F. Taylor Noggle

Resolution of Some Enantiomeric Amines of Forensic Interest by High-Performance Liquid Chromatography

The high-performance liquid chromatographic resolution of the enantiomers of amphetamine, methamphetamine, ephedrine, and pseudoephedrine is described. The sugar isothiocyanate, 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (GITC), is used as a chiral derivatizing agent, with chromatographic separations of the diastereomers formed with each amine made using a standard achiral C18 stationary phase.

Liquid Chromatographic Analysis of Some N-Alkyl-3,4-methylenedioxyamphetamines

Abstract The liquid chromatographic separation of a series of low molecular weight N-alkyl derivatives of 3,4-methylenedioxyamphetamine (MDA) is reported. The N-methyl-, N-ethyl- and N,N-dimethyl-derivatives of MDA have appeared as street drugs in recent years. These compounds are becoming significant forensic problems due to their unique pharmacological properties and relative ease of chemical synthesis. These amines were synthesized via reductive amination of the corresponding ketone with alkylamines. The UV absorption spectra for these compounds produced almost equally intense absorbance at 234 and 285 nm. The compounds were separated by reversed-phase (C18) HPLC procedures using a mobile phase of aqueous methanol at low pH.

Liquid Chromatographic Analysis of the Enantiomeric Composition of Norephedrine and Norpseudoephedrine Benzylic Inversion Products

Abstract Three of the four stereoisomers of l-phenyl-2-amino-l- propanol (phenylpropanolamine) are available as the single enantiomers. The 1S, 2S-stereoisomer is available only as a component of racemic norpseudoephedrine (S,S- and R,R-1-phenyl-2- amino-1-propanol). The 1S,2S-norpseudoephedrine was prepared from 1RI2S-norephedrine via a benzylic inversion synthetic procedure. This reaction sequence was found to invert the configuration of the benzylic hydroxyl-group in norephedrine and norpseudoephed- rine to yield the corresponding diastereomer. The configuration of the product was determined using reversed-phase liquid chroma- tography following derivatization with 2,3,4,6-tetra-O-acetyl-6-D-glucopyranosyl isothiocyanate (GITC) .

Liquid Chromatographic and Spectral Methods for the Differentiation of 3,4-Methylenedioxymethamphetamine (MDMA) from Regioisomeric Phenethylamines

Abstract The analytical profiles are described for four amines, 3,4-methylenedioxymethamphetamine (MDMA) and three isomeric phen-ethylamines of MW = 193. These four amines all contain an identical 3,4-methylenedioxyphenyl moiety, thus the regioisomerism is within the carbon-carbon bond located alpha to the amine. Therefore these phenethylamines are regioisomeric within the imine fragment (m/z = 58) which is the base peak in the electron impact mass spectrum of MDMA. The ultraviolet absorption spectra for these compounds show the characteristic methylenedioxyphenyl group absorption bands in the 235 to 280 nm range. These amines may best be differentiated by chromatographic separation and are well resolved by liquid chromatographic techniques. The four regioisomeric amines were separated using an isocratic reversed-phase system consisting of a C18 stationary phase and an acidic (pH) mobile phase. The elution order under these conditions appears to parallel the length of the carbon chain attached to the arom...

Liquid Chromatographic and Mass Spectral Analysis of N,N-Disubstituted 3,4-Methylenedioxyamphetamines

Abstract The tertiary amine N,N-disubstituted derivatives of 3,4-methylenedioxyamphetamine (MDA) were prepared and their liquic chromatographic and mass spectral properties compared to other analogues of 3,4-methylenedioxyamphetamine. The N-methyl-N-ethyl, N-methyl-N-i-propyl and N-methyl-N-n-propyl MDA derivatives were separated in a reversed-phase system consisting of a C18 stationary phase and a mobile phase of pH 4 phosphate buffer-acetonitrile (55:45). The mass spectral fragmentation of these amines is similar to that observed for the secondary amine MDA derivatives and can be used for their specific structural identification.

Liquid chromatographic and mass spectral analysis of 1-(3,4-methylenedioxyphenyl)-1-ethanamines: homologues of 3,4-methylenedioxyamphetamines

The 1-(3,4-methylenedioxyphenyl)-3-butanamines (HMDAs) are prepared via reductive amination of the corresponding ketone with a series of low molecular weight alkylamines. These amines are homologues of the N-substituted 3,4-methylenedioxyamphetamines (MDAs). Compounds of the HMDA series have UV absorption properties similar to the MDAs because both series contain the same 3,4-methylenedioxyphenyl chromophore. The HMDAs are separated via reversed-phase liquid chromatographic methods using a C18 stationary phase and an acidic aqueous acetonitrile mobile phase. The mass spectra of these potential designer drugs are very similar to the spectra of the MDA homologues having the same N-substituent.

Liquid Chromatographic Analysis of Pentazocine and Tripelennamine in Combination

Abstract A reverse phase and normal phase liquid chromatographic procedure is described for the separation of pentazocine and tripelennamine. The isocratic methods use dual wavelength detection at 254, 280, and 313 nm.