only one oxygen atom which is attached in position 4

Full Title

Heterocyclic compounds containing quinoline or hydrogenated quinoline ring systems > having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen atoms or carbon atoms directly attached to the ring nitrogen atom > with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms > Oxygen atoms > attached in position 2 or 4 > only one oxygen atom which is attached in position 4