Naphthyl Methyl Ketone
(1) Acetic anhydride (20.4 g.; 1 mol.) was gradually added to a well stirred mixture of aluminium
chloride (56 g. ; 2 mols.) in ethylene chloride (100 c.c.). After 3 hours stirring, a solution of naphthalene
(25.6 g.) in ethylene chloride (50 c.c.) was gradually added. The temperature was kept at 35c during
the addition, but was subsequently raised to 50c to complete the reaction. After decomposition with
dilute hydrochloric acid the product provided a fraction (20 g.; b. p. 163c/15 mm.; m. p. 9.0 and
mixed m. p. 9.5 with pure a-naphthyl methyl ketone) which was almost pure a-naphthyl methyl
ketone. Picrate analysis indicated 97.5% of a-ketone.
(2) A solution of acetyl chloride (8 g. ; 1 mol.) and aluminium chloride (14 g. ; 1 mol.) in ethylene
chloride (30 c.c.) was gradually added to a solution of naphthalene (13 g.) in ethylene chloride (30 c.c.)
at 35c. A ready reaction occurred, and a solid separated. The mixture was decomposed with dilute
hydrochloric acid, and the product provided a fraction (16 g. ; b. p. 163c/15 mm. ; m. p. 9.0c and mixed
m. p. 9.5 with pure a-naphthyl methyl ketone) which was almost pure a-naphthyl methyl ketone.
Picrate analysis indicated 98% of a-ketone. A similar result was obtained when the solution of naphthalene
was gradually added to the solution of acetyl and aluminium chlorides.
The acylation of naphthalene by the friedel–crafts reactionG. BaddeleyJ.
Chem. Soc.1949, S99-S103
DOI: 10.1039/JR9490000S99
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