Knowledge Seeker - 26-12-2020 at 23:40
Hello
I aimed to prepare iodobenzene from the reaction of aniline diazonium salt with KI. I distilled the resulted mixture (I carried out a simple
distillation not a steam distillation as described in the procedure) and I ended up getting a dark oily black liquid. I added to it sodium sulphite
but I did not obtain a pale yellow liquid but a kind of reddish liquid (picture below). So I'm not sure if this product is iodobenzene or not.
RustyShackleford - 27-12-2020 at 03:12
Looks like some aniline crap to me. Was the distillation performed under acidic conditions to prevent the aniline from coming over easily?
Boffis - 27-12-2020 at 03:43
When I have used aniline derivatives in any reaction I always seem to get a certain quantity of dark coloured impurities. You will need to distil it.
Check out Vogel's Textbook of Organic Chemistry for details, I have never made iodobenzene so I can't say whether you need to distil it in a vacuum,
with steam or whether you can distil it directly. Your product doesn't look that that bad for this type of reaction!
Knowledge Seeker - 29-12-2020 at 23:22
No, it wasn't. The solution was first turned alkaline according to the procedure before the distillation.
I read Vogel's procedure but I skipped the steam distillation.
Thank you for your replies.