Performing a quite old reaction: a Hoffmann Degradation/Rearrangement.
It was discovered by August Wilhelm von Hofmann Hofmann in 1881. It is a transformation that converts a primary amide to a primary amine with one fewer carbon atom:
The reaction uses elemental bromine and works in a highly basic medium, in my case for every mol of amide 10 equivalent of NaOH was needed. As the reaction proceeds, my product separated as an orange powder (as seen on the gifs), as the end it was a highly basic (pH 15-16) orange slurry. However it worked great and it was a quite spectacular reaction.
Someone on Wikipedia draw the reaction mechanism, so let’s see it:
Base abstracts an acidic N-H proton, yielding an anion.
The anion reacts with bromine in an α-substitution reaction to give an N-bromoamide.
Base abstraction of the remaining amide proton gives a bromoamide anion.
The bromoamide anion rearranges as the R group attached to the carbonyl carbon migrates to nitrogen at the same time the bromide ion leaves, giving an isocyanate.
The isocyanate adds water in a nucleophilic addition step to yield a carbamic acid (aka urethane).
The carbamic acid spontaneously loses CO2, yielding the amine product.
