☢ Deux profs de chimie en prison !? ☢ Quelle chimie dans Breaking Bad (2/n) ?

☢ Deux profs de chimie en prison !? ☢ Quelle chimie dans Breaking Bad (2/n) ?

What? 2 chemistry teachers arrested for making meth at university in … Arkansas? ♪ “Breaking Bad” credits ♪ Hello chemists! Okay, today, a little special video. We’ll talk about : news, current events, drugs, organic synthesis. So you may have heard of it on November 15, we have 2 chemistry colleagues who were arrested in an American state, Arkansas, because they are suspected of synthesizing a very very hard drug, (S) N-methyl-1-phenyl-
propan-2-amine. So you probably know it because in fact her known name is methamphetamine. So methamphetamine chemically, it’s very close to amphetamine. There is just an additionnal methyl group, so one CH₃: 1 carbon and 3 more hydrogens. But one CH₃ changes everything, because this drug is … much harder, much more devastating than amphetamine. So let’s be clear chemists, this video is not intended to judge those 2 teachers. Besides, they haven’t gone to court yet, so uh … Who knows. What interests us is the chemistry behind it. So, little tutorial for methamphetamine. No, seriously we’re just going to do it on paper, because I don’t want to end up in jail, and obviously I will not show you … how to make meth, but … We’re going to revise organic chemistry a little bit. Come on, let’s go, fasten your belts. Let’s go. Good chemists, let’s start by talking about the methamphetamine molecule. In fact, this molecule exists in 2 forms, which are mirror images of each other, a bit like your hands: my left hand is the mirror image of my right hand but I can’t overlay them. In short, without going into detail, let’s say that I represent these 2 molecules, placing all the hydrocarbon part
in the plane of your screen. The nitrogen atom can go: either backwards or forwards. And it turns out that these 2 molecules called enantiomers do not have the same biological properties. For the… cook who … seeks to synthesize his drug, methamphetamine one must get only one of these 2 molecules, and it turns out that this is where the nitrogen atom on your screen, is positioned backwards. The other molecule will not have the desired activity, and that is very important for what follows. So what betrayed our 2 colleagues? Well, we measured particularly high levels of benzyl chloride in their laboratory. And benzyl chloride, it can be used to synthesize a lot of stuff, but also methamphetamine. Good, chemists, before talking about … the famous synthesis that our colleagues could have made from benzyl chloride, I already suggest that we resume the 2 syntheses presented in the Breaking Bad series. So, the 1st synthesis, it takes place from pseudoephedrine. Pseudoephedrine, I put the diagram here, it’s this molecule, and you can get methamphetamine by reduction. I had already presented this synthesis in the recent episode which I made on Breaking Bad and the reduction will be done thanks to the red phosphorus, in the presence of iodine. And besides, we had seen that the scene with phosphine gas, it was phony, etc. I draw your attention to a very important point: the advantage of synthesis with pseudoephedrine, is that the carbon that carries the nitrogen atom is already in the right configuration That is to say, you see
the nitrogen atom on your screen, it’s backwards, and suddenly, it will ask
less work for chemists. Finally, we just have to reduce an alcohol group. So it’s a pretty simple … synthesis. It’s … it’s art! No, it’s chemistry, uh … very basic. Walt, carbon 1, it carries the alcohol group, and carbon 2, it carries the amine group. So these are 2 asymmetric carbons that we have in pseudoephedrine. Do you have another question? Well in this synthesis with pseudoephedrine, the alcohol group is reduced to an alkane, and we preserve the amine. so very clearly, we eliminate asymmetric carbon n° 1 and we keep asymmetric carbon n° 2. That’s it, chemists, for the 1st synthesis. So I hope you understand it, the big advantage of synthesis with pseudoephedrine, is that we already have carbon who has the right configuration with the nitrogen atom well positioned, and which allows to arrive only
to the right form of methamphetamine Now in the series if you remember correctly, at one point, well they have they have more pseudoephedrine They therefore turn to a second synthetic route from P2P. P2P is phenyl-2-propanone. So to make this synthesis, we’re going to do what’s called a reductive amination. So now how does reductive amination work? I’ll make it short, but basically it is done in 2 steps: in a 1st step, we will make an addition methylamine on P2P. So 2-phenyl-propanone which
will lead us to an imine. Besides, remember in the series,
at least 2 times, They have to steal enough stocks
important methylamine, precisely. And then this imine,
we’re going to reduce it to a secondary amine. So there are lots of possible conditions for reduction there I do not go into detail, but this synthesis will pose a problem. because in fact when reducing you are going to get the 2 enantiomers of methamphetamine, so the 2 forms I told you about at the beginning. and that’s not interesting because we have: one of the forms that has the desired biological activity, but the other of the forms which is useless. So finally,
it’s like we have 50% of loss. And Walt, he talks about this problem elsewhere. Listen to him. So technically, he said something stupid. In reality, we need a stereoselective synthesis here and not stereospecific. But you know what ? I want to detail this synthesis a little more so, for those who want to go further in chemistry or higher education students,
I remind you that I have a secondary channel, so I’m making a video where I’m detailing the mechanism a little bit, reductive amination, and I explain a little better to you steroselectivity / sterospecificity. I close the parenthesis. And we make a little summary: the reductive amination, uh … interesting synthesis. But we have to add … uh … a technique for have a stereoselective synthesis and therefore get the right molecule at the end. I think that with regard to the 2 syntheses of the Breaking Bad series, we’re pretty good, and now I suggest you come back, uh … to the problem of our 2 colleagues and their benzyl chloride. Well chemists, now we have benzyl chloride. Chloride … Benzyl chloride. Benzyl chloride. And from benzyl chloride, we have to switch to methamphetamine. Bah already what I propose: we’re not going to break our heads too much. Benzyl chloride,
we just have to convert it to P2P, and as we already know how to transform P2P methamphetamine by reductive amination, it’s over. Now chemistry students, I count on you: to pause there, and suggest me in the comments,
please play the game. Suggest in the comments a P2P synthesis route from benzyl chloride. Of course, several answers are possible. Okay, while you are making your proposals, huh, I’m going to read a little. Ah well, NADH / NAD + co-enzyme. We’re going to talk about it chemists soon, huh. Okay, is that good? You made me your proposals
in the comments? I will read them carefully. So. How can we do ? Well, I want to tell you: we want to create a carbon-carbon bond, since we need to lengthen the carbon chain. For that, normally, you should know that one of the most effective means, – at least within the framework of current higher education programs – is to go through a mixed organomagnesium. We offer transform benzyl chloride in benzylmagnesium chloride, and then after that we can make it react cold with an equivalent of acetic anhydride, and normally we come to P2P. Ok students, for synthesis with acetic anhydride I explain it to you on my secondary channel. And you will see that in fact: it’s not on the agenda,
but it should be there because, here it is: it’s interesting. Uh … well, it’s time to conclude. I want to say that like any self-respecting chemistry teacher, I’m a huge fan of the Breaking Bad series, but however, I don’t want to start doing meth. I wanted to wish you all, well a very happy new year 2020. Don’t take too many good resolutions because anyway, we never stick to them. Don’t drug yourself, that’s it. And then as always, thank you again … for your confidence, huh. Thanks to everyone who, who follow the adventures of Blablareau at the lab, remember if you want chemistry more daily, you can follow me on Instagram, Facebook, Twitter, and for those who want to support the creation of our videos, You can find us on Tipee, and UTip, And as for me, I tell you soon … in the lab !


