The following is a snapshot of the synthesis of ammosamide B from Synarchive:
In the final step $\ce{Mg3N2}$ is used to convert esters to amides or amides to amines. What is the mechanism of this process? How does the $\ce{N3-}$ get converted to $\ce{H2O}?$
$\ce{Mg3N2}$ is magnesium nitride. It reacts with $\ce{MeOH}$ to generate magnesium methoxide and ammonia according to online report by Buske [1]. The $\ce{NH3}$ thus generated is acting as nucleophile to react with the methyl ester to give the primary amide. It also removes two trifluoracetamide groups (or the $\ce{MeO-}$ does) to reveal the amino groups.
Quite why the authors have chosen to use this over more conventional sources of $\ce{NH3}/\ce{MeOH}$ (which is commercially available) is for them to explain.
