Butyric anhydride or butanoic anhydride is the chemical compound with the formula (CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>CO)<sub>2</sub>O. The molecule can be described as a condensation of two molecules of butyric acid with elimination of one water molecule (hence its name).
Butyric anhydride is a clear colorless liquid that smells strongly of butyric acid, which is formed by its reaction to moisture in the air.
Butyric anhydride is a combustible, corrosive liquid. It is considered water sensitive.