- Synthesis method of 3-bromo-5-methylpyridine
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The invention relates to the field of organic chemistry and particularly provides a synthesis method of 3-bromo-5-methylpyridine. The synthesis method includes the steps of: 1) performing a reaction to diethyl malonate and alkaline metal to generate a salt, and dropwise adding a toluene solution of 3-nitro-5-chloropyridine to perform a condensation reaction, and decarboxylating the product under an acidic condition to obtain 3-nitro-5-methylpyridine; 2) performing hydrogenation reduction to the 3-nitro-5-methylpyridine with Pd/C as a catalyst and methanol as a solvent, performing suction filtration and concentrating a filtrate to prepare 3-amino-5-methylpyridine; and 3) performing a reaction to the 3-amino-5-methylpyridine with an acid to generate a salt, and cooling the salt to -10 - 0 DEG C, dropwise adding liquid bromine, and then dropwise adding a sodium nitrite water solution, regulating the pH value of the solution to alkalinity and performing extraction, drying and concentration to obtain the 3-bromo-5-methylpyridine. The synthesis method is mild in reaction conditions, is high in yield, employs easy-to-obtained raw materials, is low in cost, is short in process route and has industrial prospect.
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Paragraph 0025
(2017/10/07)
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- Mild and highly selective palladium-catalyzed monoarylation of ammonia enabled by the use of bulky biarylphosphine ligands and palladacycle precatalysts
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A method for the Pd-catalyzed arylation of ammonia with a wide range of aryl and heteroaryl halides, including challenging five-membered heterocyclic substrates, is described. Excellent selectivity for monoarylation of ammonia to primary arylamines was achieved under mild conditions or at rt by the use of bulky biarylphosphine ligands (L6, L7, and L4) as well as their corresponding aminobiphenyl palladacycle precatalysts (3a, 3b, and 3c). As this process requires neither the use of a glovebox nor high pressures of ammonia, it should be widely applicable.
- Cheung, Chi Wai,Surry, David S.,Buchwald, Stephen L.
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supporting information
p. 3734 - 3737
(2013/08/23)
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- COMPOSITIONS AND THERAPEUTIC USES OF IKK-RELATED KINASE EPSILON AND TANKBINDING KINASE 1 INHIBITORS
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The invention relates to compounds, pharmaceutical compositions and medicaments comprising such compounds, and the use of these compounds, compositions, and medicaments in methods of treating diseases and disorders.
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Page/Page column 75
(2012/11/06)
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- Reduction of 2-amino-3- and -5-nitropyridine derivatives with hydrazine hydrate
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The reactions of 2-amino-3-nitropyridine and 2-amino-5-nitropyridine with hydrazine hydrate resulted in elimination of the amino group and reduction of the nitro group with formation of 3-aminopyridine. A probable reaction mechanism involves addition of hydrazine hydrate at the N-C2 bond, followed by elimination of ammonia and reduction of the nitro group to amino. 2-Amino-4-methyl-3-nitropyridine and 2-amino-5-methyl-3-nitropyridine reacted with hydrazine hydrate in a similar way.
- Smolyar,Yutilov
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experimental part
p. 115 - 118
(2009/07/19)
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- Structure-activity studies of novel cyanoguanidine ATP-sensitive potassium channel openers for the treatment of overactive bladder
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A series of novel cyanoguanidine derivatives was designed and synthesized. Condensation of N-(1-benzotriazol-1-yl-2,2-dichloropropyl)-substituted benzamides with N-(substituted-pyridin-3-yl)-N′-cyanoguanidines furnished N-{2,2-dichloro-1-[N′-(substituted-pyridin-3-yl)-N′-cyanoguanidino] propyl}-substituted benzamide derivatives. These agents were glyburide-reversible potassium channel openers and hyperpolarized human bladder cells as assessed by the FLIPR membrane potential dye (KATP-FMP). These compounds were also potent full agonists in relaxing electrically stimulated pig bladder strips, an in vitro model of overactive bladder. The most active compound 9 was evaluated for in vivo efficacy and selectivity in a pig model of bladder instability. Preliminary pharmacokinetic studies in dog demonstrated excellent oral bioavailability and a t1/2 of 15 h. The synthesis, SAR studies, and biological properties of these agents are discussed.
- Perez-Medrano, Arturo,Brune, Michael E.,Buckner, Steven A.,Coghlan, Michael J.,Fey, Thomas A.,Gopalakrishnan, Murali,Gregg, Robert J.,Kort, Michael E.,Scott, Victoria E.,Sullivan, James P.,Whiteaker, Kristi L.,Carroll, William A.
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p. 6265 - 6273
(2008/04/05)
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- A General Synthesis of Substituted Fluorenones and Azafluorenones
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Twenty-one variously substituted fluorenones and azafluorenones have been synthesized via photochemical Pschorr cyclizations of 2-diazoniodiaryl ketones as the key ring-forming step.Direct, (bipy)3RuII-, or (bipy)3RuII/CuII-photosensitized conditions were used, depending on the system to be cyclized.Where selectivities were possible in the ring closure, the isomer ratios obtained were in accord with an aryl radical as the reactive intermediate.The precursor aminodiaryl ketones were obtained from the sequence ortho lithiation of an arylpivalamide, reaction withan aryl aldehyde to give a 2-pivalamidodiarylcarbinol, oxidation to give a 2-pivalamidodiaryl ketone, and hydrolysis to give the 2-aminodiaryl ketone.
- Kyba, Evan P.,Liu, Shiuh-Tzung,Chockalingam, Kannappan,Reddy, B. Raghava
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p. 3513 - 3521
(2007/10/02)
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