1072-97-5Relevant articles and documents
Pyridinium-N-(2-pyridyl)aminides: A selective approach to substituted 2-aminopyridines
Carceller, Rosa,Garcia-Navio, Jose L.,Izquierdo, Maria L.,Alvarez-Builla, Julio
, p. 2019 - 2020 (1993)
Differently substituted 2-aminopyridines have been prepared in two steps from pyridinium-N-(2-pyridyl)aminide.
Tertiary formylated amines by microwave irradiation of N,N-dimethyl- N′-(2-pyridyl) formamidines with methyl vinyl ketone
Gomez-Garcia, Omar,Salgado-Zamora, Hector,Campos-Aldrete, Elena
, p. 21 - 23 (2014)
Treatment of N,N-dimethyl-N′-(2-pyridyl)formamidine with methyl vinyl ketone under microwave irradiation yields N-formyl-N-(3-oxobutyl)-2- pyridylamine without decomposition or polymerization of methyl vinyl ketone. The result is an alternative non-oxidat
Preparation of 2,3-Disubstituted 5-Bromo-1 H -pyrrolo[2,3- b ]pyridine Framework by Fischer Cyclization
Alekseyev, Roman S.,Amirova, Sabina R.,Terenin, Vladimir I.
, p. 3169 - 3178 (2015)
A simple synthesis of some hard-to-reach heterocycles containing 2,3-disubstituted 5-bromo-1H-pyrrolo[2,3-b]pyridine framework by FisNher indole cyclization in polyphosphoric acid has been developed. A particularly valuable feature of this synthetic route is the possibility to build a 5-bromo-7-azaindole scaffold with alkyl or aryl substituents at positions 2 and 3 from available starting materials.
Metal-Free Reduction of Aromatic Nitro Compounds to Aromatic Amines with B2pin2 in Isopropanol
Lu, Hongtao,Geng, Zhiyue,Li, Jingya,Zou, Dapeng,Wu, Yusheng,Wu, Yangjie
, p. 2774 - 2776 (2016)
A metal-free reduction of aromatic nitro compounds to the corresponding amines has been achieved by a combination of B2pin2 and KOtBu in isopropanol. A series of nitro compounds containing various reducible functional groups were chemoselectively reduced in good to excellent yields.
Nitrogen-doped graphene-activated iron-oxide-based nanocatalysts for selective transfer hydrogenation of nitroarenes
Jagadeesh, Rajenahally V.,Natte, Kishore,Junge, Henrik,Beller, Matthias
, p. 1526 - 1529 (2015)
Nanoscaled iron oxides on carbon were modified with nitrogen-doped graphene (NGr) and found to be excellent catalysts for the chemoselective transfer hydrogenation of nitroarenes to anilines. Under standard reaction conditions, a variety of functionalized and structurally diverse anilines, which serve as key building blocks and central intermediates for fine and bulk chemicals, were synthesized in good to excellent yields.
The acid-catalysed synthesis of 7-azaindoles from 3-alkynyl-2- aminopyridines and their antimicrobial activity
Leboho, Tlabo C.,Van Vuuren, Sandy F.,Michael, Joseph P.,De Koning, Charles B.
, p. 307 - 315 (2014)
The synthesis of 7-azaindoles from 3-alkynyl-2-aminopyridines using acidic conditions, namely, a mixture of trifluoroacetic acid (TFA) and trifluoroacetic anhydride (TFAA), is described. This methodology resulted in the synthesis of fifteen 7-azaindoles, with most containing substituents at the 2- and 5-positions. The majority of these were tested for antimicrobial activity against a range of bacteria and yeasts. The 7-azaindoles displayed the best activity against the yeasts, particularly against Cryptococcus neoformans, where activities as low as 3.9 μg ml-1 were observed.
Handling Hydrogen Peroxide Oxidations on a Large Scale: Synthesis of 5-Bromo-2-nitropyridine
Agosti, Alessandro,Bertolini, Giorgio,Bruno, Giacomo,Lautz, Christian,Glarner, Thomas,Deichtmann, Walter
, p. 451 - 459 (2017)
5-Bromo-2-nitropyridine was prepared from the corresponding amine via hydrogen peroxide oxidation in large scale production. This transformation initially showed low conversion, high impurity content and lack of reproducibility in lab trials. Parallel to process development, safety studies were conducted to investigate the stability of oxidant mixture, its composition and the oxidation reaction itself by reaction and adiabatic calorimetry. The resulting robust reaction conditions and appropriate safety boundaries allowed to develop a reproducible, safe protocol for the implementation of this chemistry on large scale, obtaining consistent results throughout the campaign.
