Organic Chemistry of Explosives

164 Synthetic Routes to AromaticC-Nitro Compounds

also increases crystal density and improves explosive performance.^236 Much research has been

focused into this area. Most of the methods for incorporating amino groups into potential

explosives make use of the low electron density in polynitroarylenes and use amines and

ammonia as nucleophiles to attack the corresponding halo derivatives.

Cl

NO 2

NO 2

Cl

O 2 N

OH

OH

O 2 N NO 2

NO 2

2. POCl 3 , 100 °C,
   98 %


3. pyridine,
   Et 2 O, 94 %

5 106

NH 2

NO 2

NO 2

NH 2

O 2 N

13

(DATB)

MeOH, NH 3

97 %

Figure 4.41

1,3-Diamino-2,4,6-trinitrobenzene (DATB) (13) is prepared in high yield by treating

1,3-dichloro-2,4,6-trinitrobenzene (106) with ammonia in methanol.^237 1,3-Dichloro-2,4,6-

trinitrobenzene (106) can be synthesized from the mixed acid nitration of 1,3-dichloroben-

zene,^52 or more conveniently, by treating styphnic acid (5) with pyridine followed by reflux-

ing the resulting dipyridinium styphnate with phosphorous oxychloride.206b,^237 DATB (m.p.

286 ◦C, VOD∼7500 m/s,d= 1 .84 g/cm^3 ) was once widely used in the US for applications

requiring high thermal stability and low sensitivity to impact. The use of DATB in plastic

bonded compositions with Estane, Kel F and Viton A polymers has been patented.^238

Cl

ClCl

O 2 N NO 2

NO 2

NH 2

H 2 N NH 2

O 2 N NO 2

NO 2

34 14

(TATB)

NH 3 , PhCH 3

Figure 4.42

1,3,5-Triamino-2,4,6-trinitrobenzene (TATB) (14) is the most thermally stable and impact

insensitive explosive in current use. TATB is synthesized on an industrial scale from the

tri-nitration of 1,3,5-trichlorobenzene with strong mixed acid followed by nucleophilic dis-

placement of the chloro groups of 1,3,5-trichloro-2,4,6-trinitrobenzene (34) with ammonia

in toluene under autoclave.^53 The extra amino group in TATB (m.p.> 350 ◦C with decom-

position, VOD∼8000 m/s,d= 1 .94 g/cm^3 ) compared to DATB decreases oxygen balance

but increases density and results in higher overall performance. TATB finds extensive use in

military applications requiring high thermal stability and a low sensitivity to impact and has

replaced DATB in this respect. The importance of TATB as a thermally stable explosive has

meant that its synthesis has been widely studied. The synthesis of TATB is discussed in more

detail in Section 4.8.4.

More complex explosives incorporating amino groups have been prepared from the reac-

tion of polynitroarylene halides with amine nucleophiles. Agrawal and co-workers^239 have

synthesized PADNT (107) from the reaction of 4-amino-2,6-dinitrotoluene (46) with picryl

chloride (87) in methanol; 4-amino-2,6-dinitrotoluene is synthesized from the reduction of