Show how you would use an acid chloride as an intermediate to ...

Question

Show how you would use an acid chloride as an intermediate to synthesize

(b) phenyl propionate (CH₃CH₂COOPh) from propionic acid and phenol.

Accepted Answer

Hey everyone and welcome back to another video show how you would accomplish the following conversion through an acid chloride intermediate. Final benzoate from Ben's a weak acid and fennel, the starting material is an asset so we can throw our benzoate asset. That would be benzine ring bonded to a public silic acid group. That's benzoate acid. We are not going to worry about fennel. Let's visit this are starting material and fennel what corresponds to our region? And we are forming final bands await right, this is an ester. If you look at the suffix. So if we want to draw it, we are essentially going to replace that hydrant with a final substitution. That's what it says. So let's draw our benzene ring now our ester group. Oh, oh and bond our final ring over here because it says final benzoate. Okay, so we clearly see what kind of transformation we want to achieve. As the problem suggests, it's a huge hand for us that we want to turn our asset into an acid chloride. Let's recall how it's done. Whenever you have a curb oxalic asset, you can easily turn it into an acid chloride if you use vinyl chloride that will be S O C L T. This region essentially allows you to turn your always group within the car, broke cilic asset fragment into chlorine and this is where useful because acid chlorides are more activated and more reactive than car broke Cilic assets are. So this makes perfect sense. We are just going to redraw our fragment. But instead of having that old age, we are going to turn it into chlorine because that's what we're going to do in the first step. And now that we have our acid chloride, we want to form an ester out of it. And whenever acid chlorides react with alcohols, they can form esters. The alcohol that we have is fennel. Right? So it has an a wage group. So we can essentially classified as an alcohol in this case. Simple. Let's see what's happening here. If we use fennel as our region here. So let's indicate that in blue. For later reference, we're going to use that lone pair on oxygen and the lone pair on oxygen will essentially attack the electra Philip position. As we said, it's more activated now compared to assets. Now when we're forming this oxygen carbon bond, we're going to break the pi bond, turn this oxygen into a negatively charged oxygen, which later on will restore the pi bond, followed by the loss of the leaving group. So there's no necessity to draw the intermediate completely. We can just use that shorthand representation of this part of the mechanism. And here we are essentially getting our protein ated intermediate notice that we can see how it looks like. We can actually use this structure because this is pretty much what we expect to get notice how we still have our carbonell group. We're getting that oxygen bonded to that carbon. So this is exactly what we see. But that oxygen still has hydrogen bonded. So let's add it now because auction has three bonds, it has a form of positive charge. And we simply want to remove that proton to do that. We are going to use the chloride and are informed in the previous step. So the chloride and I and would essentially capture that proton. We would transfer these auction hydrogen electrons onto oxygen in the form of a lone pair. And this is how we get our final product. Indeed. Right. So that would be it. Now let's summarize our steps. First of all, let's label this whole synthesis scheme is our final answer because we have proposed a feasible synthesis. Let's keep in mind that this is our intermediate. So you may ignore it if you wish because it's just part of our mechanism where we just wanted to show how the D. Protein nation takes place. There is no additional reaction here. It just our intermediate that we d protein it. And now let's review everything. So we started with our asset as a problem suggests we are turning it into an acid chloride using final chloride. So we are replacing a wage with cl this asset Gloria is more reactive and therefore fennel comes in, attacks the electra Philip position. We are breaking and restoring our pi bond. We have the loss of the leaving group which is the chloride ion ion and this step we are forming our protein ated intermediate and then it's D protein aided by the chloride ion ion to form our Esther. Now, the only steps that you need to understand is that we have two separate reactions, starting with an acid using final chloride to turn our asset into an acid chloride and then the final reaction is that this acid chloride reacts with fennel to form the final product so you can skip this intermediate. It's just given for your own understanding. And now based on our analysis, the final answer to this multiple choice question is A. B. Thank you for watching and I will see in the next video.

Show how you would use an acid chloride as an intermediate to synthesize
(b) phenyl propionate (CH₃CH₂COOPh) from propionic acid and phenol.

Key Concepts

Acid Chlorides

Esterification Reaction

Nucleophilic Acyl Substitution

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