ACD/Name
Generate Name from Structure

I. NOMENCLATURE

I.1. Two Name Types

ACD/Name allows you to generate systematic chemical names of two types:

• IUPAC names, widely used throughout chemical literature and databases and created according to nomenclature recommendations of International Union of Pure and Applied Chemistry, and
• Index names created according to Chemical Abstracts Service (CAS) Index nomenclature rules. Index names allow you to keep compounds that are close by nature together in alphabetized lists. It greatly simplifies creating name lists and searching for a specific compound among such lists. Index names, also referred as inverted names, are used in CAS Chemical Substance Index Guides and other CAS printed and electronic publications.

Note: In November 2006, Chemical Abstracts Service (CAS) announced several significant changes to their CAS Index nomenclature. The most important of these changes are implemented in the Index name generation algorithms of ACD/Name version 11.0. For structures that have different names according to the new rules, both names (old and new) are given.

For example:

IUPAC Name	N,N'-dimethyl-3-(phenylacetyl)quinoline-6,7-dicarboxamide
Index Name 11.0	6,7-quinolinedicarboxamide, N6,N7-dimethyl-3-(2-phenylacetyl)-
Index Name 10.0	6,7-quinolinedicarboxamide, N,N'-dimethyl-3-(phenylacetyl)-

The most distinct difference between the two name types is an opposite order of citation of the main parts of the name: parent, substituents, and modifications, together with unchanged names of parent acids, in the index names.

More specific differences between IUPAC and Index names will be specified in the corresponding sections of this document. For each structure, both names are given if they are not equal.

Note: Index naming algorithms have been developed by ACD/Labs alone and CAS makes no warranty or guarantee about its effectiveness or accuracy. If you require chemical substance names for reporting to regulatory agencies, they should be manually checked or obtained directly from CAS.

I.2. General Organic Compounds

ACD/Name treats most general organic compounds according to IUPAC recommendations on Nomenclature of Organic Chemistry [1, 2] and CAS Index nomenclature rules [3] within the scope of possibilities and restrictions described below. The stereochemistry conventions followed are those in Reference [3, 4].

I.3. Other Compound Classes

Specific areas of nomenclature, such as Biochemical and Inorganic Nomenclature, are treated to some extent according to published recommendations [4, 5, 6] and within the restrictions described below. These are: natural product parent structures, amino acid derivatives, carbohydrates and some inorganic and organometallic compounds.

All the structures that do not belong to the above-mentioned areas of Biochemical and Inorganic Nomenclature or are beyond the specified restrictions for these areas are treated according to general organic nomenclature rules or naming is refused.

I.4. Name Language and Formatting

ACD/Name supports generation of IUPAC names in English, French, and German languages. User can set their naming language preference in the Preferences dialog.

For example:

Note that in German, the first letter of the name is capitalized.

In some cases it is desirable to use chemical names with a capitalized first letter, for example, in databases or catalogs. As soon as capitalization rules for chemical names are not so simple and obvious, ACD/Name includes the option to choose to capitalize the first letter of a name or not. This option works both for IUPAC and Index names.

For example:

I.5. Non-Preferred Names

Some structures are not assigned the most preferred IUPAC or Index names but, if this is the case, such names vary only slightly from the preferred ones. For official purposes the generated names must be manually checked or corrected.

I.6. References

1. International Union of Pure and Applied Chemistry, Organic Chemistry Division, Commission on Nomenclature of Organic Chemistry, Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F and H, Pergamon Press, 1979.
2. International Union of Pure and Applied Chemistry, Organic Chemistry Division, Commission on Nomenclature of Organic Chemistry (III.1), A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993), Blackwell Scientific Publications, Oxford, 1993.
3. American Chemical Society. Chemical Abstracts Service, "Naming and Indexing of Chemical Substances for Chemical Abstracts, Appendix IV", Chemical Abstracts Index Guide, Columbus: American Chemical Society.
4. International Union of Pure and Applied Chemistry, Organic Chemistry Division, Commission on Nomenclature of Organic Chemistry (III.1), Commission on Physical Organic Chemistry (III.2),
5. Basic Terminology of Stereochemistry (IUPAC Recommendations 1996), Pure and Applied Chemistry, Vol. 68, No. 12. pp.2193-2222, 1996.
6. International Union of Pure and Applied Chemistry and International Union of Biochemistry and Molecular Biology, IUPAC-IUB Joint Commission on Biochemical Nomenclature, The Nomenclature of Steroids (Recommendations 1989), Eur. J. Biochem., Vol. 186, pp.429-458 (1989).
7. International Union of Pure and Applied Chemistry and International Union of Biochemistry and Molecular Biology, Joint Commission on Biochemical Nomenclature, Nomenclature of Carbohydrates (Recommendations 1996), Pure and Applied Chemistry, Vol. 68, No. 10, pp.1919-2008, 1996.

Note: In addition to the specified above recommendations, ACD/Name naming algorithms take into account recent IUPAC nomenclature recommendations, which can be found at the following Web site: http://www.chem.qmw.ac.uk/iupac/

II. GENERAL LIMITATIONS

II.1. Restrictions

Number of Atoms

Up to 255 in any single structure (excluding H).

Number of Cycles

Up to 15 in any polycyclic system.

II.2. Allowed Elements and Charges

Structures may contain 97 elements of the Periodic Table from Hydrogen through Lawrencium, excluding noble gas elements (He - Rn).

Chains and Cycles

May include C, N, P, As, Sb, Bi, O, S, Se, Te, B, Si, Ge, Sn, Pb, F, Cl, Br, and I.

Functional Groups

May include C, N, P, As, Sb, O, S, Se, Te, B, Si, F, Cl, Br, and I.

Positive, Negative Charges, and Radicals

On any supported element within the restrictions specified in the corresponding sections.

Note: IUPAC and Index naming limitations are different.

II.3. IUPAC and Index Name Differences

There are some cases where the IUPAC and Index naming algorithms differ, and cannot be described briefly. For all such cases, a special note will appear.