Acetic anhydride

Acetic anhydride (acetyl oxide) is a liquid with a strong offensive odor. It is an irritating and corrosive chemical that must be handled with care. The production of acetic anhydride from acetic acid occurs via the intermediate formation of ketene where one mole of acetic acid loses one mole of water:

Acetic anhydride is mainly used to make acetic esters and acetyl salicylic acid (aspirin).