THE ELEMENT
The chemistry of cocaine While we are surrounded by constant conversations about drugs and their dangers, we rarely consider how they have come about and what effect they have on us. Consider the class A drug cocaine holding second place on the list of the most commonly used illegal drugs in the world. Whilst you may know about its white powder appearance and possibly a little about its effects - do you know what it actually is, or why it even holds that amount of power upon such a large number of humans? The beauty about chemistry is that it is all around us, and in everything. So, by taking such a commonly known yet confusing concept of illegal drugs and actually learning about the science behind it, we can clear up some misconceptions about it, what it does to you, and how we test for it. Hopefully, this will make you never want to go near it! Cocaine, or its IUPAC name: methyl (1R,2R,3S,5S)-3-(benzoyloxy)-8methyl-8-azabicyclo[3.2.1] octane-2carboxylate, is a strong stimulant made from coca leaves from one of the four species of plant in the Erythroxylaceae family. Its chemical formula is C17H21NO4 and it is what is known as a tropane alkaloid. This sounds complicated, but it is just explaining that it belongs to a class of alkaloids and secondary metabolites and has a tropane ring in its chemical 18
structure. To understand this, we need to break it down - alkaloids are naturally occurring organic compounds containing at least one nitrogen atom, secondary metabolites are organic compounds produced by bacteria, fungi or plants that are not used in their normal processes and a tropane ring just refers to the bonding of the compounds! See, not complicated, just unfamiliar. As you now know, cocaine is actually naturally occurring. So, how was it found? Three thousand years BC, ancient Incas in the Andes chewed coca leaves, because the coca bush grows wild there. The bush makes cocaine from the amino acid Lglutamine as a protection mechanism to stop insect predators from eating it, and studies show that its leaves contain around 0.3-0.7% cocaine. The ancient Incas chewed coca leaves in order to get their hearts racing and to make their breathing faster, getting more oxygen into their bodies, in order to counter the effect of living in the mountains. Nowadays, cocaine users don’t actually chew leaves 'thanks' to the work of a few chemists, starting with Heinrich Wackenroder, who was a German pharmaceutical chemist that was able to produce an extract of the active ingredient in the coca leaves. He did this by creating a solution with 84% ethanol and 14% water producing a solution that reacted with isinglass (purified gelatin) solution and iron (III) chloride - so we weren’t quite there yet. Two years later, Friedrich Gaedecke was able to evaporate an aqueous extract of the leaves, and
