ACD/Name

Introduction

R-0.1.2 Position of locants

Locants (numerals and/or letters) are placed immediately before the part of the name to which they relate, except in the case of traditional contracted forms (see R-2.5).

Examples to R-0.1.2

Hex-2-ene (R-3.1.1)

(formerly 2-Hexene)

Cyclohex-2-en-1-ol (R-5.5.1.1)

(formerly 2-Cyclohexen-1-ol)

O-Acetyl-N-methylhydroxylamine (R-5.4.4)

2-Naphthyl (R-2.5)

(a contracted form of Naphthalen-2-yl)

(not Naphth-2-yl)

2-Pyridyl (R-2.5)

(a contracted form of Pyridin-2-yl)

(not Pyrid-2-yl)

Next:
R-0.1.3 Punctuation
R-0.1.4 Numerical (multiplicative) prefixes
R-0.1.5 Enclosing marks
R-0.1.6 Italicization
R-0.1.7 Elision and addition of vowels
R-0.1.8 Order of prefixes

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This HTML reproduction is as close as possible to the published version [see IUPAC, Commission on Nomenclature of Organic Chemistry. A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993), 1993, Blackwell Scientific publications, Copyright 1993 IUPAC]. If you need to cite these rules please quote this reference as their source.

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