The nitrolysis of hexamine 251of hexamine nitrolysis and the distribution of products obtained. Variations in such conditions
have been extensively studied and have allowed the synthesis of a wealth of cyclic and linear
nitramines.
5.15.3.1 Low temperature nitrolysis of hexamine
The nitrolysis of hexamine at low temperature has led to the synthesis of a number of cyclic
nitramines. The reaction of hexamine dinitrate (241) with 88 % nitric acid at− 40 ◦C, followed
by quenching the reaction mixture onto crushed ice, leads to the precipitation of 3,5-dinitro-3,5-
diazapiperidinium nitrate (242) (PCX) in good yield;^193 PCX is an explosive equal in power to
RDX but is slightly more sensitive to impact. The reaction of PCX (242) with sodium acetate
in acetic anhydride yields 1-acetyl-3,5-dinitro-1,3,5-triazacyclohexane (82) (TAX), which on
further treatment with dilute alkali in ethanol yields the bicycle (243).^220
N NH 2 NO 3NNO 2O 2 NNNNO 2O 2 N AcNNN NNNNO 2O 2 N NO 2NO 2NNN
NONO 2O 2 NNNNNO 2O 2 NCH 2 OEtNNN NNNNO 2O 2 N NO 2NO 2(CH 2 ) 6 N 4 .2HNO 3245 24682
(TAX)242
(PCX)244 24388 % HNO 3- 40 °C, 50 %
Ac 2 O, NaOAcdilute
alkali,
EtOH- HNO 3 ,
- 30 °C
- NaNO 2
- HNO 3 ,
-30 °C
100 % HNO 3dilute
alkali,
EtOH- 31 °C O
N- EtOH
241Figure 5.109 Low temperature nitrolysis of hexamineThe reaction of hexamine dinitrate (241) with 98 % nitric acid at− 30 ◦C, followed by
quenching with aqueous sodium nitrate, yields the nitrosamine (244).^220 When the same
reaction is cautiously quenched with ethanol the ethoxyether (245) is obtained.^220 Treatment
of the ethoxyether (245) with cold absolute nitric acid yields the bicyclic ether (246).^220
Treatment of any of the cyclic nitramines (242)–(246) with nitric acid and ammonium nitrate in
acetic anhydride yields RDX.^220 Hexamine dinitrate is often used in low temperature nitrolysis
experiments in order to avoid the initial exotherm observed on addition of hexamine to nitric
acid.