2022-01-312022-01-312006-02-13Coşkun, N. ve Tunçman, S. (2006). ''Synthesis of stable azomethineylides by the rearrangement of 1,3-dipolar cycloadducts of 3,4-dihydroisoquinoline-2-oxides with DMAD''. Tetrahedron, 62(7), 1345-1350.0040-4020https://doi.org/10.1016/j.tet.2005.11.040https://www.sciencedirect.com/science/article/pii/S0040402005020429http://hdl.handle.net/11452/243211-Aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines were prepared according to a one-pot procedure involving the reaction of 2-(3,4-dimethoxyl)-ethylamine with aromatic aldehydes in TFA at reflux. The tetrahydroisoquinolines were treated with H2O2-WO42- in methanol at room temperature to give the corresponding 3,4-dihydroisoquinoline-2-oxides. Treatment of these cyclic nitrones with DMAD in toluene at room temperature gave the corresponding isoxazolo[3,2-a]isoquinolines. These compounds were heated in toluene at reflux to give the corresponding ylides in high yields (Method A). The effect of the substituents on the rate of the rearrangement of such compounds prompted us to discuss a new mechanism involving consecutive C-C bond heterolysis and 1,3-sigmatropic shift. A one-pot reaction involving the treatment of the nitrones with equimolar amounts of DMAD in refluxing toluene also gave the ylides (Method B). The structures of the prepared compound,, were elucidated by spectral means and elemental analyses.eninfo:eu-repo/semantics/closedAccessChemistryHeterocyclesSynthesisDipolar cycloadditionDMADAlkyne4-Isoxazoline rearrangement mechanismStable azomethine ylideIsoxazoloisoquinolineRearrangementOxidation with H2O2–tungstatePictet–SpenglerIsoquinoline3,4-Dihydroisoquinoline-2-oxideTHI1-Aryl-1,2,3,4-tetrahydroisoquinolineNitronesRegioN-oxidesAryl isocyanatesOrganic-synthesisCloaddition reactionsDiastereoselective additioncyImidazoline 3-oxidesRing-opening reactionsArticle0002351239000022-s2.0-3084444744513451350627Chemistry, organicNitrones; Cycloaddition Reactions; Hydroxylamines1 (3,4 dimethoxyphenyl) 6,7 dimethoxy 1,2,3,4 tetrahydroisoquinoline1 (4 chlorophenyl) 6,7 dimethoxy 1,2,3,4 tetrahydroisoquinoline1 benzo[1,3]dioxol 5 yl 6,7 dimethoxy 1,2,3,4 tetrahydroisoquinoline6,7 dimethoxy 1 (3 nitrophenyl) 1,2,3,4 tetrahydroisoquinoline6,7 dimethoxy 1 phenyl 1,2,3,4 tetrahydroisoquinolineAzomethine ylideHydrogen peroxideIsoquinoline derivativeMethanolNitrone derivativeTolueneUnclassified drugSynthesisSpectroscopyRoom temperatureReaction analysisPriority journalOxidationCycloadditionArticle