Synthesis of 1,3,5-Triamino-2,4,6-trinitrobenzene Catalyzed by heteropoly acids

The aim of this research is to provide a convenient and relatively inexpensive preparation method for synthesis of 1،3،5-triamino-2،4،6-trinitrobenzene (TATB). TATB is a reasonably powerful explosive in which ts thermal and shock stability is considerably greater than that of any other known energetic material. It is used in military applications because of its significant insensitivity to thermal and shock environments. There is also interest in employing TATB in the civilian sector for deep oil well explorations where heat-insensitive explosives are required. 1،3،5-tribromo-2،4-dinitrobenzene (TBDNB) and 1،3،5-tribromo-2،4،6-trinitrobenzene (TBTNB) are the precursors for synthesis of TATB. The use of liquid acids such as sulfuric acid، as catalyst has some disadvetages such as corrosiveness and potential danger of explosion، toxic vapors and oxidative degradation of by-products. Heteropoly acids (HPAs) catalyze a wide variety of reactions in homogeneous or heterogeneous (liquid– solid، gas–solid or liquid–liquid biphasic) systems، offering strong options for more efficient and cleaner processing compared to conventional mineral acids. Therefore، in optimal conditions، TBDNB synthesized in the presence of heteropolyacid instead of sulfuric acid with 99% yield. We also synthesized TBTNB from TBB (in a one-pot procedure) using sodium nitrate and oleum ingredients with 60% yield. Ammonolysis of TBTNB finally produced TATB with 73% yield.