| 549 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
|
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {1} |
| * | DD | .~ HETEROCYCLIC CARBON COMPOUNDS CONTAINING A HETERO RING HAVING CHALCOGEN (I.E., OXYGEN, SULFUR, SELENIUM, OR TELLURIUM) OR NITROGEN AS THE ONLY RING HETERO ATOMS (Class 540, subclass 1) {2} |
| 200 | DF | .~.~ Oxygen containing hetero ring (e.g., dioxirane, etc.) {16} |
| 429 | DF | .~.~.~ The hetero ring is five-membered {14} |
| 430 | DF | .~.~.~.~ Plural ring oxygens in the hetero ring {8} |
| 453 | DF | .~.~.~.~.~ Chalcogen attached indirectly to the hetero ring by nonionic bonding {1} |
| 454 |  | .~.~.~.~.~.~ The chalcogen, X, is in a -C(=X)- group |