ISSN:
0899-0042
Keywords:
oxazepam
;
racemization
;
reversed-phase and chiral stationary phase high-performance liquid chromatography
;
circular dichroism spectropolarimetry
;
mass spectrometry
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Enantiomeric and racemic oxazepam (OX), 3-O-methyloxazepam (MeOX), and 3-O-ethyloxazepam (EtOX) were used to study racemization, heteronucleophilic, and homonucleophilic substitution reactions in anhydrous acidic methanol and ethanol. Kinetics of racemization and nucleophilic substitution reactions in nondeuterated and deuterated solvents were determined by circular dichroism spectropolarimetry, chiral stationary phase high-performance liquid chromatography (HPLC), reversed-phase HPLC, and mass spectrometry. Several reactions occurred when (S)-OX, for example, was dissolved in acidic methanol: (1) (S)-OX itself underwent spontaneous racemization, (2) the 3-hydroxyl group of (S)-OX was stereoselectively substituted by the methoxy group of methanol to form MeOX enriched in (S)-MeOX, (3) the 3-methoxy group of (S)-MeOX was stereoselectively substituted by the methoxy group of methanol to form MeOX enriched in (S)-MeOX, and (4) the 3-methoxy group of (R)-MeOX was stereoselectively substituted by the methoxy group of methanol to form MeOX enriched in (R)-MeOX. Repetitive reactions 3 and 4 eventually resulted in a racemic MeOX. Similar reactions occurred for an enantiomeric OX in acidic ethanol. © 1996 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
