Phenol sulfate esters: ultraviolet, infrared, 1H and 13C nuclear magnetic resonance spectroscopic investigation

1978 ◽  
Vol 56 (20) ◽  
pp. 2681-2685 ◽  
Author(s):  
Mark A. Ragan
Keyword(s):  
Spectroscopic Investigation ◽  
Spectroscopic Properties ◽  
Synthetic Methods ◽  
Sulfate Ester ◽  
H Nmr ◽  
Naturally Occurring ◽  
13C Nuclear Magnetic Resonance ◽  
Supplementary Material ◽  
Related Compounds ◽  
C Nmr

Renewed interest in naturally occurring phenol sulfate ester salts has necessitated modem spectroscopic investigation of these compounds. Synthetic methods, plus spectroscopic (uv, ir, 1H nmr, 13C nmr), chromatographic, and electrophoretic properties are given for the potassium salts of phenyl sulfate (1), pyrocatechol disulfate (2), resorcinol disulfate (3), hydroquinone disulfate (4), phloroglucinol mono- (5), di- (6), and tri- (7) sulfates, and for the 2-sulfate (8) and 2,5-disulfate (9) of 1,2,3,5-tetrahydroxybenzene (10). 13C nmr chemical shift effects resulting from the replacement of phenolic —OH with —OSO3K are reported. Spectroscopic properties of the related compounds 1,2,3-tribenzyloxybenzene (11), 2,6-dibenzyloxy-1,4-benzoquinone (12), 2,6-dimethoxy-1,4-benzoquinone (13), 1,3-dibenzyloxy-2,5-dihydroxybenzene (14), and of a tentatively identified 1,3-dibenzyloxy-2,5-dihydroxybenzene monoethyl ether (15) are available as supplementary material.

13C nuclear magnetic resonance spectral and conformational analysis of naturally occurring tetrahydrofuran lignans

1979 ◽  
Vol 57 (4) ◽  
pp. 441-443 ◽  
Author(s):  
Sebastião F. Fonseca ◽  
Lauro E. S. Barata ◽  
Edmundo A. Rúveda ◽  
Paul M. Baker
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Conformational Analysis ◽  
Nmr Spectra ◽  
H Nmr ◽  
Naturally Occurring ◽  
Nmr Data ◽  
Benzylic Carbon ◽  
13C Nuclear Magnetic Resonance ◽  
C Nmr

The 13C nmr spectra of the naturally occurring stereoisomers of the tetrahydrofuran lignans were recorded and the signals assigned. Based on these assignments, on the observed sensitivity of the benzylic carbon shifts to the orientation of the aryl groups, and on the comparison with previously reported 1H nmr data, the most probable conformations for the mentioned stereoisomers are suggested.

Synthesis and Structure Assignment of 2-(4-Methoxybenzyl)cyclohexyl β-D-Glucopyranoside Enantiomers

2006 ◽  
Vol 71 (10) ◽  
pp. 1470-1483 ◽  
Author(s):  
David Šaman ◽  
Pavel Kratina ◽  
Jitka Moravcová ◽  
Martina Wimmerová ◽  
Zdeněk Wimmer
Keyword(s):  
Analytical Data ◽  
Chiral Hplc ◽  
Nmr Analysis ◽  
Target Structure ◽  
Enantiomerically Pure ◽  
Whole Cells ◽  
H Nmr ◽  
Structure Assignment ◽  
Related Compounds ◽  
C Nmr

