- Deaminative chlorination of aminoheterocycles
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Selective modification of heteroatom-containing aromatic structures is in high demand as it permits rapid evaluation of molecular complexity in advanced intermediates. Inspired by the selectivity of deaminases in nature, herein we present a simple methodology that enables the NH2 groups in aminoheterocycles to be conceived as masked modification handles. With the aid of a simple pyrylium reagent and a cheap chloride source, C(sp2)?NH2 can be converted into C(sp2)?Cl bonds. The method is characterized by its wide functional group tolerance and substrate scope, allowing the modification of >20 different classes of heteroaromatic motifs (five- and six-membered heterocycles), bearing numerous sensitive motifs. The facile conversion of NH2 into Cl in a late-stage fashion enables practitioners to apply Sandmeyer- and Vilsmeier-type transforms without the burden of explosive and unsafe diazonium salts, stoichiometric transition metals or highly oxidizing and unselective chlorinating agents. [Figure not available: see fulltext.]
- Cornella, Josep,Faber, Teresa,Gómez-Palomino, Alejandro,Ghiazza, Clément
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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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- Small molecule inhibitors of anthrax edema factor
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Anthrax is a highly lethal disease caused by the Gram-(+) bacteria Bacillus anthracis. Edema toxin (ET) is a major contributor to the pathogenesis of disease in humans exposed to B. anthracis. ET is a bipartite toxin composed of two proteins secreted by the vegetative bacteria, edema factor (EF) and protective antigen (PA). Our work towards identifying a small molecule inhibitor of anthrax edema factor is the subject of this letter. First we demonstrate that the small molecule probe 5′-Fluorosulfonylbenzoyl 5′-adenosine (FSBA) reacts irreversibly with EF and blocks enzymatic activity. We then show that the adenosine portion of FSBA can be replaced to provide more drug-like molecules which are up to 1000-fold more potent against EF relative to FSBA, display low cross reactivity when tested against a panel of kinases, and are nanomolar inhibitors of EF in a cell-based assay of cAMP production.
- Jiao, Guan-Sheng,Kim, Seongjin,Moayeri, Mahtab,Thai, April,Cregar-Hernandez, Lynne,McKasson, Linda,O'Malley, Sean,Leppla, Stephen H.,Johnson, Alan T.
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supporting information
p. 134 - 139
(2017/12/06)
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- Dehalogenation degradation method for halogenated pyridine compound
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The invention provides a dehalogenation degradation method for a halogenated pyridine compound. The halogenated pyridine compound is adopted as a raw material, alcohol is adopted as a hydrogen source, water is adopted as a solvent, reacting is carried out for 3-10 h under normal pressure at the temperature of 20 DEG C to 120 DEG C under the action of a supported catalyst, and the halogenated pyridine compound is subjected to dehalogenation degradation in situ through water phase hydrogen production. A pyridine ring of the halogenated pyridine compound at least contains an F or Cl or Br or I substituent group. The supported catalyst is composed of an active component and a carrier, the active component is composed of a mixture of transition metal and other metal, the transition metal is one of Rh, Pd, Pt and Ni, and other metal is one of Se, Ca, Ba, La and Ce. The carrier is one of activated carbon, kieselguhr, zeolite, gamma-Al2O3, AlF3 and MgO. H2 is not directly used as a reduction agent, activated hydrogen is prepared through in-situ catalysis to directly participate in reacting, the advantages of being high in reaction activity, high in selectivity, high in safety, environmentally friendly and the like are achieved, and good application prospects are achieved.
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-
Paragraph 0023; 0024
(2016/12/16)
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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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- A general approach to (trifluoromethoxy)pyridines: First X-ray structure determinations and quantum chemistry studies
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The previously unknown 2-, 3-, and 4-(trifluoromethoxy)pyridines have now become readily accessible by means of an efficient and straightforward large-scale synthesis. Their regioselective functionalization by organometallic methods has been studied and has afforded new and highly important building blocks for life-sciences-oriented research. In addition, the first X-ray crystallographic structure determinations of (trifluoromethoxy)pyridines have been performed. Lowest-energy conformations of (trifluoromethoxy)pyridines and (trifluoromethoxy)pyridinium cations were determined by in silico studies. A general and efficient route to (trifluoromethoxy)pyridines is reported. Regioselective functionalization by organometallic methods afforded new and highly important building blocks for life-sciences-oriented research. The first X-ray crystallographic structure determinations of (trifluoromethoxy)pyridines have been performed and supported by in silico studies.
- Manteau, Baptiste,Genix, Pierre,Brelot, Lydia,Vors, Jean-Pierre,Pazenok, Sergiy,Giornal, Florence,Leuenberger, Charlotte,Leroux, Frederic R.
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experimental part
p. 6043 - 6066
(2011/02/26)
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- CHEMICAL COMPOUNDS AND PROCESSES
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The present invention relates generally to chemical compounds and methods for their use and preparation. In particular, the invention relates to chemical compounds which may possess useful therapeutic activity, use of these compounds in methods of therapy and the manufacture of medicaments as well as compositions containing these compounds.
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Page/Page column 74
(2008/12/06)
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- PYRIDINE DERIVATIVES AND THEIR USE AS MEDICAMENTS FOR TREATING DISEASES RELATED TO MCH RECEPTOR
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The present invention encompasses novel substituted pyridine compounds of Formula (I), which act as MCH receptor antagonists. These compositions and pharmaceutical compositions thereof are useful in the prophylaxis or treatment of improving memory function, sleeping and arousal, anxiety, depression, mood disorders, seizure, obesity, diabetes, appetite and eating disorders, cardiovascular disease, hypertension, dyslipidemia, myocardial infarction, binge eating disorders including bulimia, anorexia, mental disorders including manic depression, schizophrenia, delirium, dementia, stress, cognitive disorders, attention deficit disorder, substance abuse disorders and dyskinesias including Parkinson's disease, epilepsy, and addiction.
