Coupling of C-nitro-NH-azoles with arylboronic acids. A route to N-aryl-C-nitroazoles

Abstract

SummaryA method for the synthesis of N-aryl-C-nitroazoles is presented. A coupling reaction between variously substituted arylboronic acids and 3(5)-nitro-1H-pyrazole catalyzed by copper salt has been carried out in methanol in the presence of sodium hydroxide to afford the desired N-aryl-C-nitroazoles in good yields. This synthetic route has also been successfully applied to obtain N-phenyl derivatives of 4-nitropyrazole, 2-nitroimidazole, 4(5)-nitroimidazole and 3-nitro-1,2,4-triazole.

Synthesis of 1-(N-nitropyrazolyl)-1Н-tetrazoles – a new type of heteronuclear N-nitropyrazole derivatives

“…As reported in the literature, 14,[38][39][40][41][42][43][44][45] N-nitration in the majority of cases proceeds selectively, giving only one isomer. In the monosubstituted 3(5)-Rpyrazole series, N-nitration occurs at the endocyclic nitrogen atom, which is the most distant from the 3(5)-R Chemistry of Heterocyclic Compounds 2015, 51(8), 695-703 Table 2.…”

Properties and Promise of Catenated Nitrogen Systems As High-Energy-Density Materials

“…N -Nitropyrazole ( 86 ) is normally prepared by direct nitration of pyrazole. ,, With an improved oxygen balance of −78%, it has been considered for its energetic properties as a model compound for decomposition of nitroazoles. However, 86 has a predicted VoD of only 6800 m/s and P CJ = 189 kbar .…”

Cu‐Catalyzed Chan–Evans–Lam Coupling Reactions of 2‐Nitroimidazole with Aryl Boronic Acids: An Effort toward New Bioactive Agents against S. pneumoniae

“…However, this method provides a single example of arylated-2nitroimidazole with low yields of 40 %. [43] Most of the reported methods are plagued with harsh reaction conditions, poor selectivity, and poor yield. Therefore, the development of a new synthetic protocols is required, which can be applied to a broad range of nitroimidazoles.…”

“…developed the method for the formation of N ‐aryl‐ C ‐nitroazoles using C‐nitroazoles with aryl boronic acids. However, this method provides a single example of arylated‐2‐nitroimidazole with low yields of 40 % [43] . Most of the reported methods are plagued with harsh reaction conditions, poor selectivity, and poor yield.…”