The Chemistry of Powder and Explosives - Sciencemadness Dot Org

130
AROMATIC NITRO COMPOUNDS
m-cresol is the only one which yields a trinitro derivative directly.
Moreover, synthetic phenol from benzene, through chlorobenzene
by the Dow process, is purer and probably cheaper in
times of stress.
Of the hydrocarbons toluene is the only one which nitrates
sufficiently easily and yields a product which has the proper
physical and explosive properties. Trinitrotoluene is the most
widely used of the pure aromatic nitro compounds. It melts at
such temperature that it can be loaded by pouring. It is easily
and surely detonated, and is insensitive to shock, though not
insensitive enough to penetrate armor-plate without exploding
until afterwards. It is powerful and brisant, but less so than
trinitrobenzenc which would offer certain advantages if it could
be procured in sufficient quantity.
Of the xylenes, the meta compound yields a trinitro derivative
more readily than toluene does, but trinitro-m-xylene (TNX)
melts somewhat higher than is desirable and is not quite powerful
enough when used alone. It has been used in shells in mixtures
with TNT and with ammonium nitrate. The other xylenes yield
only dinitro derivatives by direct nitration. A mixture of o- and
p-xylene may be converted into an explosive—an oily mixture of
a large number of isomers, which has been used in the composition
of non-freezing dynamites—by chlorinating at an elevated
temperature in the presence of a catalyst (whereby chlorine is
substituted both in the side chain and on the nucleus), then
nitrating, then hydrolyzing (whereby both chlorines are replaced
by hydroxyl groups, the nuclear chlorine being activated by the
nitro groups), and finally nitrating once more.
CH3 CH2—Cl
NO2-,
NO
CH2—ONOj