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Topic: Enamine Formation  (Read 6121 times)

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Offline Ariana

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Enamine Formation
« on: August 05, 2009, 02:10:29 PM »


I'm stuck right at the beginning for this question. I've tried to go through the similar mechanism of an enamine formation by reaction with an aldehyde/ketone, but obviously I can't take a proton from an alpha carbon since there is no hydrogen.

Any suggestions?

Offline sjb

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Re: Enamine Formation
« Reply #1 on: August 05, 2009, 02:33:32 PM »
You won't form an enamine from this reaction. Your reactant is not an aldehyde or ketone. What is the nature of your transition state after the nitrogen attacks the carbonyl?

Offline Ariana

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Re: Enamine Formation
« Reply #2 on: August 05, 2009, 02:35:53 PM »
True, I understand. Tho, I haven't learnt any other reaction. The next various steps are:

2) SOCl2, benzene, 80 C
3) a) LiAh4, ether b) H3O+, O C
4) Carboxylic acid

Offline Ariana

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Re: Enamine Formation
« Reply #3 on: August 05, 2009, 05:26:53 PM »
Hmm. I got everything till step 3. Now, I'm just stuck on step 4 (carboxylic acid). Any suggestions? Here's what I have so far:


Offline sjb

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Re: Enamine Formation
« Reply #4 on: August 06, 2009, 03:13:41 PM »
Hmm. I got everything till step 3. Now, I'm just stuck on step 4 (carboxylic acid). Any suggestions? Here's what I have so far:



Seems reasonable, though I'm not sure SOCl2 will "dehydrate" the tertiary amide - I know it works on primary amides though. Don't forget the nitrile is linear, as well. Now, at the end you have an acid and an amine. How can amines act? Why did you need two equivalents of diethylamine in step 1?

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