Four Syntheses of 4‐Amino‐3,5‐dinitropyrazole

Abstract

in Wiley Online Library (wileyonlinelibrary.com).In this paper, syntheses of 4-amino-3,5-dinitropyrazole from four different starting materials are described. The starting materials were 4-nitropyrazole, 4-nitro-3,5-dimethylpyrazole, 3,5-dinitropyrazole, and 4-chloropyrazole, respectively. They are compared in terms of yield, number of steps and suitability for scale-up into pilot scale production. The overall yield, calculated from commercially available starting materials, ranged from 21% in the case of synthesis via 3,5-dinitropyrazole up to 61% for the one starting from 4-chloropyrazole. With numerous factors taken into account, the latter was chosen for a pilot scale study and the product could be produced in batches of 200 g.

Energized nitro-substituted azoles through ether bridges

“…Bis(chloromethyl)ether, 9 5-trinitromethyltetrazole, 11 sodium 5nitrotetrazole, 16 4-choro-3,5-dinitropyrazole, 4b 4-amino-3,5dinitropyrazole, 4b 3,5-dinitro-1,2,4-triazole, 17 3-ntiro-1,2,4triazole, 18 3,4-dinitropyrazole, 19 3,5-dinitropyrazole 20 Impact and friction sensitivity measurements were made using a standard BAM Fallhammer and a BAM friction tester. Densities were determined at room temperature by employing a Micromeritics AccuPyc 1330 gas pycnometer.…”

“…As for 6 except using a solution of potassium 3-nitro-1,2,4triazolate 19 (1.52 g, 10 mmol) and bis(chloromethyl)ether (0.58 g, 5.04 mmol) in dimethyl formamide (5 mL) Dried in air to obtain 10 (0.43 g, 42 %). White solid.…”

Covalent and Ionic Insensitive High‐Explosives

“…(c) Nitration of protected4 -aminopyrazole-3,5-dicarboxylic acid or 4-ethylcarbethoxyamino-1-ethylcarbethoxypyrazole [74].…”

“…The shortest synthetic route with the highest overall yield (61 %) is the synthesis of LLM-116 from 4-chloropyrazole (nitration followed by substitution of the chlorine atom in 3,4,5-trinitropyrazole) [74].M oreover,t his procedure is characterizedb yo nly as mall amount of wastea nd no unfavorable solvents. Therefore, this process was scaled up to as mall pilot plant scale [74].I n2 001 Schmidt et al determined the structure of LLM-116 in the solid state at 294 K( orthorhombic crystal system, P2 1 2 1 2 1 space group, 1 = 1.900 gcm À3 ) [ 73].…”

“…Another explosive, which has low sensitivity towards external stimuli due to alternating electrond onating and withdrawing groups and which may be used in low vulnerability ammunition is 4-amino-3,5-dinitropyrazole (LLM-116, ADNP), which can be obtained by (Scheme 5): (a) Amination of 3,5-dinitropyrazole by vicarious nucleophilic substitution of hydrogen( VNS) [72]) using 1,1,1-trimethylhydrazinium iodide (TMHI) [73] or 4-amino-1,2,4-triazole (4-AT) [74];…”