- Synthesis, crystal structures, and properties of the copper(I) halide coordination polymers ∞2[CuX(μ-2-chloropyrazine-N,N′)] (X = Cl, Br), ∞1[CuI(2-chloropyrazine-N)], and [Cu2I2(2-chloropyrazine)]
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The new copper coordination polymers ∞2[CuX(μ-2-chloropyrazine-N,N′)] (X = Cl (I), Br (II), ∞1[CuI(2-chloropyrazine-N)] (III) and [Cu2I2(2-chloropyrazine)] (IV) has been prepared by the reaction of the copper(I) halides with 2-chloropyrazine at room-temperature or under hydrothermal conditions. The crystal structures of the 1:1 compounds I and II consist of zig-zag CuX single chains running parallel to the crystallographic a-axis which are linked by the 2-chloropyrazine spacer molecules to sheets parallel to (010). For the iodine compound III a one-dimensional structure is Found which consists of CuX double chains running parallel to the crystallographic a-axis. The thermic properties of all compounds were investigated in different gas atmospheres using simultaneously differential thermal analysis and thermogravimetry (DTA-TG) as well as temperature resolved X-ray powder diffraction. On heating, tire 1:1 compounds I and II decompose directly to the corresponding copper(I) Halides, whereas the thermal decomposition of III occcur via IV as an intermediate.
- Naether, Christian,Wriedt, Mario,Je, Inke
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- 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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- Preparation method of 2, 6-dichloropyrazine
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The invention discloses a preparation method of 2, 6-dichloropyrazine. The method comprises the following steps: taking glycine and glyoxal as raw materials, carrying out ammoniation and cyclization reactions to prepare 2-hydroxypyrazine sodium; and reacting 2-hydroxypyrazine sodium with thionyl chloride under the catalytic action of N,N-diisopropylethylamine to prepare 2-chloropyrazine; wherein pyridine is used as a solvent, and 2-chloropyrazine is subjected to chlorination of chlorine to obtain 2,6-dichloropyrazine. The method has the advantages that the raw material namely glycine is cheapand easily available, and phosphorus oxychloride is not used as a chlorination reagent, so that the generation of organic phosphorus-containing wastewater is greatly reduced, and an effective way is provided for efficient green industrial production of 2, 6-dichloropyrazine.
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Paragraph 0034; 0038-0039; 0047-0052
(2020/04/22)
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- SUBSTITUTED ARYLPYRAZINES
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Arylpyrazine compounds are provided, including arylpyrazines that can bind with high affinity and high selectivity to CRF1 receptors, including human CRF1 receptors. The invention thus includes methods for treatment of disorders and diseases associated with CRF1 receptors, including CNS-related disorders and diseases, particularly affective disorders and diseases, and acute and chronic neurological disorders and diseases.
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- Pyrazinoic acid esters as antituberculosis agents
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Pyrazinoic esters have been prepared. Compounds of this group are effective against mycobacteria including Mycobacteria tuberculosis, pyrazinamide-resistant Mycobacteria tuberculosis, Mycobacteria bovis and Mycobacteria kansasii.
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- SYNTHESIS AND 1H AND 13C NMR SPECTRA OF SULFUR DERIVATIVES OF PYRAZINE DERIVED FROM AMIDATION PRODUCT OF 2-CHLOROPYRAZINE AND 6-CHLORO-2-PYRAZINECARBONITRILE. TUBERCULOSTATIC ACTIVITY
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Homolytic amidations of 2-chloropyrazine and 6-chloropyrazine-2-carbonitrile have been carried out to obtain products which have been used to prepare sulfur derivatives of pyrazine as potential tuberculostatic agents.The 1H and 13C NMR spectra of the products have been measured and interpreted, and the antituberculotic activity has been evaluated.
