|  | C |
SECTION C — CHEMISTRY AND METALLURGY

CHEMISTRY

|  | C07 |
ORGANIC CHEMISTRY (such compounds as the oxides, sulphides, and oxysulphides of carbon, cyanogen, phosgene, hydrocyanic acid and salts thereof Fulltext... Hierarchy... Expanded...C01; macromolecular compounds Fulltext... Hierarchy... Expanded...C08; dyes Fulltext... Hierarchy... Expanded...C09; fermentation products Fulltext... Hierarchy... Expanded...C12)

|  | C07 |
Note(s) Salts of a compound, unless specifically provided for, are classified as that compound, e.g. aniline hydrochloride is classified as containing carbon, hydrogen and nitrogen only (in Fulltext... Hierarchy... Expanded...C07C 87/52), sodium oxalate is classified as oxalic acid (in Fulltext... Hierarchy... Expanded...C07C 55/06), and a mercaptide is classified as the mercaptan. Metal chelates are dealt with in the same way. Similarly, metal alcoholates and metal phenates are classified in Fulltext... Hierarchy... Expanded...C07C and not in Fulltext... Hierarchy... Expanded...C07F— the alcoholates in Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...C07C 31/28-C07C 31/32 and the phenates as the corresponding phenols in Fulltext... Hierarchy... Expanded...C07C 39/00. In the absence of an indication to the contrary, and with the exception referred to below, a compound is always classified in the last appropriate place in the classification system, e.g. a compound containing an acyclic chain and a heterocyclic ring is classified only as a heterocyclic compound, and a sterol is classified only as a cyclopentanophenanthrene compound. In general, and in the absence of an indication to the contrary (such as groups Fulltext... Hierarchy... Expanded...C07C 59/24, Fulltext... Hierarchy... Expanded...C07C 59/26), the terms "acyclic" and "aliphatic" are used to describe compounds in which there is no ring; and, if a ring were present, the compound would be taken by the "last place" rule to a later group for cycloaliphatic or aromatic compounds, if such a group exists. Where a compound or an entire group of compounds exists in tautomeric forms, it is classified as though existing in the form which is classified last in the system, unless the other form is specifically mentioned earlier in the system. Albumens, proteins, alkaloids of unknown structure, glucosides of unknown structure are examples of compounds to be found unter Fulltext... Hierarchy... Expanded...C07G. Inventions dealing with the preparation of chemical compounds might be classified both according to the type of reaction employed and according to the type of compound prepared, if suitable groups or sub-groups exits.

|  | C07B |
GENERAL METHODS AND APPARATUS OF ORGANIC CHEMISTRY

|  | C07C |
ACYCLIC AND CARBOCYCLIC COMPOUNDS

|  | C07C |
Note(s) Inventions dealing with the preparation of chemical compounds may, if suitable groups exist, be classified both according to the type of reaction employed and according to the type of compounds prepared.

|  | C07D |
HETEROCYCLIC COMPOUNDS (peptides containing heterocyclic groups Fulltext... Hierarchy... Expanded...C07C 103/52)

|  | C07D |
Note(s) In the absence of an indication to the contrary (such as the mention of isatoic anhydride in Fulltext... Hierarchy... Expanded...C07D 87/10), the cyclic anhydride of a polycarboxylic acid is classified with the acid in Fulltext... Hierarchy... Expanded...C07C. In this sub-class When applying the "last place" rule, it is necessary to remember that the rule only applies in the absence of an indication to the contrary. Such an indication may take the form of a group specifically worded to cover particular compounds, e.g. "Fulltext... Hierarchy... Expanded...C07D 91/52.....Thiazolo-pyrimidines", which substances might otherwise have been classified in Fulltext... Hierarchy... Expanded...C07D 99/00) The indication may also take the form of the phrase "condensed with one or more other rings", and in this case the term "other rings" includes any ring except one which is covered later in Fulltext... Hierarchy... Expanded...C07D. Thus, for example, in spite of the wording of the Guide Heading before Fulltext... Hierarchy... Expanded...C07D 59/00, the compound is to be found in Fulltext... Hierarchy... Expanded...C07D 63/18, and not under Fulltext... Hierarchy... Expanded...C07D 99/00, as might have been supposed at first sight. It is also to be noted that there is no specific mention under Fulltext... Hierarchy... Expanded...C07D 63/00 of tetrahydrothiophene condensed with one or more other rings, but the use in Fulltext... Hierarchy... Expanded...C07D 63/02 of the plural form of the name implies that this group includes those compounds, the term "other rings" having the same meaning as give above. This is covered by Fulltext... Hierarchy... Expanded...C07D 63/02. It is also noteworthy that the alkaloids scopoline, morphine, and strychnine have for convenience been places under Fulltext... Hierarchy... Expanded...C07D 43/00, although they contain heterocyclic oxygen, and do not, accordingly, fit strictly under the Guide Heading before Fulltext... Hierarchy... Expanded...C07D 23/00. A further complication arises in the case of condensed ring systems, namely: which rings must be taken into account when determining the classification. The rule is as follows: Only single rings are to be considered, and bridged rings are to be ignored except where the bridged-ring system is one, such as quinoline, which is specifically named in the classification. Thus in the case of the compound only te two C5N rings are considered, and not the bridged C8N2 one, and the correct classification is under Fulltext... Hierarchy... Expanded...C07D 39/00 and not under Fulltext... Hierarchy... Expanded...C07D 53/00).

|  | C07F |
ACYCLIC, CARBOCYCLIC, OR HETEROCYCLIC COMPOUNDS CONTAINING, OUTSIDE ANY RING, ELEMENTS OTHER THAN HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULPHUR, SELENIUM, AND TELLURIUM, WITH OR WITHOUT THE LATTER SPECIFIED ELEMENTS (acetylides Fulltext... Hierarchy... Expanded...C07C 11/26; metal-containing porphyrins Fulltext... Hierarchy... Expanded...C07D 27/76)

|  | C07G |
COMPOUNDS OF UNKNOWN CONSTITUTION