- Efficient Phosphorus-Free Chlorination of Hydroxy Aza-Arenes and Their Application in One-Pot Pharmaceutical Synthesis
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The chlorination of hydroxy aza-arenes with bis(trichloromethyl) carbonate (BTC) and SOCl2 has been effectively performed by refluxing with 5 wt % 4-dimethylaminopyridine (DMAP) as a catalyst. Various substrates are chlorinated with high yields. The obtained chlorinated aza-arenes can be used directly with simple workup for succedent one-pot synthesis on a large scale.
- Wang, Jian,Li, Yan-Hui,Pan, Song-Cheng,Li, Ming-Fang,Du, Wenting,Yin, Hong,Li, Jing-Hua
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supporting information
p. 146 - 153
(2020/03/10)
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- Transition-metal-free decarboxylative halogenation of 2-picolinic acids with dihalomethane under oxygen conditions
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A convenient and efficient method for the synthesis of 2-halogen-substituted pyridines is described. The decarboxylative halogenation of 2-picolinic acids with dihalomethane proceeded smoothly via N-chlorocarbene intermediates to afford 2-halogen-substituted pyridines in satisfactory to excellent yields under transition-metal-free conditions. This new type of decarboxylative halogenation is operationally simple and exhibits high functional-group tolerance.
- Zhang, Xitao,Feng, Xiujuan,Zhang, Haixia,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 5565 - 5570
(2019/10/22)
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- Concise Entries to 4-Halo-2-pyridones and 3-Bromo-4-halo-2-pyridones
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Methods for the synthesis of both simple 4-halo-2-pyridones and more functionalized 3,4-di- and (3,4,5-tri)-halo-2-pyridones are described that are based on a combination of Sandmeyer and regioselective (copper-mediated) halogenation, with a 2-chloro or a 2-benzyloxy moiety serving as a masked 2-pyridone.
- Honraedt, Aurélien,Gallagher, Timothy
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supporting information
p. 67 - 69
(2015/12/26)
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- Large-scale solvent-free chlorination of hydroxy-pyrimidines,-pyridines,- pyrazines and-amides using equimolar POCl3
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Chlorination with equimolar POCl3 can be efficiently achieved not only for hydroxypyrimidines, but also for many other substrates such as 2-hydroxy-pyridines,-quinoxalines, or even-amides. The procedure is solvent-free and involves heating in a sealed reactor at high temperatures using one equivalent of pyridine as base. It is suitable for large scale (multigram) batch preparations.
- Wang, Han,Wen, Kun,Wang, Le,Xiang, Ye,Xu, Xiaocheng,Shen, Yongjia,Sun, Zhihua
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experimental part
p. 4533 - 4544
(2012/06/30)
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- Synthesis of a naphthyridone p38 MAP kinase inhibitor
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Compound 1 is a p38 MAP kinase inhibitor potentially useful for the treatment of rheumatoid arthritis and psoriasis. A novel six-step synthesis suitable for large-scale preparation was developed in support of a drug development program at Merck Research Laboratories. The key steps include a tandem Heck-lactamization, N-oxidation, and a highly chemoselective Grignard addition of 4-(N-tert-butylpiperidinyl)-magnesium chloride to a naphthyridone N-oxide. The N-oxide exerted complete chemoselectivity via chelation in directing the Grignard addition to the α position as opposed to 1,4-addition on the enelactam. The dihydropyridyl adduct was in situ aromatized with isobutylchloroformate followed by heating in pyridine. Syntheses of Grignard precursor, N-tert-butyl-4-chloro-piperidine, were accomplished via transamination with a quaternary ammonium piperidone or via addition of methylmagnesium chloride to an iminium ion. Utilizing this chemistry, multi-kilogram preparation of compound 1 was successfully demonstrated. American Chemical Society.
- Chung, John Y. L.,Cvetovich, Raymond J.,McLaughlin, Mark,Amato, Joseph,Tsay, Fuh-Rong,Jensen, Mark,Weissman, Steve,Zewge, Daniel
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p. 8602 - 8609
(2007/10/03)
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- Arylpiperaszine derivatives, to the process for the production thereof and to the use thereof as therapeutic agents
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The invention relates to compounds of the general formula (I): to the process for preparing them, and to the use thereof as a therapeutic agent.
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Page/Page column 22
(2008/06/13)
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- Unique tandem heck-lactamization naphthyridinone ring formation between acrylanilides and halogenated pyridines
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The Heck coupling of acrylanilides with 4-bromo-2-chloro-3-iodo-pyridine using palladium acetate can produce bis-Heck products or undergo an unusual tandem Heck-lactamization ring formation to generate 5-chloro-1-aryl-1,6- naphthyridin-2(1H)-ones.
- Cvetovich, Raymond J.,Reamer, Robert A.,DiMichele, Lisa,Chung, John Y. L.,Chilenski, Jennifer R.
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p. 8610 - 8613
(2007/10/03)
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- Migration du lithium en serie pyridinique: double catalyse et reformage. Acces aux derives de la bromo-2 lithio-3 pyridine et des bromo-4 halogeno-2 lithio-3 pyridines
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The lithium of an organolithium-pyridinic derivative can be moved from one position to an another by an intermolecular reaction.Two new reactions are possible for pyridinic organic synthesis: the isomerisation of any lithio derivative to a more stable one, and a reaction that transforms a mixture of various bromo-lithio derivatives into a single one.The processes involved and the experimental tools used are described in terms of the 2-bromo-3-lithio- and 4-bromo-2-halogeno-3-lithiopyridines derivatives synthesis.
- Mallet, Marc,Branger, Gilles,Marsais, Francis,Queguiner, Guy
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p. 319 - 332
(2007/10/02)
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