Nitroguanidine from guanidine nitrate

we dehydrate the previously made guanidine nitrate in concentrated sulfuric acid to form nitroguanidine. this is done at a temperature of around 10C and below. the crude product was recrystallized from boiling water to yield the fluffy needle like crystals of nitroguanidine ready for the next step. we plan to reduce the nitroguanidine to aminoguanidine for yet another different method to synthesize 5-Aminotetrazole.