Glucosylation of the cis- and trans-isomers of 2-(4-methoxybenzyl)cyclohexan-1-ol (1a/1b, 2a/2b, 1a or 2a) was performed to prepare the corresponding alkyl β-D-glucopyranosides, mainly to get analytical data of pure enantiomers of the glucosides (3a-6b), required for subsequent investigations of related compounds with biological activity. One of the employed modifications of the Koenigs-Knorr synthesis resulted in achieving 85-95% yields of pure β-anomers 3a/3b, 4a/4b, 3a or 4a of protected intermediates, with several promoters and toluene as solvent, yielding finally the deprotected products 5a/5b, 6a/6b, 5a or 6a as pure β-anomers. To obtain enantiomerically pure β-anomers of the target structure (3a, 4a, 5a and 6a) for unambiguous structure assignment, an enzymic reduction of 2-(4-methoxybenzyl)cyclohexan-1-one by Saccharomyces cerevisiae whole cells was performed to get (1S,2S)- and (1S,2R)-enantiomers (1a and 2a) of 2-(4-methoxybenzyl)cyclohexan-1-ol. The opposite enantiomers of alkyl β-D-glucopyranosides (5b and 6b) were obtained by separation of the diastereoisomeric mixtures 5a/5b and 6a/6b by chiral HPLC. All stereoisomers of the products (3a-6b) were subjected to a detailed 1H NMR and 13C NMR analysis.

Triazolopyridine nucleosides. II. Glycosylations of 3-oxo-s-triazolo[4,3-a]pyridines with accompanying conversions into 2-oxo-s-triazolo[1,5-a]pyridine nucleosides

1977 ◽  
Vol 55 (5) ◽  
pp. 831-840 ◽  
Author(s):  
Brian Maurice Lynch ◽  
Suresh Chandra Sharma
Keyword(s):  
General Structure ◽  
Spectroscopic Properties ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
H Nmr ◽  
Pyridine Nitrogen ◽  
Methyl Derivatives ◽  
Fragmentation Patterns ◽  
Ribose Moiety ◽  
C Nmr

3-Oxo-s-triazolo[4,3-a]pyridine and various C-methyl derivatives (general structure 1) have been converted into the 2-β-D-ribofuranosyl species 2 and thence 4 via Friedel–Crafts catalyzed reaction with tetra-O-acetyl-β-D-ribofuranose, followed by deblocking. During the course of these reactions, rearrangements into the isomeric 3-β-D-ribofuranosyl-2-oxo-s-triazolo[1,5-a]-pyridines occur through ring-opening of the pyridine rings yielding species 3 and 5. The proportion of rearrangement products is dependent upon the position and number of the C-methyl substituents.Structural assignments for these compounds are based upon comparisons of spectroscopic properties (1H nmr, 13C nmr, uv) with model compounds from each isomeric series; structural assignments for these models are based on unequivocal mass-spectral fragmentation patterns. Unlike related triazolopyridine nucleosides with the ribose moiety attached to a pyridine nitrogen (Lynch and Sharma (1976)), there are no unusual aspects in the conformations of the nueleosides of types 4 and 5.

scholarly journals Synthesis of compounds related to the anti-migraine drug eletriptan hydrobromide

2012 ◽  
Vol 8 ◽  
pp. 1400-1405 ◽  
Author(s):  
Suri Babu Madasu ◽  
Nagaji Ambabhai Vekariya ◽  
M N V D Hari Kiran ◽  
Badarinadh Gupta ◽  
Aminul Islam ◽  
...  
Keyword(s):  
Mass Spectroscopy ◽  
Acute Treatment ◽  
Selective Serotonin ◽  
Spectroscopic Techniques ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
H Nmr ◽  
Related Compounds ◽  
C Nmr ◽  
Anti Migraine Drug

Eletriptan hydrobromide (1) is a selective serotonin (5-HT1) agonist, used for the acute treatment of the headache phase of migraine attacks. During the manufacture of eletriptan hydrobromide the formation of various impurities were observed and identified by LC–MS. To control the formation of these impurities during the preparation of active pharmaceutical ingredients, the structure of the impurities must be known. Major impurities of the eletriptan hydrobromide synthesis were prepared and characterized by using various spectroscopic techniques, i.e., mass spectroscopy, FTIR , 1H NMR, 13C NMR/DEPT, and further confirmed by co-injection in HPLC. The present study will be of great help in the synthesis of highly pure eletriptan hydrobromide related compounds.

