Final answer:
To recover an amine from its salt form, a base like NaOH is added to the solution containing the amine salt, resulting in the liberation of the free amine which can be isolated by extraction or distillation.
Step-by-step explanation:
To recover the amine from its salt form, typically a base is added to the solution containing the amine salt to neutralize the acid bound to the amine, thus releasing the free amine. This procedure is commonly applied to the hydrochlorides of amine drugs to increase their solubility in an aqueous solution, making them more bioavailable. For example, the hydrochloride salt of an amine can be treated with a strong base like sodium hydroxide (NaOH) where the amine will take a proton from a water molecule and the acid will form its corresponding salt after capturing the hydroxide ion. This results in the liberation of the free amine which can then be isolated, usually by extraction into an organic solvent or by distillation if it is volatile. The reaction is as follows:
Amine hydrochloride + NaOH → Free amine + Water + NaCl
For instance, if we have aniline hydrochloride, adding NaOH would yield aniline, water, and sodium chloride. By adjusting the pH ideally with a basic solution, amides can also be hydrolyzed to produce an organic acid and ammonia or an amine, depending on whether the hydrolysis is acidic or basic. In both processes, once the amine is free, it can be separated from the reaction mixture.