July 18, 2024, 12:59:16 AM
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Topic: Saponification Troubles  (Read 750 times)

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Offline manganesequeen

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Saponification Troubles
« on: June 12, 2024, 03:14:14 PM »
Hello all! Recently I have been attempting to successfully perform a saponification on a molecule that is essentially three benzoates tethered by ether chains. On a small scale I was successfully able to isolated the carboxylic acid product, however getting the conditions correct was quite finicky. In the first reaction I ran, the crude 1H NMRs I took in situ showed only the carboxylate was present (the carboxylate had limited solubility in the MeOH/dioxane mixture though), but when I acidified it the 1H NMR showed 2 species with very similar peaks in about a 1:2 ratio. In another small scale attempt I added DI Water after the carboxylate formed to get it all to dissolve in solution, when I acidified this reaction, the 1H NMR showed the presence of only one species. Now that I am scaling this rxn up, I am unable to simply add water to force the carboxylate into solution. I have tried adding gross excess of NaOH, adding large amounts of DI water, and refluxing the rxn in MeOH. Nothing seems to get this carboxylate into solution. Any advice? Or any ideas why I may have been getting 2 species in the acidified NMR?

Offline rolnor

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Re: Saponification Troubles
« Reply #1 on: June 13, 2024, 02:28:35 AM »

Can you tell us the actual compounds you are working with?

Offline manganesequeen

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Re: Saponification Troubles
« Reply #2 on: June 13, 2024, 12:40:33 PM »
sure, I attached a picture below.

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