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Topic: Propose mechanism for this reaction  (Read 2032 times)

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Offline Fireredburn1

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Propose mechanism for this reaction
« on: December 17, 2014, 04:56:01 AM »
What is the mechanism for this reaction?



Here's my attempt. My guess is that formaldehyde will react with one of the amine group to form an imine group. But here's where I am stuck at. It seems almost impossible to insert an oxygen atom into the final product if I were to go by an imine intermediate.

There oxygen atom must have been from the formaldehyde but it is obvious that isn't from an nucleophilic addition.

Help will be greatly appreciated!

Offline Hunter2

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Re: Propose mechanism for this reaction
« Reply #1 on: December 17, 2014, 05:31:53 AM »
Both amine groups build Aminomethanol.  -NHR + H2CO => -NHR-CH2-OH

Both groups eliminate water and build the ether.

Offline Fireredburn1

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Re: Propose mechanism for this reaction
« Reply #2 on: December 17, 2014, 05:42:57 AM »
Both amine groups build Aminomethanol.  -NHR + H2CO => -NHR-CH2-OH

Both groups eliminate water and build the ether.

How did I not realise that? thank you so much! but why would an imine not be formed instead?

Offline Hunter2

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Re: Propose mechanism for this reaction
« Reply #3 on: December 17, 2014, 06:36:29 AM »
I think you will not have 100% yield side reaction can be the imine. But the double bond of imine is easily to open again. Maybe it will produced in between.

Offline orgopete

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Re: Propose mechanism for this reaction
« Reply #4 on: December 17, 2014, 08:17:40 AM »
An imine (or iminium ion) is an intermediate. Addition of the oxygen from the aminomethyl group to the imine is the mechanism for the cyclic ether formation. Imines are reversible.
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