[Jonathan]

Hello

what is the best way to clean HCL from a protaneted amine?

i can't wash my product with methanol because it seems like it dissolves in it to good (no product left).
ether and hexan don't to the job very well.
will acetone wash do to job?
or maybe if i leave it in the evaporator for a few mints is enough?

any way, what is the best way to discard leftovers of HCL?

Thanks a lot

[Borek]

You need some base, using nonpolar solvents won't work.

[Jonathan]

thanks for the answere.

base is not a good solution for me, because i need it as a salt form(a base will take the H from the amine and it will not be a salt any more).

plus the molecule is sensitive to base so it is not an option.

[Borek]

OK, you want to wash excess HCl, but to keep you product as hydrochloride, I have misread your post.

[kryptoniitti]

Maybe saturated NaCl(aq) solution could work...

[Jonathan]

mmm...

i had a problem same problem once but with triflouroacetic-acid (TFA) which is less fun to work with. i putted it in the evaporator with ether a few times (i needed about 5 times) until it evaporated (also had no time so needed to evaporated it asap). but this way is not very ecological so i thought there is a way that waist less material. there definitely must be one.

maybe leave it in the evaporator for a long time or so or wash it with a bit of some solvent. i will try the evaporator but i thought someone should know haw to discard easily excess of HCL.

don't anyone know it

thanks any way.

[gericox]

Did you have initially the free amine ?
If yes, why don't try to solubilize this free amine in MeOH and then bubling HCl gaz. And then dry to obtain your ammonium salt?

[Jonathan]

gericox i didn't do what you offered because the amine molecule is sensitive to base so i couldn't "free" it.

and i don't like working with HCL gas so much even when i can i prefer working with solvents.
the all reaction is in concentrated HCL.

but thanks for the good idea.

[HP]

You may use freshly prepared wet silver oxide (Ag2O) which will react with HCl forming white precipitate of AgCl and water..

[gericox]

Did you try dissolution in MeOH and then after addition of small portions of ether?