In a dry
200-ml. flask fitted with a ground-joint
reflux condenser and protected from moisture by a
calcium chloride tube are put
66 g. (0.32 mole) of α-bromonaphthalene (Note
1),
35 g. (0.39 mole) of dry powdered cuprous cyanide (Note
2), and
30 ml. of pyridine (Note
3) in the order mentioned. This mixture is heated in a
Wood's metal bath (Note
4) at 215–225° for 15 hours. The resulting dark brown solution is poured while still hot (about 100°) into a flask containing
150 ml. of aqueous ammonia (sp. gr. 0.90) and 150 ml. of water. About
140 ml. of benzene is added, and the flask is stoppered and shaken until all the lumps have disintegrated. After the mixture has cooled to room temperature,
100 ml. of ether is added and the mixture is filtered (Note
5). The filtrate is transferred to a
1-l. separatory funnel, and the aqueous layer is separated (Note
6). The
ether-
benzene layer is washed successively with (
a) four
100-ml. portions of dilute aqueous ammonia (Note
7), (
b) two
100-ml. portions of 6 N hydrochloric acid (Note
8), (
c) two 100-ml. portions of water, and (
d) two
100-ml. portions of saturated sodium chloride solution. The
ether and
benzene are removed by distillation from a
water bath, and the residue is distilled under reduced pressure from a
125-ml. modified Claisen flask. The temperature rises rapidly, and the yield of colorless
α-naphthonitrile, b.p.
173–174°/27 mm. (
166–169°/18 mm.), is
40–44 g. (
82–90%) (Note
9) and (Note
10).