22353-33-9Relevant academic research and scientific papers
meta-Nitration of Arenes Bearing ortho/para Directing Group(s) Using C?H Borylation
Li, Xuejing,Deng, Xingwang,Coyne, Anthony G.,Srinivasan, Rajavel
, p. 8018 - 8023 (2019/05/29)
Herein, we report the meta-nitration of arenes bearing ortho/para directing group(s) using the iridium-catalyzed C?H borylation reaction followed by a newly developed copper(II)-catalyzed transformation of the crude aryl pinacol boronate esters into the corresponding nitroarenes in a one-pot fashion. This protocol allows the synthesis of meta-nitrated arenes that are tedious to prepare or require multistep synthesis using the existing methods. The reaction tolerates a wide array of ortho/para-directing groups, such as ?F, ?Cl, ?Br, ?CH3, ?Et, ?iPr ?OCH3, and ?OCF3. It also provides regioselective access to the nitro derivatives of π-electron-deficient heterocycles, such as pyridine and quinoline derivatives. The application of this method is demonstrated in the late-stage modification of complex molecules and also in the gram-scale preparation of an intermediate en route to the FDA-approved drug Nilotinib. Finally, we have shown that the nitro product obtained by this strategy can also be directly converted to the aniline or hindered amine through Baran's amination protocol.
Reactions of 3-R-5-nitropyridines with nucleophiles: Nucleophilic substitution vs conjugate addition
Bastrakov, Maxim A.,Nikol'skiy, Vladislav V.,Starosotnikov, Alexey M.,Fedyanin, Ivan V.,Shevelev, Svyatoslav A.,Knyazev, Daniil A.
, (2019/11/11)
A number of 3-R-5-nitropyridines were synthesized and their reactions with various types of nucleophiles were investigated. The reaction outcome depends on the nature of a nucleophile: in case of anionic O-, N- and S-nucleophiles the previously unreported substitution of non-activated nitro group occurred while carbon nucleophiles underwent dearomatization of the pyridine ring with the formation of products of 1,2- and 1,4-addition.
Preparation of nitropyridines by nitration of pyridines with nitric acid
Katritzky, Alan R.,Scriven, Eric F. V.,Majumder, Suman,Akhmedova, Rena G.,Vakulenko, Anatoliy V.,Akhmedov, Novraz G.,Murugan, Ramiah,Abboud, Khalil A.
, p. 538 - 541 (2007/10/03)
Preparation of nitropyridines by nitration of pyridines with nitric acid was discussed. Trifluoroacetic anhydride was chilled in an ice bath and the pyridine or substituted pyridines were slowly added and stirred at chilled conditions for 2 h. Relative amounts of the reactants were required for the nitration of pyridine were characterized by 1H and Nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. It was observed that the yields of β-nitropyridines obtained using the standard protocol were generally higher than those obtained using N2O3.
The synthesis of β-nitropyridine compounds
Bakke, Jan M.,Ranes, Eli,Riha, Jaroslav,Svensen, Harald
, p. 141 - 144 (2007/10/03)
Pyridine and a number of substituted pyridines have been nitrated by reaction with N2O5 followed by reaction with an aqueous solution of SO2xH2O or NaHSO3. The dependence of the yields on the pH of the aqueous reaction medium, on the concentration of SO2xH2O-HSO3-, on addition of methanol to the aqueous phase, and on the reaction temperature were investigated. The yields obtained with NaHSO3 were: 3-nitropyridine 77%, 2-methyl-5-nitro-pyridine 36%, 3-methyl-5-nitropyridinc 24%, 3-acetyl-5-nitropyridine 18%, 5-nitropyridine-3-carboxylic acid 15%, 3-chloro-5-nitropyridine 11%, 4-methyl-3-nitropyridine 39%, 4-acetyl-3-nitropyridine 67%, 4-cyano-3-nitropyridine 45%, 4-phenyl-3-nitropyridine 68%, 4-formyl-3-nitropyridine 62% (from reaction in liquid SO2), 3-nitropyridine-4-carboxylic acid 48%, methyl 3-nitropyridine-4-carboxylate 75%, 2,3-dimethyl-5-nitropyridine 37%, 2,4-dimethyl-5-nitropyridine 64%, 3-nitroquinoline 10% and 4-nitroisoquinoline 42%.
