Differentiation of trifluoromethylbenzylpiperazines (TFMBZPs) and trifluoromethylbenzoylpiperazines (TFMBOPs) by GC-MS

Two series of regioisomers - the trifluoromethylbenzylpiperazines (TFMBZPs) and the trifluoromethylbenzoylpiperazines (TMFBOPs) were synthesized and analyzed as potential “hybrid” derivatives of the benzylpiperazine (BZP) and 1-(3-trifluoromethylphenyl)piperazine (TMFPP) drugs of abuse. The TFMBZPs are readily differentiated from TMFBOPs by their mass spectra including differences in their mass, the base peaks in their mass spectra as well as several other unique fragment ions. However the mass spectra of each regioisomer in each of these two series have fragment ions of identical mass and thus cannot be differentiated by this analytical method alone. Furthermore, chemical derivatization by perfluoroacylation did not offer any additional unique marker fragment ions in the mass spectrum to allow identification of one regioisomer in a series to the exclusion of the other two regioisomers. The perfluoroacylamides of the regioisomers in the TFMBZP series and the regioisomers in the TMFBOP series were readily separated by GC on the stationary phase Rtx-200 and eluted in an order similar to other perfluoroacyl-derivatives of other benzyl- and benzoylpiperazine compounds reported earlier.