Fused polycyclic nitrogen-containing heterocycles 24. Three-component condensation of diethyl 2,4,6-trioxoheptanedicarboxylate with salicylaldehydes and ammonium acetate as a new method for the synthesis of 7- and 9-substituted benzo[e]pyrano[4,3-b]pyridines
作者:V. A. Mamedov、L. P. Sysoeva、A. M. Murtazina、E. A. Berdnikov、A. T. Gubaidullin、S. F. Kadyrova、E. V. Mironova、I. A. Litvinov
DOI:10.1007/s11172-009-0195-z
日期:2009.7
The three-component condensation of diethyl 2,4,6-trioxoheptanedicarboxylate with salicylaldehyde and its 3,5-dichloro-, 3-methoxy-, and 5-methoxy-substituted derivatives in EtOH in the presence of ammonium acetate affords tricyclic products, viz., tetrahydrobenzo[e]-pyrano[4,3-b]pyridines. In the reaction with 3-nitrosalicylaldehyde, the intramolecular closure of the pyran ring does not occur due to the deactivation of the hydroxy group by the nitro group, and this reaction stops at the formation of the monocyclic product, viz., tetrahydropyridin-4-one.
2,4,6-三氧代庚二酸二乙酯与水杨醛及其3,5-二氯、3-甲氧基和5-甲氧基衍生物在乙醇中,在乙酸铵的存在下,三组分缩合生成三环产物,即四氢苯并[e]-吡喃并[4,3-b]吡啶。在与3-硝基水杨醛反应时,由于羟基被硝基基团失活,吡喃环不会发生分子内闭合,反应停止于形成单环产物,即四氢吡啶-4-酮。