"Chemistry is in the News"
To Accompany Wade Organic Chemistry 4/e.
Chapter 19. Amines
The world is in peril.
With each passing day, more people become methamphetamine addicts. You see it in the news over and over again - the relentless tide of Clandestine meth labs springing up out of nowhere, disappearing, then reappearing elsewhere. The United States is getting its first taste of methamphetamine's addictive chemical magic. In the politically chaotic region of South-East Asia, the situation is worse still.
Thailand is not far from the drug's birthplace: China. In the late 1880's, the Chinese first developed ephedrin for its medicinal value. Since then the drug has evolved into what we recognise as modern day meth.
|Law enforcement in Thailand is proactively pursuing new avenues by which the drug's spreading use can be slowed, in this case, at its source. They are using a technique called high performance liquid chromatography (HPLC), based on the principle of separating the drug's enantiomers by way of diastereomeric derivatives. The enantiomers form complexes with chiral substances present in the chromatography column. The diastereomeric complexes have different chemical properties, and, therefore, are easily separable. The results reveal the starting materials and methods of synthesis used by the "meth factories" hidden deep in Thailand's jungle. Different manufacturers (there are thought to be as many as 17 major ones) employ different techniques to synthesize the drug.|
Classified as a stimulant (properties similar to adrenaline), methamphetamine
increases concentration, gives a false sense of superiority, and places the user
in a more or less euphoric state. However these effects come with great cost, a
come down, or "crash", which far
exceeds the good feelings and stamina felt initially: severe depression, chronic
hallucinations, irritability, and severe paranoia, to name only a few. Driven by
the irresistable addictiveness of the drug, stemming largely from the need to
avoid the eventual crash, meth's use is strongly established in the Western
United States and is quickly pushing east. Perhaps with a unified effort of
improved education, coupled with a stronger counter offensive against its
guerrilla-style mass production, this drug may someday witness its own "crash."
Pertinent Text References
Chapter 19. Amines
Chapter 5.16B. Chromatographic Resolution of Enantiomers
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Question 1: The Thai forensic scientists used High Performance Liquid Chromatography to identify the enantiomers present in the racemic methamphetamine mixtures that constituted the confiscated drug samples. Is this the most effective test for this purpose? Would other methods of analysis, such as Gas Chromatography, be useful as well?
Question 2: How many stereoisomers does methamphetamine have? Draw every isomer, labeling the chiral center(s) with an R/S designation.
Question 3: The methamphetamine producers in Thailand would most likely use ephedrine (and its synthetic stereoisomer, psuedo-ephedrine) as a starting material. How would the composition of the starting materials, in regards to stereochemistry, affect the end product, and thus the results of the chromatography test?
Question 4: In what other ways might the drug samples from separate manufacturers differ? What about impurities? What analysis methods would be best suited for identifying any foreign compounds? Where might these substances enter during the synthesis process? What purpose would they serve, if any?
Question 5: In the 16th century, Western imperialism brought diseases
to South-East Asia that decimated the native population, due to the region's
lack of exposure to European pathogens. Is the 20th century's methamphetamine
epidemic comparable to the disaster of the past? Who bears the responsibility
for this latest outbreak? The destabilized political situation of the third
world or the inescapable deluge of Western technological influence? Regardless
of fault, this tragic situation must be rectified. On whose shoulders does this