Organic Chemistry of Explosives

Diazocines 269

Eaton and co-workers^10 synthesized the cubane-based dinitrourea (42) viaN-nitration of

the cyclic urea (41) with nitric acid–acetic anhydride. Cubane-based nitramide (43) is prepared

from theN-nitration of the corresponding bis-amide with acetic anhydride–nitric acid.^11 Bis-

nitramine (44) is prepared from theN-nitration of the corresponding diamine with TFAA–nitric

acid.^12

43 N

N

CO 2 CH 3

CH 3 O 2 C

NO 2

NO 2

44 N

N

CH 2 C(NO 2 ) 2 F

F(NO 2 ) 2 CCH 2

NO 2

NO 2

Figure 6.10

6.5 Diazocines

Diazocines are eight-membered heterocycles containing two nitrogen atoms. TheN-nitro and

N-nitroso derivatives of 1,5-diazocines are energetic materials with potential for use in high-

energy propellants.

2 N NNO

O 2 N NO 2

O 2 N NO 2

HN

CH 2 C(NO 2 ) 2

CH 2 C(NO 2 ) 2

N

CH 2 CH(NO 2 ) 2

CH 2 CH(NO 2 ) 2

46

O 2 N

AcOH

2 K

45

HNO 3 , H 2 SO 4 ,

CH 2 Cl 2

71 %

2 CH 2 O, RNH 2

MeOH (aq)

47, R = H, 85 %

48, R = Me, 15 %

R

Figure 6.11

Adolph and Cichra^13 synthesized a number of polynitroperhydro-1,5-diazocines and com-

pared their properties with the powerful military explosive HMX. A type of Mannich condensa-

tion was used to form the 1,5-diazocine rings; the condensation of ammonia and methylamine

with formaldehyde and bis(2,2-dinitroethyl)nitramine (46)^14 forming diazocines (47) and (48)

respectively. 1,3,3,7,7-Pentanitrooctahydro-1,5-diazocine (47) isN-nitrated to 1,3,3,5,7,7-

hexanitrooctahydro-1,5-diazocine (52) in near quantitative yield using mixed acid.

NNON

O 2 N NO 2

O 2 N NO 2

N

CH 2 CH(NO 2 ) 2

CH 2 CH(NO 2 ) 2

49

ON

2 CH 2 O, RNH 2

MeOH (aq)

50, R = H, 81 %

51, R = i-Pr, 47 %

AcOH

R

Figure 6.12