Simple carboxylic acids are named as derivatives of the parent alkane, using the suffix -oic acid

1. Select the longest continuous carbon chain, containing the carboxylic acid group, and derive the parent name by replacing the -e ending with -oic acid.
2. Number the carbon chain, beginning at the end nearest to the carboxylic acid group.
3. Number the substituents and write the name, listing substituents alphabetically.
4. Carboxylic acid substituents attached to rings are named using the suffix -carboxylic acid.

Several simple examples are shown below:

In the first example, the parent chain is a pentane and the carboxylic acid group is assigned as carbon #1. On the pentane parent, there is an ethyl group in position #2; hence the name, 2-ethylpentanoic acid.

In the second example, there are two potential four-carbon chains; in this case, the chain with the most substituents is selected as parent, (a butanoic acid). Attached to the butanoic acid at carbon #2 is an ethyl group and at carbon #3, a bromine; hence the name 3-bromo-2-ethylbutanoic acid.

In the third example, the carboxylic acid is attached to a cycloalkene ring and will therefore be named as a "carboxylic acid" substituent (rule #4). The parent ring is a cyclohexene ; letting the carboxylic acid be carbon #1, the name is 2-cyclohexenecarboxylic acid.

In the last example, the name is based on benzoic acid as the parent. In this case, we simply number the substituents to give the lowest number sequence at the first point of difference and arrange alphabetically; 5-bromo-2-methylbenzoic acid.