Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: redballoons on January 14, 2013, 09:57:41 PM
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Starting with succinic anhydride, give the reagents and/or conditions necessary to produce...
NH4+-OOCCH2CH2CONH2
First I would added H2O/H+ to the succinic anhydride to open the ring and give...
HOOCCH2CH2COOH
Then I would add NH3...
This is where I'm getting confused because I have two mechanisms in my notes for adding NH3 to a carboxylic acid.
1.) R-COOH + NH3 :rarrow: R-COO-NH4+ (used during imide formation)
2.) R-COOH + HNR2 :rarrow: R-CONR2 (used during amide formation)
Which one is right?
And how can I get CONH2 at one end but COO-NH4 at the other?
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Ok so I have done some more research and I would still add H2O/H+ to get...
HOOCCH2CH2COOH
Then I would add SOCl2 :rarrow: R-COCl
Then I would add NH3 :rarrow: R-COO-NH4+ + HCl
Then I could heat it :rarrow: R-CONH2 + H2O
But is there a way to protect one end so that it doesn't go from R-COO-NH4+ to R-CONH2 when heated?
Or am I making this way more difficult then it really is?
Would adding 2NH3 to succinic anhydride result in the desired product? It would have a similar reaction to the addition of concentrated ammonia solution added to ethanoic anhydride.
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Going back, are you certain the following reaction will equate to the carboxylate ammonium salt? Go through the mechanism. What is the nucleophile and what is the electrophile?
RCOCl + NH3 :rarrow: R-COO-NH4+
You were making it a bit more complicated, but it seems you now managed to make your compound in one step. :)
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Why not just use concentrated ammonia?
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Hint, I think the answer could be the reaction of two equivalents of ammonia with succinct anhydride. Can you determine why this might succeed?