Hello,

I expect that thiazin nitrogen in certain conditions can react as a nucleophile (probably preformed amide anion) and attack the imide carbonyl carbon. I do not expect sulfur to be reactive towards the imide.

Ammonia itself break imides, however thiazin nitrogen is less nucleophilic, it recats with acyl halogenides and anhydrides, and it can be alkylated (there is a lot of examples in scifinder) but imides are less reactive derivatives so in order these two to react you need to adapt the condtions.