xonu - 4-7-2023 at 07:55
Recently I've acquired some aniline hydrochloride, with the purpose of making some metal complexes and salts, but the reagent is a greenish colour,
and yields a bunch of extra insoluble junk in solution. The discolouration afaik is acceptable, but im not sure about the insoluble stuff.
An attempted synthesis of anilinium tetrachlorocuprate (1:6 CuCl2:Aniline HCl in acidic solution heated until boiling) yielded tar, and while trying
to freebase aniline the same insoluble impurity moved to the top layer.
Are there any ways of purifying this material? I've seen steam distillation and a solvent washing with ethyl acetate mentioned on the forum, but i do
not have space for a distillation and no ethyl acetate yet.
Picture attached is how the reagent looks like, with it being slightly less grey and more green in real life
[Edited on 4-7-2023 by xonu]
unionised - 4-7-2023 at 13:39
I used to clean up phenylenediamine by dissolving it in dilute HCl, filtering it, washing out "brown stuff" with ether and then adding NaOH to recover
the free base.
The same might work for aniline.
On the other hand, you are going to have problems even with clean aniline...
https://onlinelibrary.wiley.com/doi/abs/10.1002/pola.21695
[Edited on 4-7-23 by unionised]
xonu - 5-7-2023 at 07:52
I acidifed it and gravity filtered it to use in an azo dye synthesis, and got a light brown solution, seems like the impurity either reacts with acid
or is very insoluble in water/brought out of solution with acid