H C
O
OH
C
H 3 C
O
OH
C
O
OH
Methanoic acid
Formic acid
Ethanoic acid
Acetic acid
Benzenecarboxylic acid
Benzoic acid
Nomenclature of carboxylic acids
The root name is based on the longest continuous chain of carbon atoms
bearing the carboxyl group. The -e is replaced by -oic acid. The chain is
numbered starting with the carboxyl carbon atom. The carboxyl group takes
priority over any other functional groups as follows: carboxylic acid >
ester > amide > nitrile > aldehyde > ketone > alcohol > amine > alkene >
alkyne.
C
O
OH
CH 3 CH 2
C
O
OH
CH 3 CH 2 CH 2
C
O
OH
CH 3 CH 2 CH 2 CH 2
OH
O
N
H 2
CH C
O
OH
CH 3 CH 2 CH
OMe
C
O
OH
C
H 2
Propanoic acid
Propionic acid
Butanoic acid
Butyric acid
Pentanoic acid
Valeric acid
4-Aminobutanoic acid
Propenoic acid
Acrylic acid
2-Methoxybutanoic acid
Cycloalkanes with carboxyl substituents are named as cycloalkanecarboxylic acids. Unsaturated acids are named using the name of the alkene
with -e replaced with -oic acid. The chain is numbered starting with the
carboxyl group, a number designates the location of the double bond and Z
or E is used.
CO 2 H
CH 3
H
CH 2 CO 2 H
C
H 3
C 2 H 5
CHCH 3
C
O
O
H
3-Methylcyclohexanecarboxylic acid
2-Cyclohexylpropanoic acid
(E)-4-Methyl-3-hexenoic acid
Aromatic acids are named as derivatives of benzoic acids, with ortho, meta
and para indicating the location relative to the carboxyl group.
CO 2 H
CO 2 H
Cl
CO 2 H
NH 2
Benzoic acid
Benzene carrboxylic acid
p-Aminobenzoic acid
o-Chlorobenzoic acid
90
CH4 ORGANIC FUNCTIONAL GROUPS