- Green preparation method of anti-cancer drug palbociclib intermediate
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The invention belongs to the technical field of chemicals, and particularly relates to a green preparation method of an anti-cancer drug palbociclib intermediate. Zirconium nitrate and ammonium metatungstate are used as raw materials, a Zr/W composite oxide is prepared by adopting a homogeneous precipitation method, and an acidified tungsten/zirconium bimetallic oxide is prepared by sulfuric acid impregnation and is used for catalyzing hydrogen peroxide to oxidize 2-amino-5-bromopyridine to prepare 2-nitro-5-bromopyridine. The catalytic oxidation process is green and pollution-free, and waste acid cannot be generated; and the oxidation process is relatively mild, basically no 3, 5-dibromo-2-aminopyridine byproduct is generated in the oxidation process, and the purity and yield of the crude product are relatively high.
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Paragraph 0030-0069
(2021/04/14)
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- Bismuth nitrate as a source of nitro radical in ipso-nitration of carboxylic acids
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Aromatic nitro compounds are extensively used in synthetic chemistry. We disclose a new approach to obtain nitroarenes regioselectively starting from carboxylic acids under acid-free reaction conditions.
- Agasti, Soumitra,Maiti, Siddhartha,Maity, Soham,Anniyappan,Talawar,Maiti, Debabrata
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p. 120 - 124
(2019/05/22)
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- A Palumbo Xilin synthesis of intermediates method (by machine translation)
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The present invention provides a Palumbo Xilin synthesis of intermediates method, and in particular relates to technical field of drug synthesis, the invention of the Palumbo vial is means intermediate 4 - (6 - aminopyridin - 3 - yl) piperazine - 1 - carboxylic acid tert-butyl, in order to 2 - amino - 5 - bromo pyridine as the starting material, through oxidation, coupling, reduction to obtain the target product of the process route, to the influence of factors experimental study of the system, compared with the conventional preparation process, the invention process route in the production cost, the operation of the technique, the product yield and purity and environmental protection there are obviously increased and improved. (by machine translation)
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Paragraph 0023; 0024; 0025; 0026
(2018/10/19)
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- Handling Hydrogen Peroxide Oxidations on a Large Scale: Synthesis of 5-Bromo-2-nitropyridine
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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.
- Agosti, Alessandro,Bertolini, Giorgio,Bruno, Giacomo,Lautz, Christian,Glarner, Thomas,Deichtmann, Walter
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p. 451 - 459
(2017/03/24)
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- Preparation method of 2-nitro-5-bromopyridine
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The invention relates to a preparation method of 2-nitro-5-bromopyridine. The 2-nitro-5-bromopyridine is adopted as a starting raw material, glacial acetic acid is adopted as a solvent, peracetic acid is adopted as an auxiliary material, and distillation, washing, alkali washing, filtering, drying and recrystallization are performed to obtain a target product. According to the method, the synthesis yield is high, the equipment corrosion is small, the safety is high, acetic acid can be recycled, the cost is saved, and little environmental pollution is caused.
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Paragraph 0035; 0044; 0045
(2017/02/17)
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- Synthesis of dicationic carbazole and 4′-amino-(3,3'-bipyridine)-4-ol and the spectral characteristics of carbazoles
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The dicationic carbazole compound, 3,6-dimethyl-3,6-diazacarbazole diiodide (8) was prepared with 3-bromopyridine as a starting material by a six-step synthesis. The intermediates and target compound were confirmed by IR, NMR and MS. Meanwhile, UV-visible and fluorescent characteristics of 3,6-diazacarbazole (7) and 3,6-dimethyl-3,6-diazacarbazole diiodide (8) were investigated. It was found that fluorescence decay over time of dicationic carbazole existed in low ionic strength and high ionic strength could stabilize the fluorescence of dicationic carbazole.
- Wang,Li,Ye,Guo,Jia
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p. 4632 - 4636
(2013/07/25)
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- 2- [ (2-SUBSTITUTED) -IND0LIZIN-3-YL] -2-OXO-ACETAMIDE DERIVATIVES AS ANTIFUNGAL AGENTS
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The invention provides compounds of formula (I), and pharmaceutically acceptable salts thereof wherein: Rl, R2, R3, R4, R5, R6, R7, X and X1 are as defined herein. These compounds are useful in the manufacture of medicaments for use in the prevention or treatment of a fungal disease. Compounds of formula (I), and agriculturally acceptable salts thereof, may also be used as agricultural fungicides.
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Page/Page column 113
(2008/12/05)
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- A simple Cu-catalyzed coupling approach to substituted 3-pyridinol and 5-pyrimidinol antioxidants
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(Chemical Equation Presented) A convenient approach to 3-pyridinols and 5-pyrimidinols via a two-step Cu-catalyzed benzyloxylation/catalytic hydrogenation sequence is presented. The corresponding 3-pyridinamines and 5-pyrimidinamines can be prepared in an analogous sequence utilizing benzylamine in lieu of benzyl alcohol. The radical-scavenging ability of these derivatives are preliminarily explored and reveal that the increased acidities of the pyridinols and pyrimidinols render them susceptible to more significant kinetic solvent effects when compared to phenols.
- Nara, Susheel J.,Jha, Mukund,Brinkhorst, Johan,Zemanek, Tony J.,Pratt, Derek A.
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supporting information; experimental part
p. 9326 - 9333
(2009/04/06)
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- p-(sulfonyl) aryl and heteroarylamines as anti-inflammatory agents
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This invention relates to anti-inflammatory and analgesic compounds, especially to certain p-(sulfonyl)phenyl amino derivatives, pharmaceutical compositions containing them, methods for their use, and methods for preparing these compounds.
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- Synthesis of a fluorine-18 labeled derivative of epibatidine for in vivo nicotinic acetylcholine receptor PET imaging
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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.
- Dolci, Lilian,Dolle, Frederic,Valette, Heric,Vaufrey, Francoise,Fuseau, Chantal,Bottlaender, Michel,Crouzel, Christian
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p. 467 - 479
(2007/10/03)
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