- Bromination of quinoxaline and derivatives: Effective synthesis of some new brominated quinoxalines
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The synthesis of brominated quinoxaline derivatives starting from several kinds of quinoxaline by different bromination strategies was studied. First the synthesis of some brominated quinoxalines was accomplished along with the development of an alternative and effective synthesis of some known compounds. A new, clean, and effective synthetic method for selective reduction of quinoxaline to 1,2,3,4-tetrahydroquinoxaline was also developed. The products obtained were characterized by means of NMR spectroscopy, elemental analyses, and mass spectrometry.
- U?ar, Sefa,E?siz, Sel?uk,Da?tan, Arif
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p. 1618 - 1632
(2017/03/08)
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- A highly practical and convenient halogenation of fused heterocyclic N-oxides
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A novel, simple and practical method for the regioselective halogenation of fused heterocyclic N-oxides has been developed. It employs Vilsmeier reagent, generated in situ by POX3and DMF, as both the activating agent and the nucleophilic halide source. The method is amenable across a broad range of substrates, including quinolines, isoquinolines and the diazine N-oxides, possessing a variety of substitution patterns. Furthermore, all of the reagents associated are cheap and easy to obtain. The potential extension of this method to a one-pot oxidation/halogenation sequence that obviates the need for isolation of the N-oxide intermediates is also presented.
- Wang, Dong,Wang, Yuxi,Zhao, Junjie,Li, Linna,Miao, Longfei,Wang, Dong,Sun, Hua,Yu, Peng
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p. 5762 - 5768
(2016/08/30)
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- Heteroaryl-substituted naphthalenes and structurally modified derivatives: Selective inhibitors of CYP11B2 for the treatment of congestive heart failure and myocardial fibrosis
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Recently we proposed inhibition of aldosterone synthase (CYP11B2) as a novel strategy for the treatment of congestive heart failure and myocardial fibrosis. In this study the synthesis and biological evaluation of heteroaryl-substituted naphthalenes and quinolines (1-31) is described. Key step for the preparation of the compounds was a Suzuki cross-coupling. Activity of the compounds was determined in vitro using human CYP11B2 and selectivity was evaluated toward the human steroidogenic enzymes CYP11B1, CYP19, and CYP17. A large number of highly active and selective inhibitors of CYP11B2 was identified. The most active inhibitor was the 6-cyano compound 8 (IC 50 = 3 nM) showing a competitive type of inhibition (Ki value = 1.9 nM). The 6-ethoxy derivative 5 was found to be the most selective CYP11B2 inhibitor (IC50 = 12 nM; Ki value = 8 nM; CYP11B1 IC50 = 5419 nM; selectivity factor = 451), showing no inhibition of human CYP3A4 (50 nM) and CYP2D6 (20 nM). Docking and molecular dynamics studies using our homology modeled CYP11B2 structure with selected compounds were performed. Caco-2 cell experiments revealed a large number of medium and highly permeable compounds and metabolic studies with 2 using rat liver microsomes showed sufficient stability.
- Voets, Marieke,Antes, Iris,Scherer, Christiane,Müller-Vieira, Ursula,Biemel, Klaus,Barassin, Catherine,Marchais-Oberwinkler, Sandrine,Hartmann, Rolf W.
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p. 6632 - 6642
(2007/10/03)
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- Application of phosphonium salts to the reactions of various kinds of amides
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The phosphonium salts 1 and 2 prepared from triphenylphosphine and N-halogenosuccinimide proved to be applicable to the conversion of amide compounds. Especially, halogenation of electron-deficient heteroaromatic alcohols with these reagents seems to be a convenient method compared to the halogenation with phosphorus oxyhalides.
- Sugimoto, Osamu,Mori, Miho,Moriya, Keisuke,Tanji, Ken-Ichi
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p. 1112 - 1118
(2007/10/03)
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- A facile bromination of hydroxyheteroarenes
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Bromination of hydroxyheteroarenes using P2O5/Bu4NBr proceeds under mild conditions to afford high yields of various bromoheteroarenes. This procedure is successfully applied to large-scale syntheses of bromoheteroarenes.
- Kato, Yoshiaki,Okada, Shigemitsu,Tomimoto, Koji,Mase, Toshiaki
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p. 4849 - 4851
(2007/10/03)
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- A facile halogenation of some hydroxyheterocycles using triphenylphosphine and N-halosuccinimide
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Some hydroxyheterocycles were halogenated to give the corresponding haloheterocycles using triphenylphosphine and N-halosuccinimide. In comparison with the usual method using phosphorus oxyhalide, the haloheterocycles were easily isolated.
- Sugimoto, Osamu,Mori, Miho,Tanji, Ken-ichi
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p. 7477 - 7478
(2007/10/03)
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