Schleimsäure - 9-5-2015 at 11:40
Yesterday I tried the preparation of acetanilide.
On versuchschemie I found a synthesis without the use of acetic anhydride. Though I've got 2 l of it, I didn't want to waste any.
So I just used ca. 40ml of aniline and ca. 80ml of 99,5% acetic acid. Heating for 3 hours under reflux and then putting the still hot mixture into
slightly HCl acidified water.
Now the chrystals perticipating were quite clear. I didn't weigh them nor did I put them into the desiccator yet after vacuum filtration and 1 day
drying on air. But anyway they have a clear smell of acetic acid. Acetanilide shouldn't smell of acetic acid.
My question is how do I get rid of the acetic acid within the product?
Just basify/neutralize it with NaHCO3 for example?
[Edited on 9-5-2015 by Schleimsäure]
byko3y - 9-5-2015 at 13:21
Yes, NaHCO3 should work. Until you have anilinium acetate in the crystals, you need only to get rid of acetic acid. I'm sure that even a slight amount
of HCl contacting with acetanilide is enough to produce a noticable odor of acetic acid (which smells horribly).
Try recrystallizing the neutral product from water, aqueous ethanol, benzene or toluene (xylene probably should also work, though I don't know).