NMR Studies of Drugs. Applications of a Chiral Lanthanide Shift Reagent to Methoxamine in Chloroform-dor Acetonitrile-d3.
作者:
Michael DeArment,
Michelle Eastabrooks,
KunisiS. Venkatasubban,
Ronnie Benshafrut,
Robert Rothchild,
Helen Wyss,
期刊:
Spectroscopy Letters
(Taylor Available online 1994)
卷期:
Volume 27,
issue 4
页码: 533-555
ISSN:0038-7010
年代: 1994
DOI:10.1080/00387019408007258
出版商: Taylor & Francis Group
关键词: LSR;Eu(HFC)3;Bidentate chelation;Stereoisomer;Europium;Enantiomeric excess;Optical purity;Analysis;Adrenergic (vasopressor);NMR shift reagents;One-and two-dimensional NMR;COSY;α-(1-Aminoethyl)-2,5-dimethoxybenzenemethanol (erythro);“Anomalous
数据来源: Taylor
摘要:
The1H NMR spectra of racemic (erythro) methoxamine free base, 1,1-(1-aminoethyl)-2,5-dimethoxybenzenemethanol, have been studied at or near ambient temperatures in CDCl3or CD3CN with the added chiral lanthanide shift reagent (LSR), tris[3-(heptafluoropropylhydroxymethylene)-(+)-camphorato] europium (III), 2. Spectrometers operating at 60, 200 and 300 MHz were employed; some COSY spectra were acquired to support assignments. Enantiomeric shift differences (Δ Δ Δ) were observed for several nuclei of 1 with added 2 in either CDCl3or CD3CN and an “anomalous” (upfield) shift was seen for the NCH signal. A high degree of signal broadening was seen for runs with either solvent, and surprising similarity was found for the slopes in plots of chemical shift versus [2]/[1] molar ratios for the different nuclei of 1 whether the hydrogen bond donor solvent (CDCl3) or the hydrogen bond acceptor solvent (CD3CN) was used. Together with the anomalous shift noted above, these results are interpreted as consistent with strong bidentate chelation of2by1.
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