In the body, acetanilide is partially converted into a mixture of acetaminophen and aniline. Acetaminophen provides painkilling characteristics, but aniline is toxic and interferes with the hemoglobin of the blood. When its dangerous properties were realized, chemists sought an alternative and soon developed a synthetic version of acetaminophen. This manufactured substance quickly replaced acetanilide in pharmacies because it is not as prone to generate blood disorders, and it continues to be widely used today.