Breaking down the chemistry in ‘Breaking Bad’

Unless you’ve been living underneath a rock for the past decade or so, then you have been well-acquainted with the classic modern tale of AMC’s “Breaking Bad,” the story of Walter White — cancer-stricken husband, father and high school chemistry teacher — who is willing to go to any (and every) length imaginable to provide for his family if he should succumb to his cancer.

Thanks to the University of Oklahoma organic chemistry professor Dr. Donna Nelson, the series has been hailed for its high level of scientific accuracy and attention to detail, something that has been deeply appreciated by the STEM community after the sciences could be so grossly simplified or exaggerated at times in pop culture.

However, exactly how accurate is Vince Gilligan and the rest of the minds behind Breaking Bad when it comes to the actual chemistry that is the catalyst (pun intended) for the story progression? Moreover, what’s the chemistry behind all of the on-screen magic we see? Let’s take a look at a couple of examples.  

(Note: In absolutely no way does any of this article endorse actually performing the “experiments” and science performed on the show. This is simply an investigation of the scientific accuracy that we saw on the screen.)

The product

So anyone who has seen this show knows the main product that Walter uses his chemistry expertise to produce: (S)-N-methyl-1-phenyl-propane-2-amine, also known as N-methylamphetamine, popularly referred to as “crystal meth.” At first, Walt goes about the synthesis using pseudoephedrine, a plant-based phenyl ethylamine alkaloid that is usually found in cold medicine.

The synthesis involved an extraction of (S)-pseudophedrine from that cold medicine, then a reduction (possibly using red phosphorous) to get the stereospecific (S)-N-methamphetamine.

However, Walt and his partner-in-crime, Jesse Pinkman, realized that relying on buying cold medicine for their base reagents was not feasible nor sustainable.

This is when Walt needs to use his chemistry knowledge for an alternate route of synthesis, the “Blue-Meth synthesis,” where he then uses phenyl acetic acid and acetic acid, under extremely high temperatures and reduced with thorium oxide, to get phenylacetone. The phenylacetone is then introduced to methylamine to get N-methylimine, which Chemistry Views points out can be done in either a multistep or one-pot reaction. A reductive amination is then done on the N-methylimine, possibly using mercury aluminium amalgam to get N-methamphetamine.

However, let’s look closely at the two products from the two routes of synthesis: (S)-N-methamphetamine versus N-methamphetamine. Obviously, the alternate “Blue-Meth synthesis” route yields a racemic mixture of products (S)/(R)-N-methyl methamphetamine. However, it is known that the human body reacts to different chemicals based on stereochemistry, i.e. if something is either (S) or (R). So how does Walt and Jesse solve this problem of stereospecificity? After all, there is no real indication from the show how the duo controls for stereochemistry in their product.

Good question, Walt.

However, it is pretty interesting to see how the two think of different routes of synthesis to get to the (allegedly) same product — just another example of the value in learning the many ways and different reagents one can use in their synthesis reactions to get to a desired product. (However, just make sure you use your chemistry knowledge for good and not for crime and evil!)

The mercury and the explosion

One of my favorite scenes in the entire series, Walt goes into Tuco’s office and outsmarts him by sneaking in extremely volatile and unstable fulminate of mercury, which Tuco mistakenly believes is crystal meth.  Walt throws a single crystal onto the floor of the office, and the resulting explosion is large enough to take out the floor of the building, and leaves the building in ruins, meanwhile everyone inside gathers their bearings while Walt is standing menacingly over everyone with an entire bag full of fulminate of mercury.

The explosion pathway, according to Jonathan Hare of the Royal Society of Chemistry, could be:

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In an extremely exothermic reaction, the formation of mercury vapors result from the impact, friction or heat from throwing the unstable fulminate of mercury onto the floor.

 

However, Hare points out that Walt’s crystals are way too big and unstable to simply carry around like Walt did without setting them off. Even in the unlikely event that he was able to prevent detonating them too early, the first explosion Walt causes by throwing the crystal on the floor and the subsequent shock wave would have surely detonated the rest in Walt’s bag. Also, that little dramatic exchange Tuco and Walt had after the latter played the proverbial chemical card up his sleeve? Well, according to Hare, that exchange in reality would have had to have been delayed for awhile, as the shock wave and explosion would have led them to be unable to hear for quite awhile.

Either way, it is interesting — and frankly, quite exciting — as a chemist to be able to spot the chemistry in “Breaking Bad,” and to be able to understand and explain some of the show’s most climactic scenes in the context of Walt and Jesse’s science.

Miko