Yorty2040 - 14-5-2024 at 16:23
I was always under the assumption that urea hydrolyzed by hydroxide performing nucleophilic attack on the carbonyl to form a tetrahedral intermediate,
then proton transfer, then expulsion of ammonia as a leaving group to form carbamic acid, then proton transfer to form the zwitterion, then lysis of
the carbon-nitrogen bond to form ammonia and CO2.
But apparently that's not the case, and there are conditions where it can actually break down via an isocyanate intermediate? I understand the precise
mechanism and rates are very pH dependent, but it's been awhile since Org Syn classes and I'm very rusty with mechanisms.
[Edited on 15-5-2024 by Yorty2040]