Volume 26, Issue 2 (April 1981)
Carbon-13 Nuclear Magnetic Resonance Spectra of Trimethoxyamphetamines—A Comparison of Predicted with Experimental Results
Chemical shifts of the 13C-nuclear magnetic resonance spectra of the six trimethoxyamphetamines were predicted from results previously found for the monomethoxyamphetamines and dimethoxyamphetamines. The spectra were then determined and the signals assigned by an internally consistent analysis in comparison with the predicted shifts. Data from the spectra and details of their interpretation are presented. The agreement between found and predicted chemical shifts is excellent. The information is valuable for the structural authentication of reference materials. Differences in the chemical shifts of the methoxyl signals are related to conformational effects. The ortho and para shielding parameters discerned can be used to predict the spectra and thus identify unknowns in the absence of reference material.