Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• authors reported that with 1.4 equivalents of nitric acid at 20 °C a yield of 77% of mono nitrophenols can be achieved. An important example of continuous flow nitration leading to alkyl nitropyrazoles was reported by Pelleter and Renaud [31]. The nitration products 3-methyl-4-nitropyrazole (29), 3,5

• -dimethyl-4-nitropyrazole (31) and 3-ethyl-4-nitropyrazole (32) were obtained with nitrating mixture and were expected to show detonating properties under severe confinement (Scheme 9). This flow synthesis did not allow the pressure inside the reactor to undergo rapid variations in a short time, thereby

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

• Marta K. Kurpet,
• Aleksandra Dąbrowska,
• Małgorzata M. Jarosz,
• Katarzyna Kajewska-Kania,
• Nikodem Kuźnik and
• Jerzy W. Suwiński

Beilstein J. Org. Chem. 2013, 9, 1517–1525, doi:10.3762/bjoc.9.173

• 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

• consistent with the analysis of regioisomers of 1-substituted-C-nitropyrazoles presented by Larina and Lopyrev in their review on nitroazoles [35]. Table 1 contains exemplified structures of 3-nitro-, 4-nitro- and 5-nitropyrazole derivatives and shows the differences in chemical shifts of carbon atoms in

• particular isomers. The examples do not include the 1-aryl substituent, which is present in our product, but general trends in chemical shifts can be observed. The C–NO2 signal in 5-nitropyrazole is shifted by about 10 ppm downfield in comparison to the C–NO2 signal in 3-nitropyrazole, what agrees with

Chemistry of polyhalogenated nitrobutadienes, 10: Synthesis of highly functionalized heterocycles with a rigid 6-amino-3-azabicyclo[3.1.0]hexane moiety

• Viktor A. Zapol’skii,
• Jan C. Namyslo,
• Armin de Meijere and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2012, 8, 621–628, doi:10.3762/bjoc.8.69

• feasible. Keywords: isothiazole; nitrochlorobutadiene; nitropyrazole; nucleophilic substitution; pyrimidine; small rings; Introduction Nitropolychlorobutadienes are potent precursors for a variety of highly functionalized acyclic and (hetero)cyclic compounds. The readily accessible 2-nitroperchloro-1,3

Synthesis and oxidation of some azole-containing thioethers

• Andrei S. Potapov,
• Nina P. Chernova,
• Vladimir D. Ogorodnikov,
• Tatiana V. Petrenko and
• Andrei I. Khlebnikov

Beilstein J. Org. Chem. 2011, 7, 1526–1532, doi:10.3762/bjoc.7.179

• ; N, 25.98. 1,1'-(Sulfinylbis(ethane-2,1-diyl))bis(3,5-dimethyl-4-nitropyrazole) (10). To thioether 3 (0.647 g, 2.33 mmol), НNO3 (1.61 mL of 68% aqueous solution, 23.3 mmol) and Н2SO4 (8 mL of 96% aqueous solution) were added. After the mixture was allowed to stand for 24 h at room temperature, water

Michael-type addition of azoles of broad-scale acidity to methyl acrylate

• Sławomir Boncel,
• Kinga Saletra,
• Barbara Hefczyc and
• Krzysztof Z. Walczak

Beilstein J. Org. Chem. 2011, 7, 173–178, doi:10.3762/bjoc.7.24

• 4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 4(5)-nitroimidazole, 4,5-diphenylimidazole, 4,5-dicyanoimidazole, 2-methyl-4(5)-nitroimidazole, 5(4)-bromo-2-methyl-4(5)-nitroimidazole and 3-nitro-1,2,4-triazole to methyl acrylate as an acceptor was carried out. The optimisation process involved the

• industry[27]. Results and Discussion 4-Nitropyrazole (1a), 3,5-dimethyl-4-nitropyrazole (1b), 4(5)-nitroimidazole (1c), 4,5-diphenylimidazole (1d), 4,5-dicyanoimidazole (1e), 2-methyl-4(5)-nitroimidazole (1f), 4(5)-bromo-2-methyl-5(4)-nitroimidazole (1g) and 3-nitro-1,2,4-triazole (1h) were used as Michael