ISSN:
0899-0042
Schlagwort(e):
temazepam
;
3-O-methyltemazepam
;
3-O-ethyltemazepam
;
stereoselectivity
;
nucleophilic substitution
;
racemization
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Enantiomeric 3-O-methyltemazepam and 3-Oethyltemazepam were highly stereoselectively substituted by the 3-methoxy group of methanol in acidic anhydrous methanol and by the 3-ethoxy group of ethanol in acidic anhydrous ethanol, respectively. The stereoselectivity of the homonucleophilic substitution reactions was determined by circular dichroism spectropolarimetry and gas chromatography-mass spectrometry. In anhydrous solutions containing 0.5 M D2SO4 at 50°C, for example, the stereoselectivity was ∼63:1 for enantiomeric 3-O-methyltemazepam in CD3OD and ∼94:1 for enantiomeric 3-O-ethyltemazepam in C2D5OD. The high stereoselectivity at C3 position was primarily due to the presence of a methyl group at N1 position. © 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.
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
