohexa-2,5-dienone derivatives. Ten products with different substitutions in the aromatic ring were synthetized and characterized using 1H- and 13C-NMR and mass spectrometry. The 3,5-dichlorinated compound showed highest antifungal activity against the phytopathogen Botrytis cinerea, while the p-methoxylated compound had the lowest activity; however, the antifungal activity of the products was higher than the activity of the substrates of the reactions. Finally, the results suggested that these compounds produced damage in the fungal cell wall.

scholarly journals Synthesis and characterization of thiacalix[3]triazine and 1,3,5-tris(4- bromophenyl)benzene for chemsensor application

2018 ◽  
Vol 1 (6) ◽  
pp. 163-176
Author(s):  
Ha Tran Nguyen ◽  
Anh Tuan Luu
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Chemical Structure ◽  
Synthesis And Characterization

The synthesis of thiacalix[3]triazines and 1,3,5- tris(4-bromophenyl)benzene have been synthesized via simple steps and was characterized to determine the chemical structure. The structure of Thiacalix[3]triazines was characterized via 1H NMR and 13C NMR that conformed the expected structure of compound. In addition, the thiacalix[3]triazines exhibited the λmax at 560 nm and λonset at 720 nm which corresponding to the bandgap of 1.7 ev. Thiacalix[3]triazines, cyclotrimeric metacyclophanes with direct S linkages between the heteroaryl constituents, were shown to associate with anion that could be useful for chemsensor application.

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