DETERMINATION OF COMPOSITIONS AND CONFIGURATIONS OF GIS-A-AND CIS-B-OHMEFENTANYL BY HPLC AND ¹HNMR

Ohmefentanyl (1)is an extremely potent analgesic agent with high affinity and selectivity for opioid μ receptors. Using HPLC and HNMR spectral analysis,the compositions of two pairs of cis-form enantiomers :cis-A-l and cis-B-l, were confirmed as a mixture of equal parts of cis-(+)-(3R,4S,2'S)-1+cis-(-)-(3S,4R,2'R)-1 and a mixture of equal parts of cis-(-)-(3R, 4S,2'R)-1+cis-(+)-(3S, 4R,2'S)-1,respectively.