Study on protolytic equilibria of lorazepam and oxazepam by UV and NMR spectroscopy
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Updated: Sep 26, 2026

Syntheses, Crystallization, and Spectroscopic Characterization of 3,5-Lutidine N-Oxide Dehydrate
Published on: April 24, 2018
G V Popović1, D M Sladić, V M Stefanović
1Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, P.O. Box 146, 11000, Belgrade, Yugoslavia. gpopovic@chem.bg.ac.yu
Abstract:
Protolytic equilibria in homogeneous and heterogeneous systems of lorazepam and oxazepam, which are sparingly soluble ampholytes from the class of 1,4-benzodiazepines, were studied at 25 degrees C and ionic strength of 0.1 M. Acidity constants and equilibrium constants in a heterogeneous system were determined. On the basis of the analysis of the corresponding 13C- and 1H-NMR spectra, deprotonation site in the molecules of the investigated compounds was predicted. Finally, the correlation between chemical shifts in the 1H-NMR spectra and the acidity of the amide proton of 1,4-benzodiazepines was established.
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