You answered a earlier post on a question for someone with the same question I am trying to answer.

Question

The hydrolysis of tocainide
you stated only the NH2 group hydrolyses NH2 + HOH -> NH3^+ OH^-

I understand that part but I need to understand why the amimine only hydrolyses. Am I to understand that the amide part is unchanged and if so why?

I will try and recreate the structural formulae as best I can

Benzene ring with 2 CH3 attached. One N attached to ring. N has a C attached and one H to it. The C attached to the N is attached to a CH which in turn has a CH3 and a NH2 attached to it.
So, there is a amide and a amine here.
I don't understand enough about hydroysis yet. I can work it out OK with one functional group but have trouble when there is more than one. If the amide hydroysed then I would get a acid and a alcohol. Somewhere along the line I have missed something don't like answering anything without understanding it properly. I would be very grateful for your help me once before and put it over clearer than my tutor.

It's tough to draw structures, or even describe them, on the computer. I looked up the structure of tocainide in my home copy of The Merck Index.

Amines are basic and, by the Bronsted-Lowry theory, accept protons from water. Reaction with water is hydrolysis. Amines usually are basic enough that they require nothing more than addition of water to react. Amides are neutral. The -CONH2 (amide) group CAN be hyrolyzed but it is tougher to do so. Under (usually) high acidic conditions (such as strong HCl), the -CONH2 group forms NH3 + the corresponding RCOOH acid and those two react to form the ammonium salt (RCOO^- + NH4^+). Under (usually) high basic conditions (such as NaOH or KOH), the RCOO^- + NH4^+ salt is formed directly without going through the intermediate steps. The way I understood the problem, it was a simple hydrolysis withough strong acid or alkali present. I hope this helps.

Thank you very much for taking the time to help me