18 thoughts on “☢ Deux profs de chimie en prison !? ☢ Quelle chimie dans Breaking Bad (2/n) ?”

  • Je vous donne ce lien d'une vidéo informative sur les flics lors d'une perquisition de drogues. Un poil hors sujet mais je tenais à partager (en plus c'est drôle). https://youtu.be/j5aOQ7HAG4I

  • pour la synthèse de p2p : synthèse magnésienne (benzène-C-MgCl + éthanal) puis oxydation du groupement alcool (réactifs de Jones ou Sarret)

  • vivien martinan says:

    J'ai adoré !
    Ps: J'ai absolument rien compris, mais ça fait classe de dire, "Ouais, je regarde des vidéos sur la chimie". 🙂

  • Blablareau au labo says:

    Dis-moi en commentaires quelles scènes de film ou série tu souhaites que je décrypte !

    Pour ceux qui souhaitent plus de détails, n’oubliez pas d’aller voir les liens en description (vidéos de la chaîne secondaire notamment).

  • Salut! Super vidéo pour se détendre sans oublier que les partiels c'est après demain 🙂
    Bon jsuis pas au point en orga ahah
    C'est quel niveau à peu près ? (Je suis en L2 a la fac)

  • Je me disais que je devais vraiment être éclaté pour rien comprendre …
    Jusqu'à ce que je réalise que c'était au programme de SPÉ et non de SUP x)

  • Sciencationelle says:

    Il a été montré que la deoxygénation par cette méthode HI/P faisait passer potentiellement par une methylaziridine, donc le centre stereogène dont tu parles ici n'est pas conservé. L'acide iodhydrique peut acidifier l'hydroxyle et conduire à une élimination de l'eau et l'azote peut contribuer à ce départ d'eau. C'est la majeur raison pour laquelle la méthamphétamine qui circule n'est pas énantiopure bien que la pseudo-ephedrine le soit.

    (j'peux te filer la source, mais pas en publique)

  • Salut. Je n'ai rien compris à ta vidéo, donc je voulais savoir si pour la comprendre, c'était mieux d'avoir vu toutes les vidéos de ta chaîne avant ou si il faut tout simplement des bonnes connaissances en ' chimie (désolé pour mon ignorance, je suis plus calé en physique…)

  • argh, la chimie orga de première année est un peu limite pour piger. La biochimie aucun soucis mais là je suis à la rue. (nostalgie d'avoir maitrisé la synthèse de la myéline…)

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