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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: stinemarkussen on January 17, 2012, 08:09:02 AM

Title: Work-up with DMA
Post by: stinemarkussen on January 17, 2012, 08:09:02 AM

I have performed a reaction in DMA (Dimethylacetamide), but I have a hard time getting rid of the solvent. An easy way would be to hydrolyse the solvent with acid, giving water soluable products, but I have a boc-group in my compound which I would like to keep.

Any suggestions?

Kind regards

Title: Re: Work-up with DMA
Post by: fledarmus on January 17, 2012, 08:14:21 AM

Dissolving the compound in ethyl acetate and washing several times with water should get rid of the DMA. While I usually extract with chloroform rather than ethyl acetate, I've found when working with DMA or DMF that significant amounts of it go with the chloroform. This doesn't usually happen when I'm using ethyl acetate.

Title: Re: Work-up with DMA
Post by: stinemarkussen on January 17, 2012, 11:40:47 AM

Thanks for your help.

I dissolved it in DCM and washed with water several times, but could not get rid of it. I have probably just not washed it enough, but my compound is to some degree watersoluable, so it is not the best solution to wash it to many times.
Now I have managed to freezedried the DMA of, so the problem is solved.

Title: Re: Work-up with DMA
Post by: fledarmus on January 17, 2012, 12:01:17 PM

Yes, freeze-drying is a good choice!  :)

DCM has the same problem as chloroform - both DMA and DMF will get carried through, they are just too soluble in the organic solvent. That is why I switch to ethyl acetate when I need to remove those solvents.