Organic Chemistry of Explosives

270 Nitramines and Their Derivatives

HNO 3 , H 2 SO 4

90 %

99 %

HNO 3 , Ac 2 O

0–5 °C

96 %

HNO 3 , H 2 O

40–45 °C

47 %

HNO 3 , H 2 SO 4

NHN

O 2 N NO 2

O 2 N

O 2 N NO 2

47

NHN

O 2 N NO 2

ON

O 2 N NO 2

50

NN

O 2 N NO 2

ON NO

O 2 N NO 2

54

NN

O 2 N NO 2

O 2 N

O 2 N NO 2

53

NO

NN

O 2 N NO 2

O 2 N

O 2 N NO 2

52

NO 2

Figure 6.13

Adolph and Cichra^13 prepared someN-nitroso-1,5-diazocines from the condensation

of bis(2,2-dinitroethyl)nitrosoamine (49) with formaldehyde and various amines. 3,3,7,7-

Tetranitro-1-nitrosooctahydro-1,5-diazocine (50), the product obtained from the Mannich con-

densation of (49), formaldehyde and ammonia, was used to prepare nitro- and nitroso- 1,5-

diazocines (52), (53), and (54).

NNNs

NF 2

NF 2

F 2 N

F 2 N

Ns

55

NN

NF 2

NF 2

NO 2

F 2 N

F 2 N

O 2 N

56

Ns = p-NO 2 C 6 H 4 SO 2 (HNFX)

HNO 3 , H 2 SO 4 , 70 °C

6 weeks, 16 %

or

HNO 3 , CF 3 SO 3 H, 55 °C

40 hours, 65 %

Figure 6.14

The search for new high-energy compounds has led to the incorporation of difluoramino

(NF 2 ) functionality into 1,5-diazocines. Chapman and co-workers^15 synthesized the energetic

heterocycle 3,3,7,7-tetrakis(difluoroamino)octahydro-1,5-dinitro-1,5-diazocine (56) (HNFX)

from the nitrolysis of theN-nosyl derivative (55). This nitrolysis is very difficult because the

amide bonds of (55) are highly deactivated, and the problem is made worst by the steric hin-

drance at both amide bonds. Treatment of (55) with standard mixed acid requires both elevated

temperature and up to 6 weeks reaction time for complete amide nitrolysis and formation of

HNFX (56). Chapman and co-workers found that a solution of nitric acid in triflic acid led

to complete amide nitrolysis within 40 hours at 55◦C. Solutions of nitric acid in superacids

like triflic acid are powerful nitrating agents with the protonitronium cation^16 (NO 2 H^2 +)asthe

probable active nitrating agent.