C
SECTION C — CHEMISTRY; METALLURGY
 C

Note(s)

In section C, the definitions of groups of chemical elements are as follows:

  • Alkali metals: Li, Na, K, Rb, Cs, Fr
  • Alkaline earth metals: Ca, Sr, Ba, Ra
  • Lanthanides: elements with atomic numbers 57 to 71 inclusive
  • Rare earths: Sc, Y, Lanthanides
  • Actinides: elements with atomic numbers 89 to 103 inclusive
  • Refractory metals: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W
  • Halogens: F, Cl, Br, I, At
  • Noble gases: He, Ne, Ar, Kr, Xe, Rn
  • Platinum group: Os, Ir, Pt, Ru, Rh, Pd
  • Noble metals: Ag, Au, Platinum group
  • Light metals: alkali metals, alkaline earth metals, Be, Al, Mg
  • Heavy metals: metals other than light metals
  • Iron group: Fe, Co, Ni
  • Non-metals: H, B, C, Si, N, P, O, S, Se, Te, noble gases, halogens
  • Metals: elements other than non-metals
  • Transition elements: elements with atomic numbers 21 to 30 inclusive, 39 to 48 inclusive, 57 to 80 inclusive, 89 upwards

The following notes are meant to assist in the use of this part of the classification scheme; they must not be read as modifying in any way the elaborations.

  1. Section C covers:
    1. pure chemistry, which covers inorganic compounds, organic compounds, macromolecular compounds, and their methods of preparation;
    2. applied chemistry, which covers compositions containing the above compounds, such as: glass, ceramics, fertilisers, plastics compositions, paints, products of the petroleum industry. It also covers certain compositions on account of their having particular properties rendering them suitable for certain purposes, as in the case of explosives, dyestuffs, adhesives, lubricants, and detergents;
    3. certain marginal industries, such as the manufacture of coke and of solid or gaseous fuels, the production and refining of oils, fats and waxes, the fermentation industry (e.g. brewing and wine-making), the sugar industry;
    4. certain operations or treatments, which are either purely mechanical, e.g. the mechanical treatment of leather and skins, or partly mechanical, e.g. the treatment of water or the prevention of corrosion in general;
    5. metallurgy, ferrous or non-ferrous alloys.
    1. In the case of operations, treatments, products or articles having both a chemical and a non-chemical part or aspect, the general rule is that the chemical part or aspect is covered by section C.
    2. In some of these cases, the chemical part or aspect brings with it a non-chemical one, even though purely mechanical, because this latter aspect either is essential to the operation or treatment or constitutes an important element of it; it has seemed, in fact, more logical not to dissociate the different parts or aspects of a coherent whole. This is the case for applied chemistry and for the industries, operations and treatments mentioned in Notes (1)(c), (d) and (e). For example, furnaces peculiar to the manufacture of glass are covered by class C03 and not by class F27.
    3. There are, however, some exceptions in which the mechanical (or non-chemical) aspect carries with it the chemical aspect, for example:
    4. In still other cases, the pure chemical aspect is covered by section C and the applied chemical aspect by another section, such as A, B or F, e.g. the use of a substance or composition for:
    5. When the chemical and mechanical aspects are so closely interlocked that a neat and simple division is not possible, or when certain mechanical processes follow as a natural or logical continuation of a chemical treatment, section C may cover, in addition to the chemical aspect, a part only of the mechanical aspect, e.g. after-treatment of artificial stone, covered by class C04. In this latter case, a note or a reference is usually given to make the position clear, even if sometimes the division is rather arbitrary.

  
CHEMISTRY
 C07
ORGANIC CHEMISTRY (such compounds as the oxides, sulfides, or oxysulfides of carbon, cyanogen, phosgene, hydrocyanic acid or salts thereof C01; organoclay material C01B 33/21; macromolecular compounds C08; dyes C09; fermentation products C12; fermentation or enzyme-using processes to synthesise a desired chemical compound or composition or to separate optical isomers from a racemic mixture C12P; production of organic compounds by electrolysis or electrophoresis C25B 3/00, C25B 7/00)  [2]
 C07

Note(s)

