Why are amines soluble in HCl?

1 Answer
Nov 9, 2015

Because of the acid base reaction:

#R_3N(aq) + HCl(aq) rarr R_3N*H^+Cl^(-)(aq)#


The amine is now a salt and is in principle water soluble (a quaternary ammonium salt is formulated as #R_4N^+#). Another way to describe the product is as trialkylamine hydrochloride, #R_3N*HCl#; in both instances the nitrogen is quaternized. In organic synthesis, this basicity often allows the separation of amine products into the aqueous phase (as the salt), prior to treatment with conc. hydroxide and extraction into an organic phase as the parent amine.