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Page/Page column 81
(2010/10/20)
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- Regiochemically flexible substitutions of di-, tri-, and tetrahalopyridines: The trialkylsilyl trick
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(Chemical Equation Presented) 2,4-Difluoropyridine, 2,4-dichloropyridine, 2,4,6-trifluoropyridine, 2,4,6-trichloropyridine and 2,3,4,6-tetrafluoropyridine react with standard nucleophiles exclusively at the 4-position under halogen displacement. However, the regioselectivity can be completely reversed if a trialkylsilyl group is introduced in the 5-position of the 2,4-dihalopyridines or in the 3-position of the 2,4,6-trihalopyridines or 2,3,4,6-tetrahalopyridine. Then only the halogen most remote from the bulky silyl unit (at the 2-position in the case of the 2,4-halopyridines, at the 6-position with the other substrates) gets involved in the exchange process. After removal of the silyl protective group the nucleophile is invariably found to occupy the nitrogen-neighboring position.
- Schlosser, Manfred,Bobbio, Carla,Rausis, Thierry
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p. 2494 - 2502
(2007/10/03)
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- Rerouting nucleophilic substitution from the 4-position to the 2- or 6-position of 2,4-dihalopyridines and 2,4,6-trihalopyridines: The solution to a long-standing problem
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(Chemical Equation Presented) 2,4-Difluoro-, 2,4,6-trifluoro-, and 2,3,4,6-tetrafluoropyridine undergo nucleophilic substitution preferentially if not exclusively at the 4-position. However, after the introduction of a trialkylsilyl group at C-3 or C-5, t
- Schlosser, Manfred,Rausis, Thierry,Bobbio, Carla
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p. 127 - 129
(2007/10/03)
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- Reaction of N-fluoropyridinium fluoride with isonitriles: A convenient route to picolinamides
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Reaction of N-fluoropyridinium fluoride generated in situ with a series of isonitriles led to the formation of the corresponding picolinamides in good yields. A similar reaction sequence for quinoline yielded the respective derivatives of 2-quinoline carboxylic acid. The proposed reaction mechanism involves the intermediate formation of a highly reactive carbene species.
- Kiselyov, Alexander S.
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p. 2279 - 2282
(2007/10/03)
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- Pyridinyl amides and imides for use as fungicides
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Compounds of Formula (I), their N-oxides and agriculturally suitable salts are disclosed which are useful as fungicides formula (I), (II) wherein A is a substituted pyridinyl ring; B is a substituted pyridinyl ring; W is C═L or SOn is O or S; R
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- Strategies for the selective functionalization of dichloropyridines at various sites
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Whereas 2,3-dichloropyridine and 2,5-dichloro-4-(lithiooxy)-pyridine undergo deprotonation exclusively at the 4- and 2-positions, respectively, optional site selectivity can be implemented with 2,5- and 3,4-dichloropyridine (which are attacked, depending on the choice of the reagents, at either the 4- or 6- and either the 2- and 5-positions, respectively). Upon treatment with lithium diisopropylamide, 2,4-dichloro-3-iodopyridine, 3,5-dichloro-4-bromopyridine and 2,6-dichloro-3-iodopyridine afford 5-, 2- and 4-lithiated intermediates, but the latter isomerize instantaneously to species in which lithium and iodine have swapped places, the driving force being the low basicity of C-Li bonds when flanked by two neighboring halogens.
- Marzi, Elena,Bigi, Anna,Schlosser, Manfred
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p. 1371 - 1376
(2007/10/03)
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- First regioselective c-2 lithiation of 3- and 4-chloropyridines
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We have shown that the BuLi/LiDMAE reagent promotes the clean and regioselective C2 lithiation of 3- and 4-chloropyridines, while other reagents such as LDA or BuLi/TMEDA lead to classical ortho lithiation products or mixtures of regioisomers. The method was successfully applied to the preparation of various reactive 2,3- and 2,4-disubstituted pyridines.
- Choppin, Sabine,Gros, Philippe,Fort, Yves
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p. 603 - 606
(2007/10/03)
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- Preparation of substituted 2-chloropyridines
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A process for the preparation of a substituted 2-chloropyridine derivatives of the formula STR1 in which R1, R2, R3 and R4 represent hydrogen or various other radicals, which comprises reacting a pyridine-1-oxide of the formula STR2 with an aromatic carbonyl chloride in the presence of an inert organic solvent and in the presence of an acid acceptor at a temperature between about -20° C. and 200° C.
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- Process for the preparation of substituted 2-chloropyridines
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A new process has been found for the preparation of substituted 2-chloropyridine derivatives of the formula (I) STR1 wherein R1 to R4 have the meanings as defined in the description. The new process is characterized in that pyridine 1-oxides of the formula II STR2 are reacted with a chlorine-containing phosphoric acid derivative from the series of the chlorophosphoric esters and chlorophosphoramides in the presence of an inert organic solvent and in the presence of an acid acceptor at temperatures between -20° C. and 200° C., and the resulting product is separated further, if appropriate. Compound (I) is known as an intermediate product for medicaments (cf.DE-A 2,812,585) or for insecticidel nitromethylene derivatives (cf. EP-A 163,855).
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