Directing Group Enables Electrochemical Selectively Meta-Bromination of Pyridines under Mild Conditions
Wu, Yanwei,Xu, Shanghui,Wang, Hong,Shao, Dongxu,Qi, Qiqi,Lu, Yi,Ma, Li,Zhou, Jianhua,Hu, Wei,Gao, Wei,Chen, Jianbin
, p. 16144 - 16150 (2021)
Without the use of catalysts and oxidants, a facile and sustainable electrochemical bromination protocol was developed. By introducing the directing groups, the regioselectivity of pyridine derivatives could be controlled at themeta-position utilizing the inexpensive and safe bromine salts at room temperature. A variety of brominated pyridine derivatives were obtained in 28-95% yields, and the reaction could be readily performed at a gram scale. By combining the installation and removing the directing group, the concept ofmeta-bromination of pyridines could be verified.
Halogenation of pyridinium-N-(2'-pyridyl)aminide: An easy synthesis of halo-2-aminopyridines
Burgos,Delgado,Garcia-Navio,Izquierdo,Alvarez-Builla
, p. 8649 - 8654 (1995)
The regioselective halogenation of pyridinium-N-(2'-pyridyl)aminide 1 with N-chloro, bromo or iodosuccinimide under mild conditions is described. The method, combined with a reduction of the N-N bond, allows an easy preparation of 5-halo and 3,5-dihalo-2-aminopyridines 4.
Synthesis of a fluorine-18 labeled derivative of epibatidine for in vivo nicotinic acetylcholine receptor PET imaging
Dolci, Lilian,Dolle, Frederic,Valette, Heric,Vaufrey, Francoise,Fuseau, Chantal,Bottlaender, Michel,Crouzel, Christian
, p. 467 - 479 (1999)
Epibatidine (exo-2-(2'-chloro-5'-pyridyl)-7-azabicyclo[2.2.1]heptane), a natural compound isolated from the skin of the Ecuadorian poison frog Epipedobates tricolor, is the most potent nicotinic acetylcholine receptor (nAChR) agonist reported to date. In order to visualize and quantify in vivo these receptors in human brain using Positron Emission Tomography (PET), [18F]norchlorofluoroepibatidine (exo-2-(2'-[18F]fluoro-5'-pyridyl)-7-azabicyclo[2.2.1]heptane), a fluorine-18 (t(1/2): 110min) radiolabeled derivative of epibatidine has been designed. The corresponding 2'-bromo-, 2'-iodo- and 2'-nitro exo-2-(5'-pyridyl)-7-azabicyclo[2.2.1]heptane analogues as labeling precursors, as well as norchlorofluoroepibatidine as a reference compound have been synthesized by reductive, stereoselective, palladium-catalyzed Heck-type coupling between an N-Boc protected azanorbornene and the corresponding halopyridine. [18F]Norchlorofluoroepibatidine has been radiolabeled with fluorine-18 by nucleophilic aromatic substitution from the corresponding Boc-protected halo- and nitro precursors using [18F]FK-K222 complex in DMSO by conventional heating (at 150-180°C for 10min) or microwave activations (at 100 Watt, for 1 to 2.5min), followed by TFA-removal of the protective group. Typically, using the microwave activation procedure, 60-80mCi (2.22-2.96 GBq) of pure [18F]norchlorofluoroepibatidine could be obtained in less than 2h (110-115min) from the bromo labeling precursor, with specific radioactivities of 1.5-2.5Ci/μmol (55.5-92.5GBq/μmol) calculated for End of Bombardment. The preliminary PET experiments in baboon (Papio papio) with [18F]norchlorofluoroepibatidine show a high uptake and a rapid accumulation of the radiotracer into the brain within 30min. In the thalamus, a nAChR rich area, uptake of radioactivity reached a maximum at 40min (10% I.D./100mL tissue). The ratio of radioactivity thalamus/cerebellum (the latter being a nAChR poor area) was 2 at 40min and increased with time, up to 4.3 at 160min. Its specific regiodistribution and its high ratio of specific-to-nonspecific binding confirm the ideal profile of [18F]norchlorofluoroepibatidine as a suitable radioligand for PET imaging of nAChRs in the brain. Copyright (C) 1999 Elsevier Science Ltd.
