Classification

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Depending upon the number of hydrogen atoms that are replaced by an alkyl or aryl group in ammonia, amines are classified as primary (1o), secondary (2o) and tertiary (3o). If only one hydrogen atom is replaced then amines of the form R-NH2 or primary amines (1o) are obtained. If two of the three hydrogen atoms are replaced by alkyl/aryl groups then secondary amines are formed. If all the three hydrogen atoms are replaced by alkyl/aryl group then tertiary amines are obtained.

There is yet another class of compound, besides these three types of amines, in which N atom is quaternary. Such compounds are called quaternary ammonium salts. They are regarded as derivatives of ammonium salt in which all the four H atoms are replaced by alkyl or aryl groups.

Example:

[(C₂H₅)₄]Cl^- is tetraetyle ammonioum chloride

The root name is based on the longest chain with the -NH attached.

The chain is numbered so as to give the amine unit the lowest possible number.

CH₃NHCH₂CH₃

Tertiary amines

Tertiary amines have three alkyl group attached to the N.

The root name is based on the longest chain with the -N attached.

The chain is numbered so as to give the amine unit the lowest possible number.

The other alkyl groups are treated as substituents, with N as the locant.

(CH₃)3N

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