128 Synthetic Routes to AromaticC-Nitro Compounds
NO 2 NO 2NO 2NO 2NO 2O 2 NNO 2 NO 2O 2 NO 2 N16O 2 NO 2 NO 2 NNH 2 NH 2NH 2NH 2NH 2 H 2 NH 2 N13 14
1,3-diamino-2,4,6-
trinitrobenzene
(DATB)1,3,5-triamino-2,4,6-
trinitrobenzene
(TATB)NHNO 2 NO 2NO 2 NO 2O 2 N O 2 NO 2 N O 2 NNHNNHNHNNNN,N'-bis(1,2,4-triazol-3-yl)-4,4'-diamino-
2,2',3,3',5,5',6,6'-octanitroazobenzene
(BTDAONAB)17CH CH NNNO 2NO 2NO 2O 2 NO 2 N15
3,3'-diamino-2,2',4,4',6,6'-
hexanitrobiphenyl
(DIPAM)2,2',4,4',6,6'-hexanitrostilbene
(HNS)Figure 4.3Interest in polynitroarylenes has resumed over the past few decades as the demand for
thermally stable explosives with a low sensitivity to impact has increased. This is mainly due
to advances in military weapons technology but also for thermally demanding commercial
applications i.e. oil well exploration, space programmes etc. Explosives like 1,3-diamino-
2,4,6-trinitrobenzene (DATB) (13), 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) (14), 3,3′-
diamino-2,2′,4,4′,6,6′-hexanitrobiphenyl (DIPAM) (15), 2,2′,4,4′,6,6′-hexanitrostilbene (HNS,
VOD ∼7120 m/s, d= 1 .70 g/cm^3 ) (16) andN,N′-bis(1,2,4-triazol-3-yl)-4,4′-diamino-
2,2′,3,3′,5,5′,6,6′-octanitroazobenzene (BTDAONAB) (17) fall into this class. TATB is the
benchmark for thermal and impact insensitive explosives and finds wide use for military, space
and nuclear applications.
Some liquid nitro compounds have found past use in explosive compositions. A mixture
of 2,4-dinitroethylbenzene and 2,4,6-trinitroethylbenzene, known as K-10, currently finds use
as an energetic plasticizer in some propellant formulations. K-10 plasticizer, also known as
Rowanite 8001, is manufactured by Royal Ordnance in the UK and also finds use as a plasticizer
in PBXs.
4.3 Nitration
The direct nitration of aromatic substrates is usually the method of choice for the synthesis of
aromatic nitro compounds on both industrial and laboratory scales. Other routes are usually only
considered when the required product has an unusual substitution pattern or is so deactivated
that nitration is exceptionally difficult. Many of these alternative methods are limited to a
laboratory scale.
Olah^1 showed that nitrations can be split into the three categories of electrophilic, nucle-
ophilic and free radical nitration. Free radical nitrations are extensively used for the industrial
synthesis of low molecular weight nitroalkanes from aliphatic hydrocarbons. Nucleophilic ni-
tration is the basis for a number of important methods for the synthesis of nitro and polynitro
alkanes. Generally speaking only electrophilic nitration is of preparative importance for the