SEARCH Articles Figures Tables 5-Membered rings heteroatoms Five Heteroatoms Five-Membered Heterocycled Five-Membered Rings with Two Heteroatoms Five-membered heterocycles Five-membered heterocycles with two Five-membered heterocycles with two heteroatom Five-membered heterocycles with two heteroatoms Five-membered heterocyclic rings Five-membered heterocyclics Five-membered ring Five-membered rings heteroatoms Heteroatom heterocycles Heteroatomic Rings Heteroatoms Heterocycles Heterocycle, five ring Heterocycles with Two Heteroatoms Heterocycles with heteroatoms Heterocyclic 5- membered ring Of heterocycles: five-membered rings with Of heterocyclic rings