What’s the proper way to convert a freebase to hydrochloride?

Dan Martin Follow

If it is soluble in organics. HCl in dimethyl ether. You can dilute elthe Et2O as mich as you want. Afterwards evaporation of residual ether and HCl.More

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Jerome Zoeller Follow

In this case, if I evaporate the residual solvent, how can I determine how much of my compound has been converted?More

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Dean Moncaster Follow

It really depends alot on the solubility of your compounds. I use iPrOH/ether, so solubilize the compound in iPrOH, add a few drops (!) of ~5M isopropanolic HCl and add ether. You can also reflux it for an hour or so, cool it overnight in a fridge and then filter the crystals.More

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Daniel Lynge Follow

On small scale, you can generate HCl gas by addition of conc. H2SO4 to solid NaCl in a separate flask and transfer the HCl gas by tubing and pasteur pipette directly to your product solution. You would use excess of HCl gas in that case. Obviously you need to decide if your product is prone to other reactions.More

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Aubrey Berry Follow

Have you calculated the moles of product you have because you might be adding too much HCl and it looks like its just all HClMore

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Jason Green Follow

Thanks for your comment. I surely can calculate the moles, I was just describing a generic scenario. I never had to do a hydrochloride on purpose, just once in the past, and if I recall correctly they told me in that occasion that “just leave the basic compound under stirring with excess acid for a long time, it will surely be all salted”, but it feels a superficial approach both back then and now!More

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