beerwiz
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My organic molecule is in the ethyl acetate, how to dry it before precipitating?
I extracted the organic layer with ethyl acetate, now I need to dry the ethyl acetate. But how do I dry it? I know there's plenty of water in it. I
want to dry it before precipitating the compound. If there's any water in there, yields will be low.
What should I use? Mol sieves 4A? Potassium carbonate?
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JJay
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http://www.chem.ucla.edu/~bacher/Specialtopics/Drying%20Agen...
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Cactuar
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Do not put drying agents in wet EtOAc, it contains roughly 8 % water. First shake it with brine and separate and then add your drying agents. What
agent you should use depends on your compound but NaSO4 and MgSO4 are the most common ones.
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JJay
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While I haven't done this with ethyl acetate, specifically, in other solvents, when you use potassium carbonate as a drying agent, if there is a lot
of water in the solvent, it will draw out enough water to form an aqueous layer that you can remove with a pipette. You can do that repeatedly until
the potassium carbonate no longer liquifies and then add more until no clumping occurs. I'm pretty sure it would do the same with even very wet ethyl
acetate.
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Texium
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Thread Moved
2-10-2018 at 10:46 |
beerwiz
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I've been using anhydrous MgSO4 and since the compound is basic it may have been precipitating out before I'm able to get to it and going in the trash
after I filtered off the MgSO4. Can I use the Potassium carbonate to dry Ethyl Acetate and DCM? Does the Potassium carbonate need to be anhydrous? How
do I make it anhydrous, same way as epsom salt (in the microwave)?
I have the basic organic molecule in ethyl acetate, someone suggested I use tartaric acid in methanol to precipitate it out. Will that work or will
mostly tartaric acid precipitate out since it's not soluble in the ethyl acetate (or DCM)?
[Edited on 7-10-2018 by beerwiz]
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ninhydric1
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Doug's Lab uses potassium carbonate for drying everything, including ethyl acetate and DCM. I personally use calcium chloride because it's readily
available but I believe CaCl2 isn't compatible with some compounds (amines, I believe, I'm not sure).
The philosophy of one century is the common sense of the next.
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morganbw
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I actually may study this problem you are having, and I do wish I could offer some advice but the closest that I have come to this molecule was an
instance where the son of my niece and his friend got into trouble, with the law and their college, with a plan to extract it from plant material.
Good luck, I do believe that you have gotten some good advice and hopefully you have enough of this to eventually purify it.
Read the advice you have been given carefully, some of it has been good.
[Edited on 10/8/2018 by morganbw]
[Edited on 10/9/2018 by morganbw]
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Tsjerk
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@morganbw
Huh? what in the world are you talking about?
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morganbw
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I mistook this thread for the other one where he is trying to separate dimethyltryptamine from his solvent.
Both threads are very similar and I responded to the wrong one.
This thread "Have organic molecule base in Ethyl acetate, precipitate with tartaric acid in methanol" located in the beginning section.
Sorry for making a confusing post.
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