AcCl

Acetyl chloride, also known as ethanoyl chloride and abbreviated AcCl, is an organochlorine compound with the formula CH3COCl. It is a colorless, volatile liquid that fumes in air and has a sharp, penetrating odor. The molecule contains a carbonyl group adjacent to a chloride substituent, classifying it as an acyl chloride.

Acetyl chloride is highly reactive, especially toward water, alcohols, and amines. Hydrolysis in water yields acetic acid and hydrogen chloride: CH3COCl + H2O → CH3COOH + HCl. It is therefore a strong acetylating agent used to form esters, amides, and other acetyl derivatives. It is widely employed in organic synthesis, pharmaceutical production, and polymer chemistry.

Preparation: Commercially, acetyl chloride is produced by reacting acetic acid with thionyl chloride (SOCl2) or phosphorus trichloride, generating acetyl chloride along with byproducts such as SO2 and HCl.

Safety and handling: Acetyl chloride is corrosive and fumes in moist air. It reacts violently with water and releases HCl gas, which is corrosive and acrid. It should be handled in a fume hood, with appropriate PPE, under dry, inert conditions, and stored in tightly closed containers away from moisture and oxidizers.

See also: acetyl group; acyl chloride.