Ammonia derivative condensation

[aquafreshlovin]

Advertisement - Members don't see this ad

Ph-Ch2-COH + NH2-CO-NH-NH2 ---> ?

The answer is:
Ph-CH=N-NH-CO-NH2

MY question is, why can't the answer also be:
Ph-CH2-CH=N-CO-NH-NH2 ???

Is there a special rule where specific amine end has to be added onto the carbonyl carbon? Please explain!

 

[doc3232]

Ok, the reason is the OH on COOH and the NH2 on CONH2 are both quite unreactive. They rarely react and if they do it will require a high temp.
The double bonded oxygen on a COOH is more reactive than the OH on it.
Rule of thumb: Don't attack with those two things I previously mentioned because they are very stable as is, which means they won't react.
I hope that helps.
GOOD LUCK

 

[ucla2134]

Ok, the reason is the OH on COOH and the NH2 on CONH2 are both quite unreactive. They rarely react and if they do it will require a high temp.
The double bonded oxygen on a COOH is more reactive than the OH on it.
Rule of thumb: Don't attack with those two things I previously mentioned because they are very stable as is, which means they won't react.
I hope that helps.
GOOD LUCK

Hi doc, i don't understand why it is not reactive, is it because it is next to CO group which withdrawing electron of N?
Thank you.

 

[doc3232]

To the previous poster: Resonance makes the C--OH into a C==OH +charge Which is a very bad nucleophile and will not attack the electrophile.

 

[ucla2134]

To the previous poster: Resonance makes the C--OH into a C==OH +charge Which is a very bad nucleophile and will not attack the electrophile.

I understand now. Thank you so much