NMR Studies of Drugs. 5-Methyl-5-phenylhydantoin. Applications of Lanthanide Shift Reagents in Polar Solvents to a Non-Chelating Substrate |
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| Authors: | Robert Rothchild Shari Braddock Stacey Traviglia Kunisi S Venkatasubban |
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| Institution: | 1. The City University of New York, John Jay College of Criminal Justice, Toxicology Research and Training Center, Science Department , 445 West 59th Street, New York, NY, 10019-1199;2. University of North Florida, Department of Natural Sciences , P.O. Box 17074, Jacksonville, FL, 32216 |
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| Abstract: | The 200.1 MHz 1H NMR spectra of 5-methyl-5-phenylhydantoin, 1, have been studied in CD3CN solution at ambient temperatures 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 reagent, tris3-(heptafluoropropylhydroxymethylene)-(+)-camphorato] europium (III), 3. Although 1 cannot chelate the LSRs, use of sufficiently high LSR:1 molar ratios served to compensate for competitive binding of LSR by the polar solvent, and permitted substantial lanthanide-induced shifts to be observed with 2 or 3. With 3, significant enantiomeric shift differences were produced for the ortho aryl protons and for the CH3 signals. The ortho proton signal appears to offer excellent potential for direct determination of enantiomeric excess of 1. These results demonstrate the utility of LSRs 2 or 3 even in a polar solvent with a nonchelating substrate. |
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| Keywords: | NMR shift reagents Europium Eu(FOD)3 Eu(HFC)3 Stereoisomers Optical purity Enantiomeric excess Anticonvulsant Chiral 5-Methyl-5-phenyl-2 4-imidazolidinedione Analysis Chelation |
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