Show how the following compounds can be synthesized from benze...

Question

Show how the following compounds can be synthesized from benzene:

b. m-chloroethylbenzene

Accepted Answer

Hey, everyone and welcome back, show how the following compound can be prepared using the given starting material and any necessary regions, the starting material is benzene and we are producing one chloro three prop benzene. Now, let's think about this problem. We're adding two substituent to benzene plural group that is Oro and Parra directing. And we are adding an group, our propal group which is also an or and para directing in addition to that chloral group is deactivating. So we have to keep it in mind in our sentences. OK. So if they are directing to or and power positions, basically, that means we cannot add any of them at first, right? Because adding one of them will direct the other one to orto positions. So we are going to label or two positions with respect to chlorine and power position with respect to chlorine. And similarly, those exact positions correspond to an group. So what is the way for us to avoid that? We can actually think of adding a carbon needle group first such as a key zone, right? If we add our carbon group, it will be meta directing. So that means we can essentially, first of all, perform the craft as which will allow us to sufficiently direct our chloral group to the metas position. So let's see how that works. We are starting with Benzine and our goal is to perform the Friedel crafts. As let's remember the regions needed for that. If we want to add a carbonyl group, we are going to use an acid chloride. So our first step will be to add 1 to 3 carbon atoms as our side chain. So that means we're going to use our Carboni group with three carbon atoms. So we have 123, right? And then because we need to use an acid chloride, we're going to add chlorine on the other side of our Carboni group. Now, we want to make sure that we're also using aluminum chloride as our catalyst so that we can form our electro file easily. And in the second step, we want to use an excess amount of water and we will soon understand why. So the product that we are forming in the first reaction corresponds to the benzene ring and then we are adding our Carboni group so that our carbon gets bonded to the carbel group upon the removal of chlorine. So I got our carbonyl group and basically that's how we get our key zone. Now, specifically the reason why an excess amount of water is needed is because aluminum chloride can then bond to oxygen, right. Oxygen has lone pairs and aluminum has a pre orbital. So we want to use an excess amount of water to prevent that and isolate our product well done. And now we know that our carbon group is metal directing. So we are going to label our math positions. It doesn't matter which one you consider they're equivalent with respect to the line of symmetry. And we want to add our chloro substituent. So we are performing our chlorination and to do that, we want to use chlorine in the presence of iron three chloride, right, just as defined by the electro filic aromatic substitution. We want to use an appropriate catalyst. We already know that our carbon group is meta directing. So that means in this reaction, we are going to form our chlorinated product. OK. Well done. So now the question is how do we get our prop group instead of our carbon group? We essentially want to get rid of our CEO and replace it with AC two group. So that means we can redo it using the Wolf Kisner reduction. So for the very final step, we want to recall the Wolf Kushner reduction, which requires us to use several compounds or specifically more appropriately, we could say that this would be hydro. So that would be H two and N H two or basically end to each four if you wish, right? And we also want to use an acre a solution of a strong base hydroxide in the presence of heat. So these regions will allow us to perform the final reduction stop. And in that step, we are going to get rid of our carbonyl group and we are going to get our desired alkyl group. Simply speaking, we can just take our structure and true the required propane chain because now we are reducing our carbon group and we're getting our chain well done. So we got our synthesis scheme and we are going to label it as our final answer. The first step is the Friedel Craft isolation, right? We are going to use water afterwards to isolate our keto. Then our ketone is meta erecting and we are going to use Electromatic substitution with chlorine in the presence of iron three chloride to add our chloral group. And the final step is the Wolf Kisner reduction to form the final kiel group out of the Carbel group. Thank you for watching and I hope to see you in the next video.

Show how the following compounds can be synthesized from benzene:
b. m-chloroethylbenzene

Key Concepts

Electrophilic Aromatic Substitution (EAS)

Regioselectivity in Substitution Reactions

Chlorination of Aromatic Compounds

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