Gabriel Synthesis

Let's talk about a really efficient way to make primary means. And that's through the Gabriel synthesis. So, guys, the Gabriel synthesis is going to use a really weird looking molecule called potassium thalidomide. Now, I know that's like a lot of continents at the beginning, you could kind of get jumbled up there. But just consider the pH. Almost to be silent. It's Salome where it's like, I don't know you gotta You gotta move your lips a little bit weird on that one. Um, Anyway, the point here, being that you need to go to recognize this molecule, not necessarily draw it from scratch. Now, the potassium thalidomide is a secondary die. Am I that can yield primary means in much better yield. Now, obviously, um, I'm talking about something that we haven't mentioned yet and much better yields in respect to what? What? Is it better at making primary means, you know? Then then what's the other reaction that we're comparing it to? What I'm talking about here is ah mean alc elation. So if you haven't watched this video yet, it's fine, but basically amino population and Gabriel synthesis kind of our compare and contrast because They're two different ways to make primary means. And one of them is very inefficient amino population. Whereas Gabriel synthesis is much more efficient. If you haven't watched a me inoculation yet, then I mean, you can go ahead and review it, but just letting you know that's what I'm referring to. Okay, so this is gonna be really are ideal way to make specific primary means of our choosing. So what you do is you take your potassium Salome or just thala might in general, and you're gonna use three re agents you're gonna use K O H. We're gonna use and alcohol. He lied. So I'm gonna put here a primary alcohol. He lied. That's gonna become important in a second. So I'm gonna put here are ex primary alcohol. Hey, lad. And then finally, we're gonna use hydrazine. So it's N h two n. H two. That's called hydrazine. Okay. And effectively, what winds up happening is that these all sort of like their own purpose. Okay, the k o. H. Is going to turn deep protein ate the nitrogen. Okay, And it's gonna turn the thalidomide into what we call potassium Saleh mind. Okay, So, potassium Salomon would actually be what it's called after the first step. So it have an n negative K positive. Okay, now, this happens to be an excellent nuclear file, because if you think about it and negative, that's one of the strongest basis that there are that there is. So it's gonna be pretty good at de protein eating stuff, attacking stuff, etcetera. So I'm gonna put here strong nuclear file. Okay? What's great about that is that now I can react this with an alcohol. Hey, Lights, let's say a primary alcohol. Hey, lied like, here we go. Um, you know, a three carbon alcohol. Hey, lied. And what we can do, guys, is just a s and two. So this is just another s and two mechanism that you need to know. You can never forget the backside attack. So via s. And two, we can do a backside attack kick out the chlorine. What I wind up getting is I wind up getting and our groups now, whatever our group that Waas, let's just go ahead and draw three carbon chain there. But we've got a problem. We've got this great. Our group on the nitrogen eventually The goal of this is to release the nitrogen from the Salam. I'd I want to completely get rid of the fallow mine and just release this nitrogen. Send it off the solution. That's my product. But how do I unlock the nitrogen from the rest of the molecule guys? That's where the hydrazine comes in. And that's gonna be the complicated part of this mechanism. So I'm just gonna put here plus end to H four, right? That's the molecular formula for hydrazine. I'm sorry. My head's in the way. So just plus n to H four and what that's eventually going to yield is a product is this and with my three carbon chain, but now has two hydrogen. Okay, maybe thinking is that hydrazine to protein ate? Well, yes, it protein it's, but it also serves to completely unlock it from the fallow mine. How does that happen? We're gonna go to the next video I'm gonna teach you as the full mechanism so that you guys will not only have this is like the shortened version which should be sufficient for most applications if you just want to know how the reaction's gonna work. But if you're asked to give the full mechanism that we're gonna do in the next video, So let's go ahead and scroll down and do the full mechanism.

Alright, guys. So for this mechanism, remember that there's three steps. There's the Ko HD protein ating the nitrogen of the Salome to make the potassium thalidomide. Then there's an S and two backside of attack that happens with the primary mean And then there's the hydrazine reaction that's gonna follow a mechanism that we're gonna talk about now. I really just want to focus on the third step here because the first two we already did on the top of the page. So here I just want to focus on the third step, which is what happens when you introduce hydrazine to the nitrogen that now has an R group. Now, keep in mind for my reaction on top. I think I was using a pro Paul group, but this will be true of any our group that's attached to the nitrogen. What happens next? Somehow we need to get this nitrogen completely off of the Salomon. Well, this is where the hydrazine kicks in. So, guys, the Hydra gene is very nuclear, Philip because it's got these two nitrogen that both have lone pairs. Right on top of that, Saleh might. Even though it's a weird molecule, it has some structures we've seen before. For example, it's a di am. It's that means it can react. This carbon carbon can react like any amad would in the presence of a nuclear file. And remember, that am It's if you haven't gone to the section yet. It's fine, but just letting you know that Amit are considered carb oxalic acid derivatives, meaning that they follow a mechanism called nuclear feel like a seal substitution or n a s. Okay, this is the topic of several videos that I have. So if you want to brush up on N a s, feel free to go through those videos and then you learn about how other Ammons react in similar situations. So anyway, guys, how is this gonna look like? Well, your nitrogen is going to do in any s reaction forming a Tetra Hydro Intermediate. So what are Tetrahedron Intermediate will look like is like this. Oh, negative. Now attached to N h two n. H two. Now notice this is gonna be positive because now there's an extra bond to that nitrogen. Then I've got the rest of the ring and are and my carbon Neil. It's getting ugly and I'm closing out the ring. Okay, So, guys, this is the first step. Now, the second step is that we wanted to a proton transfer because this nitrogen is actually gonna stay in place. Whereas the nitrogen with our group, I'm trying to get it to leave. So this nitrogen is gonna grab hydrogen from that leadership, and we're gonna wind up getting is I'm just gonna right here. Proton transfer. Oh, pro time transfer after we get that proton transfer our molecule now look like this and are h And I'm sorry. This should be still a teacher. He troll Intermediate O negative N h and H two Perfect. Okay. And we've got ah, formal charge. Mhm positive. Right there on the nitrogen. Okay, so now in this next step, it's gonna be the second part of any s you kick out believing Group. So I would reform my double bond, kick out my end, and what I get now is something looks like this double bond attached to N. H. And each to and then what I have done here Double bond attached toe en our with an H. And that's neutral now. Okay, so hopefully that's making sense so far. Um, now, keep in mind that are is the important part. This is the part that I'm trying to release. Remember? This is gonna be end are that's my amine that I'm trying to get out of here. Well, guys, the next step is just gonna be times to It's gonna be the now, basically, this whole reaction that I just drew happens twice. Okay, so one more time, what you're gonna get is that now this nitrogen attacks and forms the tetrahedron Intermediate, eventually kicking out the nitrogen. So what, we're gonna wind up getting and doing a proton transfer. So eventually, what you wind up getting is something. Looks like that. Looks like this. Carbonell nitrogen, nitrogen, carbon eel. And these nitrogen is now have one h each and you will be saying, Well, why do they only have one h one before the hydrazine had to? H is because they did two proton transfers. But the guys, the really important part isn't that part. What I really care about is this that I'm gonna have now end h two, because we had two Proton transfers and our this is the product I care about because this is my primary, amine and guys. This is a very consistent, easy way to make primary means without having to worry about Polly ALC elation without having to worry about mixture of products. The Gabriel synthesis, even though it uses a weird molecule. The whole point is that we can now release the primary mean really of our choosing. And I don't have to worry about cross products or any kind of weird Polly Alc elated products as opposed to some other forms of making primary means that are less efficient. Alright, guys. So that's it for that mechanism. Let's close out this video.