The Chemistry of Powder and Explosives - Sciencemadness Dot Org

HEXANITRODIPHENYLAMINE 185
Carter 111 in 1913 and studied further by Hoffman and Dame 112
in 1919 and by Marshall 113 in 1920.
NO2 NO2 NO2
NO, / / NO2 NO;
-NO2 NO2
\
-NO;
NO2 NO2
Dinitrochlorobenzene reacts with 2 equivalents of aniline, when
the materials are warmed together in the absence of solvent or
when they are stirred together vigorously with water 80-90°,
to form dinitrodiphenylamine in practically quantitative yield,
along with 1 equivalent of aniline hydrochloride. The use of the
second molecule of aniline to combine with the hydrogen chloride
involves unnecessary expense, and the same results may be
accomplished by means of some mineral alkali or acid-neutralizing
substance like sodium acetate or sodium or calcium carbonate.
The product, which is insoluble in water, separates in
bright red needles. Pure 2,4-dinitrodiphenylamine, recrystallized
from alcohol or from benzene, melts at 156-157°. The crude
product is nitrated in one or in two stages to the hexanitro
compound.
Preparation of Hexanitrodiphenylamine (Two-Stage Nitration). Seventy
grams of aniline and 32 grams of precipitated calcium carbonate
are stirred up together with water in such manner as to form a homogeneous
suspension, and the mixture is heated to about 60°. Dinitrochlorobenzene,
150 grams, previously melted, is poured in slowly in a
fine stream while the stirring is continued and the mixture is heated
gradually to about 90°, the rate of heating being regulated by the
progress of the reaction. The product is washed with hydrochloric acid
to free it from aniline and calcium carbonate, then with water until free
from chlorides, and dried in the oven at 100°.
Fifty grams of finely powdered dinitrodiphenylamine is added in
small portions at a time to 420 grams of nitric acid (d. 1.33), which is
stirred vigorously while the temperature is maintained at 50-60°. The
progress of the nitration is followed by observing the color change from
111 Z. ges. Schiess- u. Sprengstoffw., 8, 205, 251 (1913).
112 /. Am. Chem. Sec, 41, 1013 (1919).
113 J. hid. Eng. Chem., 12, 336 (1920).