Novel piperidine-fused benzoxazino- and quinazolinonaphthoxazines鈥攕ynthesis and conformational study

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• 作者：Rená ; ta Csü ; tö ; rtö ; ki^a ; Istvá ; n Szatmá ; ri^a ; Matthias Heydenreich^b ; Andreas Koch^b ; Ines Starke^b ; Ferenc Fü ; lö ; p^a ; ^{fulop@pharm.u-szeged.hu} ; Erich Kleinpeter^b ; ^{ekleinp@uni-potsdam.de}
• 关键词：Quinazolines ; Naphthoxazines ; DFT structural study ; Conformational analysis ; NMR spectroscopy
• 刊名：Tetrahedron
• 出版年：2012
• 期刊代码：107_00404020
• 类别：ch
• 出版时间：5 August, 2012
• 卷：68
• 期：31
• 页码：6284-6288
• 文件大小：469 K

摘要

The reactions of 1-(amino(2-hydroxyphenyl)methyl)-2-naphthol (3) and 1-(amino(2-aminophenyl)methyl)-2-naphthol (6) with glutardialdehyde resulted in the formation of piperidine-fused benzoxazinonaphthoxazine 4 and quinazolinonaphthoxazine 7, respectively, both in diastereopure form.

The full conformational search protocols of 4 and 7 were successfully carried out by NMR spectroscopy and accompanying molecular modelling; the global minimum-energy conformers of all diastereomers were computed, and the assignments of the most stable stereoisomers, G_tct¹ for 4 and G_tct¹ for 7, were corroborated by spatial NOE information relating to the H_7a-H_10a-H_15b and H,H coupling patterns of the protons in the flexible part of the piperidine moiety. Additionally, mass spectrometric fragmentation was investigated in collision-induced dissociation experiments. The elemental compositions of the ions were determined by accurate mass measurements.