Synthesis of CL-20 by Nitration of TADFIW in the Presence of Heteropolyacids as Heterogeneous Catalysts

Hexanitrohexaazaisowurtzitane (HNIW or Cl-20) is a high-energetic material with a cage structure. It is considered as the most powerful explosive. It is usually prepared via nitration of precursors with concentrated nitric and sulfuric acids. Herein, the usage of an efficient catalyst affording mild reaction condition for nitration of 2, 6, 8, 12-tetraacetyl-4, 10-diformyl-2, 4, 6, 8, 10, 12-hexaazaisowurtzitane (TADFIW) is reported. It has been well documented that heteropolyacids (HPAs) are an efficient and green catalysts. So here it is used as nitric acid activator. This strategy gave a milder condition for nitration reaction. Also the reactions can be carry out in a reasonably lower temperature. Using a new nitrating agents, concentrated sulfuric acid was eliminated from the reaction conditions. Meanwhile, the effect of the reaction temperature, time and other factors on the yield was investigated. The structure and purity of the compounds were characterized by elemental analysis, HPLC, IR and 1HNMR.