Abstract
The 60 MHz <sup>1</sup>H NMR spectra of racemic 3,4-methylenedioxyamphetamine (MDA), <i>1</i>, have been studied with the achiral shift reagent, tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) europium (III), <i>2</i>, and the chiral tris[3-(trifluoromethylhydroxymethylene)-<i>d</i>-camphorato]europium (III), <i>3</i>. Moderate values of the enantiomeric shift difference, ΔΔδ, were observed for each of the benzylic protons and the CH<sub>3</sub>, with the use of added <i>3</i> in CDCl<sub>3</sub> solutions at 28°C. The CH<sub>3</sub> resonance was analytically useful for direct optical purity assays; as little as 3% of the minor enantiomer should be detectable. The (+)-isomer of <i>1</i> had its CH<sub>3</sub> absorption at higher field in spectra shifted by <i>3.</i> Appropriate peak height measurements were determined for best accuracy in optical purity assays. The relative abundances of the different conformers with respect to C<sub>α</sub>-C<sub>β</sub> bond rotation based on coupling constants in the CH<sub>2</sub>CH moiety are discussed.
PDF Article
More Like This
Intracavity absorption spectroscopy of HCl isotopes, H2O, CH4, C2H4, and C2H6 in the 3.1–3.4 µm spectral range using a Cr:CdSe laser
Peter Fjodorow, Mikhail P. Frolov, Yuri V. Korostelin, Vladimir I. Kozlovsky, Christof Schulz, Stanislav O. Leonov, Yan K. Skasyrsky, and Nikolai N. Yuryshev
Opt. Express 30(22) 40347-40356 (2022)
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription
Add to BibSonomy