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XXXV TIAFT Annual Meeting Poster Presentations
EPIMERIZATION STUDIES OF LSD USING 1H NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY

Salamone S.J., Li Z., McNally A.J., Vitone S. and Wu R.

Roche Diagnostic Systems, Inc., 1080 US Highway 202, Somerville, NJ 08876, USA
A study was conducted to determine the conditions needed to achieve the equilibrium concentration for the epimerization of d-lysergic acid diethylamide (LSD) to iso-LSD. The reaction was followed by integration of the C-9 resonance of LSD and iso-LSD by proton nuclear magnetic resonance (NMR). The C-9 resonance of LSD and iso-LSD appear as singlets at 6.35 ppm and 6.27 ppm respectively. Starting with pure LSD, the conversion to iso-LSD is attained at temperatures above 37° C and pHs above 7.0. The LSD/iso-LSD ratio of 9:1 is achieved after one week at 45° C or two weeks at 37° C. Starting with iso-LSD, the conversion to LSD requires more vigorous conditions. The 9:1 LSD/iso-LSD ratio is attained only after six weeks at a temperature of 45° C and a pH of 9.7. At lower pHs, the reaction proceeds more slowly. The 9:1 LSD/iso-LSD ratio is achieved whether the starting material is LSD or iso-LSD and therefore represents an equilibrium concentration (K=9). In addition, the more vigorous conditions needed to achiev equilibrium of iso-LSD to LSD demonstrates the difficulty in extraction of the epimerizable proton of iso-LSD. This study is the first to quantitate the epimerization of LSD by NMR techniques and establishes the conditions needed to induce epimerization in solution.

  Abstract 109

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