- Synthetic method of medicinal raw material 2 and 5 - dibromopyridine
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The invention relates to the technical field of preparation of dibromopyridine, and discloses a synthetic method of a pharmaceutical raw material 2 and 5 - dibromopyridine, which comprises S1: temperature rising, 2 -aminopyridine and acetic anhydride added into a four-port flask. S2: Cooling, Step S1 The raw material reaction was completely followed by a cooling treatment, followed by stirring by adding bromoethane, heating at a heating temperature of 30 - 60 (degree) C, heating time of 20 - 40 minutes, and stirring again to obtain a mixture A. S3: Monol Bromo. To the method, raw materials can be pre-mixed, so that the raw materials can be preliminarily reacted, the reaction B effect is improved, bubbles are generated after reaction, the next crystallization is facilitated, cost can be reduced through accurate control of temperature and raw materials in the process, and the method is safer and more reliable.
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Paragraph 0018; 0021; 0024
(2021/10/05)
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- Preparation method 2-5 - dibromopyridine
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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.
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Paragraph 0017-0025
(2021/09/21)
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- The difference in the CO2adsorption capacities of different functionalized pillar-layered metal-organic frameworks (MOFs)
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The excessive use of fossil energy has caused the CO2concentration in the atmosphere to increase year by year. MOFs are ideal CO2adsorbents that can be used in CO2capture due to their excellent characteristics. Studies of the structure-activity relationship between the small structural differences in MOFs and the CO2adsorption capacities are helpful for the development of efficient MOF-based CO2adsorbents. Therefore, a series of pillar-layered MOFs with similar structural and different functional groups were designed and synthesized. The CO2adsorption tests were carried out at 273 K to explore the relationship between the small structural differences in MOFs caused by different functional groups and the CO2adsorption capacities. Significantly, compound6which contains a pyridazinyl group has a 30.9% increase in CO2adsorption capacity compared to compound1with no functionalized group.
- Gao, Xiang-Jing,Zheng, He-Gen
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supporting information
p. 9310 - 9316
(2021/07/12)
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- Preparation method of 2, 5-dibromopyridine
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The invention discloses a preparation method of 2, 5-dibromopyridine, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: reacting 2-hydroxypyridine serving as a raw material with a bromination reagent to obtain 2-hydroxy-5-bromopyridine; and then reacting with a bromination reagent under the action of a Lewis acid catalyst to obtain 2, 5-dibromopyridine. The method is completed in two steps, an isomer obtained in the first step of reaction does not need to be purified, and a product with the purity of 99.5% or above can be obtained through recrystallization once in the last step.
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Paragraph 0026-0031
(2021/04/21)
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- Synthesis method of 2, 5-dibromopyridine
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The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of 2, 5-dibromopyridine, and the method comprises the following steps: (1) adding 2-aminopyridine and acetic anhydride into a four-neck flask, refluxing, and completely reacting by thin-layer chromatography tracking; (2) when the temperature of the reaction solution in the step (1) isreduced to 20-25 DEG C, dropwise adding liquid bromine, reacting for 2-3 hours at 45-55 DEG C after completion of the dropwise adding, adding water into the system until all solids are dissolved, dropwise adding a sodium hydroxide solution, continuously reacting for 30-40 minutes when a large amount of precipitate is generated, and carrying out suction filtration, drying and recrystallization to obtain 2-amino-5-bromopyridine; and (3) adding the 2-amino-5-bromopyridine into a hydrogen bromide solution, dropwise adding a sodium nitrate solution in the presence of a catalytic amount of cuprous bromide, controlling the temperature to be -5 to15 DEG C, and reacting for 2-5 hours to obtain the 2, 5-dibromopyridine. The method has the beneficial effects of mild reaction conditions, high yield, accessible raw materials, lower cost and fewer product byproducts, reduces the composite load of later separation, and has industrial prospects.
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Paragraph 0017; 0020; 0021-0023; 0024-0026; 0028
(2020/02/17)
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- A 2, 5 - dibromo pyridine synthesis method
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The invention belongs to the field of organic synthetic technology, in particular to a 2, 5 - dibromo pyridine synthesis method, comprises the following steps: (1) the 2 - aminopyridine and acetic anhydride is added to the four flasks reflux, thin-layer chromatography tracking reaction is complete; (2) step (1) of reaction fluids in a temperature drop to 20 - 25 °C when, [...], paused, 45 - 55 °C reaction 2 - 3 hours, water is added to the system to all the solid dissolved, sodium hydroxide solution, a large amount of precipitation of the reaction to continue 30 - 40 minutes, filtered, drying, by recrystallization to obtain 2 - amino - 5 - bromo pyridine; (3) the 2 - amino - 5 - bromo pyridine is added in a solution of hydrogen bromide, in the presence of a catalytic amount of cuprous bromide, dropping sodium nitrate solution, temperature control in the - 5 - 15 °C, reaction 2 - 5 hours, shall be 2, 5 - dibromo pyridine. The method of the invention is beneficial effect: mild reaction conditions, high yield, and raw materials are easy, and the cost is low, few by-products of the product, reduces the later separation of the composite load, has industrialized prospect.
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Paragraph 0020; 0022; 0023; 0025; 0026; 0028
(2019/05/28)
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- 2,5-DIBROMOPYRIDINE AND PROCESSES OF PREPARATION
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Provided herein is a process for the preparation of 2,5-dibromopyridine.
