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284 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

With lead in the presence of dilute nitric acid, 2,4-dinitrotoluene forms inflam-

mable organo-metallic products (for further details see p. 306, Kovache and

Thibon’s work).

An acetone solution of 2,4-dinitrotoluene treated with a 10 per cent solution

of KOH gives a blue colour (the Janovsky reaction), unlike the 2,6-isomer, which

gives no colour at all.

Dinitrotoluenes derived from m- nitrotoluene react with sodium sulphite to

form sodium salts of nitrosulphonic acid, e.g.:

(9)

The reaction occurs with more difficulty than the corresponding one with the

unsymmetrical trinitrotoluenes and requires a higher temperature or more con-

centrated solutions of sodium sulphite. The reaction of “sulphitation” of dinitro-

toluene may be used in practice for removing m-nitrotoluene derivatives from

mixtures of dinitro-isomers. Thus the sulphitation of trinitrotoluene becomes un-

necessary.

Dinitrotoluenes are able to form molecular compounds with condensed ring

aromatic hydrocarbons and also with amines. According to Kremann [24], 3,5-

dinitrotoluene is the most ready to form such compounds, while the others can

be ranged according to their decreasing ability to do so in the following order:

2,4-, 2,6-, 3,4-.

Here is a list of some of the molecular compounds obtained by Kremann:

with: naphthalene

naphthalene

acenaphthene

acenaphthene

aniline

p- toluidine

β -naphthylamine

α -naphthylamine

α -naphthylamine

Dinitrotoluene

isomer

2.4-

3,5-

2,4-

3,5-

3,5-

3,5-

3,5-

2,4-

3,5-

Molecular m. p.,°C

proportion

1:1

1:1

1:1

1:1

1:1

1:1

1:1

1:l

1:1

59

63.2

61

94

46.5

non uniform

53

107.8

62

Aniline, p- toluidine and β -naphthylamine do not combine with 2,4-dinitrotoluene.

TOXICITY

Dinitrotoluene is regarded as a poisonous substance, but in a less degree than

dinitrobenzene. If has been suggested that poisoning by dinitrotoluene should
be ascribed to the impurities present in it, mostly dinitrobenzene.