A new synthesis of TATB using inexpensive starting materials and mild reaction conditions

TATB is currently manufactured in US by nitration of the expensive TCB to give 2,4,6-trichloro-1,3,5-trinitrobenzene which is then aminated to yield TATB. Elevated temperatures (150 C) are required for both reactions. There is a need for a more economical synthesis of TATB that also addresses current environmental issues. We have recently found that 1,1,1-trimethylhydrazinium iodide (TMHI) allows the amination of nitroarenes at ambient temperature via Vicarious Nucleophilic Substitution of hydrogen. TMHI reacts with picramide in presence of strong base (NaOMe or t-BuOK) to give TATB in over 95% yield. TMHI and picramide can be obtained from either inexpensive starting materials or surplus energetic materials from demilitarization activities, such as the 30,000 metric tons of UDMH (surplus rocket propellant) from the former Soviet Union

Recent studies on the chemical conversion of energetic materials to higher value products

The objective of our program is to develop novel, innovative solutions for the disposal of surplus energetic materials (high explosives, propellants) resulting from the demilitarization of nuclear and conventional munitions. Historically, energetic materials have been disposed of by open burning/open detonation (OB/OD) which is becoming unacceptable due to public concerns and increasingly stringent environmental regulations. The use of energetic materials as chemical feedstocks for higher value products potentially provides environmentally sound and cost-effective alternatives to OB/OD. The conversion of UDMH (unsymmetrical dimethylhydrazine, 1,1-dimethylhydrazine) and Explosive D (ammonium picrate) to higher value explosives such as 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and 1,3-diamino-2,4,6-trinitrobenzene (DATB) illustrates our approach. TATB is a reasonably powerful high explosive whose thermal and shock stability is considerably greater than that of any other known material of comparable energy. We have developed a new synthesis of TATB that can utilize surplus UDMH (propellant) and Explosive D (high explosive) as starting materials

New synthesis of TATB process development studies

We described a new synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) in 1996 at the 27th International Annual Conference of ICT. 1,1,1-trialkylhydrazinium salts are highly reactive reagents which aminate nitroaromatic compounds through vicarious nucleophilic substitution (VNS) of hydrogen. When applied to picramide, these reagents produce TATB in high yield. Traditionally, TATB has been manufactured in the USA by nitration of the relatively expensive and domestically unavailable 1,3,5-trichlorobenzene (TCB) to give 2,4,6-,trichloro- 1,3,5-trinitrobenzene (TCTNB) which is then aminated to yield TATB. Elevated temperatures (150{degrees}C) are required for both reactions. Our new VNS synthesis potentially affords an inexpensive and a more environmentally benign preparation of TATB. We describe in this report our progress in scaling up the synthesis of TATB from the laboratory to the pilot plant. We will discuss structure and control of impurities, changes in yield/quality with reaction conditions, choice of solvents, workup and product isolation, safety, and environmental considerations. Particle size characterizations as well as small-scale safety and performance testing will also be discussed

Effect of counter-ion on packing and crystal density of 5,5′-(3,3′-bi[1,2,4-oxadiazole]-5,5′-diyl)bis(1H-tetrazol-1-olate) with five different cations

In energetic materials, the crystal density is an important parameter that affects the performance of the material. When making ionic energetic materials, the choice of counter-ion can have detrimental or beneficial effects on the packing, and therefore the density, of the resulting energetic crystal. Presented herein are a series of five ionic energetic crystals, all containing the dianion 5,5′-(3,3′-bi[1,2,4-oxadiazole]-5,5′-diyl)bis(1H-tetrazol-1-olate), with the following cations: hydrazinium (1) (2N2H5+·C6N12O42−), hydroxylammonium (2) 2NH4O+·C6N12O42− [Pagoria et al.. (2017). Chem. Heterocycl. Compd, 53, 760–778; included for comparison], dimethylammonium (3) (2C2H8N+·C6N12O42−), 5-amino-1H-tetrazol-4-ium (4) (2CH4N5+·C6N12O42−·4H2O), and aminoguanidinium (5) (2CH7N4+·C6N12O42−). Both the supramolecular interactions and the sterics of the cation play a role in the density of the resulting crystals, which range from 1.544 to 1.873 Mg m−1. In 5, the tetrazolate ring is disordered over two positions [occupancy ratio 0.907 (5):0.093 (5)] due to a 180° rotation in the terminal tetrazole rings

High Power Explosive with Good Sensitivity: A 2:1 Cocrystal of CL-20:HMX

A novel energetic cocrystal predicted to exhibit greater power and similar sensitivity to that of the current military standard explosive 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) is presented. The cocrystal consists of a 2:1 molar ratio of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), a powerful explosive too sensitive for military use, and HMX. A predicted detonation velocity 100 m/s higher than that of β-HMX, the most powerful pure form of HMX, was calculated for the cocrystal using Cheetah 6.0. In small-scale impact drop tests the cocrystal exhibits sensitivity indistinguishable from that of β-HMX. This surprisingly low sensitivity is hypothesized to be due to an increased degree of hydrogen bonding observed in the cocrystal structure relative to the crystals of pure HMX and CL-20. Such bonding is prevalent in this and other energetic cocrystals and may be an important consideration in the design of future materials. By being more powerful and safe to handle, the cocrystal presented is an attractive candidate to supplant the current military state-of-the-art explosive, HMX

High Power Explosive with Good Sensitivity: A 2:1 Cocrystal of CL-20:HMX

A novel energetic cocrystal predicted to exhibit greater power and similar sensitivity to that of the current military standard explosive 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) is presented. The cocrystal consists of a 2:1 molar ratio of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), a powerful explosive too sensitive for military use, and HMX. A predicted detonation velocity 100 m/s higher than that of β-HMX, the most powerful pure form of HMX, was calculated for the cocrystal using Cheetah 6.0. In small-scale impact drop tests the cocrystal exhibits sensitivity indistinguishable from that of β-HMX. This surprisingly low sensitivity is hypothesized to be due to an increased degree of hydrogen bonding observed in the cocrystal structure relative to the crystals of pure HMX and CL-20. Such bonding is prevalent in this and other energetic cocrystals and may be an important consideration in the design of future materials. By being more powerful and safe to handle, the cocrystal presented is an attractive candidate to supplant the current military state-of-the-art explosive, HMX