A 13C nuclear magnetic resonance study of aliphatic ketone protonation in sulfuric acid solutions

1976 ◽  
Vol 54 (5) ◽  
pp. 718-725 ◽  
Author(s):  
Robert A. McClelland ◽  
William F. Reynolds
Keyword(s):  
Sulfuric Acid ◽  
Molecular Size ◽  
Nuclear Magnetic Resonance Study ◽  
Suitable Alternative ◽  
Acidic Solutions ◽  
H Nmr ◽  
Organic Bases ◽  
13C Nuclear Magnetic Resonance ◽  
Sulfuric Acid Solutions ◽  
C Nmr

A 13C nmr investigation of the protonation in sulfuric acid of the aliphatic ketones MeCOR (R = Me, Et, i-Pr, tert-Bu), 3-pentanone, and the cyclic ketones from cyclobutanone through cyclooctanone is reported. With the exception of cyclobutanone which is considerably less basic, these ketones are all very similar in their basicity, with half-protonation in the region 73–78% H2SO4. The acidity dependence of the protonation is discussed; there appears to be a small dependence on molecular size. 13C nmr is shown to be a suitable alternative to 1H nmr in the study of the protonation of weak organic bases in strongly acidic solutions.

Approaches to the synthesis of triterpenoids. VI. The synthesis of 3,3,10aβ-trimethyl-l,2,3,4,4aβ,5,8,9,10,10a-decahydrophenanthren-7(6H)-one, a potential intermediate for pentacyclic triterpene synthesis

1981 ◽  
Vol 59 (6) ◽  
pp. 1010-1017 ◽  
Author(s):  
John W. ApSimon ◽  
David Moir ◽  
Kazuyuki Yamasaki
Keyword(s):  
Nmr Spectra ◽  
Efficient Synthesis ◽  
Pentacyclic Triterpene ◽  
Naturally Occurring ◽  
Ring Junction ◽  
Triterpene Synthesis ◽  
Synthetic Intermediate ◽  
Related Compounds ◽  
C Nmr

Investigations of the CDE ring construction of naturally occurring triterpenoids are described. The efficient synthesis of 3,3,10aβ-trimethyl-1,2,3,4,4aβ,5,8,9,10,10a-decahydrophenanthren-7(6H)-one(25) has been achieved. The D/E ring junction of the molecule, as well as that of related compounds, has been established by the use of 13C nmr spectra. The synthetic intermediate 25 can be considered as a key substance for a synthetic entry to friedelin (1) in addition to β-amyrin (23).

Electronic structure of low-spin six-coordinate iron(III) meso-tetrapropylchlorin complexes

2014 ◽  
Vol 18 (08n09) ◽  
pp. 778-791 ◽  
Author(s):  
Akira Ikezaki ◽  
Jyunpei Ono ◽  
Yoshiki Ohgo ◽  
Mari Fukagawa ◽  
Takahisa Ikeue ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Ground State ◽  
Nmr Spectra ◽  
Spectroscopic Properties ◽  
H Nmr ◽  
Axial Ligands ◽  
Splitting Parameter ◽  
Nmr Signals ◽  
Electronic Ground ◽  
C Nmr

Low-spin iron(III) tetrapropylchlorins [ Fe ( T n PrC ) L 2]± (L = HIm, 1-MeIm, DMAP, CN-, 4-CNPy, tBuNC) adopt the dxy-type ground state regardless of the nature of axial ligands. Among the complexes examined, [ Fe ( T n PrC )( t BuNC )2]+ has shown quite unique spectroscopic properties as described below. (1) 1 H NMR signals were extremely broad as compared with those of other complexes. In particular, 5,20- CH 2(α) signal was too broad to detect. (2) No signals except C γ were observed in 13 C NMR spectra. (3) Tetragonal splitting parameter (|Δ|) estimated by the EPR g values at 4.2 K reached as much as 12.4 λ, which is the largest |Δ| value among all the low-spin iron(III) porphyrins and porphyrinoids reported previously. On the basis of these results, we have concluded that [ Fe ( T n PrC )( t BuNC )2]+ adopts the low-spin iron(III) with (dxz, dyz)4(dxy)1 electronic ground state at 4.2–30 K where the EPR spectra are taken, while it should be expressed as the low-spin Fe ( II ) chlorin π-radical cation [ Fe II ( T n PrC .)( t BuNC )2]+ at ambient temperature where the NMR spectra are taken.