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Page/Page column 3-4
(2019/01/08)
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- Preparation of 2,3-Disubstituted 5-Bromo-1 H -pyrrolo[2,3- b ]pyridine Framework by Fischer Cyclization
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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.
- Alekseyev, Roman S.,Amirova, Sabina R.,Terenin, Vladimir I.
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p. 3169 - 3178
(2015/10/19)
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- SPIRO-SUBSTITUTED OXINDOLE DERIVATIVES HAVING AMPK ACTIVITY
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The present invention relates to compounds of formula (I), which have valuable pharmacological properties, in particular are activators of AMPK and which are therefore useful in the treatment of certain disorders that can be prevented or treated by activation of this receptor. The compounds are suitable for treatment and prevention of diseases which can be influenced by this receptor, such as metabolic diseases, in particular diabetes type 2.
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Page/Page column 107
(2015/01/07)
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- OLEFIN SUBSTITUTED OXINDOLES HAVING AMPK ACTIVITY
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The present invention relates to compounds of formula (I), which have valuable pharmacological properties, in particular are activators of AMPK and which are therefore useful in the treatment of certain disorders that can be prevented or treated by activation of this receptor. The compounds are suitable for treatment and prevention of diseases which can be influenced by this receptor, such as metabolic diseases, in particular diabetes type 2.
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Page/Page column 102
(2015/01/07)
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- Preparation of highly reactive pyridine- and pyrimidine-containing diarylamine antioxidants
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We recently reported a preliminary account of our efforts to develop novel diarylamine radical-trapping antioxidants (Hanthorn, J. J. et al. J. Am. Chem. Soc. 2012, 134, 8306-8309) wherein we demonstrated that the incorporation of ring nitrogens into diphenylamines affords compounds which display a compromise between H-atom transfer reactivity to peroxyl radicals and stability to one-electron oxidation. Herein we provide the details of the synthetic efforts associated with that report, which have been substantially expanded to produce a library of substituted heterocyclic diarylamines that we have used to provide further insight into the structure-reactivity relationships of these compounds as antioxidants (see the accompanying paper, DOI: 10.1021/jo301012x). The diarylamines were prepared in short, modular sequences from 2-aminopyridine and 2-aminopyrimidine wherein aminations of intermediate pyri(mi)dyl bromides and then Pd-catalyzed cross-coupling reactions of the amines and precursor bromides were the key steps to yield the diarylamines. The cross-coupling reactions were found to proceed best with Pd(η3-1-PhC3H 4)(η5-C5H5) as precatalyst, which gave higher yields than the conventional Pd source, Pd2(dba) 3.
- Hanthorn, Jason J.,Valgimigli, Luca,Pratt, Derek A.
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experimental part
p. 6908 - 6916
(2012/10/08)
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- SUBSTITUTED DIARYLAMINES AND USE OF SAME AS ANTIOXIDANTS
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The present invention relates to substituted heteroaromatic dianlamine compounds of Formula I and II, their pharmaceutically acceptable salts, and compositions thereof useful as antioxidants, wherein each of X, Y and Z are independently a carbon or nitrogen atom; R1 and R2 are each independently a hydrogen or an electron donating group, but are not both hydrogen, and wherein R1 and R2 are each bonded to a carbon atom in their own respective aryl ring.
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Page/Page column 45-46
(2013/02/28)
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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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- Heteroaryloxy-beta-carboline derivatives, their preparation and their use as medicinal agents
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Heteroaryloxy-β-carboline derivatives of general Formula I STR1 wherein R1 is an optionally substituted heteroaryl residue, R2 is hydrogen, lower alkyl or lower alkoxyalkyl, X is a COOR3 -group wherein R3 means H or lower alkyl, or represents a CONR4 R5 -group wherein R4 and R5 mean respectively hydrogen or lower alkyl, R4 and R5 being capable of forming, together with the nitrogen atom, a 5- to 6-membered heterocycle, or means an oxadiazolyl residue of the formula STR2 wherein R6 means hydrogen, lower alkyl or cycloalkyl, are valuable pharmaceuticals.
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- Process for making 2-bromopyridine
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Disclosed is the improvement to the Craig process for producing 2-bromopyridine by the diazotization-bromination reaction of 2-aminopyridine with HBr in the presence of Br2 and a diazotization agent wherein the improvement is to conduct the reaction in the additional presence of H2 SO4 and to employ a molar ratio of HBr:2-aminopyridine in the range from about 1:1 to about 3.5:1 and to employ a molar ratio of H2 SO4 :HBr in the range from about 2:8 to about 8:2.
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- Method for preparing 2,5-dihalo- and 2,5,6-trihalopyridines
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A method for preparing 2,5-dihalo- and 2,5,6-trihalopyridines corresponding to the formula SPC1 Wherein each X independently represents chloro, fluoro or bromo and R represents hydrogen, chloro, fluoro or bromo which comprises reacting a halohydrazinopyridine of one of the formulas SPC2 With an excess of an aqueous alkali metal hydroxide in the presence of a reaction medium from the group consisting of loweralkanols of 1 to 4 carbon atoms and loweralkylglycols of 2 to 4 carbon atoms.
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