C CHEMISTRY; METALLURGY
C07 ORGANIC CHEMISTRY
C07D HETEROCYCLIC COMPOUNDS
405/00 Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom
C07D405/02 containing two hetero rings
C07D405/12 linked by a chain containing hetero atoms as chain links