Basic Organic Nomenclature

Carboxylic Acid Derivatives - Amides

Suffix:    -amide

Prefix:    carbamoyl-

There are a number of derivatives of carboxylic acids generated by replacing the -OH of the acid with another group. All of the derivatives have a lower priority in naming than the acid. The first, and lowest priority derivative is an amide, where the -OH has been replaced by a -NH2. Similar to acids, the carbon atom of the amide will be atom number 1 in the numbering scheme. Since it always occurs at the end(s) of the chain of carbon atoms, the number is omitted. In naming the amide, the final -e of the alkane is replaced by -amide. The general formula for an amide is CnH2nNO.

When the -CONH2 group is attached to a ring, the amide is named as a cycloalkanecarbamide (or an older way is a cycloalkanecarboxamide).

Examples naming simple amides:

Compound Name
Line Drawing
3D Model
methanamide
or 
formamide
ethanamide
or
acetamide
 propanamide
2-methylpropanamide
cyclobutanecarbamide
ethanediamide*

* note: the terminal -e is retained as the diamide begins with a consonant.

Examples naming more complex amides:

Compound Name
Line Drawing
2-hydroxypropanamide
5,5-dimethyl-3-oxohexanamide
 4-amino-6-heptenamide


Similar to amines, the N atom can have alkyl substituents attached to it. These substituents locations are indicated by a N-alkyl group in the name. i.e.

N,N-dimethylformamide (DMF)




Amides as Substituents:

In more complex molecules with higher priority functional groups, the amide is named as a carbamoyl- substituent. It is located by numbering the longest chain of carbons (according to the higher priority functional group) and locating the -CONH2 group by this numbering scheme.

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