Aluminium Chloride: Hydrogen Chloride over Hot Aluminium

Anhydrous aluminium chloride is the catalyst of Friedel-Crafts chemistry, used for phthalocyanine green and anthraquinone. Gattermann (1914): pass dry hydrogen chloride over aluminium shavings in a hard-glass tube heated along its length; white vapours of the chloride condense in a wide-necked bottle. Everything must be dry, and the air must be driven out first or hydrogen and air can explode. The product fumes in moist air. The picture: our own drawing.