TNT: Trinitrotoluenes and Mono and Dinitrotoluenes

THE THEORETICAL NITRATION OF TOLUENE 23
nitro-group can then easily replace the sulphonic
group.
The formation of the small amount of meta nitrotoluene
is explained thus by Holleman: (2) "It is
apparent that there is an opposition between the ortho
and para derivatives on one hand, and the meta derivatives
on the other. Either tjhe first two are the chief
products, or the last. Concerning the temperature
of the reaction, it has been proved that the quantity
of the by-products is the smaller, the lower the temperature
of nitration." This statement of Holleman
is based on earlier work by himself, and in a paper he
gives this tabulation: (3)
Temp, of Nitration.
Deg. C.
-30 0
30
60
CONSTITUTION OF MIXTURE OF UNITS
Ortho.
Percent.
55.6
56.0
56.9
57.5
Meta.
Per Cent.
2.7
3.1
3.2
4.0
Para.
Per Cent.
41.7
40.9
39.9
38.9
Considering, then, the mixture of mononitrotoluenes
to consist of, approximately, 38 per cent para, 4 per
cent meta, and 58 per cent ortho nitrotoluene; the
reactions which occur on nitrating to dinitrotoluene
will be investigated.
This nitration takes both the ortho and para nitrotoluenes
largely to but one dinitrotoluene—the 1-2-4
modification—but a small amount of 1-2-6 is formed.
The nitro-group here, as before, conscientiously follows
the law of orientation and enters a position meta to