- Effect of Extended Benzannelation Orientation on Bergman and Related Cyclizations of Isomeric Quinoxalenediynes
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A combined computational and experimental study was conducted to examine the effect of extended benzannelation orientation on C1-C5 and C1-C6 cyclization of acyclic quinoxalenediynes. Calculations (mPW1PW91/cc-p
- Valenzuela, Stephanie A.,Cortés, Alondra J.,Tippins, Zakery J. E.,Daly, Morgan H.,Keel, Terell E.,Gherman, Benjamin F.,Spence, John D.
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Read Online
- Pyrazine compound and application thereof
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The invention discloses a pyrazine compound and application thereof. In particular, the present invention provides a compound represented by the formula (I), wherein the extractant composed of the compound has a high extraction rate for lithium ions, and the organic phase is easy to enrich lithium-7 isotopes, so as to realize the extraction and separation of lithium isotopes.
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Paragraph 0150; 0152-0153
(2019/07/04)
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- Furazan ring opening upon treatment of benzofurazan with ethanolamine to yield quinoxalines
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Heating of benzofurazans with ethanolamine in the presence of catalytic amount of p-toluenesulfonic acid leads to quinoxalines.
- Samsonov
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experimental part
p. 2510 - 2512
(2009/02/05)
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- THE MEISENHEIMER REACTION OF 1,4,5,8-TETRAAZAPHENANTHRENE AND BENZOQUINOXALINE N-OXIDES
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1,4,5,8-Tetraazaphenanthrene-N1-oxide (II) react with POCl3 to give equivalent amounts of 2-chloro-tetraazaphenanthrene (V) and 9-chloro-tetraazaphenanthrene (VI).Benzoquinoxaline-N1-oxime (IV) gives with the same reagent 2-chloro-benzoquinoxaline (IX, 57percent) and 9-chloro-benzoquinoxaline (X, 15percent).This last result suggests that the chloride ion has entered position 9- of II rather than position 10-, in agreement with electronic effects.
- Nasielski-Hinkens, R.,Faucon, F.,Owen, J. P.
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p. 953 - 960
(2007/10/02)
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- Reduction of Aromatic Nitro Compounds by Ethylenediamine. A New Selective Reagent for the Synthesis of Symmetric Azo Compounds
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Ethylenediamine selectively reduces aromatic nitro compounds RC6H4NO2 (R = H, m-CH3, p-CH3, and m-Ph) at 150 deg C to symmetric azo compounds RC6H4N=NC6H4R in good yield but does not reduce their ortho-substituted analogues.The diamine does not react with o- or p-nitroanilines but reduces the meta isomer to 1,3-diaminobenzene and 3,3'-diaminoazobenzene.Its reaction with o- and p-halonitrobenzenes gives substitution products H2NCH2CH2NHC6H4NO2.Nitrosobenzene is reduced to aniline and azobenzene, while α-nitroso-β-naphthol is converted to 1,4-phenanthroline.Among a variety of other amines tested, only 1,3-propylenediamine reduces nitrobenzene to azobenzene.A mechanism for the reaction is proposed.
- Chung, T. F.,Wu, Y. M.,Cheng, C. H.
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p. 1215 - 1217
(2007/10/02)
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