Acetyl Chloride: Glacial Acetic Acid and Phosphorus Trichloride

Acetyl chloride is the step between acetic acid and acetic anhydride. Gattermann (1914): run 80 g of phosphorus trichloride into 100 g of glacial acetic acid, warm at 40 to 50 °C until the hydrochloric acid gas slows and two layers form, then distil the acetyl chloride off and redistil it at 51 °C. Yield 80 to 90 g. Keep everything dry: moisture destroys it. The picture: Gattermann's own drawing of the apparatus.