Abstract
The seven regioisomeric N-bromodimethoxybenzyl derivatives of 3-TFMPP were synthesized via reductive amination of the seven commercially available bromo-dimethoxybenzaldehydes. The capillary GC elution profiles for these compounds generally follow the degree of methoxy group substituent crowding on the aromatic ring. The electron ionization mass spectra show a series of major fragment ions common to all seven regioisomeric compounds. The base peak in the EI mass spectra for many of the seven regioisomers occurs at m/z 229 and is the result of contributions from two isobaric fragments, the trifluoromethylphenylpiperazine cation as well as the Br-79 bromodimethoxybenzyl cation. Several low intensity ions are related to the specific regioisomeric substitution patterns for the bromodimethox-ybenzyl moieties and provide some differentiation for this set of seven compounds. These unique ions allow the seven compounds to be divided into sub-groups and in some cases allow specific isomer identification from only the EI-MS data. The 950 cm(-1) to 550 cm(-1) lower portion of the fingerprint region in the vapor phase infrared spectra can be used to identify each of the bromodimethoxybenzyl regioisomers after EI-MS fragmentation patterns provide focus on the individual structural sub-groups of compounds in this study.