Chromatographic and mass spectral studies on methoxymethcathinones related to 3,4-methylenedioxymethamphetamine

The methoxymethcathinones are uniquely regioisomeric with the controlled drug substance 3,4-methylenedioxymethamphetamine (3,4-MDMA) or Ecstacy. The various isomeric forms of the methoxymethcathinones have mass spectra essentially equivalent to 3,4-MDMA. They all have a molecular weight of 193 and major fragment ions in their electron ionization mass spectra at m/z58 and 135/136. Differentiation by mass spectrometry was only possible after formation of the perfluoroacyl derivatives, pentafluoropropionylamides (PFPA), and heptafluorobutrylamides (HFBA). Gas chromatographic separation on nonpolar stationary phases successfully resolved the three methcathinones from 2,3- and 3,4-MDMA as the PFPA and HFBA derivatives.