MASS SPECTRAL AND CHROMATOGRAPHIC STUDIES ON A SERIES OF REGIOISOMERS AND ISOBARIC DERIVATIVES RELATED TO METHYLENEDIOXYMETHAMPHETAMINES Except when reference is made to the work of others, the work described in this dissertation is my own or was done in collaboration with my advisory committee.This dissertation does not include proprietary or classified information. _____________________________ Tamer A. Awad Certificate of Approval: ________________________ ________________________ Jack DeRuiter C. Randall Clark, Chair Professor Professor Pharmacal Sciences Pharmacal Sciences ________________________ ________________________ Forrest T. Smith Joe F. Pittman Associate Professor Interm Dean Pharmacal Sciences Graduate School MASS SPECTRAL AND CHROMATOGRAPHIC STUDIES ON A SERIES OF REGIOISOMERS AND ISOBARIC DERIVATIVES RELATED TO METHYLENEDIOXYMETHAMPHETAMINES Tamer A. Awad A Dissertation Submitted to the Graduate Faculty of Auburn University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Auburn, Alabama December 15, 2006 MASS SPECTRAL AND CHROMATOGRAPHIC STUDIES ON A SERIES OF REGIOISOMERS AND ISOBARIC DERIVATIVES RELATED TO METHYLENEDIOXYMETHAMPHETAMINES Tamer A. Awad Permission is granted to Auburn University to make copies of this dissertation at its discretion, upon request of individuals or institutions and at their expense. The author reserves all publication rights. ____________________ Signature of Author ____________________ Date of Graduation iii DISSERTATION ABSTRACT MASS SPECTRAL AND CHROMATOGRAPHIC STUDIES ON A SERIES OF REGIOISOMERS AND ISOBARIC DERIVATIVES RELATED TO METHYLENEDIOXYMETHAMPHETAMINES Tamer A. Awad Doctor of Philosophy, December 15th, 2006 (M. Pharm. Sci., Suez Canal University, 2000) (B. Pharm. Sci., Cairo University, 1993) 314 Typed Pages Directed by C. Randall Clark The popular drug of abuse 3,4-methylenedioxymethamphetamine (MDMA) has regioisomeric and isobaric substances of mass equivalence, which have similar analytical properties and thus the potential for misidentification. Direct regioisomers of MDMA include ring and side chain methylenedioxy substitution patterns and the indirect regioisomers include methoxymethcathinones. The methoxy methyl ring substituted methamphetamines constitute the major category of isobaric substances evaluated in this study. The direct and indirect regioisomers of MDMA and also isobaric substances related to MDMA were synthesized and compared to MDMA by using gas chromatographic and spectrometric techniques. The spectrometric studies of the direct regioisomers and iv isobaric substances of MDMA indicated that they can not be easily differentiated by mass spectrometry or ultraviolet (UV) spectrophotometry. The synthesized compounds were converted to their perfluoroacyl derivatives, pentafluropropyl amides (PFPA) and heptaflurobutryl amides (HFBA), in an effort to individualize their mass spectra and to improve chromatographic resolution. Derivatized MDMA was easily distingushed from its derivatized direct and indirect regioisomers using mass spectrometry. Unique fragment ions were observed for the various direct regioisomeric side chains and the methoxymethcathinones. However, it was hard to characterize perfluroacyl derivatives of MDMA from most of the derivatized methoxy methyl ring substituted methamphetamines (isobaric substances) of the same side chain substitution pattern. Gas chromatographic studies indicated that the optimum separation of direct and indirect regioisomers of MDMA was obtained when a 100% dimethyl polysiloxane column was used at gradient temperature program rates. Isobaric substances related to MDMA were divided into subset groups based on the methoxy group position on the aromatic ring and were found to have different elution properties than MDMA and therefore misidentification due to co-elution can be eliminated using 100% dimethyl polysiloxane and trifluoropropyl methyl polysiloxane columns. The mass spectral and chromatographic properties of methoxy methyl ring substituted phenyl acetone, as key intermediates in synthesizing methoxymethyl methamphetamines, were also evaluated and the ten ketones were separated from each other as well as from methylenedioxy-2- propanone on a permethylated beta cyclodextrin column using gradient temperature program rates. v ACKNOWLEDGMENTS During the preparation of this dissertation many people, both in Auburn University and the East Alabama Forensic Toxicology Laboratory, USA, have given me support. I am most grateful to them all. Especially I would like to thank: Professor C. Randall Clark, no words can express my sincere gratitude to him, for his continuous encouragement, guidance, support and patience. His lessons in the art of chromatography are invaluable to me. With such a