Propanoüülkloriid

Propanoüülkloriid, also known as propionyl chloride, is an acyl halide with the chemical formula CH3CH2COCl. It is a colorless liquid with a pungent odor. Propionyl chloride is an organic compound that is derived from propanoic acid by replacing the hydroxyl group with a chlorine atom. Its structure features a carbonyl group bonded to an ethyl group and a chlorine atom.

This compound is highly reactive due to the presence of the electronegative chlorine atom, which makes the carbonyl carbon electrophilic. Propionyl chloride is typically synthesized by reacting propanoic acid with chlorinating agents such as thionyl chloride (SOCl2), phosphorus trichloride (PCl3), or phosphorus pentachloride (PCl5). The reaction with thionyl chloride is a common laboratory method for its preparation.

Propionyl chloride is a valuable reagent in organic synthesis. It is primarily used for the introduction of the propionyl group (CH3CH2CO-) into other molecules through acylation reactions. This is often achieved by reacting it with alcohols to form esters, with amines to form amides, and in Friedel-Crafts acylation reactions with aromatic compounds to form ketones. Its reactivity makes it useful in the synthesis of various pharmaceuticals, agrochemicals, and other fine chemicals. Due to its corrosive nature and reaction with moisture, it must be handled with care in anhydrous conditions.