Org. Synth. 1941, 21, 89
DOI: 10.15227/orgsyn.021.0089
α-NAPHTHONITRILE
[1-Naphthonitrile]
Submitted by M. S. Newman
Checked by R. L. Shriner and F. J. Wolf.
1. Procedure
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).
2. Notes
1.
The
α-bromonaphthalene was redistilled just before use and the fraction boiling at
153–154°/22 mm. taken.
2.
"Baker's Analyzed"
cuprous cyanide (powdered) was used. The
cuprous cyanide must be dry.
3.
Pure
pyridine dried over
barium oxide was used. A considerable amount of heat is liberated on addition of the
pyridine to the mixture.
4.
A fused salt bath consisting of 8.5 parts (by weight) of
sodium nitrite and 10 parts of
potassium nitrate has a melting point of about 140° and may replace the metal bath.
5.
The cuprammonium solution attacks
filter paper and hence this solution is best filtered through a fritted-glass filter. Two layers of ordinary toweling cloth on a
Büchner funnel may also be used.
6.
It is occasionally necessary to add an additional
50–100 ml. of ether to facilitate separation.
7.
If the final ammoniacal wash solution is not colorless, the
ether/
benzene solution should be washed with additional
100-ml. portions of dilute aqueous ammonia.
8.
If a precipitate separates during this operation it should be removed by filtration.
9.
The yields vary with the quality of the
cuprous cyanide. One lot of this reagent gave yields of only
60–75%. Larger amounts may be run, but the amount of
pyridine used should be reduced to decrease the reflux. For a 2-mole run,
160 ml. of pyridine was satisfactory. The yield of the large runs was
81%.
10.
α-Chloronaphthalene (b.p.
144–146.5°/29 mm.) may be used in place of
α-bromonaphthalene, but 24 hours' heating at 245–250° is required. The yields are about the same.
3. Discussion
α-Naphthonitrile has been prepared from
α-naphthylamine by the Sandmeyer reaction,
1 from
α-chloronaphthalene,
2 from
α-bromonapththalene3 by heating with
cuprous cyanide, by heating the
sodium salt of α-naphthalenesulfonic acid with
sodium cyanide4 or with
potassium ferrocyanide,
iron, and
ferric oxide,
5 by heating
α-naphthamide with
phosphorus pentachloride6 or with
sodium chloroaluminate,
7 and by distilling
α-naphthoic acid with
dicyandiamide.
8
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
α-naphthylamine
α-bromonapththalene
sodium chloroaluminate
dicyandiamide
calcium chloride (10043-52-4)
hydrochloric acid (7647-01-0)
ammonia (7664-41-7)
Benzene (71-43-2)
ether (60-29-7)
phosphorus pentachloride (10026-13-8)
iron (7439-89-6)
sodium cyanide (143-33-9)
sodium chloride (7647-14-5)
barium oxide
Cuprous Cyanide (544-92-3)
sodium nitrite (7632-00-0)
pyridine (110-86-1)
α-Bromonaphthalene (90-11-9)
potassium ferrocyanide
potassium nitrate (7757-79-1)
ferric oxide (1309-37-1)
α-Naphthoic acid (86-55-5)
α-Naphthonitrile,
1-Naphthonitrile (86-53-3)
sodium salt of α-naphthalenesulfonic acid (130-14-3)
α-naphthamide (2243-81-4)
α-Chloronaphthalene (90-13-1)
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