wonderful personality, he makes you feel that the advisor- graduate student relationship is a father- son relationship which I will be proud of for the rest of my life. He and his wife, Margaret, are the best family we had away from home. Professor Jack DeRuiter, who significantly helped developing my synthesis skills throught lectures and support in the laboratory. His encouragement was of utmost importance. Dr. Forrest Smith, his outstanding lectures in organic synthesis enabled me to have a solid background that should enable me to sucessfuly continue my career in medicinal chemistry. In addition to all these people, I would like to express my thanks to Dr. Abdel-Hady family for their love and support and to my sincere gratefulness to my beloved wife, Maha, for her patience and encouragement and to my son, Saif, for the joy he gives me and the motive to finish this work. Above all, thanks to GOD for giving me the power to achieve this work. vi Style manual or journal used Journal of Medicinal Chemistry Computer software used Microsoft Word and ChemDraw Ultra 7.0 vii TABLE OF CONTENTS LIST OF FIGURES ......................................................................................................... xiv LIST OF SCHEMES......................................................................................................xviii LIST OF TABLES.......................................................................................................... xxii LIST OF ABBREVIATION.......................................................................................... xxiv 1 LITERATURE REVIEW ................................................................................................ 1 1.1 INTRODUCTION .................................................................................................... 1 1.2 PHARMACOLOGY OF 3,4-MDMA ........................................................................ 4 1.2.1 History............................................................................................................. 4 1.2.2 Behavioral effects........................................................................................... 5 1.2.3 Neurochemical effects.................................................................................... 7 1.2.4 Neurotoxicity .................................................................................................. 9 1.2.5 Metabolism ................................................................................................... 14 1.2.6 Structure-activity relationships of MDMA-like substances .................... 18 1.2.6.1 Amine Substituents ............................................................................... 19 1.2.6.2 Side chain length and branching........................................................... 19 1.2.6.3 Beta substitution.................................................................................... 20 1.2.6.4 Ring substitution................................................................................... 21 1.3.1 Synthesis of precursors ................................................................................. 23 1.3.1.1 Safrole as starting material.................................................................... 24 1.3.1.2 Isosafrole as starting material ............................................................... 25 1.3.1.3 Piperonal as starting material................................................................ 27 1.3.1.4 3,4-Methylenedioxyphenylacetic acid as starting material................... 28 1.3.1.5 3,4-Methylenedioxyphenylacetonitrile as starting material.................. 30 1.3.2 Synthesis of 3,4-methylenedioxyamphetamines........................................... 31 1.3.2.1 The reductive amination route .............................................................. 31 1.3.2.1.1 Catalytic hydrogenation.................................................................... 32 viii 1.3.2.1.2 Sodium cyanoborohydride................................................................ 32 1.3.2.1.3 Sodium borohydride.......................................................................... 33 1.3.2.1.4 Aluminum amalgam.......................................................................... 33 1.3.2.2 The Leuckart reaction ........................................................................... 34 1.3.2.3 The nitropropene route.......................................................................... 35 1.3.2.4 The bromopropane route....................................................................... 36 1.3.3 Synthesis of 3,4-methylenedioxyphenylbutanamines................................... 37 1.3.4 Synthesis of 2,3-methylenedioxyphenalkylamines......................................