NITRO DERIVATIVES OF NAPHTHALENE^421α− Nitronaphthalene (m. p. 60-61°C; b. p. 304°C), MN or MNN, forms pale yellow
needles, having the specific smell of a nitro compound. It is insoluble in water, but
readily dissolved by most organic solvents.
α− Nitronaphthalene yields molecular compounds with picric acid, trinitrotoluene,nitromannite (described in the chapters dealing with these explosives).
When directly nitrated, naphthalene gives α− nitronaphthalene possibly with
some traces of β− nitronaphthalene.
β− Nitronaphthalene (m. p. 79°C) can only be obtained by an indirect route
from β− naphthylamine, and hence it has not found any practical use.
According to Patart, α− nitronaphthalene is formed as the result of nitrating
naphthalene with a mixture of a composition within the range:
HNO 3 30-50%
H 2 SO 4 0-30%
H 2 O 40-50%As Pascal’s [20] investigations have shown, α− nitronaphthalene forms with
naphthalene a eutectic melting at 36.7°C. The eutectic contains 26.5% of naph-
thalene. During the first stage of nitration, therefore, when both naphthalene
and α− nitronaphthalene are present in the nitrator, a temperature of over 36.7°C
should be maintained (e.g. 40-50°C) so as to keep the substance being nitrated
in a molten state.
To this end some nitration methods recommend introducing into the nitrator
a certain quantity of nitronaphthalene from the previous batch before the process
begins.
After most of the naphthalene has been nitrated, the temperature in the nitrator
shall be raised to 55-60°C to keep the nitration product molten, which will greatly
facilitate the nitration.
α− Nitronaphthalene is used as a component of explosive mixtures, as for example
with picric acid for filling shells, and also in explosives used in mines and in chlorate
explosives (Vol. III).DINITRO DERIVATIVES OF NAPHTHALENE
There are three isomeric dinitronaphthalenes, derivatives of α− nitronaphthalene.
α− (1,5), β− (1,8), and γ− (1,3)-isomers known:α
m. p. 215-216°Cβ
m. p. 170-172°Cγ
m. p. 144°C