Synthesis of 2,3-and 3,4-methylenedioxyphenylalkylamines and their regioisomeric differentiation by mass spectral analysis using GC-MS-MS

3,4-methylenedioxyamphetamine (MDA) derivatives are increasingly abused cen tral nervous system stimulants with neurotoxic properties, In recent years a number of controlled substance analogs (designer drugs) with high structu ral variety reached the illegal market making their identification an arduo us task. The underivatized compounds give very similar or even virtually id entical electron impact mass spectra containing mainly intense C(n)H(2n+)2N (+) immonium ions. Using tandem mass spectrometry (MS-MS) the additional st ructural information contained in the collision induced dissoziation (CID) mass spectra of molecular ions using electron impact (EI) and especially ch emical ionization (CI) allowed an unequivocal differentiation of 18 studied regioisomeric 1-(methylenedioxyphenyl)-2-propanamines and 1- (methylenedio xyphenyl)-2-butanamines. Further synthetic methods are presented for 1-(3,4-methylenedioxyphenyl)-N- propyl-2-N-isopropyl-1-(3,4-methylenedioxyphenyl)-2-butanamine and four 1-( 2,3-methylenedioxyphenyl)-2-butanamines. N-alkylated 1-(3,4-methylenedioxyp henyl)-2-butanamine compounds (e.g. MBDB) are also known to be abused psych oactive agents (entactogenes) without the sympatomimetic effects of the 3,4 -methylenedioxyamphetamines. (C) 2000 Elsevier Science Ireland Ltd. All rig hts reserved.