Preparation of 3,3′-diamino-4,4′-azofurazan

#The present invention relates to derivatives of 3,4-diaminofurazan useful as insensitive high explosive materials. This invention was made with government support under a contract with the Department of Energy (Contract No. W-7405-ENG-36).

#The synthesis of 3,4-diaminofurazan was first reported by Coburn in J. Heterocyclic Chem., vol. 5, pp. 83-87 (1968). Since then a large body of work has been accumulated on the oxidation of 3,4-diaminofurazan, especially by Russian scientists, e.g., Solodyuk et al., in Zh. Org. Khim., vol. 17(4), pp. 756-759 (1981) wherein the compounds 3,3′-diamino-4,4′-azoxyfurazan (DAAF) and 3,3′-diamino-4,4′-azofurazan (DAAzF) were described. They used a variety of peroxide reagents on 3,4-diaminofurazan to prepare 3,3′-diamino-4,4′-azoxyfurazan (DAAF), 3,3′-diamino-4,4′-azofurazan (DAAzF) and 3-amino-4-nitrofurazan usually as mixtures which were separated by differing solubilities. However, no characterization of the explosive properties of these compounds was reported.

#One previously known explosive formulation included a combination of 2,2′,4,4′,6,6′-hexanitrostilbene (HNS) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). While this formulation has been useful, it suffers some drawbacks in terms of performance and safety. Improved formulations including TATB have been sought.

#The present invention is concerned with insensitive, high explosive materials. The particular insensitive, high explosive materials of the present invention include 3,3′-diamino-4,4′-azoxyfurazan (DAAF) and 3,3′-diamino-4,4′-azofurazan (DAAzF). Neither compound has previously been known as insensitive, high explosive material.

#In addition to the use of these particular compounds as insensitive, high explosive materials, the present invention is concerned with compositions including 3,3′-diamino-4,4′-azofurazan and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB).

#By the term “insensitive”, it is generally meant that the material has a drop height of greater than 320 cm as measured by using a 2.5 kg falling weight (Type 12).