Organic Chemistry of Explosives

282 Nitramines and Their Derivatives

6.10 Other energetic nitramines

H 2 C

H 2 C

CH 2

N

CH 2

N

NO 2

NO 2

CH 2 OAc

128

O 2 N

CH 3 COBr

CH 3 CON 3 ,

CH 2 Cl 2

• 10 °C, 97 % 79 %
  N

N H 2 C

H 2 C

CH 2

N

CH 2

N

NO 2

NO 2

CH 2 Br

129

O 2 N

N

N H 2 C

H 2 C

CH 2

N

CH 2

N

NO 2

NO 2

CH 2 N 3

130

(AZTC)

O 2 N

N

N

Figure 6.37

Some energetic compounds are engineered to contain two or more different energetic func-

tionalities. The azido group has a high heat of formation and so its presence in energetic mate-

rials is favorable on thermodynamic grounds. However, compounds containing only the azido

‘explosophore’ rarely find use as practical explosives. More common is the incorporation of

other functionality into such compounds. In the case of 1-(azidomethyl)-3,5,7-trinitro-1,3,5,7-

tetraazacyclooctane (130) (AZTC), an azido derivative of HMX, the azidomethyl group triggers

initial thermal decomposition and makes AZTC much more sensitive to initiation than HMX.

AZTC (130) is prepared from the reaction of the acetate ester (128) with acetyl bromide, fol-

lowed by treating the resulting bromide (129) with a solution of acetyl azide.^51 Direct treatment

of the acetate ester (128) with azide nucleophile leads to decomposition of the eight-membered

ring. The azido groups of the energetic azido-nitramine (131), known as DATH, are a similar

trigger for its decomposition.^52

N 3 N

NO 2 NO 2 NO 2

131

(DATH)

NNN 3

Figure 6.38

Some energetic materials contain both nitramine and nitrate ester functionality. Tris-X

(132), a high performance explosive (VOD∼8700 m/s) with a low melting point (69◦C), is

synthesized from the reaction of 2,4,6-tris(aziridino)-1,3,5-triazine with dinitrogen pentoxide

in chloroform at subambient temperature (Section 5.8.1).^53 A homologue of Tris-X, known

as Methyl Tris-X, has been synthesized using the same methodology.^53 However, the thermal

stability of Tris-X is only marginally acceptable suggesting that this family of explosives is

unlikely to be used for munitions.

R

N

NO 2

ONO 2

R = alkyl

133

N

N

N

NCH 2 CH 2 ONO 2

O 2 NOCH 2 CH 2 N NCH 2 CH 2 ONO 2

NO 2

O 2 N

NO 2

132

(Tris-X)

Figure 6.39