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.
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Bradlow,Vanderwerf
, p. 73,79 (1951)
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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.
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.
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.
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.
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Sasaki et al.
, p. 5121,5129 (1971)
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Method for synthesizing 2-amino-3-chloro-5-trifluoromethylpyridine
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Paragraph 0007; 0020-0021; 0026-0027; 0032-0033, (2021/02/06)
The invention discloses a method for synthesizing 2-amino-3-chloro-5-trifluoromethylpyridine, and belongs to the technical field of organic synthesis. Specifically, starting from 2-aminopyridine, three chemical reactions of bromination, chlorination and coupling are involved, and two organic solvents are used in the whole process; and after the three-step reaction, recrystallization treatment is carried out to obtain the high-purity 2-amino-3-chloro-5-trifluoromethylpyridine. The method is mild in reaction condition and easy to control, and the obtained product is high in purity; reaction rawmaterials and organic solvents are easy to obtain and low in price, and a new way is provided for large-scale production.
Preparation method 2-5 - dibromopyridine
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Paragraph 0017-0025, (2021/09/21)
The invention relates to the technical field of preparation of dibromopyridine, and discloses 2-5 - dibromopyridine preparation method which comprises the following steps S1: mixing reaction, putting 2 - aminopyridine into a reactor, adding acetone, adding bromate and N -bromosuccinimide. S2: Acetone was recovered, acetone was recovered by distillation under reduced pressure, and then filtered to collect the remaining solid. S3: The finished product was prepared, the collected remaining solids were placed in a reactor, and then sodium hydroxide solution was added followed by stirring to obtain 2 - amino -5 - bromopyridine. By adding N - bromosuccinimide and heating in batches, the reaction efficiency of N - bromosuccinimide is improved, the use amount is reduced, the cost is reduced, the raw materials can be recycled by recycling acetone, the cost is reduced, 2 - amino -5 - bromopyridine yield and the purity can be improved.
