Hello again! In this installment, we’re going to get down to brass tacks with methamphetamine synthesis. Season one of Breaking Bad opens with Walt cooking meth in a run-down RV with his partner Jesse. I had to do a little “research” to refresh my memory about the process they claimed to use.
Jesse and Walt began their meth making operation by converting pseudoephedrine to methamphetamine. Commercially available pseudoephedrine (PSE), often known as Sudafed, is generally sold over-the-counter in boxes of 24, each tablet containing 30 milligrams of the active ingredient. In recent years, PSE has been phased out, in favor of
phenylephedrine phenylephrine, a compound with similar decongestant properties, but one which cannot be easily modified to make methamphetamine.
Remember last time when I talked about the two enantiomers of methamphetamine? When making meth, stereochemistry is important and we only want the dextrorotary enantiomer because the levorotary enantiomer is not as potent of a stimulant. Pseudoephedrine makes for a convenient starting point because it is already dextrorotary. You’ll notice pseudo and methamphetamine look very similar. In fact, the only difference is that -OH group we need to get rid of. Fortunately (or unfortunately), a simple, one-step process called reduction does just that, yielding enantiomerically pure d-methamphetamine. All you need is some red phosphorous, hydroiodic acid, some solvent, and a blatant disregard for your personal safety.
On a small scale, this method was favored because the materials needed are all readily available, and fairly inexpensive. The difficulty, as Walt and Jesse discussed, was scalability. Each box of PSE will yield only about 600 milligrams of methamphetamine, but purchasing fifty boxes of Sudafed from your local Walgreens is sure to attract some attention. To give you an idea about how little that is, consider a heavy meth user may use as much as 1000 milligrams each day. Not to mention the reaction will generate deadly phosphine gas, and can spontaneously ignite.
From that lengthy list of drawbacks, it’s no wonder Walt began to look for an alternative method of making meth. He later settled on a synthetic route involving phenyl-2-propanone, referred to as “P2P” in illicit drug manufacturing. So check back next time, when I’ll be discussing the famous P2P cook, producing Walt’s signature blue meth.