| 564 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {1} |
| 1 | DF | .~ AMINO NITROGEN CONTAINING (E.G., UREA, SULFONAMIDES, NITROSAMINES, OXYAMINES, ETC., AND SALTS THEREOF) {37} |
| 305 | DF | .~.~ Benzene ring containing {24} |
| 307 | DF | .~.~.~ Amino nitrogen and a ring bonded directly to the same ring, and any other amino nitrogen in the compound is bonded directly to one of the rings {2} |
| 309 | | .~.~.~.~ Benzidines |