Sodium 5‐nitrotetrazolate dihydrate (NaNT) is a useful precursor compound for the synthesis of lead‐free primary explosives; however, currently employed syntheses for the compound are tedious, dangerous, and plagued by impurities. Through comprehensive analysis, we elucidate the identity of the most detrimental impurities and further report an improved procedure for preparation of NaNT, which greatly improves the purity, while avoiding the handling of acid copper(II) nitrotetrazolate, a highly sensitive explosive intermediate. In the new procedure, 5‐aminotetrazole is diazotized with sodium nitrite, cupric sulfate, and nitric acid. Copper is precipitated as its oxide and the aqueous solution evaporated. After soxhlet extraction with acetone, large crystals of NaNT are obtained. The prepared material is suitable for preparation of lead azide replacement DBX‐1 [copper(I) 5‐nitrotetrazolate] as evidenced by successful use in M55 stab detonators.

Copper(I) 5-nitrotetrazolate (DBX-1) has emerged in recent years as a primary explosive that could serve as a replacement for lead azide (LA), a widely used explosive that has fallen out of favor due to its toxicity and chemical compatibility issues. While there is a significant amount of interest in this material, the development of DBX-1 has been hampered by the tedious and poorly understood chemical process for its preparation. To consistently produce DBX-1, two explosive intermediates must be isolated, and one of them requires purification. In this article, we present an improved process for the synthesis of DBX-1. In this process, neither of these intermediates needs to be handled by an operator, and the purification step is no longer necessary. It would be practical to perform the entire process under remote control, a necessity for energetic material manufacturing. We discuss the implications of our findings for the development of a robust process for the reproducible production of high quality DBX-1.

The long‐time elusive structure of the acid copper(II) salt intermediate in the production of DBX‐1 is presented. The single‐crystal X‐ray shows infinite chains of copper(II) ions complexed by six 5‐nitrotetrazolate anions are aligned along the sixfold axis. Hydronium ions are located on the threefold axis with additional neutral water molecules.

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