[OrganicH2O]

I was just thinking about 2 possible mechanisms for the base promoted hydrolysis of a carbamic acid to an amine and sodium carbonate. I attached a picture with two mechanisms labeled "A" and "B". I understand that carbamic acids are not very stable, and that this is probably starting with a reactive intermediate.

It seems any mechanism I draw has some part that looks pretty nasty. Presumably this would require heat. No matter what, it seems I have to form a mediocre nitrogen anion leaving group. I can either expel the leaving group directly from the conjugate base, or form a tetrahedral intermediate, perhaps a di-anion, and expel the leaving group that way.

It all seems much simpler in neutral or acidic conditions. If it's basic, this is actually stabilizing the ion by favoring formation of the conjugate base, and making it unlikely that the nitrogen can be protonated before leaving.

[Orcio_87]

Look here:

Inga Christenson "Alkaline hydrolysis of some carbamic acid esters" Acta Chem Scand (1964)

First mechanism:

H₂N-COOH ---> NH₃ + CO₂

is supported.