  1. In this class, the following term is used with the meaning indicated:
    • "preparation" covers purification, separation, stabilisation or use of additives, unless a separate place is provided therefor. [4]
  2. In this class, in the absence of an indication to the contrary, and with the exception referred to below, a compound is classified in the last appropriate place, e.g. a compound containing an acyclic chain and a heterocyclic ring is classified only as a heterocyclic compound, and a steroid is classified only as a cyclopentanophenanthrene compound. In general, and in the absence of an indication to the contrary (such as groups C07C 59/58, C07C 59/70), 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.
  3. Inventions dealing with chemical compounds and their preparation are classified in the groups for the type of compound prepared. The processes of preparation are also classified in the groups for the types of reaction employed, if of interest. General processes for the preparation of a class of compounds falling into more than one main group are classified in the groups for the processes employed, when such groups exist. The compounds prepared are also classified in the groups for the types of compound prepared, if of interest.
  4. In this class, in the absence of an indication to the contrary, the compounds containing carboxyl or thiocarboxyl groups are classified as the relevant carboxylic or thiocarboxylic acids, unless the "last place rule" (see Note (2), above) dictates otherwise; a carboxyl group being a carbon atom having three bonds, and no more than three, to hetero atoms, other than nitrogen atoms of nitro or nitroso groups, with at least one multiple bond to the same hetero atom and a thiocarboxyl group being a carboxyl group having at least one bond to a sulfur atom, e.g. amides or nitriles of carboxylic acids, are classified with the corresponding acids. [5]
  5. Anhydrides and halides of carboxylic acids are classified as the relevant acids unless otherwise indicated. 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 group C07C 211/46), sodium malonate is classified as malonic acid (in C07C 55/08), 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 subclass C07C and not in subclass C07F, the alcoholates in groups C07C 31/28-C07C 31/32 and the phenates as the corresponding phenols in group C07C 39/235 or C07C 39/44. Salts or adducts formed between two or more organic compounds are classified according to all compounds forming the salts or adducts. [2]
 C07B
GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR (preparation of carboxylic acid esters by telomerisation C07C 67/47; telomerisation C08F)
 C07B

Note(s)

  1. In this subclass, the functional group which is present already in some residue being introduced and is not substantially involved in a chemical reaction, is not considered as the functional group which is formed or introduced as a result of the chemical reaction. [4]
  2. In this subclass, the following term is used with the meaning indicated:
    • "separation" means separation only for the purposes of recovering organic compounds. [4]
  3. In this subclass, in the absence of an indication to the contrary, an invention is classified in the last appropriate place according to the type of reaction employed, noting the bond or the functional group which is formed or introduced as a result of the chemical reaction. [4]

 C07C
ACYCLIC OR CARBOCYCLIC COMPOUNDS
 C07C

Note(s)

  1. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "bridged" means the presence of at least one fusion other than ortho, peri or spiro;
    • two rings are "condensed" if they share at least one ring member, i.e. "spiro" and "bridged" are considered as condensed;
    • "condensed ring system" is a ring system in which all rings are condensed among themselves;
    • "number of rings" in a condensed ring system equals the number of scissions necessary to convert the ring system into one acyclic chain;
    • "quinones" are compounds derived from compounds containing a six-membered aromatic ring or a system comprising six-membered aromatic rings (which system may be condensed or not condensed) by replacing two or four CH groups of the six-membered aromatic rings by C=O groups, and by removing one or two carbon-to-carbon double bonds, respectively, and rearranging the remaining carbon-to-carbon double bonds to give a ring or ring system with alternating double bonds, including the carbon-to-oxygen bonds; this means that acenaphthoquinone or camphorquinone are not considered as quinones. [5]
  2. In this subclass, in the absence of an indication to the contrary, a process is classified in the last appropriate place. [3]
  3. In this subclass, in the absence of an indication to the contrary, "quaternary ammonium compounds" are classified with the corresponding "non-quaternised nitrogen compounds". [5]
  4. For the classification of compounds in groups C07C 1/00-C07C 71/00 and C07C 401/00-C07C 409/00:
    • a compound is classified considering the molecule as a whole (rule of the "whole molecule approach");
    • a compound is considered to be saturated if it does not contain carbon atoms bound to each other by multiple bonds;
    • a compound is considered to be unsaturated if it contains carbon atoms bound to each other by multiple bonds, which includes a six-membered aromatic ring,
    unless otherwise specified or implicitely derivable from the subdivision, as in group C07C 69/00, e.g. C07C 69/712[5]
  5. For the classification of compounds in groups C07C 201/00-C07C 395/00, i.e. after the functional group has been determined according to the "last place rule", a compound is classified according to the following principles:
    • compounds are classified in accordance with the nature of the carbon atom to which the functional group is attached;
    • a carbon skeleton is a carbon atom, other than a carbon atom of a carboxyl group, or a chain of carbon atoms bound to each other; a carbon skeleton is considered to be terminated by every bond to an element other than carbon or to a carbon atom of a carboxyl group;
    • when the molecule contains several functional groups, only functional groups linked to the same carbon skeleton as the one first determined are considered;
    • a carbon skeleton is considered to be saturated if it does not contain carbon atoms bound to each other by multiple bonds;
    • a carbon skeleton is considered to be unsaturated if it contains carbon atoms bound to each other by multiple bonds, which includes a six-membered aromatic ring. [5]

