3-Chloropropiophenone, also known as 3-chloro-1-phenylpropan-1-one, is a chemical compound with the molecular formula C9H9ClO. It is a derivative of propiophenone with a chlorine atom attached to the third carbon atom of the alkyl chain. This compound is commonly used as an intermediate in organic synthesis, particularly in the preparation of various pharmaceuticals, agrochemicals, and fine chemicals. Its molecular structure consists of a phenyl group attached to a three-carbon chain containing a carbonyl group and a chlorine atom, imparting specific chemical reactivity.