Heptanoic acid, also called enanthic acid, is an organic compound composed of a seven-carbon chain terminating in a carboxylic acid. It is an oily liquid with an unpleasant, rancid odor. It contributes to the odor of some rancid oils. It is slightly soluble in water, but very soluble in ethanol and ether.
Heptanoic acid is used in the preparation of esters, such as ethyl heptanoate, which are used in fragrances and as artificial flavors.
It is also one of many additives in cigarettes.