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432 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

As Pascal [20] found, in the nitration of 1,5-dinitronaphthalene a product of the

following percentage of isomers can be obtained:

1,3,5- 24.2%

1,4,8- 8.8%

1,2,5- (?) 47.5%

The rest (19.5%) consists of resinous products difficult to identify, plus un-

changed dinitronaphthalene.

Using lower nitration temperatures (e.g. 65°C) results in a decrease of the y-isomer

content. The contents of isomers in the product are then:

1,3,5- 34.4%

1,2,5- (?) 58.9%

Resinous substances are present in 6.7%.

According to Pascal, by the nitration of 1,8-dinitroniphthalene two isomers:

1,3,8- 85.1%

1,4,8- 9.6%

may be obtained, along with amorphous products and unconverted dinitronaph-

thalene.

Pascal also obtained, by nitrating naphthalene to trinitronaphthalene, a mixture

of isomers of the composition:

1,3,5- 11-14.7% 1,4,8- 6-10%

1,3,8- 54.3-57.6% 1,2,5- (?) 21.5-25.5x

Patart reports that trinitronaphthalene can be prepared from naphthalene

(1 part) using nitration mixtures (30 parts) of the composition:

HNO 3 18-100%

H 2 SO 4 0-76%

H 2 O 0-6%

When starting from dinitronaphthalene mixtures :

HNO 3 15-100%

H 2 SO 4 0- 70%

H 2 O 0- 15%

should be used for the preparation of trinitronaphthalene.

CHEMICAL PROPERTIES OF TRINITRONAPHTHALENE ISOMERS

1,3,5- (α)− and 1,3,8- (β)− trinitronaphthalenes form the following molecular

compounds α 3 .β, α.β, α.β 3 (Pascal [20]).

Trinitronaphthalenes can be oxidized relatively easily to form corresponding

nitrophthalic acids.

Some of the nitro groups can be relatively readily substituted by a methoxy

or ethoxy group when heated with the corresponding sodium alcoholate. The

oxidation of such a compound leads in the first place to rupture of the ring with

the alkoxy group.

Oxidation reactions have been utilized for determining the constitution of trini-

tronaphthalene isomers.