C CHEMISTRY; METALLURGY
C07 ORGANIC CHEMISTRY
C07D HETEROCYCLIC COMPOUNDS
213/00 Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
C07D213/02 having three double bonds between ring members or between ring members and non-ring members
C07D213/04 having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom