The Nomenclature of Amines

An amine is a compound in which one or more hydrogens of ammonia have been replaced by alkyl groups. Amines are classified as primary, secondary, and tertiary, depending on how many alkyl groups are attached to the nitrogen. Primary amines have one alkyl group attached to the nitrogen, secondary amines have two, and tertiary amines have three. 

The number of alkyl groups attached to the nitrogen determines whether an amine is primary, secondary, or tertiary. 

Be sure to note that the number of alkyl groups attached to the nitrogen determines whether an amine is primary, secondary, or tertiary. In contrast, whether the X (halogen) or OH group is attached to a primary, secondary, or tertiary carbon determines whether an alkyl halide or alcohol is primary, secondary, or tertiary (Sections 3.4 and 3.6). 

The common name of an amine consists of the names of the alkyl groups bonded to the nitrogen, in alphabetical order, followed by amine. The entire name is written as one word (unlike the common names of alcohols, ethers, and alkyl halides, in which  

The lUPAC system uses the suffix amine to denote the amine functional group. The e at the end of the name of the parent hydrocarbon is replaced by amine —similar to the way alcohols are named. Also similar to the way alcohols are named, a number identifies the carbon to which the nitrogen is attached, and the number can appear before the name of the parent hydrocarbon or before amine. The name of any alkyl group bonded to nitrogen is preceded by an A (in italics) to indicate that the group is bonded to a nitrogen rather than to a carbon. 

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The nomenclature of amines was considered briefly in Section 7-8. We shall give only a short review here to focus on the main points. Amino compounds can be named either as derivatives of ammonia or as amino-substituted compounds ... 

The nomenclature of amines differs from that of the alcohols. The des nations primary, secondary, and tertiary refer to the number of substituents on the ammonia nitrogen ... 

The nomenclature of amines is exceptional. By very long custom radical names may be attached to the ending amine, as in ethylamine but it is equally correct to add amine to the parent name, as indicated in Table 4, giving names such as phenanthren-1-amine, quinolin-8-amine, or even ethanamine. The latter practice is often reserved for more complex cases but that is not a necessary limitation. The same alternatives exist for ammonium salts. Secondary and tertiary amines are treated as substitution products of the most complex constituent primary amine, with N- prefixes when substitution elsewhere might be reasonable, as in triethylamine, dimethylamine,... 

Common names of the compounds arc used throughout this volume. Preparations appear in the alphabetical order of common names of the compound or names of the synthetic procedures. The Chemical Abstracts indexing name for each title compound, if it differs from the common name, is given as a subtitle. Because of the major shift to new systematic nomenclature adopted by Chemical Abstracts in 1972, many common names used in the text are immediately followed by the bracketed, new names. Whenever two names are concurrently in use, the correct Chemical Abstracts name is adopted. The prefix n- is deleted from w-alkanes and w-alkyls. In the case of amines, both the common and systematic names are used, depending on which one the Editor-in-Chief feels is more appropriate. All reported dimensions are now expressed in Systeme International units. 

We observed that cyclic esters (lactones) may be formed when the carboxyl electrophile and hydroxyl nucleophile are in the same molecule (see Section 7.9.1). Similarly, cyclic amides are produced when carboxyl and amine groups are in the same molecule, and are again most favoured when this results in the generation of strain-free five- or six-membered rings. Cyclic esters are termed lactones, whereas cyclic amides are in turn called lactams. The nomenclature of lactams is similar... 

In the names of amines, the general use of suffixes and prefixes is not always observed. Normally, the suffix -amine would be added to the name of the parent hydride and engender names such as methanamine (CH3-NH2). Further substitution on the nitrogen atom would then be indicated by prefixes, leading to names that appear very cumbersome, such as A -methylmethanamine for (CH3)2NH and N,N-dimethylmethanamine for (CH3)3N. The traditional names of methylamine, di-methylamine and trimethylamine are much simpler. In these names, the term amine is not a suffix. It is, in fact, the name of the parent hydride, NH3, which now serves as the basis of substitutive names. Names such as diethylamine and tributylamine are representative of the preferred nomenclature. Diamines are named accordingly, as with ethane-1,2-diamine for H2N-CH2-CH2-NH2 and propane-1,3-diamine for H2N-[CH2]3-NH2. There are allowed alternatives for these last two compounds ethylenediamine and propane-1,3-diyldiamine. 

Hydroxy, thiol, and amino groups in pyrimidine exist in tautomeric equilibria with their oxo, thioxo, and imino forms. An amino group in an electrophilic position exists predominantly as such, and the compound is named as an amine. Pyrimidines with a hydroxy or thiol group in an electrophilic position are dominated by the oxo or thioxo forms and are named as such, or with -one or -thione suffixes, if these are the principal groups. In the benzenoid 5-position, these derivatives are mainly present in the hydroxy, thiol, or amino forms and are named as such. Similar considerations apply to the nomenclature of quinazolines and perimidines <1996CHEC-II(6)93>. 

Diene complexes give allyls on nucleophilic attack. Note how the cisoid conformation of the butadiene in Eq. 8.18 gives rise to an anti methylallyl (in the nomenclature of allyl complexes, a substituent is considered as syn or anti with respect to the central CH proton). Equation 8.19 is interesting in that the amine acts in this case as a carbon, not as a nitrogen nucleophile. ... 

The Naming of Chiral Drugs. The nomenclature of chiral compounds is difficult and sometimes confusing. We have already introduced the prefixes R and S, (- -) and (—), and D and L. We have already seen many common names for drugs that have an implied chirality, as in methamphet-amine and ephedrine. The hyphenated prefixes R/S, D/L, and + / — render the alphabetic indexing of pharmaceutics problematic. One approach to this problem that has been used to help with this issue is to select drug names where the chirality has been imbedded into the common chemical name. One example that we have discussed is esomeprazole,... 

If the lactolhydroxyl group is substituted by NHj at C-atom i, one speaks of glycosylamines, or, by substitution with NHR, of iV-glycosides. Glyc-amines are i-amino-i-deoxy sugar alcohols. The nomenclature of the compounds found in nature, which are formed partly or entirely from amino sugars, is still not uniform. ... 

Alkylamines are named m two ways One method adds the ending amine to the name of the alkyl group The other applies the principles of sub stitutive nomenclature by replacing the e ending of an alkane name by amine and uses appropriate locants to identify the position of the ammo group Arylammes are named as derivatives of aniline... 

Twenty-two years later the isolation of the anti-pernicious anemia factor" was announced independently by Smith (5) and Riches (6). Seven years of chemical studies identified 5,6-dimethylbenzimidazole (7), D-ribose (5) and amino-propanol (9) as components of the anti-pemicious anemia factor", but the tetrapyrroline ring structure containing Co(III) awaited the X-ray crystallographic data on the cyano-derivative by Hodgkin and White (10—15). Once the structure of the antipemicious anemia factor was determined it was called Vitamin B12 (cyanocobal-amin). The recommendations of a number of commissions forms the basis of the present system of nomenclature for this molecule and these are presented in Fig. 1. 

In a systematic study of the effects of variation of the tetramine involved in formation of the hexadentate N402 donor Schiff base the linear 3,3,3-, 3,2,3-, 2,3,2- or 2,2,2-tetramines, where the numbers refer to the number of carbon atoms between the amine groups (note 2,2,2-tetramine is synonymous with the nomenclature trien used previously) have been condensed with salicylaldehyde, acetophenone or benzophenone [206]. Crystal struc-... 

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