Synthesis of 2-Substituted-6,7-dimethoxy- and 6,7,8-Trimethoxy-3-hydroxyquinolin-4(1H)-ones

1999 ◽  
Vol 64 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Pavel Hradil ◽  
Jan Vaněček ◽  
Jan Hlaváč ◽  
Juraj Ševčík
Keyword(s):  
Nmr Spectroscopy ◽  
Polyphosphoric Acid ◽  
New Method ◽  
Thermal Cyclization ◽  
H Nmr ◽  
Nitro Derivatives ◽  
Phenacyl Esters

Acetonyl and phenacyl esters of 4,5-dimethoxy- and 3,4,5-trimethoxyanthranilic acids 3 were prepared by reduction of corresponding nitro derivatives 2. Acetonyl 4,5-dimethoxyanthranilate (3a) was prepared by reaction of 4,5-dimethoxyanthranilic acid and chloroacetone. Cyclization of these acetonyl and phenacyl esters in polyphosphoric acid provided the corresponding 2-substituted-6,7-dimethoxy- and 6,7,8-trimethoxy-3-hydroxyquinolin-4(1H)-ones 4. A new method of the thermal cyclization is also described. The structure of the prepared compounds was confirmed by 1H NMR spectroscopy.

Conformational study on ribonucleoside O-phosphonylmethyl derivatives by 1H NMR spectroscopy

1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Conformational Study ◽  
H Nmr ◽  
Conformational Properties

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.

Monitoring the encapsulation of chlorin e6 derivatives into polymer carriers by NMR spectroscopy

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1576-1586 ◽  
Author(s):  
Sara Pfister ◽  
Luca Sauser ◽  
Ilche Gjuroski ◽  
Julien Furrer ◽  
Martina Vermathen
Keyword(s):  
Relaxation Time ◽  
Nmr Spectroscopy ◽  
Core Region ◽  
Chlorin E6 ◽  
Polypropylene Glycol ◽  
Polymer Carriers ◽  
H Nmr ◽  
Line Shape Analysis ◽  
Dynamic Methods ◽  
Derivatives Of

The encapsulation of five derivatives of chlorin e6 with different hydrophobicity and aggregation properties into a series of five poloxamer-type triblock copolymer micelles (BCMs) with varying numbers of polyethylene and polypropylene glycol (PEG, PPG) units was monitored using 1H NMR spectroscopy. NMR chemical shift and line shape analysis, as well as dynamic methods including diffusion ordered spectroscopy (DOSY) and T1 and T2 relaxation time measurements of the chlorin and the polymer resonances, proved useful to assess the chlorin–BCM compatibility. The poloxamers had high capability to break up aggregates formed by chlorins up to intermediate hydrophobicity. Physically entrapped chlorins were always localized in the BCM core region. The loading capacity correlated with chlorin polarity for all poloxamers among which those with the lowest number of PPG units were most efficient. DOSY data revealed that relatively weakly aggregating chlorins partition between the aqueous bulk and micellar environment whereas more hydrophobic chlorins are well retained in the BCM core region, rendering these systems more stable. T1 and T2 relaxation time measurements indicated that motional freedom in the BCM core region contributes to encapsulation efficiency. The BCM corona dynamics were rather insensitive towards chlorin entrapment except for the poloxamers with short PEG chains. The presented data demonstrate that 1H NMR spectroscopy is a powerful complementary tool for probing the compatibility of porphyrinic compounds with polymeric carriers such as poloxamer BCMs, which is a prerequisite in the development of stable and highly efficient drug delivery systems suitable for medical applications like photodynamic therapy of tumors.

Different submicellar solubilization mechanisms revealed by 1H NMR and 2D diffusion ordered spectroscopy (DOSY)

2020 ◽  
Vol 22 (19) ◽  
pp. 11075-11085
Author(s):  
Mengjian Wu ◽  
Zhaoxia Wu ◽  
Shangwu Ding ◽  
Zhong Chen ◽  
Xiaohong Cui
Keyword(s):  
Nmr Spectroscopy ◽  
Sodium Dodecyl Sulfate ◽  
1H Nmr ◽  
Sodium Dodecyl ◽  
Butyl Methacrylate ◽  
H Nmr ◽  
Molecular Scale ◽  
Two Systems ◽  
Dodecyl Sulfate ◽  
Triton X

