[zilalti]

I'm looking over a synthesis of Prozac and I'm having a little trouble understanding one of the mechanism behind the reaction. http://www.nitrogenorder.org/molweek/sep2005/04sep05.shtml

The last step of the reaction is the loss of a methyl group via Glycol, KOH and H20 however I can't think how this would work. Can anyone help?

[agrobert]

Well first of all you are not losing a methyl group.  You are losing a cyano group which was strategically installed so that is could be removed in a controlled and well known fashion.  The cyano group -CN is a carboxylic acid synthon meaning that its chemistry is similar to that of a carboxylic acid.  The last reaction involves nucleophilic attack of the cyano group by the glycol under basic heated conditions.  You are right, if it were loss of a methyl it would be very confusing.

[zilalti]

ah i see my mistake. I missed out the penultimate step when copying down the mechanism. Thanks for the reply.

[lutesium]

Why do we use a dimethylamine counterpart instead of a mono-methylamine??? This is a very good raction scheme for the students as it shows the useability of the Von Braun reaction!!! I know that the reason that we 're using the dimethyl amine is that it serves as a protecting group but from which step???

Maybe it serves as to stabilize the molecule from -maybe- harsh reaction conditions

Lutesium...