with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms

Full Title

Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom > with only hydrogen or carbon atoms directly attached to the ring nitrogen atom > having one double bond between ring members or between a ring member and a non-ring member > with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms