Organic Chemistry of Explosives

278 Nitramines and Their Derivatives

H 2 N

O

CHO

CHO

+

N

NN

N

O

O 2 N

O 2 N

NO 2

NO 2

106

(TNGU)

O

N

NN

N

O

NO 2

105

(DINGU)

O

N

H

H

N

H

N

N

H

OO

104

20 % N 2 O 5

in 100 % HNO 3

100 % HNO 3 or

HNO 3 , H 2 SO 4

H

H

O 2 N

NH 2

Figure 6.28

TNGU (106) is a powerful explosive with a detonation velocity of 9150 m/s and one

of the highest crystal densities (2.04 g/cm^3 ) reported for known C,H,N,O-based energetic

materials.^38 ,^39 However, like allN,N′-dinitroureas, TNGU is readily hydrolyzed by cold water

and of limited use as a practical explosive. DINGU (105), being anN-nitrourea, is more

hydrolytically stable than TNGU and decomposes only slowly on treatment with boiling water.

DINGU has been classified as an insensitive high explosive^40 (IHE) but is less energetic than

TNGU, having a detonation velocity of 7580 m/s and a density of 1.99 g/cm^3. This insensitivity

to impact is attributable to intramolecular hydrogen bonding in the nitrourea framework. The

simplicity with which DINGU is synthesized from cheap and readily available starting materials

has prompted research into its use in PBXs and LOVA munitions.^41

Chinese chemists^42 reported the base hydrolysis of TNGU. The product, 1,1,2,2-

tetranitraminoethane, has been used to prepare a series of heterocyclic nitramines via con-

densation reactions and may find future use for the synthesis of heterocyclic caged nitramines.

N

H

H

N

H

N

N

H

O

N

NN

N

O

O 2 N

O 2 N

O 2 N

O 2 N

NO 2

NO 2

NO 2

N

NN

N

O

N

N

CHO

CHO

HO

HO

H 2 NNH 2

O

. 2HCl

109

(K-55)

110

(HK-55)

(^108) 90 % HNO 3 ,
Ac 2 O, < 10 °C
72 %
100 % HNO 3 ,
Ac 2 O, 20–50 °C
49 %
HCl (aq)
107

• H
  Figure 6.29