- "The methylamine keeps flowing, no matter what. We are not ramping down. We're just getting started. Nothing stops this train."
- ―Walter White
Methylamine (CH3NH2) is an organic compound. The gas is a derivative of ammonia, but with one H atom replaced by a methyl group. It is the simplest primary amine. It is sold as a solution in methanol, ethanol, THF, and water, or as the anhydrous gas in pressurized metal containers.
In Breaking Bad, methylamine is used by Walter White and Jesse Pinkman as they use reductive amination of phenylacetone (P2P) to yield methamphetamine - a process they devised to circumvent the need to buy pseudoephedrine. This P2P and methylamine-based cook produces what became infamously known as "Blue Sky" in the American southwest. Though methylamine-based methamphetamine was traditionally considered less refined version next to its pseudoephedrine-based counterpart (Hank Schrader describing it as "biker meth"), Walt's chemistry expertise helped eliminate any differences in quality between the two methods.
During the course of the series, methylamine is not synthesized by either Walter White or Jesse Pinkman, and thus the search for methylamine for use as a methamphetamine precursor is a large plot point throughout the series. For example, Walt and Jesse once stole methylamine from a warehouse, and, on a later date, from a freight train. The source of methylamine during their cook sessions in the superlab was Golden Moth Chemical.
Methylamine is prepared commercially by the reaction of ammonia with methanol in the presence of a silicoaluminate catalyst. Dimethylamine and trimethylamine are coproduced; the reaction kinetics and reactant ratios determine the ratio of the three products. The product most favoured by the reaction kinetics is trimethylamine.
- CH3OH + NH3 → CH3NH2 + H2O
In this way, more than 400M kg are produced annually.
In the laboratory, methylamine hydrochloride is readily prepared by treating formaldehyde with ammonium chloride.
- NH4Cl + H2CO → [CH2=NH2]Cl + H2O
- [CH2=NH2]Cl + H2CO + H2O → [CH3NH3]Cl + HCOOH
The colourless hydrochloride salt can be converted to the amine by the addition of strong base, like NaOH:
[CH3NH3]Cl + NaOH → CH3NH2 + NaCl + H2O
After realizing they couldn't find the supplies needed to continue the production of meth, Walter White and Jesse Pinkman decide to steal a barrel of methylamine from a lab in order to be able to continue ("A No-Rough-Stuff-Type Deal").
Walt and Jesse continue to use the barrel for cooking sessions, after Saul Goodman gives Walt an advice to cook meth "while the sun still shines," Walt and Jesse spend 2 days cooking in the desert, using most of the methylamine inside the barrel.
Season 3Walt is forced to destroy the RV, since Hank Schrader's investigation led him to find the RV and almost discover that Walt is behind the production of the Blue Sky. The RV is destroyed in a junkyard, and it is assumed that the barrel of methylamine was destroyed with it.
Season 5Walt, Jesse, and Saul are talking about how they are going to find more methylamine, realizing they need it prior to beginning to cook again. Later, it is revealed that Lydia Rodarte-Quayle provided Gus with methylamine in the past. Mike Ehrmantraut asks Lydia if she can still get some methlyamine and Jesse is sent to the Madrigal warehouse to get a barrel. Lydia and Jesse discover that the barrel had a bug from the DEA, preventing them from using it, but Lydia gives them another plan to steal methylamine from a freight train.
Walt, Jesse and Todd Alquist are able to steal methylamine from the train, and it is kept inside a tank in the headquarters of Vamonos Pest. At one point, Jesse and Mike decided to sell their part of the methylamine to another dealer, so Walt hid the tank inside the Car Wash he owns, and convinced Mike to let him keep using the methylamine for production.