Together with Julius Axelrod, he discovered that acetanilide and phenacetin both metabolize to paracetamol. These included acetanilide, phenacetin, and paracetamol (acetaminophen). However, unlike phenacetin, acetanilide and their combinations, paracetamol is not considered carcinogenic at therapeutic doses. Acetanilide is slightly soluble in water, and stable under most conditions. Axelrod and Brodie discovered that acetanilide, the main ingredient of these pain-killers, was to blame. Acetanilide is an odourless solid chemical of leaf or flake-like appearance. For example, reaction of aniline with acetyl chloride provides acetanilide (CH-CO-NH-CH). The amides formed from aniline are sometimes called anilides, for example CH-CO-NH-CH is acetanilide.