The Chemistry of Powder and Explosives - Sciencemadness Dot Org

HEXANITROAZOBENZENE 189
nitrocarbanilide is washed thoroughly with water and allowed to dry in
the air.
Ten grams of crude tetranitrocarbanilide is added to a mixture of 16
grams of concentrated sulfuric acid (d. 1.84) and 24 grams of nitric acid
(d. 151), and the material is heated on the steam bath for 1 hour with
constant stirring. The mixture, after cooling, is treated with cracked ice
and water, and filtered. The product, washed with 500 cc. of cold water,
then with 500 cc. of hot water, and dried in the air, is hexanitrocarbanilide
of stititffactory quality for use as an explosive.
Pure hexanitrocarbanilide crystallizes from acetone-ligroin in
pale yellow rosettes which soften and darken at 204° and melt
at 208-209° with decomposition. It yields picric acid when
warmed with dilute sulfuric acid, and trinitroaniline when boiled
with strong ammonia water. A deep ruby-red color is developed
when hexanitrocarbanilide is allowed to stand at ordinary temperatures
in contact with strong ammonia water. Tetranitrocarbanilide,
dinitroaniline, trinitroaniline, picric acid, and dinitrophenol
do not give this color.
Hexanitrocarbanilide is a brisant high explosive suitable for use
in boosters, reinforced detonators, detonating fuse, primer caps,
etc. For the detonation of 0.4 gram, it requires 0.19 gram of mercury
fulminate. It is slightly stronger than TNT in the sand test
and of about the same sensitivity as tetryl in the drop test. It
explodes spontaneously at 345°.
Hexanitroazobenzene
Hexanitroazobenzene may be prepared from dinitrochlorobenzene
and hydrazine by the reactions indicated below:
y V...N=K-< y-NO»
NO2 \ NO2 KO*yf NO2
-NO2
NO2 NO*
The first of these reactions takes place in hot-water suspension
in the presence of sodium or calcium carbonate. The resulting
tetranitrohydrazobenzene is both nitrated and oxidized by the
mixed acid in the next step. Pure 2,2',4,4',6,6'-hexanitroazoben-