All Questions
Tagged with synthesis purification
12
questions
2
votes
0
answers
50
views
Palladium coupling reactions and purification
I tried to synthesize 2-(6-fluoropyridin-3-yl) acetic acid from 5-(Chloromethyl)-2-fluoropyridine using Pd(OAc)2/PPh3 catalyst,Na2CO3 and DCC. I eluted my product on TLC with Ethyl acetate/hexane/...
- 47
4
votes
0
answers
273
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Exchange of Fluorine to Oxygen for Fluorophosphonic acid by silylating agents or other methods?
[Warning, long post!]
Dear all,
I am confronted with a seemingly easy transformation. I want to remove a fluorine atom at a fluor phosphonic acid salt. The usual method to achieve this is the basic ...
- 799
1
vote
0
answers
33
views
Avoid triethylphosphate as a side product during P-C-P coupling reaction with diethylchlorophosphate with LDA
I have a reaction in which I perform a deprotonation of an acidic proton at a phosphate and later do a P-C-P coupling. The coupling partner is diethylchlorophosphate. Deprotonation is performed with ...
- 799
2
votes
0
answers
64
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Mixture is eluted too early from alumina in flash column chromatography
I have recently tried to purify my reaction mixture by column chromatography. Because my reaction mixture had poor resolution in silica-based TLC, I used neutral alumina-based TLC plate. After I ...
- 1,101
1
vote
0
answers
111
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Recovery of precipitated polymer
I have recently newly synthesized the polymer. Based on its structure I tried to precipitate its concentrated solution in dichloromethane by dropping it into methanol. It seemed to work. The methanol ...
- 1,101
3
votes
1
answer
169
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Is it possible to filter Stille catalysts using syringe filter?
I'm conducting an organic synthesis involving Stille coupling.
Stille coupling uses $\ce{Pd2(dba)3}$ and $\ce{P(o-tol)3}$ as catalysts.
Both catalysts dissolves in toluene which is the solvent of my ...
- 1,101
3
votes
3
answers
293
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Synthesis of anhydrous sodium tungstate
I am interested in preparing an anhydrous sample of sodium tungstate (Na2WO4), which is normally found as the dihydrate. Finding an example of this in literature is proving difficult, I am interested ...
- 264
1
vote
2
answers
3k
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How to acid-wash sand?
I need some acid-washed sand to smooth out boiling in diethyl ether synthesis. I aready have pre-washed sand for general filtration purposes, but it is not labeled as acid-washed.
Unfortunately, I ...
- 147
10
votes
1
answer
1k
views
Purification/Extraction of Sodium Permanganate
I read this question and answer, and it seemed like a rather nice way to make sodium permanganate. Using the method with sodium hydroxide, I produced a solution. Once filtered and decanted, it was ...
- 512
1
vote
0
answers
1k
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How to crystallize out reaction mixture from DMF?
Reaction was carried out in DMF, and TLC shows that the reaction has completed. But how to separate reaction mixture i.e. product from DMF?
Edit
Steglich Esterification was carried out and the ...
- 101
5
votes
1
answer
34k
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Why is crystalline aspirin washed with chilled water in the purification process?
Take as example this
or even better this:
Wash the crystals with 2-3 ml of chilled water.
Why does the aspirin need to be cooled down? And why do we wash the aspirin with chilled water?
- 153
9
votes
1
answer
927
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Is it safe to condense water into a liquid nitrogen trap?
I'm trying to remove water from an imidazolium salt (i.e. dry the salt). However I want to know if it is safe to remove the water under vacuum. Is it safe to condense water into a liquid nitrogen ...
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