GC-MS and GC-IRD Studies on Ethoxyphenethylamines Related to MDEA, MDMMA and MDBD

Abstract

Three regioisomeric 3,4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equal mass have been reported as drugs of abuse in recent years. These compounds are 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 3,4-methylenedioxy-N,N-dimethylamphetamine (MDMMA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB). Ring substituted ethoxyphenethylamine regioisomers were synthesized. These regioisomers are compounds with an isobaric relationship to the controlled drug substances MDEA, MDMMA and MBDB, all have molecular weights of 207 and major fragment ions in their electron ionization mass spectra at m/z 72 and 135/136. The trifluoroacetyl, pentafluoropropionyl and heptafluorobutryl derivatives of the secondary amines were evaluated in GC–MS studies. The mass spectra for these derivatives were significantly individualized and the resulting unique fragment ions allowed for specific identification. These perfluoroacyl derivatives showed reasonable gas chromatographic resolution on the non-polar stationary phase Rtx-1. GC-IRD studies provided structure-IR spectral relationships used for the discrimination of the three target drugs (MDEA, MDMMA and MBDB) from the other nine ring substituted ethoxyphenethylamine regioisomers. In addition GC-MS and IRD studies were done on the ketone precursors of the ethoxyphenethylamines and ketone precursors of the drug of abuse MDEA, MDMMA and MBDB. The ketones have shown reasonable gas chromatographic resolution on the non-polar stationary phase Rtx-1. GC-IRD studies provided structure-IR spectral relationships used for the discrimination of the ketone precursors of the drugs (MDEA, MDMMA and MBDB) from the other six ring substituted ethoxyphenethyl ketones regioisomers.