achem500
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Catalysts for Fischer Esterification
Is sulfuric acid the only acid that can be used as a catalyst in a Fischer esterification? Any help is appreciated.
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kavu
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No, many acids are able to activate carbonylic oxygen to make it more electrophilic. Protonation or Lewis acid coordination can be used. Commonly
employed proton donors are phosphoric acid, dry HCl, H2SO4, toluenesulfonic acid, acidic ion exchange resins such as Amberlyst 15. Numerous Lewis
acids have been used, a more comprehensive list can be found from http://www.organic-chemistry.org/namedreactions/fischer-este....
An OTC alternative for these reagents is the good old sodium bisulfate.
[Edited on 3-8-2012 by kavu]
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achem500
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Thanks! I take it that I should use an equivalent amount during a future reaction? or should I use an excess of one reagent?
Also, how could I obtain dry HCl? Straight HCl gas or very concentrated aqueous solution? Does water upset a Fischer esterification?
Thanks a bunch
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Nicodem
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https://www.sciencemadness.org/whisper/viewthread.php?tid=13...
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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achem500
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Thank you
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Housane
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Am I right that sodium bisulfite is a direct weight for weight replacement
Green QD's so far
Feel free to correct grammar or incorect knknowledge. We are all learning.
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DavidJR
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Replacement for what?
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Abromination
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There are a great many posts on this already. Sulfuric acid is the best one, all though there are many others. Boric acid does not work, there are a
lot of threads that say it may. Sulfonated styrene works, i think tosylic acid works, and I have heard that anhydrous sodium bisulfate works. Do some
research to find what you need.
List of materials made by ScienceMadness.org users:
https://docs.google.com/spreadsheets/d/1nmJ8uq-h4IkXPxD5svnT...
--------------------------------
Elements Collected: H, Li, B, C, N, O, Mg, Al, Si, P, S, Fe, Ni, Cu, Zn, Ag, I, Au, Pb, Bi, Am
Last Acquired: B
Next: Na
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Tsjerk
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Quote: Originally posted by Abromination  | | There are a great many posts on this already. Sulfuric acid is the best one, all though there are many others. Boric acid does not work, there are a
lot of threads that say it may. Sulfonated styrene works, i think tosylic acid works, and I have heard that anhydrous sodium bisulfate works. Do some
research to find what you need. |
Sulfonated styrene has the benefit of being a solid, making workup easier.
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Abromination
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| Quote: Originally posted by Tsjerk | | Quote: Originally posted by Abromination | | There are a great many posts on this already. Sulfuric acid is the best one, all though there are many others. Boric acid does not work, there are a
lot of threads that say it may. Sulfonated styrene works, i think tosylic acid works, and I have heard that anhydrous sodium bisulfate works. Do some
research to find what you need. |
Sulfonated styrene has the benefit of being a solid, making workup easier. |
Speaking of which, I tore open a brita filter to remove the resin and found it to be mixed pretty evenly with the activated carbon. The beads are also
pretty small. In going to try to separate them but I’m not expecting much.
List of materials made by ScienceMadness.org users:
https://docs.google.com/spreadsheets/d/1nmJ8uq-h4IkXPxD5svnT...
--------------------------------
Elements Collected: H, Li, B, C, N, O, Mg, Al, Si, P, S, Fe, Ni, Cu, Zn, Ag, I, Au, Pb, Bi, Am
Last Acquired: B
Next: Na
-------------- |
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