Synthesis of 3-nitramino-4-nitrofurazan:
Into a clean, dry, 300-mL 3-neck round-bottomed flask equipped with a vacuum adapter (for nitrogen), rubber septum, magnetic stirring bar and thermometer is added 99.94 g of 10% dinitrogen pentoxide in anhydrous methylene chloride via syringe. It is immediately set in a nitromethane/dry ice bath and cooled to -20 C, and the septum is exchanged for a glass stopper. Add 9.75 g of aminonitrofurazan, with stirring, over an 8 minute period at such a rate as to keep the temperature below -17 C. Any residue can be rinsed down with 2 mL of anhydrous methylene chloride. The cooling bath is exchanged for an ice bath and the mixture is stirred for 3.5 hours while keeping the temperature below 10 C. The mixture is transferred to a single-neck flask and the solvent is removed under vacuum at room temperature. The crystals just obtained are subject to high vacuum for 30 minutes to remove any trace of nitric acid. Yield is nearly 100%. The 3-nitramino-4-nitrofurazan can be purified by recrystallizing from 16.2 mL of dry chloroform per gram of product. The crystals are precipitated by storing the hot chloroform in a freezer for 16 hours.
Synthesis of ammonium 3-nitramino-4-nitrofurazan:
Into a clean round-bottomed flask equipped with magnetic stirring bar, thermometer and set into an ice bath prepare a solution of 0.5 g of 3-nitramino-4-nitrofurazan in 4 mL of water. Add 0.20 g of 29% ammonium hydroxide, with stirring, via a syringe over a 2 minute period while keeping the temperature below 7 C. Stir the mixture for 10 minutes at 7 C, and then for 1 hour at room temperature. The water is removed by heating the flask at 38 C under vacuum. Final yield of ammonium 3-nitramino-4-nitrofurazan is a mere 105%. The crystals can be purified by dissolving in ethyl acetate and precipitated by adding hexanes at -20 C.
Synthesis of potassium 3-nitramino-4-nitrofurazan:
Into a clean round-bottomed flask equipped with magnetic stirring bar, thermometer and set into an ice bath prepare a solution of 0.5 g of 3-nitramino-4-nitrofurazan in 4 mL of water. Add a solution of 0.1957 g of potassium hydroxide in 2 ml of water, with stirring, via a syringe over a 3 minute period while keeping the temperature below 10 C. Stir the mixture for 10 minutes at 10 C, and then for 1 hour at room temperature. The water is removed by heating the flask at 38 C under vacuum. Final yield of potassium 3-nitramino-4-nitrofurazan is 102%.
Synthesis of sodium 3-nitramino-4-nitrofurazan:
Into a clean round-bottomed flask equipped with magnetic stirring bar, thermometer and set into an ice bath prepare a solution of 0.5 g of 3-nitramino-4-nitrofurazan in 4 mL of water. Add a solution of 0.1263 g of sodium hydroxide in 2 ml of water, with stirring, via a syringe over a 4 minute period while keeping the temperature below 10 C. Stir the mixture for 10 minutes at 10 C, and then for 1 hour at room temperature. The water is removed by heating the flask at 38 C under vacuum. Final yield of sodium 3-nitramino-4-nitrofurazan is 105%.
Synthesis of zinc 3-nitramino-4-nitrofurazan:
Into a clean round-bottomed flask equipped with magnetic stirring bar, thermometer and set into an ice bath prepare a solution of 0.546 g of 3-nitramino-4-nitrofurazan in 4.3 mL of water. Add 0.1396 g of zinc over a 2 minute period while keeping the temperature below 7 C. Stir the mixture for 10 minutes at 7 C, and then for 1 hour at room temperature. The water is removed by heating the flask at 38 C under vacuum. Final yield of zinc 3-nitramino-4-nitrofurazan is 107%.
