orthonym.validation.spelling.checks_prefixes#

Note

Internal API. Names and behaviour may change between releases.

Spelling checks of two substituent prefixes whose general-nomenclature spelling is not the PIN (registered with:func:orthonym.validation.pin_spelling.register).

A round trip proves the molecule, never the spelling: OPSIN reads ‘2-[(2,6-dichlorophenyl)amino]-2- oxoethyl’ and ‘1-methyl-2-oxoethyl’ back to the structures of the preferred ‘2-(2,6-dichloroanilino)- 2-oxoethyl’ and ‘1-oxopropan-2-yl’. A producer that writes the general form must not ship it as a PIN. Both checks read the RDKit structure and the name text only.

  • “Retained names” (the Blue Book): “The prefix name ‘anilino’ is retained as the preferred prefix for C6H5-NH– with full substitution allowed. The name ‘phenylamino’ may be used in general nomenclature.” Its examples (:26151-:26153) ‘anilino (preferred prefix) phenylamino’, ‘4-chloroanilino (preferred prefix) (4-chlorophenyl)amino’; with the nitrogen substituted too, (:26298) ‘:26308’ ‘3-(N-methylanilino)phenol (PIN)’ against ‘3-[methyl(phenyl)amino]phenol’. The structure side is a nitrogen outside any ring bonded to a benzene ring that is no part of a fused system.

  • “Retained prefixes no longer recommended as approved prefixes” (:16398),:16416 ‘butan-2-yl (preferred prefix) 1-methylpropyl’; (:16334) “The prefixes isopropyl, isopropylidene, and trityl are retained for use in general nomenclature but no substitution of any kind is allowed”, with:24402 ‘propan-2-yl (preferred prefix) 1-methylethyl isopropyl’ under “PREFIXES DERIVED FROM PARENT HYDRIDES”; “Retained prefixes that are preferred prefixes” (:16270),:24412 ‘-C(CH3)3 tert-butyl (preferred prefix) 1,1-dimethylethyl’; (:40549) “Method (1) generates preferred IUPAC names”: ‘propan-2-yl (PIN) 1-methylethyl’ (:40558). The structure side is the group itself, a saturated carbon with its two or three carbon neighbours.

  • (:22660) “The principal substituent chain has the greater number of skeletal atoms, i.e., the longest chain”: a methyl cited at locant 1 of an alkyl chain (‘1-methyl-2-oxoethyl’, ‘1-methylbutyl’) is a carbon that extends the chain, so the group is named on the longer chain (‘1-oxopropan-2-yl’, ‘pentan-2-yl’). The check reads the prefix block of every unbranched alkyl stem in the name; the structure side is an acyclic methyl on a branched acyclic carbon.

  • “Hydrazine and derivatives” (:38507): “For H2N-NH– ‘hydrazinyl’”; an amino group cited on an amino group (‘aminoamino’, ‘(methylamino)amino’) is the hydrazine unit and takes ‘hydrazinyl’. The structure side is a nitrogen-nitrogen single bond.

  • (:40620), Table 7.2 “Suffixes for Radicals of Amines, Imines and Amides” (:40622): ‘-iminyl’ is the suffix of the radical =N•. A closed-shell structure takes no ‘-iminyl’ word: R-CH=N- joined through nitrogen is ‘(R-ylidene)amino’ “Substitutive names for imines”,:26529), and R-C(=NH)- joined through carbon is an acyl group,:26540). The structure side is a molecule without a radical electron or a free valence.

orthonym.validation.spelling.checks_prefixes.anilino_prefix_check(mol, name)#

(:26139): C6H5-N< is cited as the prefix ‘anilino’, whatever else the ring and the nitrogen carry,:26308); ‘(phenyl)amino’ and ‘phenylamino’ are the general spelling. A name that cites the general spelling for a molecule that holds such a nitrogen is not the PIN.

orthonym.validation.spelling.checks_prefixes.propan_2_yl_check(mol, name)#

(:16334,:24402) and (:40549): the group CH3-CH(-)-CH3 is ‘propan-2-yl’, never ‘1-methylethyl’.

orthonym.validation.spelling.checks_prefixes.butan_2_yl_check(mol, name)#

(:16398),:16416: the group CH3-CH2-CH(-)-CH3 is ‘butan-2-yl’, never ‘1-methylpropyl’.

orthonym.validation.spelling.checks_prefixes.tert_butyl_check(mol, name)#

(:16270,:24412): the group -C(CH3)3 is ‘tert-butyl’, never ‘1,1-dimethylethyl’.

orthonym.validation.spelling.checks_prefixes.chain_methyl_check(mol, name)#

(:22660): the principal chain of a substituent group is its longest chain, so a methyl at locant 1 of an alkyl chain is a chain atom the name leaves out of the stem. Only an alkyl stem is judged (not the end of a ring or replacement name), and only when the structure holds that group: the chain of the stem’s length with a methyl on its first atom.

orthonym.validation.spelling.checks_prefixes.hydrazinyl_check(mol, name)#

(:38507): H2N-NH- is ‘hydrazinyl’ and its substituted forms are cited from it (‘2-methylhydrazin-1-yl’,,:2869); ‘aminoamino’ and ‘(methylamino)amino’ are not.

orthonym.validation.spelling.checks_prefixes.iminyl_word_check(mol, name)#

(:40620), Table 7.2 (:40622): ‘-iminyl’ is the suffix of the radical =N•, so a name of a structure with no radical electron and no free valence holds no such word.