The molecule is a 5-membered aromatic 1,3-oxazole ring (position 1 = O, 3 = N).

Ring substituents:
1. At carbon-2, the single ring hydrogen is replaced by deuterium.
2. At carbon-4 a linear azide group (-N3) (i.e., the ring carbon forms a single bond to a nitrogen, which is double-bonded to a positively charged nitrogen, itself double-bonded to a negatively charged terminal nitrogen).