Possible Extraction of Mesembrine Using Acid/Base Method (Help Please)

[goddywoddy]

Hello, So I am not a professional chemist, so I would appreciate any advice you all have to give. Here is the idea:



1.Acidify destilled water with acetic acid to pH 4.Then add the acified water to the plant material. Let it soak for an hour or so and perhaps boil it (not sure). 99% of the Mesembrine should become in salt form. Filter everything through a coffe filter. Repeat this step 2 more times to get everything out from the plant parts and then combine the acified liquids.

2. Defat. Add approx. half as much naphta or hexane as the acified liquid. This will be mixed together and allowed to separate. Discard the naphta or hexane and keep the acidified solution. Repeat 2 more times. Mesembrine is poorly soluble in naptha/hexane which is why it is used for defat.

3. Then add NaOH solution to the acidifed solution until the pH of the whole mixture reaches 12. (99% of alkaloid should be in freebase form)

4. Pull with dichloromethane 3 times and collect the Dichloromethane.

5.Then, Add acetic acid/anhydrous methanol solution until a pH 4.

Now, if the acetic acid/methanol is added. Will mesembrine acetate crystals precipitate out?

Please add or edit something if necessary!

It would be great if you could give suggestions on how to improve this.

 

[InMotion]

What I was trying to tell you was it will not 'crash' out if you use an aq. acid. It will go into the water layer however(3 acid pulls). If you add acetic acid to anhydrous methanol it will no longer be anhydrous, unless you have access to glacial acetic acid or acetic anhydride(not worth it). You could however use methanol and fumaric acid, citric acid, tartaric acid, etc. Or perhaps even dry acetone instead of methanol.

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The pH values should be sufficient however according to the pKa's listed.