Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: fingolfn on October 25, 2007, 10:28:34 AM

Title: Removal of DCU From DCC coupled Amide Crude
Post by: fingolfn on October 25, 2007, 10:28:34 AM

Hey guys,

I am having trouble removing the DCU side product from an amide product and I was wondering if anyone had any ideas/tricks?

Title: Re: Removal of DCU From DCC coupled Amide Crude
Post by: wintermute on October 25, 2007, 03:08:17 PM

what solvent did you use for your reaction? how did you work-up the reaction? it is said that acetonitrile is sometimes better than dcm or chloroform since dcu is less soluble in it. you can cool down the solution of your product to get rid of all dcu.
alternatively, dissolve your product in ethyl acetate and refrigera it to precipitate dcu.

Title: Re: Removal of DCU From DCC coupled Amide Crude
Post by: agrobert on October 25, 2007, 07:37:36 PM

Depends on the amount of work you want to do.  I have had success doing DCC coupling in methylene chloride.  Reaction purification involves cooling methylene chloride to 0 C and filtering DCU through a frit funnel with vacuum.  There will be some DCU in filtrate which can be removed by column chromatography.