Thermal Decomposition of Nitropyrazoles

AbstractFully nitrated five-membered heterocycles (pyrazoles), polynitropyrazoles in particular, have been actively studied as promising high-energy materials. Polynitropyrazoles have high density and high enthalpy of formation combined with reduced sensitivity to external stimuli. We have studied non-equilibrium processes of thermal decomposition of the first members of high-energy polynitropyrazoles row, i.e., 3,4–dinitropyrazole, 3,5–dinitropyrazole, and 3,4,5-trinitropyrazole, under atmospheric and increased pressures. The use of increased pressure allowed to reduce the influence of evaporation process of 3,5–dinitropyrazole and to determine the temperature and heat effect of its decomposition, which was found to exceed this value for HMX. For the first time evolved gas products were identified for each stage of decomposition. As a result the probable thermal decomposition pathway for the investigated materials was suggested

Adamantyl-ureas with pyrazoles substituted by fluoroalkanes as soluble epoxide hydrolase inhibitors

A series of soluble epoxide hydrolase (sEH) inhibitors containing halogenated pyrazoles was developed. Inhibition potency of the obtained compounds ranges from 0.8 to 27.5 nM. 1-Adamantyl-3-[(4,5-dichloro-1-methyl-1Н-pyrazol-3-yl)methyl]urea (3f, IC50 = 0.8 nM) and 1-[(Adamantan-1-yl)methyl]-3-[(4,5-dichloro-1-methyl-1Н-pyrazol-3-yl)methyl]urea (4f, IC50 = 1.2 nM) were found to be the most potent sEH inhibitors within the described series

Novel energetic CNO oxidizer: Pernitro-substituted pyrazolyl-furazan framework

There is a need for dense energetic oxidizers whose composition is restricted to carbon, hydrogen, nitrogen and oxygen atoms as chlorine-free alternative to current oxidizers of energetic materials such as explosives, propellants and pyrotechnics. High nitrogen heterocyclic frameworks containing trinitromethyl units are an attractive and increasingly important class of oxygen-rich compounds. Herein, for the first time, a synthetic method has been developed for the preparation of a new (pyrazole-3-yl)furazan framework bearing a nitro group in the furazan ring. From this framework, 3-nitro-4-(4-nitro-1-(trinitromethyl)-1H-pyrazol-3-yl)furazan (15) and 3-(3,4-dinitro-1-(trinitromethyl)-1H-pyrazol-5-yl)-4-nitrofurazan (16) have been produced. The combination of positive enthalpy of formation, high density, favorable physical and thermal properties, and reasonable sensitivity with the promising theoretical energetic performance of these oxygen-rich compounds offers materials not only of fundamental interest, but also for potential practical applications, for example, as promising candidates to new environmentally benign rocket propellants