Synthesis of Several Hydroxylated 23-(Benzimidazol-2-yl-, Benzoxazol-2-yl and Benzothiazol-2-yl)norcholanes and Some Related Compounds

1995 ◽  
Vol 60 (2) ◽  
pp. 257-275 ◽  
Author(s):  
Thi Thu Huong Nguyen ◽  
Jiří Urban ◽  
Eva Klinotová ◽  
Jan Sejbal ◽  
Jiří Protiva ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Succinic Anhydride ◽  
Benzimidazole Derivative ◽  
Acid Chlorides ◽  
H Nmr ◽  
Hydroxy Compounds ◽  
Related Compounds ◽  
Anti Hiv ◽  
C Nmr

The bile acids Ia - Id (lithocholic, chenodeoxycholic, deoxycholic, cholic) and their derivatives (O-acetylated acids and O-acetylated acid chlorides) reacted under various conditions with 1,2-diaminobenzene, 2-aminophenol and 2-aminothiophenol and afforded the title benzimidazoles II and VII, benzoxazoles V and benzothiazoles VI. Alkylation of the benzimidazole derivative IIa with 2-dimethylaminoethyl chloride resulted in 3α-hydroxy-23-[1-(2-dimethylaminoethyl)ben zimidazol-2-yl]- norcholane (IVa). The use of 1,2-diamino-4-methylbenzene enabled the preparation of 3α-acetoxy-23-[5(6)-methylbenzimidazol-2-y l]norcholane (VIII). Reactions of the 3α-hydroxy compounds IVa, Va and VIa with succinic anhydride resulted in the hemisuccinates IVi - VIi. The boric acid mediated condensation of O-acetyllithocholic acid (Ie) with 3,4-diaminopyridine gave compound X which was transformed to 3α-acetoxy-23-[1H-imidazo(4,5- c)pyridin-2-yl]norcholane (IX). The structure of the products was corroborated by the mass, IR, 1H NMR and 13C NMR spectra. Some of the compounds were tested for antileukemic and for the anti-HIV activity in vitro.

1,2-Bis(1-aryl-3-alkyltriazen-3-yl)ethanes and related compounds

1998 ◽  
Vol 76 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Donald L Hooper ◽  
Ian R Pottie ◽  
Marc Vacheresse ◽  
Keith Vaughan
Keyword(s):  
Nmr Spectroscopy ◽  
Line Broadening ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Ir And Nmr Spectroscopy ◽  
Diazonium Coupling ◽  
Significant Line ◽  
Related Compounds ◽  
C Nmr

A series of novel bistriazenes, the 1,2-bis(1-aryl-3-methyltriazen-3-yl)ethanes, Ar-N T N-NMe-CH2CH2-NMe-N T N-Ar, have been synthesized by diazonium coupling with N,N'-dimethylethylenediamine. These bistriazenes are stable crystalline compounds and have been unequivocally characterized by IR and NMR spectroscopy (1H and 13C), and elemental analysis. The structures of two compounds in the series have been confirmed by X-ray crystallography. The 1H NMR spectra show significant line broadening of the N-methyl resonances arising from the restricted rotation around the N2-N3 bond of the triazene units. The presence of strongly electron-withdrawing groups on the aryl ring restricts the rotation to the point where the N-methyl signals of the rotamers are distinct even at room temperature; four resonances of the N-methyl signal are clearly evident and these can be assigned to the anti-anti, syn-syn, and syn-anti conformations of the bistriazene. Diazonium coupling with N,N'-diethylethylenediamine affords the N,N'-diethyl homologues of the bistriazenes, which have been similarly characterized. As model compounds to assist in spectroscopic analysis, a series of related triazenes, the 1-(1-aryl-3-methyltriazen-3-yl)-N,N-dimethyl-2-ethanamines, were prepared by diazonium coupling with N,N,N'-trimethylethylenediamine. These dialkyltriazenes exist mainly as oils, but characterization was achieved by IR, 1H NMR, and 13C NMR spectroscopy, also showing the presence of two rotamers in solution when strongly electron-withdrawing substituents are bonded to the aryl moiety.Key words: triazene, bistriazene, diazonium, ethylenediamine, molecular dynamics, NMR.

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