urbaf2

332 CHEMISTRY AND TECHNOLOGY OF EXPLOSIVES

of amines (Brown and Campbell [142]). It has also been utilized for determining

the structure of unsymmetrical isomers of trinitrotoluene (p. 336). The isomers

react with hydrazine and phenylhydrazine in a similar way.

Brady, Hewetson and Klein [139] studied the action of aromatic amines on

unsymmetrical trinitrotoluene. They obtained diphenylamine derivatives, e.g. :

(28)

Reaction with sodium sulphite

This reaction is of great practical importance, since it is the simplest and most

frequently used way of removing the unsymmetrical isomers from crude TNT.

The reaction involves the following transformations, taking place at room temper-

ature:

(29a)

(29b)

(29c)

The solution of sodium dinitrotoluenesulphonates formed is of a characteristic

light red colour. The reaction is carried out using either a 2-3% solution at a

temperature of 70-80°C or a 6-8% solution at room temperature to 30°C.

Brady, Hewetson and Klein [139] tried to elucidate the mechanism of the reaction

of sulphitation of unsymmetrical trinitrotoluenes. They assumed the formation

of an addition product of sodium sulphite and the nitro compound in the first

stage.