- Synthesis of tri- and tetracyclic condensed quinoxalin-2-ones fused across the C-3 - N-4 bond
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We have studied the preparation of some fused quinoxalinones by Stevens rearrangement of a spiro-quinoxaline-derived ammonium ylide or by treatment of N-(2,4-dinitrophenyl)-and N-(2-nitrophenyl)imino acids with different reducing agents. We have reinvestigated and clarified some related processes found in the literature starting from imino acids derivatives. Additional reactions of the fused quinoxalinones, as well as the useful dehydrogenation/decarboxylation of some easily available 1-arylindoline-2-carboxylic acids to the corresponding 1-arylindoles, are also reported. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Chicharro, Roberto,De Castro, Sonia,Reino, Jose L.,Aran, Vicente J.
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p. 2314 - 2326
(2007/10/03)
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- o-Nitroaniline Derivatives. Part 12. The Reaction of N-(2,4-Dinitrophenyl)-sarcosine Ethyl Ester with Bases: Some Novel Redox Processes Revealed by X-Ray Crystallography
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According to the base used, the title reaction gives, either 2-amino-2'-methylamino-5,5'-dinitro-ONN-azoxybenzene (9) or 2,2'-bis(methylamino)-5,5'-dinitrooazoxybenzene (10), together with 1-hydroxy-4-methyl-7-nitroquinoxaline-2,3-dione (13).Reaction of compound (13) with thionyl chloride gives 5-chloro-1-methyl-6-nitroquinoxaline-2,3-dione (12).Possible mechanisms for these novel reactions are discussed.The structures of (i) the diacetyl derivative of the azoxy compound (9), (ii) compound (12), and (iii) the monohydrate of (13), have been established by X-ray crystallography.All three compounds give monoclinic crystals.Compound (8) has space group P21/n, with 4 molecules in a cell of dimensions a = 19.949(4), b = 10.289(4), c = 9.101(2) Angstroem, β = 97.98(2) degree; R = 0.030 for 1270 reflections.Compound (12) has space group P21/c, with 4 molecules in a cell of dimensions a = 6.922(1), b = 10.857(3), c = 13.192(2) Angstroem, β = 100.87(1) degree; R = 0.055 for 956 reflections.Compound (13)*H2O has space group C2/c, with 8 formula units in a cell of dimensions a = 16.130(3), b = 7.173(1), c = 18.215(3) Angstroem, β = 97.67(2) degree; R = 0.037 for 1244 reflections.
- McFarlane, Michael D.,Smith, David M.,Ferguson, George,Kaitner, Branko
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p. 893 - 902
(2007/10/02)
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