Efficient Procedure for High-Yield Synthesis of 4-Substituted 3,5-Dinitropyrazoles Using 4-Chloro-3,5-dinitropyrazole
摘要:
The transformations of readily available 4-chloro-3,5-dinitropyrazole and its N-methylated derivative under the action of anionic S-/O-nucleophiles and neutral N-nucleophiles were studied. Independent of the substrate's charge (anionic, R = H, or neutral, R = Me), the nucleophilic substitution proceeds exclusively at position 4 replacing the chlorine nucleofuge. As a result of this study, the effective synthetic method for the preparation of 4-substituted 3,5-dinitropyrazoles via the nucleophilic substitution in 4-chloro3,5-dinitropyrazole was elaborated.
Synthesis and Comparison of the Reactivity of 3,4,5-1<i>H</i>-Trinitropyrazole and Its<i>N</i>-Methyl Derivative
作者:Igor L. Dalinger、Irina A. Vatsadze、Tatyana K. Shkineva、Galina P. Popova、Svyatoslav A. Shevelev、Yuliya V. Nelyubina
DOI:10.1002/jhet.1026
日期:2013.7
(1) has been obtained via nitration of 3,5‐dinitropyrazole with mixture of sulfuric and nitric acids. Compound 1 reacts with excess ammonia and aliphatic amines, in the presence of bases with NH‐azoles, phenols, thiols, and triflouroethanol at mild conditions in water. All these reactions occur as the nucleophilic substitution of the nitro‐group at position 4 in 1 affording 4‐R‐3,5‐dinitropyrazoles.