534 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
* | DD | ORGANIC COMPOUNDS (CLASS 532, SUBCLASS 1) {8} |
573 | DF | .~ Azo {51} |
816 | DF | .~.~ Exactly two azo groups attached indirectly to each other by nonionic bonding {7} |
821 | .~.~.~ Plural benzene rings bonded directly to the same chalcogen or -C(=X)- group, wherein X is chalcogen, and are between the azo groups |