calculated performance improvements are expected from a particularly new class of compounds , geminal - bis - substituted heterocyclic nitramines , when formulated into explosives and propellants . this invention involves novel and nonintuitive methods for the preparation of certain derivatives of 2 , 2 - bis - n - nitro - 1 , 3 - propanediamine which are suitable precursors leading to 5 , 5 - bishexahydro - 1 , 3 - dinitropyrimidine . the invention also involves novel and nonintuitive methods for the preparation of rnfx , a specific member of a general class of compounds with the substructure 2 , 2 - bis - n - nitro - 1 , 3 - propanediamine . rnfx is produced by the use of key intermediates , including tetrahydropyrimidin - 5 - ones , which allow formation of the target structural subcomponent , 2 , 2 - bis - n - nitro - 1 , 3 - propanediamine , and a more specific substructure of 2 , 2 - bis - n , n ′- dinitro - 1 , 3 - propanediamine . in addition , this invention involves 5 , 5 - bishexahydropyrimidine derivatives , related geminal - bisalkylene derivatives , and novel precursors to these new derivatives , by the use of certain novel key intermediates .