Sixty-nine grams (3.0 gram atoms) of freshly cut sodium is placed in a
1-l. round-bottomed flask with
400 ml. of dry xylene (Note
1) and heated until all the
sodium is melted. The flask is closed with a
rubber stopper and shaken vigorously to form finely powdered
sodium (Note
2). When cool, the contents are transferred to a
5-l. three-necked round-bottomed flask, and the
xylene is decanted. The powdered
sodium is then washed with two
100-ml. portions of anhydrous ether by decantation, after which
1 l. of anhydrous ether is added. The flask is placed on a
steam bath and fitted with a
Hershberg stirrer, an upright condenser, and a
500-ml. dropping funnel. The condenser and funnel are protected from moisture by
calcium chloride tubes. Through the dropping funnel is then added with stirring
138 g. (175 ml., 3.0 moles) of absolute ethanol at such a rate that gentle refluxing occurs. The mixture is refluxed and stirred for 6 hours after the addition is complete.
The reaction mixture is then rapidly extracted with five 1-l. portions of water (Note
6).
Acetic acid is added to the water solution until it is acid to litmus. The acidified solution is warmed to 50° on a steam bath and maintained at approximately that temperature for 2 hours. It is subsequently allowed to stand at room temperature for 48 hours, during which time the
triacetylbenzene crystallizes.
The crude yellow crystalline solid (m.p. in the range
150–162°) is collected on a filter; the yield is
84–94 g. (
41–46%). It is recrystallized by dissolving in hot
ethanol (18 ml. of ethanol per gram), adding
2 g. of Norit, filtering through a
steam-heated funnel (Note
7), and cooling the filtrate in an
ice bath. The yield of shiny white crystals, m.p.
162–163°, is
62–79 g. (
30–38%) (Note
8).