Alkyl‐Bridged Bis‐5‐azidotetrazoles: A Safe Way of Preparation

The general, high‐yielding synthesis of extremely dangerous alkylated bis‐5‐azidotetrazoles is presented. The preparation using 5‐bromotetrazoles for the generation of tetrazolyl hydrazines, which are then converted into the corresponding bis‐5‐azidotetrazoles, presents a safe, large‐scale preparation of alkylated bis‐5‐azidotetrazoles. In this work, 1,2‐bis(5‐azido‐1H‐tetrazol‐1‐yl)ethane, 1,2‐bis(5‐azido‐1H‐tetrazol‐1‐yl)‐1‐methylethane, and 1,4‐bis(5‐azido‐1H‐tetrazol‐1‐yl)butane were synthesized and characterized by 1H, 13C, and 15N NMR spectroscopy, vibrational spectroscopy (IR), and mass spectrometry. The crystal structure of 1,2‐bis(5‐azido‐1H‐tetrazol‐1‐yl)ethane was determined by single‐crystal X‐ray diffraction. In addition, the thermal behavior of the bis‐5‐azidotetrazoles was investigated by differential scanning calorimetry and their sensitivity towards friction and impact were determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)