Addition of Amine Derivatives

Concept: Concept: Ammonia Derivatives

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Video Transcript

In this video, we’re going to discuss all the different things that you can make when you react an ammonia derivative with a carbonyl.
At this point you should feel pretty comfortable with the reaction of ammonia with a carbonyl. We know that in the acidic environment, you add ammonia to a carbonyl and you're going to get it an imine, nitrogen double bond carbon. Looks like a carbonyl except it’s a nitrogen. What would happen if instead of reacting with NH3, you take out one of the Hs, so NH2 and you replace it with something else. Let's say you replace it with another amine. Then what would happen? This is where you get your imine derivatives. Ammonia derivatives are going to yield what we can call in general imine derivatives.
Because your imine derivatives all look exactly like imine except that they just have different functional groups coming off of the nitrogen. I would commit these to memory if I were you because they're functional groups you should know and you never know if your professor mixes it up and instead of giving you a normal amine gives you hydrazine.
Then what would happen? Hydrazine is the name of NH2 with another any NH2. When hydrazine reacts with a carbonyl in an acidic environment, it makes hydrazine. Damn, that's confusing. Hydrazine goes to hydrazone. It makes sense. The names are super similar but make sure that you don't mix up the two. One easy way to think about it is that hydrazine and ketone make hydrazone. Hydrazine would be the mixture of both. What if you reacted with an NH2 and an OH? That’s called a hydroxylamine and that's going to give you functional group called an oxime. An oxime would be an imine with an OH coming off of the top. Finally, if you were to take a hydrazine but put a phenol on it, that's a phenylhydrazine. Phenylhydrazine is going to yield phenylhydrazone when you react it with ketone.
These are all different combinations that all follow the exact same mechanism as an imine addition except that they're just derivatives of an amine that reacts to make a derivative of the imine as a product. Now, I’m giving you a problem down here. Go ahead and see what you get. See if you can figure out how to react this big molecule with ketone and then I'll show you the answer.

Concept: Example: Brady's Reagent

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Video Transcript

So there was a lot going on on that benzene molecule but there was only one part of it that could react with the ketone and that was the hydrazine so this is just a derivative of hydrazine. In fact this molecule is actually it's called 2, 4 DNP and it's actually used as Brady's test so this is a molecule that you might actually use in a chemistry lab this semester because it's a very famous test to test for ketones. What happens is that when you make the phenylhydrazone product that phenylhydrazone will precipitate out of the solution and it usually precipitates like a yellow, orange or red colour.

If you get that precipitate you have a ketone present. So this is actually a test that's used to detect ketones. Let's see what the phenylhydrazone product would look like. Well we know that I mean obviously I'm not going to draw the whole mechanism because that's not what this question asking, just asking to predict the product, so I would go ahead and I would draw me emine but I need to attach the hydrazone part in fact it's going to be a phenylhydrazone. So I'm going to add N H, let's see what else is attached to it well we've got a benzene ring and that benzene ring has 2 nitrile groups so let's add those, N O 2, N O 2 and that would be it, that's our molecule.

So this is basically a phenylhydrazone, right? Phenylhydrazone and in fact it's a 2,4-dinitrophenylhydrazone because this is the 2,4-dinitro part. 2 and 4. So do you think you can figure out where the name comes from? It's 2,4-dinitrophenylhydrazone so that's why it's called 2, 4 DNP. It's a great example of an emine derivative and it's actually a reaction that you might see later this semester so if it comes up, you'll say hey I learned that clutch. Maybe you can tell your lab partner so that they'll know about clutch too and more people would know about us. Awesome, alright so let's move on to the next topic.