• Bulletin of the Korean Chemical Society
• /
• v.28 no.8
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• pp.1419-1421
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• 2007

• Proceedings of the PSK Conference
• /
• 2003.10b
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• pp.223.3-224
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• 2003

Chiral discrimination of ibuprofen by $^1$H-NMR using several chiral solvating agents such as (-)-brucine, (-)-cinchonidine, (1R, 2S)-(-)-ephedrine, (S)-(-)-${\alpha}$- methylbenzylamine, (-)-strychnine and L-(-)-tryptophane was investigated. Racemic ibuprofen treated with one equivalent of chiral solvating agent was preferentially crystallized. Chiral purity of each precipitates was measured by chiral HPLC and chemical shift differences(ΔΔ$\delta$) was calculated. Eventhough (S)-(-)-${\alpha}$-methylbenzylamine was most effective for the preferential recrystalization of (S)-(+)-ibuprofen, chemical shift differentiation ability was weak. (omitted)

• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.673-674
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• 1996

• Proceedings of the PSK Conference
• /
• 2003.10b
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• pp.219.1-219.1
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• 2003

$^1$H-NMR method for the determination of enantiomeric purity of (S)-(+)-ibuprofen was developed using (-)-cinchonidine as a chiral solvating agent. (S)-(+)-ibuprofen was prepared by optical resolution of racemic ibuprofen using preferential recrystallization method with (S)-(-)-${\alpha}$-methylbenzylamine and (R)-(-)-ibuprofen by semi-preparative chiral HPLC using chiral OD column and n-hexane/2-propanol/trifluoroacetic acid as a mobile phase. Several concentrations of synthetic mixture of (S)-(+)-ibuprofen and (R)-(-)-ibuprofen were added to the (-)-cinchonidine disolved in CDCl$_3$. (omitted)

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.595-598
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• 1998

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3481-3484
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• 2012

• Proceedings of the PSK Conference
• /
• 2001.10a
• /
• pp.280.3-281
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• 2001

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.216-220
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• 2004

${\beta}$-CD and CM- ${\beta}$-CD as chiral NMR shift agents were used to resolve the enantiomers of noradrenaline (NA). The stoichiometry of each complex formed between the CDs and the enantiomers of NA was found to be 1 : 1 through the continuous variation plots. The binding constants (K) of the complexes were determined from $^1H$ NMR titration curves. This result indicated that both ${\beta}$-CD and CM- ${\beta}$-CD formed the complexes with the S(+)-NA more preferentially than its R(-)-enantiomer. The K values for the complexes with ${\beta}$-CD ($K_{S(+)}$ = 537 $M^{-1}$ and $K_{R(-)}$ = 516 $M^{-1}$ was larger than those with CM- ${\beta}$-CD ($K_{S(+)}$ = 435 $M^{-1}$ and $K_{R(-)}$ = 313 $M^{-1}$), however, enantioselectivity (${\alpha}$) of S(+)- and R(-)-NA to CM- ${\beta}$-CD ( ${\alpha}$ = 1.38) was larger than that to ${\beta}$-CD ( ${\alpha}$ = 1.04), indicating that CM- ${\beta}$-CD was the better chiral NMR solvating agents for the recognition of the enantiomers of NA. Two dimensional rotating frame nuclear Overhauser enhancement spectroscopy (ROESY) experiments were also performed to explain the binding properties in terms of spatial fitting of the NA molecule into the macrocyclic cavities.