Draw the product from reaction of the following substances wit...

Question

Draw the product from reaction of the following substances with (1) Br₂ and FeBr₃ and (2) SO₃ and H₂SO₄ catalyst (red=O):

(a)

(b)

Accepted Answer

All right. Hi, everyone. So this question says to predict the product or products that will form when the molecule shown below react with the following reagents. Part one. So three and H two. So four catalyst in part two C two and FEC three, the gray spheres are carbon, the white spheres are hydrogen, blue spheres are nitrogen and red spheres are oxygen. And here we have the two models on the screen here. So recall first and foremost, right, what types of reaction that we are dealing with in this case, what I'd like to point out here is that if you consider the models for parts A and B, both of them contain benzene rings because notice how in the center for both of them, we have a six carbon ring structure with three double bonds inside of the rink. So this indicates that we are going to be dealing with substituted derivatives of benzene. Now because benzene is an aromatic compound, then the two reactions we are working with for this question are examples of electro pilic aromatic substitution or E A for short, the first set of reagents listed with. So three and H two So four as a catalyst that if you recall is sulfur nation. And the second one with CL two and fecl three as a catalyst that is halogen Nation. But more specifically, it is chlorination because we are specifically adding chlorine onto the aromatic ring, therefore replacing a hydrogen from the ring in the process. So if I consider the model of the first structure, what I'll notice here is that there are two blue spheres on adjacent carbons, each of which have two white spheres. So because blue spheres represent nitrogen and white spheres represent hydrogen, I know that I have two amino groups or two NH two groups on adjacent carbons of my benzene rig. Now, when we consider the two different eas reactions, we have to consider how many possible locations there are or the substitution itself, right? The question is in how many possible places can the new substituent add itself to? And if we consider the structure of the first reagent, which is 12 diamo benzene, then even though we have four other carbons present in the benzene ring that are not substituted, two of them are equivalent to each other or rather there are two pairs of equivalent carbons when we consider the fact that there is an element of symmetry to the molecule itself, right? So we have two pairs of equivalent carbons in this case, one labeled A and one labeled B. So because of this right, both sulfur nation and chlorination can take place on those two positions. So we get two different products, but lets consider the second structure. We also have a benzene ring as discussed previously. But notice how attached to the blue spheres that represent nitrogen, we have two red spheres that represent oxygen. So this means that we have two nitro groups present in the molecule, abbreviated as no two and they happen to be on opposite carbons in the ring itself. So in this case, let's just go ahead and observe how the positions of substituents change how many equi equivalent positions there are. Once again, we have four uns substituted carbons. But notice how there are actually two planes of symmetry present in this molecule. One is vertical and the other is horizontal because of this, right, all four carbons in between the nitro groups are actually equivalent. So for both sulfur nation and chlorination, we would only get one product because all positions are equivalent, right? So substitution on either of them would not result in a different product. So with this, out of the way I can go ahead and scroll down to where I've mapped our solution already. But I've just, I just wanted to go ahead and clarify how to identify how many types of products you would expect to see starting off with the sulfur Nation reaction of R 12 diamo benzene. So in this case, I'm going to start by drawing my diamo benzene and as discussed previously, I'm going to go ahead and jog twice because there are two different positions in which my substituents can add themselves onto. So that's NH two and NH two. So now, as discussed previously, we have two different positions when it comes to our addition, right, our substitution, one of which is adjacent to one of our amino groups. So my sulfonic acid group or so three H would install itself in close proximity to the amino groups, whereas my other position is simply one carbon away. So here is our Sulfon Nation reaction. And now the question is our chlorination reaction. Now, the positions themselves are not going to change. But instead of adding a sulfonic acid group, we are simply adding an atom of chlorine onto either of the two positions. So one product has the chlorine adjacent to the amino groups and the other product has the chlorine, one carbon away from either of the amino groups. And last but not least is our 14 Di Nitro Benzi. Now, one for the nitrobenzene is only going to form one product of each due to the fact that there are two planes of symmetry present within it, right? So when it comes to suation to start us off, I'm going to first go ahead and draw my Diniro benzene because my nitro groups are going to stay intact, right. However, my one product is going to have a sulfonic acid group for sulfur nation adjacent to either of the nitro groups. Whereas my second product is going to be very similar in terms of the location of the substituent, right? But instead of adding a sulfonic acid group, I'm simply going to add a chlorine and there you have it, right. So here are all possible products for both reactions of both starting materials. So if you stuck around to the end of this video, thank you so very much for watching and I hope we found this helpful.

Draw the product from reaction of the following substances with (1) Br₂ and FeBr₃ and (2) SO₃ and H₂SO₄ catalyst (red=O):
(a) <IMAGE>
(b) <IMAGE>

Key Concepts

Electrophilic Aromatic Substitution

Sulfonation

Reaction Mechanism

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