Chloro propionyl chloride, with the chemical formula C3H5ClO, is an acyl chloride derivative of propionic acid. It contains a reactive acyl chloride group that makes it an excellent intermediate in organic synthesis. The compound appears as a colorless to yellowish liquid with a pungent odor, typical for many organic chlorides. Its solubility in organic solvents facilitates its use in a range of chemical reactions, while its reactivity allows for the introduction of the chloro propionyl moiety into various substrates.