 C07D
HETEROCYCLIC COMPOUNDS  [2]
 C07D

Note(s)

  1. This subclass does not cover compounds containing saccharide radicals (as defined in Note (2) following the title of subclass C07H), which are covered by subclass C07H[2]
  2. In this subclass, in compounds containing a hetero ring covered by group C07D 295/00 and at least one other hetero ring, the hetero ring covered by group C07D 295/00 is considered as an acyclic chain containing nitrogen atoms. [3]
  3. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "hetero ring" is a ring having at least one halogen, nitrogen, oxygen, sulfur, selenium, or tellurium atom as a ring member; [2]
    • "bridged" means the presence of at least one fusion other than ortho, peri or spiro; [2]
    • two rings are "condensed" if they share at least one ring member, i.e. "spiro" and "bridged" are considered as condensed; [2]
    • "condensed ring system" is a ring system in which all rings are condensed among themselves; [2]
    • "number of relevant rings" in a condensed ring system equals the number of scissions necessary to convert the ring system into one acyclic chain; [2]
    • "relevant rings" in a condensed ring system, i.e. the rings which taken together describe all the links between every atom of the ring system, are chosen according to the following criteria consecutively:
      1. lowest number of ring members;
      2. highest number of hetero atoms as ring members;
      3. lowest number of members shared with other rings;
      4. last place in the classification scheme. [2]
  4. In this subclass, in the absence of an indication to the contrary:
    1. compounds having only one hetero ring are classified in the last appropriate place in one of the groups C07D 203/00-C07D 347/00. The same applies for compounds having more hetero rings covered by the same main group, neither condensed among themselves nor condensed with a common carbocyclic ring system; [2]
    2. compounds having two or more hetero rings covered by different main groups neither condensed among themselves nor condensed with a common carbocyclic ring system are classified in the last appropriate place in one of the groups C07D 401/00-C07D 421/00[2]
    3. compounds having two or more relevant hetero rings, covered by the same or by different main groups, which are condensed among themselves or condensed with a common carbocyclic ring system, are classified in the last appropriate place in one of the groups C07D 451/00-C07D 519/00[2]
  5. In this subclass:
    • where a compound may exist in tautomeric forms, it is classified as though existing in the form which is classified last in the system. Therefore, double bonds between ring members and non-ring members and double bonds between ring members themselves are considered equivalent in determining the degree of hydrogenation of the ring. Formulae are considered to be written in Kekulé form; [2]
    • hydrocarbon radicals containing a carbocyclic ring and an acyclic chain by which it is linked to the hetero ring and being substituted on both the carbocyclic ring and the acyclic chain by hetero atoms or by carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, are classified according to the substituents on the acyclic chain. For example, the compound

      is classified in group C07D 233/22, and the compound

      is classified in groups C07D 233/24 and C07D 233/26, where X —NH2, —NHCOCH3, or —COOCH3[2]

