US PATENT SUBCLASS 549 / 224
.~.~.~.~ The xanthene ring system is three cyclos of a polycyclo ring system having at least four rings (e.g., benz(c)fluorans, etc.)


Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use



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}
223  DF  .~.~.~ Xanthene ring system having a benzene ring bonded directly thereto para to the xanthene ring oxygen, wherein the carbon of a -COO- group is bonded directly to the benzene ring ortho to its position of attachment to the xanthene ring system, and spirolactone derivatives thereof (e.g., fluoresceins, chlorofluorans, etc.) {2}
224.~.~.~.~ The xanthene ring system is three cyclos of a polycyclo ring system having at least four rings (e.g., benz(c)fluorans, etc.)


DEFINITION

Classification: 549/224

(under subclass 223) Compounds which contain the xanthene ring system as three cyclos of a polycyclo ring system containing four or more rings.

(1) Note. Examples of compounds provided for herein are: [figure] [figure]