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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: gravity on December 08, 2012, 12:27:03 PM

Title: Question concerning Hofmann-Elimination
Post by: gravity on December 08, 2012, 12:27:03 PM
Hi,

I got a question concerning the Hofmann-Elimination.

There should be a reaction between:
1. 1,2-Dichloroethane +  Ammonia (aq)  :rarrow: X

2. 1,2-Dichloropropane + Ammonia (aq)  :rarrow: Y

Now X + Y  :rarrow: Piperidine + 2-Methylpiperidine + 2,5-Dimethylpiperidine.
Annotations:
ratio X : Y is 1:1, reaction under influence of OH-

Now I'm not sure if X is Ethylenediamine or 1-Amino-2-chloroethane.
And I don't know if Y is 1-Amino-2-chloropropane, 2-Amino-1-chloropropane or 1,2-Diaminopropane.

 ???

Hope you can help me ...

gravity
Title: Re: Question concerning Hofmann-Elimination
Post by: gravity on December 08, 2012, 05:07:56 PM
I guess I got an error in reasoning.

It seems to me, that the reaction between X and Y is not a Hofmann-Elimination.

It may be a normal substitution!?
The OH- may be used to neutralize the HCl which is formed if 1-Amino-2-chloroetheane and 2-Amino-1-chloropropane or 1,2-Diaminopropane are used.

So the OH- is an evidence for the previous mentioned X and Y.

If X and Y would be normal amines, the reaction between X and Y would form Ammonia instead of HCl. And the OH- would be useless.

So, am I right?

gravity