  6. In this subclass, it is desirable to add the indexing codes relating to individual components, chosen according to the guidelines mentioned under (a) to (d) below. The indexing codes, which are chosen as indicated below, have the same numbers as the classification symbols, but a colon is used instead of the oblique stroke, and should be linked. The following guidelines should be followed:
    1. For compounds classified in groups C07D 203/00-C07D 347/00 one or more appropriate places which precede the classification place may be given as additional information, e.g. in order to show essential substituents. [2]
    2. In compounds containing two or more hetero rings covered by different main groups, neither condensed among themselves nor with a common carbocyclic ring system, each hetero ring is shown as additional information. The appropriate marks are determined by scission of all other hetero rings and considering them as substituents. The locations of the scissions are chosen so as to obtain the substituents which appear in the later place in the Classification, e.g. the relevant rings of

      are considered to be

      and the invention information and additional information relating to the said compound would read:

      C07D 401/06 // (C07D 401/06, C07D 213/58, C07D 233/24). [2]

    3. For compounds containing one condensed ring system having two or more relevant hetero rings, and for which no specific group is provided, all relevant rings having hetero atoms as ring members are shown as additional information. These rings are indicated by the main group symbols of groups C07D 203/00-C07D 347/00, except of groups C07D 207/00, C07D 211/00-C07D 219/00, C07D 233/00, C07D 295/00 and C07D 309/00[2]
    4. For compounds containing two or more condensed ring systems each having two or more hetero rings, each condensed system is shown as additional information. The appropriate marks are found in the groups C07D 451/00-C07D 517/00 and determined by considering separately each condensed system in turn. [2]

 C07F
ACYCLIC, CARBOCYCLIC, OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM, OR TELLURIUM (metal-containing porphyrins C07D 487/22)
 C07F

Note(s)

  1. Attention is drawn to Note (4) following the title of class C07[2]
  2. In this subclass, organic acid salts, alcoholates, phenates, chelates or mercaptides are classified as the parent compounds. [2]

 C07G
COMPOUNDS OF UNKNOWN CONSTITUTION
 C07G

Note(s)

This subclass does not cover peptides or proteins, of unknown constitution, which are covered by subclass C07K[4]


 C07H
SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS (derivatives of aldonic or saccharic acids C07C, C07D; aldonic acids, saccharic acids C07C 59/105, C07C 59/285; cyanohydrins C07C 255/16; glycals C07D; compounds of unknown constitution C07G; polysaccharides, derivatives thereof C08B; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N 15/00; sugar industry C13)  [2]
 C07H

Note(s)

  1. This subclass covers compounds containing saccharide radicals (see the definitions in Note (3) below).
  2. This subclass does not cover polysaccharides which for the purpose of this subclass are defined as having more than five saccharide radicals attached to each other by glycosidic linkages.
  3. In this subclass, the following expressions are used with the meanings indicated:
    • "saccharide radical" which is derived from acyclic polyhydroxy-aldehydes or acyclic polyhydroxy-ketones, or from their cyclic tautomers, by removing hydrogen atoms or by replacing hetero bonds to oxygen by the same number of hetero bonds to halogen, nitrogen, sulfur, selenium, or tellurium, in accordance with either of the following definitions:
      1. It
        1. consists of an uninterrupted carbon skeleton and oxygen atoms directly attached thereto, and
        2. is considered to be terminated by every bond to a carbon atom of a cyclic structure and by every bond to a carbon atom having three bonds to hetero atoms, e.g. ester or nitrile radicals, and
        3. contains within the carbon skeleton an unbranched sequence of at the most six carbon atoms in which at least three carbon atoms—at least two in the case of a skeleton having only four carbon atoms—have one single bond to an oxygen atom as the only hetero bond, and
          1. in a cyclic or acyclic sequence, at least one other carbon atom has two single bonds to oxygen atoms as the only hetero bonds, or
          2. in an acyclic sequence, at least one other carbon atom has one double bond to an oxygen atom as the only hetero bond,

            the said sequence containing at the most one double bond, i.e. C=C or possibly ketalised C=O, in addition to the hetero bonds mentioned above under (A) or (B), e.g. the compounds

            an unbranched sequence of at the most six carbon atoms, having bonds to oxygen as defined in this Note

            n being an integer, are classified in group C07H 3/02[4]

