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 (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.

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 QUANTUM CONDUCTANCE AND ELECTRONIC PROPERTIES OF LOWER DIAMONDOID MOLECULES AND DERIVATIVES

2008 ◽  
Vol 07 (01) ◽  
pp. 63-72 ◽  
Author(s):  
YONG XUE ◽  
G. ALI MANSOORI
Keyword(s):  
Electronic Properties ◽  
Single Molecule ◽  
Building Blocks ◽  
Sodium Ion ◽  
Hydrogen Ion ◽  
Ab Initio Method ◽  
Quantum Conductance ◽  
Molecular Building Blocks ◽  
Probe System ◽  
Derivatives Of

Diamondoids and their derivatives have found major applications as templates and as molecular building blocks in nanotechnology. An ab initio method we calculated the quantum conductance and the essential electronic properties of two lower diamondoids (adamantane and diamantane) and three of their important derivatives (amantadine, memantine and rimantadine). We also studies two artificial molecules that are built by substituting one hydrogen ion with one sodium ion in both adamantane and diamantane molecules. Most of our results are based on an infinite Au two-probe system constructed by ATK and VNL software, which comprise TRANSTA-C package. By changing various system structures and molecule orientations in linear Au and 2 × 2 Au probe systems, we found that although the conductance of adamantane and diamantane are very small, the derivatives of the lower diamondoids have considerable conductance at specific orientations and also showed interesting electronic properties. The quantum conductance of such molecules will change significantly by changing the orientations of the molecules, which approves that residues like nitrogen and sodium atoms have great effects on the conductance and electronic properties of single molecule. There are obvious peaks near Fermi energy in the transmission spectrums of artificial molecules, indicating the plateaus in I–V characteristics of such molecules.

ChemInform Abstract: 1H and 13C NMR of Some α-Halo Derivatives of o-Xylene.

ChemInform ◽  
2010 ◽  
Vol 28 (41) ◽  
pp. no-no
Author(s):  
D. DE B. REZENDE ◽  
M. R. ALCANTARA ◽  
I. P. DE ARRUDA CAMPOS ◽  
V. G. TOSCANO ◽  
G. EBELING ◽  
...  
Keyword(s):  
13C Nmr ◽  
1H And 13C Nmr ◽  
Derivatives Of

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

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