Different submicellar solubilization mechanisms of two systems, Triton X-100/tetradecane and sodium dodecyl sulfate (SDS)/butyl methacrylate, are revealed on the molecular scale by 1H NMR spectroscopy and 2D diffusion ordered spectroscopy (DOSY).

scholarly journals Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Resonant Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Acetic Acid Esters ◽  
Acid Esters ◽  
Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

3-Hydroxy Retinal, a New Chromophore Identified in Insect Eyes: HPLC Separation and NMR Spectroscopic Identification of the Oxime Forms

1988 ◽  
Vol 43 (5-6) ◽  
pp. 473-475 ◽  
Author(s):  
Wolfgang Gärtner ◽  
Anette Plangger
Keyword(s):  
Nmr Spectroscopy ◽  
Separation System ◽  
Hplc Separation ◽  
H Nmr ◽  
Spectroscopic Identification

3-Hydroxy retinal acts as visual chromophore instead of retinal in the eyes of several insect orders. A HPLC separation system of the aldehyde and oxime isomers and their identification by 400 MHz 1H NMR spectroscopy is described.

scholarly journals Water-soluble β-aminobisulfonate building blocks for pH and Cu2+ indicators

RSC Advances ◽  
2016 ◽  
Vol 6 (88) ◽  
pp. 84712-84721 ◽  
Author(s):  
Maria A. Cardona ◽  
Marina Kveder ◽  
Ulrich Baisch ◽  
Michael R. Probert ◽  
David C. Magri
Keyword(s):  
Nmr Spectroscopy ◽  
Building Blocks ◽  
Water Soluble ◽  
Visible Absorption ◽  
H Nmr ◽  
Uv Visible

Two phenyl β-aminobisulfonate ligands characterised by UV-visible absorption, EPR and 1H NMR spectroscopy exhibit evidence for binding with Cu2+ in water and methanol.

Quantitative Analysis of Amygdalin and Prunasin in Prunus serotina Ehrh. using 1 H-NMR Spectroscopy

2013 ◽  
Vol 25 (2) ◽  
pp. 122-126 ◽  
Author(s):  
Lúcia P. Santos Pimenta ◽  
Menno Schilthuizen ◽  
Robert Verpoorte ◽  
Young Hae Choi
Keyword(s):  
Quantitative Analysis ◽  
Nmr Spectroscopy ◽  
Prunus Serotina ◽  
H Nmr

Synthesis, Characterization and Complexation Studies with K + and Ca2+ Cations of trans-1.2-Cyclohexanedioxydiacetamides

1988 ◽  
Vol 43 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Whei Oh Lin ◽  
Maria C. B. V. de Souza ◽  
Helmut G. Alt
Keyword(s):  
Nmr Spectroscopy ◽  
Mass Spectroscopy ◽  
H Nmr ◽  
Coordination Sites ◽  
Complexation Studies ◽  
Ir And Nmr Spectroscopy ◽  
Elemental Analyses ◽  
C Nmr

The synthesis of trans-1.2-cyclohexanedioxydiacetamides starting with trans-1.2-cyclohexane-diol is described. Eleven of these compounds are characterized by IR, 1H NMR, 13C NMR and mass spectroscopy as well as elemental analyses. Most of these compounds are suitable ionophors for the cations K+ and Ca2+. The coordination sites of these ligands in the 1:2 complexes were determined by IR and NMR spectroscopy

scholarly journals Quantification of acidic sites of nanoscopic hydroxylated magnesium fluorides by FTIR and 15N MAS NMR spectroscopy

RSC Advances ◽  
2015 ◽  
Vol 5 (109) ◽  
pp. 89659-89668 ◽  
Author(s):  
Felix Hemmann ◽  
Iker Agirrezabal-Telleria ◽  
Christian Jaeger ◽  
Erhard Kemnitz
Keyword(s):  
Nmr Spectroscopy ◽  
Mas Nmr ◽  
New Method ◽  
Extinction Coefficients ◽  
Surface Sites ◽  
Acidic Sites ◽  
Molar Extinction Coefficients

A new method is described for the calculation of molar extinction coefficients for quantitative FTIR measurements of acidic surface sites.

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