Heterocyclic compounds containing two or more hetero rings, at least one ring having oxygen atoms as the only ring hetero atoms, not provided for by group [CPC: C07D405/00] containing two hetero rings linked by a chain containing hetero atoms as chain links
Heterocyclic compounds containing two or more hetero rings, at least one ring having oxygen atoms as the only ring hetero atoms, not provided for by group [CPC: C07D405/00] containing two hetero rings linked by a chain containing hetero atoms as chain links