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Topic: Amine synthesis (Gabriel synthesis) help  (Read 2936 times)

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Offline wonka_vision

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Amine synthesis (Gabriel synthesis) help
« on: July 23, 2015, 02:43:26 PM »
Hi - I'm trying to form a ketal containing amine through the following reaction:



To drive the reaction I have been slowly adding concentrated NaOH (in water) under reflux for 24 hours. I then extract with dichloromethane in order to get a yellow oil. The problem is that I often don't get a product (it's only worked a couple of times for me out of the many times I've done this reaction). Can someone think of a reason why I could be losing my product?

Thanks

Mod edit: img tags added. Dan
« Last Edit: July 24, 2015, 02:55:32 AM by Dan »

Online kriggy

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Re: Amine synthesis (Gabriel synthesis) help
« Reply #1 on: July 23, 2015, 03:31:26 PM »
Isnt the product usualy obtained by use of hydrazine?

Offline wonka_vision

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Re: Amine synthesis (Gabriel synthesis) help
« Reply #2 on: July 23, 2015, 03:46:33 PM »
It is, but I had a really difficult time with separation last time I used hydrazine. I'm actually in a chemical engineering department, so our access to equipment is lacking.

Offline phth

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Re: Amine synthesis (Gabriel synthesis) help
« Reply #3 on: July 24, 2015, 02:00:19 AM »
The rxn is competing to form phthalamide+ROH.  You could just put NaN3+RX and then reduce N3 to NH2 by commmon hydrogenation catalysts(e.g. Pd/C wont react with ether--> http://www.organic-chemistry.org/synthesis/N1H/reductionsazides.shtm) or PPh3 http://www.organic-chemistry.org/namedreactions/staudinger-reaction.shtm  May also work better to convert it to a dithioketal which is less sensitive than ketals and can be removed with reagents such as PhI(OAc)2 if your goal is not just the exact chemical in your .png
« Last Edit: July 24, 2015, 03:12:51 AM by phth »

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