ACD/Name
Generate Name from Structure

IV. IMPLEMENTED NOMENCLATURE PROCEDURES

IV.1. Substitutive

All substitution procedures are supported by ACD/Name, for example:

IUPAC Name	4-(4-bromopent-4-en-1-yl)-2-cyanobenzoic acid
Index Name 11.0	benzoic acid, 4-(4-bromo-4-penten-1-yl)-2-cyano-
Index Name 10.0	benzoic acid, 4-(4-bromo-4-pentenyl)-2-cyano-

IV.2. Replacement in Parent Structures and Functions

Replacement in cyclic and acyclic compounds and functional groups is allowed, for example:

IUPAC Name	1,9b-diaza-6-phosphaphenalene
Index Name	1,9b-diaza-6-phosphaphenalene
IUPAC Name	P-pentylphosphonamidimidic acid
Index Name	phosphonamidimidic acid, P-pentyl-

IV.3. Additive and Subtractive

ACD/Name supports hydro prefixes and additive groups.
For example:

IUPAC Name	3,4-dihydro-1H-pyrano[4,3-c]pyridine 6-oxide
Index Name	1H-pyrano[4,3-c]pyridine, 3,4-dihydro-, 6-oxide

Dehydro prefixes and unsaturation in acycles and cycles:

IUPAC Name	6-cyclopent-2-en-1-yl-2,3-didehydroquinoline
Index Name	quinoline, 6-(2-cyclopenten-1-yl)-2,3-didehydro-

IV.4. Radicofunctional (Functional Class Names)

Supported groups only, such as:

IUPAC Name	cyclobutyl phenyl disulfide or (cyclobutyldithio)benzene
Index Name	disulfide, cyclobutyl phenyl
IUPAC Name	2-phenylpropan-2-yl hydroperoxide
Index Name 11.0	1-methyl-1-phenylethyl hydroperoxide
Index Name 10.0	hydroperoxide, 1-methyl-1-phenylethyl

IV.5. Conjunctive

The ACD/Name Index algorithm supports all conjunctive procedures.
According to the current IUPAC Recommendations, conjunctive nomenclature is not recommended. ACD/Name IUPAC naming algorithm generates substitutive or multiplicative nomenclature for such structures in accordance with recommendations.
For example:

IUPAC Name	benzene-1,2,4-triyltrimethanol
Index Name	1,2,4-benzenetrimethanol
IUPAC Name	6-(1-bromo-3-carboxy-3-chloropropyl)-5- (3-carboxy-1-chloropropyl)-3-chloropyridine-2-carboxylic acid
Index Name	2,3-pyridinedibutanoic acid, 2-bromo-6-carboxy-α2,3,5-trichloro-

IV.6. Multiplicative

Multiplicative nomenclature is an important part of chemical nomenclature, as it provides shorter and simpler names based on structural symmetry by treating identical structural fragments only once in the name.

All types of parent fragments can be multiplied, for example:

IUPAC Name	3,3'-[oxybis(chloromethanediyl)]dibenzoic acid
Index Name	benzoic acid, 3,3'-[oxybis(chloromethylene)]bis-
IUPAC Name	2,2',2'',2'''-[iminobis(ethane-2,1-diylnitrilo)]tetraethanol
Index Name	ethanol, 2,2',2'',2'''-[iminobis(2,1-ethanediylnitrilo)]tetrakis-

Note: IUPAC and Index naming limitations are different.

IV.7. Radicals and Charged Structures

ACD/Name supports the naming of various radicals, anionic and cationic structures that were previously refused.

IUPAC Name	3-methylidene-6-oxabicyclo[3.2.0]hept-4-ylium-2-yl
Index Name	6-oxabicyclo[3.2.0]hept-4-ylium-2-yl, 3-methylene-
IUPAC Name	(phenylsulfinyl)methanide
Index Name	benzene, (methylsulfinyl)-, ion(1-)

Note: IUPAC and Index naming possibilities are different.

