| 552 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
|
| * | DD | ORGANIC COMPOUNDS (Class 532, subclass 1) {11} |
| 208 | DF | .~ Polycyclo ring system containing anthracene configured ring system having at least one double bond between ring members and having oxygen single bonded or any atom double bonded directly at the 9- and 10-positions (e.g., anthraquinones, etc.) {19} |
| 238 | DF | .~.~ Nitrogen bonded directly at alpha position (i.e., 1-, 4-, 5- or 8-position) {7} |
| 255 | DF | .~.~.~ Additional carbon bonded directly to the nitrogen {3} |
| 256 | DF | .~.~.~.~ The additional carbon is part of a carbonyl group (i.e., carboxamido bonded directly at alpha position) {1} |
| 257 |  | .~.~.~.~.~ Nitrogen, oxygen, sulfur or halogen bonded directly to an additional ring |