      2. It is also a radical derived from a radical as defined in (a) above by replacing at the most four of the specified hetero bonds to oxygen by the same number of hetero bonds to halogen, nitrogen, sulfur, selenium, or tellurium; [2]
    • "heterocyclic radical" or "hetero ring" is considered to exclude saccharide radicals as defined above. [2]
  4. Attention is drawn to the Notes following the title of class C07[2]
  5. In this subclass, in the absence of an indication to the contrary, a compound is classified in the last appropriate place. [2]

 C07J
STEROIDS (seco-steroids C07C)  [2]
 C07J

Note(s)

This subclass covers compounds containing a cyclopenta [a] hydrophenanthrene skeleton or a ring structure derived therefrom:

  • by contraction or expansion of one ring by one or two atoms,
  • by contraction or expansion of two rings each by one atom,
  • by contraction of one ring by one atom and expansion of one ring by one atom,
  • by substitution of one or two carbon atoms of the cyclopenta [a] hydrophenanthrene skeleton, which are not shared by rings, by hetero atoms, in combination with the above defined contraction or expansion or not, or
  • by condensation with carbocyclic or heterocyclic rings in combination with one or more of the foregoing alterations or not. [4]


 C07K
PEPTIDES; PROTEINS (protein food compositions A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D 519/02; macromolecular compounds having statistically distributed aminoacid units in their molecules, i.e. when the preparation does not provide for a specific, but for a random sequence of the aminoacid units, homopolyamides and block copolyamides derived from aminoacids C08G 69/00; macromolecular products derived from proteins C08H 1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N 33/00)  [4]
 C07K

Note(s)

In this subclass, the following terms or expressions are used with the meanings indicated:

  • "aminoacids" are compounds in which at least one amino group and at least one carboxyl group are bound to the same carbon skeleton and the nitrogen atom of the amino group may form part of a ring;
  • "normal peptide link" is one between an alpha-amino group of an aminoacid and the carboxyl group — in position 1 — of another alpha-aminoacid;
  • "abnormal peptide link" is one between a non-alpha-amino group of an aminoacid and the carboxyl group — in position 1 — of an alpha-aminoacid, or between an alpha-amino group of one aminoacid and the carboxyl group — not in position 1 — of another aminoacid;
  • "peptides" are compounds containing a sequence of 2 to 100 aminoacid units, which are bound through at least one normal peptide link, where
    1. "linear peptides" may comprise rings formed through S—S bridges, or through an hydroxy or a mercapto group of an hydroxy- or a mercapto-aminoacid and the carboxyl group of another aminoacid (e.g. peptide lactones) but do not comprise rings which are formed only through peptide links;
    2. "cyclic peptides" are peptides comprising at least one ring formed only through peptide links; the cyclisation may occur only through normal peptide links or through abnormal peptide links, e.g. through the 4-amino group of 2,4-diamino-butanoic acid. Thus, cyclic compounds in which at least one link in the ring is a non-peptide link are considered as "linear peptides";
  • "depsipeptides" are compounds containing a sequence of at least two alpha-aminoacids and at least one alpha-hydroxy carboxylic acid, which are bound through at least one normal peptide link and ester links, derived from the hydroxy carboxylic acids, the total number of units in the sequence being 4 to 100, where
    1. "linear depsipeptides" may comprise rings formed through S—S bridges, or through an hydroxy or a mercapto group of an hydroxy-, or mercapto-aminoacid and the carboxyl group of another amino- or hydroxy-acid but do not comprise rings formed only through peptide or ester links derived from hydroxy carboxylic acids, e.g. Gly-Ala-Gly-OCH2CO2H and Gly-OCH2CO-Ala-Gly are considered as "linear depsipeptides", but HOCH2CO-Gly-Ala-Gly does not contain an ester link, and is thus a derivative of Gly-Ala-Gly which is covered by C07K 5/08;
    2. "cyclic depsipeptides" are peptides containing at least one ring formed only through peptide or ester links — derived from hydroxy carboxylic acids —, e.g. Gly-Ala-Gly-OCH2CO;
  • "proteins" are compounds containing an aminoacid sequence of more than 100 aminoacids, at least two of which are different, bound mostly through normal peptide links. [4]