Carabistouilles
Harmless
Posts: 5
Registered: 20-6-2013
Member Is Offline
Mood: No Mood
|
|
Click Chemistry
Hi everyone,
Yesterday I did a Cu-catalyzed azide-alkyne cycloaddition with CuI, in DMF, at 80*C, over night. I put ether into my homogeneous mixture to force my
product to precipiate, and I isolated it by filtration.
The problem is there is Cu residual in my precipitate, so my precipitate is a bit green.
Then, I put it through a silica column to take out the Cu, but my precipitate is still green.
My reagents are soluble in ether, and my product is not ( !), so i want to keep
this solvant.
Anyone have a solution to take out the Cu / improve my reaction? Thank you!
[Edited on 21-6-2013 by Carabistouilles]
[Edited on 21-6-2013 by Carabistouilles]
|
|
|
ElectroWin
Hazard to Others
Posts: 224
Registered: 5-3-2011
Member Is Offline
Mood: No Mood
|
|
distill the spent solvent?
|
|
|
Carabistouilles
Harmless
Posts: 5
Registered: 20-6-2013
Member Is Offline
Mood: No Mood
|
|
I did
|
|
|
polymerguy
Harmless
Posts: 1
Registered: 19-6-2013
Member Is Offline
Mood: No Mood
|
|
It'd be helpful to know some sort of structure of the product that you are expecting, or a reaction scheme.
Also, you say that your product is soluble in ether, but that it precipitated upon addition of ether to the reaction mixture? That doesn't make sense
to me.
|
|
|
sonogashira
National Hazard
Posts: 555
Registered: 10-9-2006
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Carabistouilles  |
The problem is there is Cu residual in my precipitate, so my precipitate is a bit green.
Then, I put it through a silica column to take out the Cu, but my precipitate is still green. |
Maybe your
product is green?
|
|
|
Carabistouilles
Harmless
Posts: 5
Registered: 20-6-2013
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by polymerguy | It'd be helpful to know some sort of structure of the product that you are expecting, or a reaction scheme.
Also, you say that your product is soluble in ether, but that it precipitated upon addition of ether to the reaction mixture? That doesn't make sense
to me. |
it's a dendrimeric structure
|
|
|
Dr.Bob
International Hazard
Posts: 2736
Registered: 26-1-2011
Location: USA - NC
Member Is Offline
Mood: No Mood
|
|
If your compound is not water soluble, then wash the solid product with water, Aq. EDTA, Ammonia or some other copper chelator. Otherwise,
recrystallize the product from another aprotic organic solvent and filter while hot. If your product can chelate copper, then you may have a
problem. Triazoles are normally not that soluble, depending on the substituents.
|
|
|
Nicodem
|
Thread Moved
21-6-2013 at 08:00 |
Carabistouilles
Harmless
Posts: 5
Registered: 20-6-2013
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Dr.Bob | | If your compound is not water soluble, then wash the solid product with water, Aq. EDTA, Ammonia or some other copper chelator. Otherwise,
recrystallize the product from another aprotic organic solvent and filter while hot. If your product can chelate copper, then you may have a
problem. Triazoles are normally not that soluble, depending on the substituents. |
Thank you ! i'll try EDTA next time. I find a nice document for work-up: http://chem.chem.rochester.edu/~nvd/workupformulas.html
|
|
|
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
Posts: 1986
Registered: 2-3-2011
Member Is Offline
Mood: No Mood
|
|
Just curious, what type of 1,2,3-triazole derivative did you make?
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
|
|
|
ElectroWin
Hazard to Others
Posts: 224
Registered: 5-3-2011
Member Is Offline
Mood: No Mood
|
|
are you sure it's traces of copper remaining?
maybe take a portion and see if a little phosphoric acid will precipitate the copper?
|
|
|
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
Posts: 1986
Registered: 2-3-2011
Member Is Offline
Mood: No Mood
|
|
Another possibility you might want to consider is that the triazole has formed an insoluble salt with the copper. That would explain why you are
having difficulty separating it out.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
