Organic Chemistry of Explosives

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JWBK121-09 October 11, 2006 21:24 Char Count= 0

358 Dinitrogen Pentoxide – An Eco-Friendly Nitrating Agent

process in the U.S with consideration for scale-up to industrial production.^55 The industrial

availability of the dinitrogen pentoxide–nitric acid reagent makes this a real possibility given

that the overall yield for HMX in very high, and although this reagent is still expensive to man-

ufacture, so is acetic anhydride which is used in large excess in the conventional Bachmann

nitrolysis.^56 The nitrolysis of TAT (23) and DADN (24) fails with some conventional nitrating

agents.

HN

N

NH

O

t-Bu

26

N

N

N

O

N O^2 N NO^2

2 O 5 , HNO 3

NO 2

27

(Keto-RDX or K-6)

Figure 9.14

Keto-RDX (27) has been synthesized from the nitrolysis–nitration of 2-oxa-5-tert-

butyltriazone (26) with dinitrogen pentoxide in nitric acid.^57 Pagoria and co-workers^49 also

reported the use of a very powerful nitrolysis agent for this purpose, composed of dinitrogen

pentoxide–trifluoroacetic anhydride–nitric acid.

(CH 2 )n

N

NO

28

CH 2

N

NO

(CH 2 )n

N

NO 2

29

CH 2

N

NO 2

N

N

N

N

N

N

N

N

NO 2

H

H

N

N N

N

H

H

NO 2

NO 2

NO 2

NO NO^2

2

NO 2

O 2 N

O 2 N

O 2 N

NO 2 O 2 N

N 2 O 5 , HNO 3

-30 °C

32

(^3031)
Figure 9.15
Willer and Atkins^58 used solutions of 30 % nitrogen pentoxide in nitric acid for the nitrolysis
of 1,3-dinitrosoamines (28); the latter synthesized from the reaction of 1,3-diamines with
formaldehyde followed byin situnitrosation of the resulting 1,3-diazacycles. Cyclic, bicyclic
and spirocyclic polynitramines like (30), (31) and (32) have been synthesized via this method.
Incomplete nitrolysis is observed when absolute nitric acid alone is used in these reactions.
Dinitrogen pentoxide in aprotic solvents is not usually used for nitrolysis reactions.
The nitrogen atoms of amides and related compounds are usually quite electron deficient
and these reagents are too mild to affect cleavage. However, the nitrolysis of symmetrical