1,2,3-Triazol-1-imines. Part 3: Tandem 1,3 cycloaddition–rearrangement and open chain reactions of 2-aryl-N-aroyl-4,5-dimethyl-1,2,3-triazol-1-imines with dimethyl acetylenedicarboxylate

Summarization: The tandem 1,3 cycloaddition–rearrangement and open chain reactions of 2-aryl-N-aroyl-4,5-dimethyl-1,2,3-triazol-1-imines with DMAD at room temperature and in refluxing toluene are described.Presented on: Tetrahedron Letter

Synthesis of quinoxalines by cyclization of α-arylimino oximes of α-dicarbonyl compounds

Summarization: Heating the title compounds 1 at reflux in acetic anhydride yields quinoxalines 3 and 4 via a presumed aryliminoiminyl radical 5, resulting from homolytic cleavage of the NO bond in the intermediate ester 2. The observed regioselectivity of the reaction is also rationalized by implicating such a radical.Presented on: Tetrahedron Letter