Other nitramine products from the nitrolysis of hexamine

4 Other nitramine products from the nitrolysis of hexamine 

The chemistry of l,5-dinitroendomethylene-l,3,5,7-tetraazacyclooctane (239) (DPT) is interesting in the context of the nitramine products which can be obtained from its nitrolysis under different reaction conditions. The nitrolysis of DPT (239) with acetic anhydride-nitric acid mixtures in the presence of ammonium nitrate is an important route to HMX (4) and this has been discussed in Section 5.15.2. The nitrolysis of DPT (239) in the absence of ammonium nitrate leads to the formation of l,9-diacetoxy-2,4,6,8-tetranitro-2,4,6,8-tetraazanonane (248) the latter has found use in the synthesis of energetic polymers. 

Treatment of DPT (239) with dinitrogen pentoxide in pure nitric acid leads to the isolation of the nitrate ester (249), an unstable explosive which is highly sensitive to impact and readily undergoes hydrolysis. A low nitration temperature favours the formation of (249) and its presence during the nitrolysis of hexamine is clearly undesirable. The nitrolysis of DPT (239) with one equivalent of pure nitric acid in an excess of acetic anhydride yields 1-acetomethyl-3,5,7-trinitro-l,3,5,7-tetraazacyclooctane (251), a useful starting material for the synthesis of other explosives.  

Dimethylolnitramine (252) is known to be present under the conditions of the Hale nitrolysis. If the Hale nitrolysis reaction is quenched, the RDX removed by filtration and the aqueous liquors neutralized to remove DPT, the remaining filtrate can be extracted into ether and that solution evaporated over water to give an aqueous solution of dimethylolnitramine (252).  

Dimethylolnitramine (252) readily participates in Mannich condensation reactions treatment of a aqueous solution of (252) with methylamine, ethylenediamine and Knudsen s base (254) (generated from fresh solutions of ammonia and formaldehyde) yields (253), (255) and (239) (DPT) respectively. The cyclic ether (258) is formed from the careful dehydration of dimethylolnitramine (252) under vacuum.  

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