IV.8. Isotopically modified structures

The program supports naming of isotopically substituted structures. The IUPAC and CAS naming principles for such structures differ in many aspects. ACD/Name currently supports most naming rules for the isotopically substituted structures. For example:

IUPAC Name	(2-²H1)pentane(²H2)dioic acid
Index Name	pentanedioic-2-d acid-d2

IUPAC Name	7-(35Cl)chloro(5-13C)naphthalene-1,3-diol
Index Name	1,3-naphthalenediol-5-¹³C, 7-(chloro-35Cl)-

IV.9. Variable Valence

λ-convention

Used by IUPAC and Index algorithms for the identification of non-standard bonding numbers, for example:

IUPAC Name	1,5,7,11-tetraoxa-6λ5-phosphaspiro[5.5]undecane
Index Name	1,5,7,11-tetraoxa-6λ5-phosphaspiro[5.5]undecane

Additive Hydro-prefixes and Groups

Used by the ACD/Name Index algorithm to describe the portion of non-standard valence which arises from attached hydrogens and acyclic substituents. The IUPAC naming algorithm generates appropriate names for structures according to the λ-convention. For example:

IUPAC Name	1,1-dimethyl-1,2-dihydro-1λ4,4-thiazine 1-oxide
Index Name	2H-1,4-thiazine, 1,1-dihydro-1,1-dimethyl-, 1-oxide

Element Symbols with Superscript Roman Numerals

Fused systems and monoheterocycles with cumulative double bonds which need these descriptors are not treated, for example:

5H-1,3,5-dithi(3-SIV)-azepine - not supported

Note: All cyclic systems with cumulative double bonds which need to use superscript Roman designation of variable valence are automatically refused a name by ACD/Name.

IV.10. Multicomponent Structures

Compounds of several components can be named in the current version, for example:

IUPAC Name	cyclopentanesulfonic acid - 1,5-naphthyridine (2:1) dihydrate
Index Name	cyclopentanesulfonic acid, compd. with 1,5-naphthyridine, hydrate (2:1:2)
IUPAC Name	zinc 1-methylpyridinium-2,4,6-tricarboxylate dihydrate
Index Name 11.0	pyridinium, 2,4,6-tricarboxy-1-methyl-, inner salt, zinc salt, hydrate (1:1:2)
Index Name 10.0	pyridinium, 2,4,6-tricarboxy-1-methyl-, inner salt, zinc salt (1:1), dihydrate

Note: The components are cited according to their seniority. In accordance with rules, the name of the second nontrivial component is cited in uninverted format. ACD/Index Name does not support multicomponent structures with esters or hydrazide as a less senior component.

IV.11. Indicated and Added Hydrogen, Hydro Prefixes

Added Hydrogen used to accommodate the principal groups and to reduce the number of cited hydro prefixes. Hydro prefixes treated as detachable and alphabetized with other substituents.
For example:

IUPAC Name	8,9-dihydro-2H,4H-[1,4]oxazino[2,3-h][3,1]benzoxazine-5,6(4aH,6aH)-dione
Index Name	2H,4H-[1,4]oxazino[2,3-h]-3,1-benzoxazine-5,6(4aH,6aH)-dione, 8,9-dihydro-

IV.12. Tautomeric Compounds

To avoid generation of different names for one compound that can be represented in several tautomeric forms, ACD/Name supports naming of structures in a preferred tautomeric form. Only prototropic tautomerism of the following type is supported:

where X, Y can be only uncharged O, S, Se, Te and N atoms and Z is any atom.

The procedures of choosing the preferred form are based in general on CAS nomenclature rules that use two basic principles:

• If atoms X and Y are different, the preferred form has a double bonded atom that appears earlier in the list O, S, Se, Te, N.
• If both X and Y are N-atoms, the choice is based on nomenclature rules: senior group, lowest locants, and earliest alphabetical order of the generated name.

In the following example, the preferred form contains a double bond at oxygen atom and lower locant for principal group:

Drawn form		preferred form
1H-imidazole-5-carboximidic acid		1H-imidazole-4-carboxamide

To name a structure in a preferred tautomeric form, the user needs to set the corresponding ACD/Name preferences. If the preferred tautomeric form option is set, the two structures above will acquire the same name, 1H-imidazole-4-carboxamide.