Frankenstein16 - 13-7-2016 at 07:18
Hi can anybody help me solve this problem??
Benzocaine>>>>>benzocaine Hydrochloride
I am doing an acid base extraction using benzocaine base
Using the following method
Dissolving benzocaine base in acetone
Also Using 36% hcl and methanol
I am getting a final ph of around 2.5 
How do I raise the ph and also I think this is because the acid is getting trapped inside the crystals
Anybody help?
Loptr - 13-7-2016 at 08:01
This better belongs in beginnings.
You are using too much acid. If you add a dilute HCl solution to the free base in a solvent until you have the right pH, then you need not worry about
extra acid getting trapped within the dried product. Over acidification can be harmful if the compound is acid sensitive, but I have also seen it have
weird effects on the melting point and when attempting to dry the product. If the solvents and solubility worked in your favor, you might be able to
rid yourself of this problem through crystallization or recrystallization. The most basic method would be to add more basic solution, extract back
into solvent, and then re-acidify until neutral or just slightly acidic.
The other members will likely have an easier solution, but when purifying a synthesis product, another extraction/wash wouldn't be harmful and might
help clean it up even more.
[Edited on 13-7-2016 by Loptr]