Organic Chemistry of Explosives

Nitrolysis 221

The nitrolysis of (107) with nitric acid–trifluoroacetic anhydride yields 2,4,6-trinitro-2,4,6-

triazaheptane (108).^114

The nitrolysis of substituted methylenediamines with nitronium salts can lead to a number of

products depending on the nature of the substituents within the substrate. Electron-withdrawing

or resonance-stabilizing groups favour the expulsion of an immonium ion and the formation

of a secondary nitramine in yields between 58 % and 78 %.^103

A solution of dinitrogen pentoxide in methylene chloride–acetonitrile also yields secondary

nitramines from symmetrical methylenediamines. When the substituent is aliphatic or hete-

rocyclic the nitrolysis occurs specifically at the aminal methylene and yields of secondary

nitramine between 25 % and 54 % are reported.103a

5.6.3 Nitrolysis of nitrosamines

The conversion of a nitrosamine to a nitramine can be affected by either nitrolysis or oxidation.

While the results of these two reactions are identical, they are mechanistically very different.

For this reason, the oxidation of nitrosamines is discussed separately in Section 5.9.

N

NN

NO

NOON

NN

N

NO 2

O 2 N NO 2

(^1093)
HNO 3 , 30 % H 2 O 2 ,

• 40 °C, 74 %
  or
  N 2 O 5 , HNO 3 ,


• 20 °C, 32 %

Figure 5.54

The choice of reagent determines whether a nitrosamine undergoes conversion to a nitramine

by either nitrolysis or oxidation. An example is given for the conversion of 1,3,5-trinitroso-

1,3,5-triazacyclohexane (109) to 1,3,5-trinitro-1,3,5-triazacyclohexane (3) (RDX) – the use of

30 % hydrogen peroxide in 99 % nitric acid^115 at subambient temperature goes via oxidation

of the nitrosamine functionality, whereas dinitrogen pentoxide in pure nitric acid^116 makes use

of a nitrolysis pathway via C–N bond cleavage.

(CH 2 )n (CH 2 )n (CH 2 )n

NH 2

NH 2 N

NO

CH 2

N

NO

N

NO 2

CH 2

N

NO 2

1. CH 2 O


2. HNO 2

N 2 O 5 , HNO 3

-30 °C

110

111 112

Figure 5.55

The nitrolysis of nitrosamines has been relatively unexplored because of the high toxicity of

such substrates. Atkins and Willer^117 ,^118 have prepared a number of cyclic 1,3-dinitrosamines