One doubly-bound oxygen atom in position 2, e.g. lactams

Heterocyclic compounds containing rings having one nitrogen atom as the only ring hetero atom, according to more than one of groups > with only hydrogen 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 > One doubly-bound oxygen atom in position 2, e.g. lactams

Heterocyclic compounds containing rings having one nitrogen atom as the only ring hetero atom, according to more than one of groups C07D203/00 - C07D225/00 > with only hydrogen 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 > One doubly-bound oxygen atom in position 2, e.g. lactams