GC-MS Studies on Acylated Derivatives of 3-Methoxy-4-methyl- and 4-Methoxy-3-methyl-phenethylamines: Regioisomers Related to 3 4-MDMA

A series of side chain regioisomers of 3-methoxy-4-methyl- and 4-methoxy-4-methyl-phenethylamines have mass spectra essentially equivalent to the controlled drug substance 3,4-methylenedioxymethamphetamine (3,4-MDMA); all have molecular weight of 193 and major fragment ions in their electron ionization mass spectra at m/z 58 and 135/136. In the current project, the mass spectra for the acetyl, propionyl, and trifluoroacetyl derivatives of the primary and secondary regioisomeric amines were significantly individualized. The resulting unique fragment ions enabled specific side chain identification. The trifluoroacetyl derivatives provided more fragment ions for molecular individualization among these regioisomeric substances. These trifluoroacetyl derivatives showed excellent resolution on a non-polar stationary phase such as Rtx-1. (publisher abstract modified)