Saturday, January 26, 2008

IIT JEE Revision - Amines Nomenclature

Nomenclature of aliphatic amines
Common system:
In the common system, amines are called alkylamines. The suffix amines is added to the name of the corresponding alkyl group.

Ex: Methylamine, Ethylamine, Propylamine
Second common system
In the second system of the common system, primary amines are named as the amino derivatives of the corresponding hydrocarbons and are names as aminoalkanes. The position of the amino group is indicated by Arabic numeral. The numbering of the primary chain is to be done in such a way that the carbon atom containing the amino group gets the lowest possible number.

Secondary and tertiary amines are named as nitrogen substituted primary amine.
Example: N-Methylaminoethane
Primary amine is aminoethane and N-Methyl is added to it. N- indicates that the methyl group is attached to the nitrogen atom.

IUPAC system

The aliphatic amines are called alkamines. The letter ‘e’ in the alkane is replaced by suffix amine.
Ex: methanamine, ethanamine

The position of the amino group is indicated by Arabic numeral. The numbering of the primary chain is to be done in such a way that the carbon atom containing the amino group gets the lowest possible number.
Ex: 1-propanamine, 2-propanamine

Aromatic Amines

Common system
Aromatic amines are called aryl amines. Suffix amine is added to the aryl group.

IUPAC System
The simplest aromatic amine C6H5NH2 is called benzanamine.
Other aromatic amines are named as derivatives of benzenamine and positions of other groups are indicated by numbers

Ex: Benzenamine
N-Methylbenzenamine, N,N-Dimethylbenzenamine, 2-Methylbenzenamine, 3-Methylbenzenamine

In IUPAC system, benzenamine may also be written as amino benzene.

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