Organic Syntheses, Coll. Vol. 4, p.690 (1963); Vol. 30, p.67 (1950).
Precautions should be taken to avoid contact with 1-chloromethylnaphthalene
, which is a lachrymator and a vesicant, and with the aldehyde, which seems to possess the same properties to a lesser degree.
In a 1-l. flask fitted with a reflux condenser
are placed 106 g. (0.6 mole) of 1-chloromethylnaphthalene2 (Note 1)
, 168 g. (1.2 moles) of hexamethylenetetramine
, 250 ml. of glacial acetic acid
, and 250 ml. of water. This mixture is heated under reflux for 2 hours. In about 15 minutes the solution becomes homogeneous, and then an oil starts to separate. After the reflux period, 200 ml. of concentrated hydrochloric acid
is added and refluxing is continued for an additional 15 minutes (Note 2)
. After cooling, the mixture is extracted with 300 ml. of ether
; the ether
layer is washed three times with 100-ml. portions of water, then with 100 ml. of 10% sodium carbonate
solution (Note 3)
, and again with 100 ml. of water. The ether
extract is dried with about 15 g. of anhydrous sodium sulfate
and filtered, and the ether
is removed by distillation. The residual liquid is distilled under reduced pressure, the distillate being collected at 105–107°/0.2 mm.
or 160–162°/18 mm. (Note 4)
. The yield of colorless 1-naphthaldehyde
freezing between 0.0° and 2.5° (Note 5)
is 70–77 g.
used melted at 24–26°.
Material with a lower melting point can be used, but the yield is correspondingly smaller; e.g., a sample having a melting point of 15–18°
gave a 73%
yield of slightly impure 1-naphthaldehyde
In this variation of the preparation, it is best to use a wide-bore tube as a condenser
to remove the unreacted naphthalene
. After the naphthalene
has been distilled, the wide-bore tube is replaced with an ordinary condenser
and the naphthaldehyde
is distilled in the usual manner.
The various amines and aldehydes present combine to form Schiff's bases. If these are not hydrolyzed by a strong acid, they will contaminate the final product.
The melting point of 1-naphthaldehyde
given by Stephen3
) is apparently incorrect. A sample that was purified through the bisulfite addition compound and redistilled had a freezing point of 2.5°.
In no instance could the checkers obtain a completely colorless product even though it was redistilled several times with ordinary laboratory distilling apparatus.
has been made from α-naphthonitrile
by reduction with stannous chloride
,3,15,16 sodium triethoxyaluminohydride
, 17 lithium triethoxyaluminohydride
or diisobutylaluminum hydride
by the action of aluminum chloride
, hydrogen cyanide
, and hydrochloric acid
by treatment with dichloromethyl methyl ether
in the presence of stannic chloride
and by the reaction with carbon monoxide
in the presence of boron trifluoride
and hydrogen fluoride
from α-naphthoyl chloride
by reduction with lithium tri-tert-butoxyaluminohydride
from α-naphthoic acid N,N-dimethylamide
by reduction with lithium diethoxyaluminohydride
from the 1,3-diphenyltetrahydroimidazole derivative of 1-naphthaldehyde
from the reaction of α-naphthylmethylpyridinium bromide
and hydrolysis of the resulting nitrone; 26
by the decomposition of 1-(benzenesulfonhydrazidocarbonyl) naphthalene
with sodium carbonate
and by the oxidation of α-methylnaphthalene
with selenium dioxide
This preparation is referenced from:
Copyright © 1921-, Organic Syntheses, Inc. All Rights Reserved