Chemistry of chromotropic acid. 1H and 13C NMR spectroscopy of chromotropic acid and its derivatives

1991 ◽  
Vol 69 (8) ◽  
pp. 1207-1211 ◽  
Author(s):  
Paris E. Georghiou ◽  
Chi Keung (Jimmy) Ho ◽  
Chester R. Jablonski
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Deuterium Oxide ◽  
13C Nmr Spectroscopy ◽  
Chromotropic Acid ◽  
Hydroxyl Groups ◽  
Two Dimensional ◽  
1H And 13C Nmr ◽  
C Nmr

The 1H and 13C NMR spectra of chromotropic acid (CTA) (4,5-dihydroxy-2,7-naphthalenedisulphonic acid) have been unambiguously assigned. Proton NOED spectra were used to show the proximity of both H-3 and H-6 and the hydroxyl groups. Two-dimensional 1H–13C NMR correlation spectra of CTA, of its corresponding diacetoxy derivative, and of 3-bromo- and 3,6-dibromo-CTA support the assignments. A regioselective deuterium exchange reaction of the C-3 and C-6 protons of CTA with deuterium oxide was observed during the NMR experiments. This latter finding is strongly indicative of the mode of formation, and of the nature of the chromogen formed in the reaction of CTA with formaldehyde in the well-known CTA-formaldehyde analytical reaction. Key words: chromotropic acid, 3-bromochromotropic acid, 3,6-dibromochromotropic acid.

Substituent Influences on the Keto-Enol Tautomerism in 1-(2-Hydroxyphenyl)-3-α-and -β-naphthylpropane-1,3-diones Monitored by 1H and 13C NMR Spectroscopy

2000 ◽  
Vol 55 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Jorge L. Jios ◽  
Helmut Duddeck
Keyword(s):  
Nmr Spectroscopy ◽  
Long Range ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectroscopy ◽  
1H And 13C Nmr ◽  
Tautomeric Equilibria ◽  
Hmbc Correlation ◽  
C Nmr

Synthesis of 18 1-(2-hydroxyphenyl)-3-α- and -β-naphthylpropan-1,3-diones is described. Their 1H and 13C NMR spectra were completely and unambiguously assigned using a combination of both homo- and heteronuclear (gs-COSY ), 1H -detected heteronuclear one-bond (gs-HMQC ) and long-range (gs-HMBC) correlation experiments. Substituent and conformation effects on the tautomeric equilibria were identified and interpreted in terms of steric and electronic contributions.

Identification of Aminopyrimidine Regioisomers via Line Broadening Effects in 1H and 13C NMR Spectroscopy

2004 ◽  
Vol 57 (11) ◽  
pp. 1079 ◽  
Author(s):  
James Garner ◽  
Tim Hill ◽  
Luke Odell ◽  
Paul Keller ◽  
Jody Morgan ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Diagnostic Tool ◽  
Room Temperature ◽  
Medicinal Chemistry ◽  
13C Nmr Spectroscopy ◽  
Primary Amines ◽  
Two Dimensional ◽  
Line Broadening ◽  
1H And 13C Nmr

Substituted mono- and diamino-pyrimidines were synthesized as part of our medicinal chemistry programmes. Primary amines substituted at the 4-position exhibited room-temperature line broadening effects in both 1H and 13C NMR spectroscopy due to the presence of rotamers, but these effects were not observed for substituents in the 2-position. This provided a simple diagnostic tool for the identification of regioisomers, a determination which would otherwise have required two-dimensional experiments.

Hochauflösungs-13C-NMR-Spektroskopie, VI [1]. Strukturabhängigkeit der 13C,H-Kopplungskonstanten in 6.6-disubstituierten Fulvenen / High Resolution 13C NMR Spectroscopy, VI [1]. Structure Dependence of the 13C,H Coupling Constants in 6,6-Disubstituted Fulvenes

1980 ◽  
Vol 35 (12) ◽  
pp. 1572-1574 ◽  
Author(s):  
Siegmar Braun ◽  
Ulrich Eiehenauer
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectroscopy ◽  
High Accuracy ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Structure Parameters ◽  
Structure Dependence ◽  
C Nmr

In order to study the structure dependence of the 13C,H couplings in the fulvene system the 1H-coupled 13C NMR spectra of 6,6-disubstituted fulvenes (R = R′ = C6H5, CH3, cyclopropyl and N(CH3)2) were recorded and the interesting couplings determined with high accuracy by complete analysis. They have values typical for unsaturated five membered rings with vastly localised double bonds like cyclopentadiene-1,3 and spiro[2.4]heptadiene- 4,6 and show characteristic correlations with structure parameters.

scholarly journals 1H- und 13C-NMR-spektroskopische Untersuchung an 1.4-Heteroarsenaniumsalzen / 1H and 13C NMR Spectroscopy of 1,4-Hetero-arsenanium Salts

1977 ◽  
Vol 32 (8) ◽  
pp. 908-911 ◽  
Author(s):  
Samir Samaan
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
1H And 13C Nmr ◽  
C Nmr

The synthesis of the 1,4-azarsenanium salts 3 and 6 is discribed. Conformation and configuration of the 1,4-oxa- and -azarsenanium salts have been studied via 1H and 13C NMR spectroscopy.

1H and 13C NMR Spectra of Technically Important Sodium 1- and 2-Aminonaphthalenesulfonates

1993 ◽  
Vol 58 (6) ◽  
pp. 1378-1387 ◽  
Author(s):  
Josef Jirman
Keyword(s):  
13C Nmr ◽  
Sulfonic Acid ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Deuterium Oxide ◽  
Acid Group ◽  
Sulfonic Acid Group ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
C Nmr

The 1H and 13C NMR spectra of twenty-one technically important sulfonated 1- and 2-naphthylamines have been measured in deuterium oxide. The substituent chemical shifts (SCS) of a sulfonic acid group on naphthylamine skeleton have been calculated from the chemical shifts assigned.

Mestranol: The assignment of its 1H and 13C NMR spectra by means of two-dimensional NMR spectroscopy, and its photochemical decomposition

Steroids ◽  
1985 ◽  
Vol 45 (2) ◽  
pp. 101-118 ◽  
Author(s):  
Adrianus C.J. Sedee ◽  
Gerardus M.J. Beijersbergen van Henegouwen ◽  
Monique E. de Vries ◽  
Cornelis Erkelens
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Two Dimensional ◽  
1H And 13C Nmr ◽  
Photochemical Decomposition

scholarly journals Determination of C-23 Configuration in (20R)-23-Hydroxycholestane Side Chain of Steroid Compounds by 1H and 13C NMR Spectroscopy

2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Alla A. Kicha ◽  
Anatoly I. Kalinovsky ◽  
Alexander S. Antonov ◽  
Oleg S. Radchenko ◽  
Natalia V. Ivanchina ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Side Chain ◽  
Side Chains ◽  
Model Compounds ◽  
1H And 13C Nmr ◽  
C 23 ◽  
C Nmr

Epimeric (20 R,23 R)- and (20 R,23 S)-23-hydroxycholestane steroids were synthesized. Their structures were elucidated by extensive 1H and 13C NMR spectroscopy and application of the Mosher's method. All proton and carbon signals of the side chains were assigned. Based on these assignments spectral data allow the determination of the C-23 stereochemistry of (20 R)-23-hydroxycholestane side chains of the new natural steroids by comparison with spectra of the obtained model compounds. As a result, the C-23 configuration of two steroid compounds from the starfishes Lethasterias nanimensis chelifera and Lethasterias fusca was established.

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