(1)H NMR spectral simplification with achiral and chiral lanthanide shift reagents. Tranylcypromine, trans-2-phenylcyclopropanamine.
The 60 MHz (1)H NMR spectra of racemic tranylcypromine, 1, 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), 2, and the chiral tris[3-(trifluoromethylhydroxymethylene)-d-camphorato] europium(III), 3. Appreciable values of the enantiomeric shift differences, DeltaDeltadelta, were observed for each cyclopropyl proton except for the proton beta and trans to the amino group (furthest from the expected europium complexation site). The proton alpha to the amino group showed DeltaDeltadelta as high as about 38 Hz for a 3:1 ratio of 0.71; the DeltaDeltadelta decreased at higher 3:1 ratios. Optical purity evaluations should be most practical using this alpha proton with 3:1 ratios near 1.07 to minimize interference due to peak overlap.
Hatzis
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The City University of New York, John Jay College of Criminal Justice, Department of Science, 445 West 59th Street, New York, NY 10019-1199, USA.
Rothchild
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