High-performance liquid chromatographic determination of alpha-aminonitrile enantiomers after derivatization with o-phthalaldehyde and chiral thiols.
o-Phthalaldehyde in combination with chiral thiols is described as a chiral reagent for the resolution of the enantiomers of alpha-H-alpha-aminonitriles and alpha-alkyl-alpha-aminonitriles. Separation of the resulting diastereomers was carried out by reversed-phase chromatography and the derivatives were detected at UV 340 nm. The identity of the diastereomeric derivatives was confirmed by LC-MS. Among the chiral thiols tested, N-acetyl-D-penicillamine and beta-mercaptoisobutyric acid gave the best resolution for the alpha-aminonitriles studied. For quantitative enantiomeric excess determination, beta-mercaptoisobutyric acid was chosen as this thiol could be obtained in high enantiomeric purity from a commercial source. The rate of the reaction of various alpha-aminonitriles with o-phthalaldehyde and beta-mercaptoisobutyric acid was studied. The accuracy of the method was investigated by a comparison of theoretical and measured enantiomeric excess.
Duchateau
A L L
AL
DSM Pharma Chemicals, Department of Advanced Synthesis, Catalysis and Development, 6160 MD Geleen, The Netherlands. lucien.duchateau@dsm.com
Boesten
J M M
JM
Christis
B
B
Eijnthoven
F
F
Henderickx
H J W
HJ
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013058:Mass Spectrometry; D009570:Nitriles / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D009764:o-Phthalaldehyde / Q000737:chemistry*
D009570:Nitriles; D013438:Sulfhydryl Compounds; D009764:o-Phthalaldehyde