Process Optimization for Synthesis of CL-20

Abstract

Optimization of process parameters for synthesis of 2, 4,6,8,10,4,6,8,10, of desired particle size have been described. CL-20, the most powerful high explosive, is being synthesized at the High Energy Materials Research Laboratory (HEMRL, Pune, India) by nitration of 2,6,8,4,6,8,10,. Nitration of TAIW is a mild exothermic reaction. Although information on synthesis of CL-20 is reported, no information is available on process optimization. In order to optimize the process parameters for synthesis of CL-20 to obtain higher yield and purity, a study was carried out with variation of different parametric conditions like temperature, time, concentration of nitric acid, mole ratio of reactants, quantity of solvent=anti-solvent, etc. The effect of each parameter was studied by keeping other parameters constant. In the present study it was found that for $85% yield, optimized temperature envelope was 72-85 C, nitric acid concentration range from 98 to 92%, reaction time was 1 h, and temperature during the addition of TAIW into the mixed acid was 25-40 C. In order to improve the particle size of CL-20, during the recrystallization process, the effect of parameters like addition rate of anti-solvent and rate of agitation were studied and

Energetic Salts Based on Monoanions of N,N‐Bis(1H‐tetrazol‐5‐yl)amine and 5,5′‐Bis(tetrazole)

“…The chemical shifts are given with respect to CH 3 NO 2 as external standard. The 15 N NMR spectrum of II shows three signals at d = À307.0 (N5), À104.7 (N1/N4), and 4.3 ppm (N2/N3). The signals are farther downfield than that of I (d = À315.7, À123.8, À17.9 ppm).…”

“…Modern high-energy density materials (HEDM), in which energetic nitrogen-rich salts are among the most recent and exciting developments, continue to attract considerable interest (Scheme 1). [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The attractive syntheses of novel energetic products include a wide range of neutral molecules and salts, such as nitrogen-rich salts, [4] 5-azidotetrazoles [5] and their salts, [6] derivatives of 1,5-diaminotetrazole, [7] 1,5-diamino-4-methyltetrazolium dinitramide, [8] mono-, di-, and trisubstituted nitroiminotetrazoles, [9] hypergolic ionic liq-uids, [10] energetic nitrate ester, [11] polyazido heteroaromatic compounds, [12] salts of pentanitrogen cation, [13] octanitrocubane (ONC), [14] 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), [15] and salts of N,N'-dinitrourea (DNU). [16] Novel properties, such as high density, high positive heat of formation, and high thermal stability, suggest energetic organic compounds with high nitrogen content for a variety of unique applications including gas generators, [17] smoke-free pyrotechnic fuels, [18,19] fire extinguishers onboard military aircraft, [20,21] solid fuels in micropropulsion systems, [22,23] effective precursors for carbon nanospheres [24,25] and carbon nitride nanomaterials.…”

“…Modern high‐energy density materials (HEDM), in which energetic nitrogen‐rich salts are among the most recent and exciting developments, continue to attract considerable interest (Scheme ) 1–15. The attractive syntheses of novel energetic products include a wide range of neutral molecules and salts, such as nitrogen‐rich salts,4 5‐azidotetrazoles5 and their salts,6 derivatives of 1,5‐diaminotetrazole,7 1,5‐diamino‐4‐methyltetrazolium dinitramide,8 mono‐, di‐, and trisubstituted nitroiminotetrazoles,9 hypergolic ionic liquids,10 energetic nitrate ester,11 polyazido heteroaromatic compounds,12 salts of pentanitrogen cation,13 octanitrocubane (ONC),14 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20),15 and salts of N , N′ ‐dinitrourea (DNU) 16.…”

Heteropolyacids: as efficient catalysts for the nitration of 2,4,6,8,10,12-hexaacetyl-2,4,6,8,10,12-hexaazaisowurtzitane

“…8,10 Both are easily converted to 2, 4, 6, 8, 10, 12-hexanitro-2, 4, 6, 8, 10, 12-hexaazaisowurtzitane by nitration with different nitrating systems. 8,10 Synthesis efforts have been made for a number of nitrolysable precursors to CL-20 including isowurtzitane cage substituted with nitroso, 8 formyl, 11 and acetyl, 12 groups. Synthesis of CL-20 from tetraacetylisowurtzitane (TAIW) has appeared as a favorable method, both in terms of process economy and product purity.…”

“…Synthesis of CL-20 from tetraacetylisowurtzitane (TAIW) has appeared as a favorable method, both in terms of process economy and product purity. 12 Sivabalan et al have established a process for the preparation of CL-20 by nitration of HAIW. 13 In several industrially important processes (e.g.…”