Additional hetero ring containing

Subclass of:

544 - Organic compounds -- part of the class 532-570 series

544000000 - ORGANIC COMPOUNDS (CLASS 532, SUBCLASS 1)

544000000 - 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)

544001000 - Hetero ring is six-membered having two or more ring hetero atoms of which at least one is nitrogen (e.g., selenazines, etc.)

544224000 - The six-membered hetero ring consists of two nitrogens and four carbons (e.g., 1,2-diazines, etc.)

544336000 - 1,4-diazines

544358000 - Piperazines (i.e., fully hydrogenated 1,4-diazines)

Patent class list (only not empty are listed)

Deeper subclasses:

Class / Patent application number	Description	Number of patent applications / Date published
544360000	Six-membered ring consisting of one nitrogen and five carbons (e.g., pyridine, etc.)	53
544366000	Five-membered hetero ring having two or more ring hetero atoms of which at least one is nitrogen	47
544372000	Five-membered hetero ring consisting of one nitrogen and four carbons	20
544374000	Ring chalcogen in the additional hetero ring	13