Skip to content
PCE
Search Classifications
Search for IPC and CPC classification codes or keywords
IPC Subclass
C07D

HETEROCYCLIC COMPOUNDS

Introduced: September 1968

Last revised: July 1974

Classification Context

Section:
CHEMISTRY; METALLURGY
Class:
ORGANIC CHEMISTRY
Subclass:
HETEROCYCLIC COMPOUNDS

Description

Heterocyclic compounds containing one or more atoms other than carbon in a ring structure, including nitrogen, oxygen, sulfur, phosphorus, and other heteroatoms. This subclass encompasses diverse ring systems ranging from simple five- and six-membered rings (such as pyrroles, furans, thiophenes, and pyridines) to complex polycyclic and fused ring structures. Compounds are classified by ring size, number of heteroatoms, and their position within the ring system, with separate divisions addressing specific chemical properties and synthesis routes. Adjacent subclass C07C covers acyclic and carbocyclic organic compounds, while C07B addresses general methods of organic synthesis applicable across compound classes.

Scope Notes

Glossary: Acyclic The absence of a ring structure. Acyclic chains may be linear or branched. Bridged Where two condensed rings share at least three adjacent ring members. Carbocyclic Where all ring members in a ring are carbon atoms. Condensed Where at least two rings share at least one ring member. Condensed ring system condensed ring systems A ring system in which all rings are condensed among themselves, i.e. a ring system wherein the scission of a single connection between two ring atoms cannot result in the division of the ring system into separate entities. Two or more hetero rings are considered part of the same condensed ring system if they condensed among themselves or to a common carbocycle or carbocycle system. Heterocyclic Wherein at least one ring member in a molecule containing a ring of atoms is not a carbon atom. For the purposes of classification in this subclass, a narrower definition applies wherein heteroatoms may only be chosen from nitrogen, oxygen, sulfur, selenium, tellurium or halogen. Ortho-condensed Where two condensed rings share two adjacent ring atoms in common. A ring system is deemed ortho-condensed if each ring shares only one face with any other ring, and no ring has two adjacent shared faces. Peri-condensed Where three rings in a condensed ring system share a single ring atom in common. Plant plants Any of a kingdom (Plantae) of multicellular eukaryotic mostly photosynthetic organisms typically lacking locomotive movement or obvious nervous or sensory organs and possessing cellulose cell walls. Spiro-condensed Where two condensed rings share only one atom in common. Number of relevant rings In a condensed ring system, this equals the minimum number of scissions necessary to convert the ring system into an acyclic chain, a scission being the disconnection of two bonded atoms, without regard for the bond order. Relevant rings These are the rings which account for all the bonds in a condensed system. In order to prevent ambiguity in classifying a condensed ring system, the rings which identify the ring system are determined according to the following hierarchy of criteria: the rings with the lowest number of members; the rings with the highest number of hetero atoms as ring members; the rings with the lowest number of members shared between rings; the rings with the latest place in the classification scheme. | Limiting references: Macromolecular compounds Preparation of heterocyclic organic compounds using enzymes or fermentation processes Electrolytic production of organic compounds Processes for producing compounds in which simultaneously electricity is generated Electrophoretic production of compounds

Related Keywords

ALKALOIDSHETEROCYCLIC compoundsorganic compounds containing sulfur, selenium, or tellurium wherein sulfur is within a ringorganic compounds containing SULFUR

109 direct subcodes

Child Classifications

Navigate with arrow keys, Enter to open