 The US Navy is testing HNIW for use in rocket propellants, such as for missiles, as it has lower observability characteristics such as less visible smoke.HNIW is prepared by first condensing benzylamine with glyoxal in acetonitrile under acidic and dehydrating conditions.Four of the benzyl groups are removed from hexabenzylhexaazaisowurtzitane by hydrogenolysis catalysed by palladium on carbon and the resulting secondary amine groups are acetylated in acetic anhydride.