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This is the answer to chapter 21, problem number 71, from the smith organic chemistry textbook.
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And this problem introduces celibrex or celicoxib, which is trade name celibrex.
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And we're asked to draw a stepwise mechanism for this reaction in the synthesis of the drug.
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And so this is a pretty serious mechanism.
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And i do just want to note before i begin, i'm going to be using the notation that i lay out here on this first page.
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So i'm going to be abbreviating the one phenyl ring with the methyl group as ar.
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And in the other molecule, i'll be abbreviating the whole sulfonamide group as ar prime.
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Okay.
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And hopefully that will make this much easier and faster to write.
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All right.
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So the first step of this mechanism, the hydrazine is going to attack this carbonyl here.
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These electrons will go up to the oxygen.
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And so after this first step, we are here.
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Okay.
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And so the nitrogen is now going to have a positive charge on it.
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And this oxygen is going to have three lone pairs and a negative charge.
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And so the next step is going to be a proton transfer.
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So we can just write proton transfer.
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And after that, we will be here.
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So that takes care of our charges.
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Okay.
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So from here, what needs to happen? and we are told in the problem that there is hcl in this reaction.
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So this alcohol is going to be protonated.
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So it's going to grab that acidic proton.
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So this oxygen now only has one lone pair, and it has three bonds, and so it has a positive charge.
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And so what can happen from here is the lone pair on this nitrogen can attack here to form a double bond.
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And this water is willing to leave.
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It's a good leaving group now that it's protonated, now that the alcohol is protonated.
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And so when that happens, we get to here.
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So i'm going to put the cf3 up here now.
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It's going to make this sort of easier to look at and work with.
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So here is our double bond to nitrogen.
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Nitrogen has this proton as well as the other nitrogen.
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And then that has the ar prime group on it.
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And so, of course, this nitrogen is going to have a positive charge.
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It has one too many bonds.
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Okay.
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And so the next thing that's going to happen is deprotonation there.
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And that is going to be accomplished by an equivalent of water.
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Okay.
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And so from here, what can happen is we're going to form our third ring...