with oxygen and nitrogen atoms in positions 1 and 3

Full Title

Heterocyclic compounds containing five-membered rings, condensed with other rings, with one nitrogen atom as the only ring hetero atom > Ring systems containing three or more rings > [b]- or [c]-condensed > Naphtho [c] pyrroles; Hydrogenated naphtho [c] pyrroles > with oxygen and nitrogen atoms in positions 1 and 3