[foxfourfive]

So I have an organic ketone base in an ethyl acetate solution (5:1). I need to extract this into a hydrochloride salt using either HCl gas or liquid and recrystalize for analysis.

Which is the best method for both the extraction of the salt and the recrystalization? Should the organic ether be different or is ethyl acetate suitable? I have attempted this with a number of different solvents and I'm asking what you would think is most suitable based on its ketone structure.

[Dan]

I have attempted this with a number of different solvents

It would be helpful to explain what you have tried already (and the results of these attempts).

[discodermolide]

I'm not really sure what you mean by an "organic ketone base"? Can you please elaborate?

[foxfourfive]

I'm not really sure what you mean by an "organic ketone base"? Can you please elaborate?

Sorry, the compound is a ketone, but it is an alkaloid. The part I'm struggling with is the reaction from the base to the acid salt, I had worded it wrong.

[foxfourfive]

I have attempted this with a number of different solvents

It would be helpful to explain what you have tried already (and the results of these attempts).

I have tried extracting by bubbling HCl gas through the EtOAc solution, and recrystallizing with dry IPA however I almost always end up with a fine white powder, extremely low yield (<20%). I have also used EtOH for recrystallization with similar results.

I tried a liquid/liquid extraction adjusting the pH until it was around 5.2 using 1000ml of distilled water and HCl solution but separated out into three layers: A heavy oil looking layer which sunk to the bottom of the beaker, water layer (reasonably clear) and what looked like the EtOAc on the top with some of the base suspended in it. The top layer resembled a dish and was not flat across the bottom which I found puzzling.

[discodermolide]

Have you tried making other salts?
HBr, MsOH?