- Dlabal, Karel,Palat, Karel,Lycka, Antonin,Odlerova, Zelmira
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p. 2493 - 2501
(2007/10/02)
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- Preparation and Characterization of Nickel(II), Copper(II) and Palladium(II) Complexes with 5,14-Dihydro-7,16-diethyldipyrazotetraazacyclotetradecine
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A novel macrocycle, 5,14-dihydro-7,16-diethyldipyrazotetraazacyclotetradecine, has been synthesized from 1,2-diaminopyrazine and 2-ethyl-3-ethoxyacrolein.The absorption bands appearing in the energy range greater than 20000 cm-1 were attributable to the ? --> ?* transitions.The bands in the range of the 20100-23300 cm-1 show more bathochromic shift and greater intensity than those observed for corresponding 5,14-dihydro-7,16-diethyldibenzotetraazacyclotetradecine and/or 5,14-dihydro-7,16-diethyl-(Z)-dipyridotetraazacyclotetradecine.The nickel(II), copper(II) and palladium(II) complexes of 5,14-dihydro-7,16-diethyldipyrazotetraazacyclotetradecine have been synthesized using a metal template reaction.In 1H and 13C nmr spectra, the signals of annulene skeleton for metal-free ligand and its complexes were found to observe in the lower field than those of the dibenzoanalogue.
- Hashimoto, Mamoru,Izuchi, Nobuko,Sakata, Kazunori
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p. 1705 - 1708
(2007/10/02)
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- The Mechanism of Thermal Eliminations. Part 20. The Relative Rates of Pyrolysis of the 2-Ethoxy, 2-Isopropoxy, and 2-t-Butoxy Derivatives of Pyrazine and Pyrimidine to Pyrazine-2-one, pyrimidin-2-one, respectively: Polarity of the Transition States and the Importance of Nucleophilic ...
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We have measured rates of thermal elimination of the title compounds to give the corresponding cyclic amides, between 587.0 and 698.5 K.The relative rates (primary:secondary:tertiary) at 600 K are 1:27.0:3720 for the pyrazines, and 1:26.4:4150 for the pyrimidines.These ratios are somewhat larger than for the corresponding 2-alkoxypyridines and suggest that C-O bond breaking is kinetically more significant in the pyrazines and pyrimidines, leading to a transition state with greater carbocationic character.This is consistent with electron withdrawal provided by the aza 'substituent' facilitating C-O bond cleavage.It does not however lead to a general increase in reactivity (as would be the case for pyrolysis of comparable esters) because this electron withdrawal reduces the nucleophilicity of the nitrogen involved in the elimination.This latter is particularly important for the primary and secondary compounds (which have more Ei-like transition states) than for the tertiary compounds, which therfore show a normal reactivity vs. rate spread pattern.The importance of the nucleophilicity of the nitrogen in the alkoxy-heterocycles, and its ability to be modified, may stem in part from the dual pathway available for transmission of substituent effects in the aromatic ring.
- Al-Awardi, Nouria,Taylor, Roger
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p. 1585 - 1588
(2007/10/02)
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- Reactions of Halogenomethanes in the Vapour Phase. Part 5. The Reactions of Imidazolines, Anils, and 1-Methylimidazole with Chloroform at 550 deg C, and a Comparison with their Liquid-Phase Reactions with Trichloroacetate Ion or Hexachloroacetone and Base
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The vapor-phase reactions of imidazolines and anils with chloroform at 550 deg C are compared with their liquid-phase reactions in the presence of hexachloroacetone and base or upon thermolysis with trichloroacetate ion.In the vapour-phase reactions imidazolines, unlike imidazoles, gave non-chlorinated pyrimidines, and 1-methyl-imidazole gave 2-cyanopyrrole and the four 3-chlorocyanopyridines.
- Busby, Reginald E.,Khan, Mohammad A.,Khan, Mohammad R.,Parrick, John,Shaw, C. J. Granville
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p. 1431 - 1435
(2007/10/02)
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- Reactions of Halogenomethanes in the Vapor Phase. Part 4. The Reactions of Imidazoles with Chloroform at 550 deg C, and a Comparison with their Liquid-phase Reactions with Trichloroacetate Ion or Hexachloroacetone and Base
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1-Unsubstituted imidazoles and chloroform at 550 deg C in a flow system give mainly 5-chloropyrimidines, together with 4-chloropyrimidines and chloropyrazines.The effects of methyl substituents on the ratio of products is considered.The liquid-phase reactions of 2-methyl- and 2,4,5-trimethyl-imidazole under conditions in which dichlorocarbene is said to be formed in basic or neutral conditions were studied, and compared with the gas-phase reactions with chloroform.
- Busby, Reginald E.,Khan, Mohammad A.,Khan, Mohammad R.,Parrick, John,Shaw, C. J. Granville,Iqbal, Mohammad
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p. 1427 - 1430
(2007/10/02)
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