Pelargonic acid, also known as nonanoic acid, is an organic compound with the structural formula CH3 ( CH2 ) 7CO2H. It is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor. It is almost insoluble in water, but very soluble in organic solvents. Esters and salts of pelargonic acid are called percarbonates or nominate.
The acid is named after the Pelargonium plant because the oil of its leaves contains esters of the acid.
Preparation, Occurrence, and Uses
Together with azelaic acid, it is produced industrially by the ozonolysis of oleic acid.
CH 3 (CH 2 ) 7 CH = CH (CH 2 ) 7 CO 2 H + 4 O → CH 3 (CH 2 ) 7 CO 2 H + HO 2 C (CH 2 ) 7 CO 2 H
Alternatively, pelargonic acid can be produced initially in a two-step process with tandem dimerization and hydroesterification of 1,3-butadiene. This step produces a doubly unsaturated C9-ester, which can be hydrogenated to give the ester of pelargonic acid. 2 CH 2 = CH-CH = CH 2 + CO + CH 3 OH → CH 2 = CH (CH 2 ) 3 CH = CHCH 2 CO 2 CH 3CH 2 =CH(CH 2 ) 3 CH=CHCH 2 CO 2 CH 3 + 2H 2 → CH 3 (CH 2 ) 7 CO 2 CH 3
