Reaction of succinic acid with ammonia

When succinic acid is treated with excess $$\ce{NH3}$$, what will the mechanism be? I feel both $$\ce{COOH}$$ groups should be converted to $$\ce{CONH2}$$, but this is not the product.

• Did you actually mean to say $\ce{COONH2}$? Because that is about as wrong as it gets … – Jan Aug 16 '16 at 16:23
• I actually think you mean $\ce{CONH2}$, the amide, but feel free to correct me if I'm wrong. – The_Vinz Aug 16 '16 at 17:55
• Yup.. Its amide – Adarsh chaturvedi Aug 18 '16 at 10:42
• @Jan It's not as simple as it seems... the ring actually closes. (Picture taken from here) – DHMO Jan 26 '17 at 16:05
• @DHMO I knew. But OP suggested a peroxide product which was just badly wrong ;) (Actually, it is as simple as it seems because five-membered rings are kinetically favoured and intramolecular attacks are faster than intermolecular ones, etc. etc.) – Jan Jan 26 '17 at 20:20