We obtained the corresponding amide in THF or CHCl3 but it can not be easily recrystallized to separate it from reaction mixture. Amide is of fatty acid nature.
Switch solvent to Dichloromethane, store it. At -10C overnight, Pipette Solution off and rinse 2x with precooled DCM
Switch solvent to Dichloromethane, store it. At -10C overnight, Pipette Solution off and rinse 2x with precooled DCM
Removal of dicyclohexylurea from reaction mass is always challenging job, better use modified copuling reagents like EDC reagent it may solve your problem.
Check if your amide is soluble in Acetonitrile, because dicyclohexylurea is quite insoluble in it.
Check if you amide is soluble in toluene because dicyclohexylurea is not.
If your compound is soluble in DCM, then dissolve it in DCM and add hexane (5-10%) . Leave the solution overnight in freezer. You can eliminate most of the urea. Repeating this procedure few more times would make the amide free from the urea. Also, as Mary said, if your compound is soluble in toluene, you can eliminate urea using toluene. However, cooling the solution gives you better results
You can also try acetonitrile as solvent for the amide. The DCU is quite persistent but if you can do the next reactions the urea will gradually disappear.
I'm facing the same problem, plz suggest me which is the best method for removing DCU without column chromatography.....
ONCE MORE I HAD MADE AN AMIDE REACTING AN ACID AND AN AROMATIC AMINE AND ALL I NEEDED TO DO WAS FILTER OFF THE DCU AS IT IS NOT SOLUBLE IN TOLUENE WHILE THE AMIDE WAS. BUT YOU COULD TRY THE METHOD SUGGESTED BY MURTHY ABOVE , WHEREBY YOU USE DCM AND 5-10% HEXANE WITH FREEZING. HOPE THIS WILL HELP.
Thanks. My amide was soluble in toluene and I got
to remove dicyclohexylurea
- Badges
- Science topic
- Similar topics
- Chemistry
- Organic Chemistry